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Molecules, Volume 14, Issue 9 (September 2009), Pages 3115-3843

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Research

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Open AccessArticle Iodoarylation of Arylalkynes with Molecular Iodine in the Presence of Hypervalent Iodine Reagents
Molecules 2009, 14(9), 3132-3141; doi:10.3390/molecules14093132
Received: 6 August 2009 / Revised: 18 August 2009 / Accepted: 24 August 2009 / Published: 24 August 2009
PDF Full-text (76 KB)
Abstract
Iodoarylation of arylacetylenes was performed using a simple reagent system composed of molecular iodine and [bis(benzoyloxy)iodo]benzene. Most arylacetylenes efficiently underwent the iodoarylation reaction with electron-rich arenes to give trans 1,1-diaryl-2-iodoethene adducts regio- and stereoselectively. As an exception, the iodoarylation of p-methoxyphenylacetylene resulted
[...] Read more.
Iodoarylation of arylacetylenes was performed using a simple reagent system composed of molecular iodine and [bis(benzoyloxy)iodo]benzene. Most arylacetylenes efficiently underwent the iodoarylation reaction with electron-rich arenes to give trans 1,1-diaryl-2-iodoethene adducts regio- and stereoselectively. As an exception, the iodoarylation of p-methoxyphenylacetylene resulted in a mixture of E- and Z-isomers of the corresponding product. Full article
(This article belongs to the Special Issue Organic Iodine Chemistry)
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Open AccessArticle Synthesis and Antitumor Activity of Amino Acid Ester Derivatives Containing 5-Fluorouracil
Molecules 2009, 14(9), 3142-3152; doi:10.3390/molecules14093142
Received: 15 July 2009 / Revised: 18 August 2009 / Accepted: 20 August 2009 / Published: 25 August 2009
Cited by 18 | PDF Full-text (217 KB)
Abstract
A series of amino acid ester derivatives containing 5-fluorouracil were synthesized using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC•HCl) and N-hydroxybenzotriazole (HOBt) as a coupling agent. The structures of the products were assigned by NMR, MS, IR etc. The in vitro antitumor activity tests against leukaemia
[...] Read more.
A series of amino acid ester derivatives containing 5-fluorouracil were synthesized using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC•HCl) and N-hydroxybenzotriazole (HOBt) as a coupling agent. The structures of the products were assigned by NMR, MS, IR etc. The in vitro antitumor activity tests against leukaemia HL-60 and liver cancer BEL-7402 indicated that (R)-ethyl 2-(2-(5-fluoro-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)acetamido)-3-(4-hydroxyphenyl) propanoate showed more inhibitory effect against BEL-7402 than 5-FU. Full article
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Open AccessArticle Synthesis of Novel 3,5-Dichloro-2-arylpyridines by Palladium Acetate-Catalyzed Ligand-Free Suzuki Reactions in Aqueous Media
Molecules 2009, 14(9), 3153-3160; doi:10.3390/molecules14093153
Received: 19 July 2009 / Revised: 18 August 2009 / Accepted: 25 August 2009 / Published: 26 August 2009
Cited by 7 | PDF Full-text (171 KB)
Abstract
A highly efficient palladium acetate-catalyzed ligand-free Suzuki reaction of 2,3,5-trichloropyridine with arylboronic acids in aqueous phase was developed. High yields of 3,5-dichloro-2-arylpyridines, a simple Pd source, absence of ligands, and environmentally benign as well as mild reaction conditions are important features of this
[...] Read more.
A highly efficient palladium acetate-catalyzed ligand-free Suzuki reaction of 2,3,5-trichloropyridine with arylboronic acids in aqueous phase was developed. High yields of 3,5-dichloro-2-arylpyridines, a simple Pd source, absence of ligands, and environmentally benign as well as mild reaction conditions are important features of this method. Full article
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Open AccessArticle Intramolecular Transformations of 3-Cyanoamino- and 3-Cyanoimino-1,2-diferrocenylcyclopropenes
Molecules 2009, 14(9), 3161-3175; doi:10.3390/molecules14093161
Received: 13 June 2009 / Revised: 20 July 2009 / Accepted: 12 August 2009 / Published: 26 August 2009
Cited by 3 | PDF Full-text (419 KB)
Abstract
3-Cyanoamino-1,2- and -2,3-diferrocenylcyclopropenes 6a,b and 11a,b prepared by the reaction of diferrocenylcyclopropenylium salts with sodium cyanamide undergo smooth intramolecular transformations with both conservation of the three-membered ring [affording 3-cyanoimino-1,2-diferrocenylcyclopropene (8)] and its opening [affording Z-3-morpholino- and Z-3-piperidino-3-(cyanoimino)-1,2-diferrocenylprop-1-enes 7a,b and Z-3-cyanoimino-2,3-diferrocenyl-1-methylthioprop-1-ene
[...] Read more.
3-Cyanoamino-1,2- and -2,3-diferrocenylcyclopropenes 6a,b and 11a,b prepared by the reaction of diferrocenylcyclopropenylium salts with sodium cyanamide undergo smooth intramolecular transformations with both conservation of the three-membered ring [affording 3-cyanoimino-1,2-diferrocenylcyclopropene (8)] and its opening [affording Z-3-morpholino- and Z-3-piperidino-3-(cyanoimino)-1,2-diferrocenylprop-1-enes 7a,b and Z-3-cyanoimino-2,3-diferrocenyl-1-methylthioprop-1-ene (10)]. 3-Cyano-imino-1,2-diferrocenylcyclopropene (8) reacts with hydrazine to form 3-amino-6-ferrocenyl-5-ferrocenylmethyl-1,2,4-triazine (12) and Z-2,3-diferrocenylacrylohydrazide N-cyanoimide (13) as a result of intramolecular transformations. The structures of the compounds obtained were determined by IR, 1H- and 13C-NMR spectroscopy and mass spectrometry. The structures of compounds 7a and 10 were additionally confirmed by their X-ray diffraction analysis data. Full article
(This article belongs to the Special Issue Ferrocenes)
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Open AccessArticle Synthesis and Anti-Human Immunodeficiency Virus Type 1 Activity of (E)-N-Phenylstyryl-N-alkylacetamide Derivatives
Molecules 2009, 14(9), 3176-3186; doi:10.3390/molecules14093176
Received: 1 July 2009 / Revised: 30 July 2009 / Accepted: 26 August 2009 / Published: 26 August 2009
Cited by 3 | PDF Full-text (250 KB)
Abstract
A series of (E)-N-phenylstyryl-N-alkylacetamides, 5, were synthesized by direct reduction-acetylation of β-arylnitroolefins, followed by N-alkylation. The title compounds were characterized by 1H-NMR, EIMS and IR analysis. All the synthesized compounds were assayed as HIV-1 non-nucleoside
[...] Read more.
A series of (E)-N-phenylstyryl-N-alkylacetamides, 5, were synthesized by direct reduction-acetylation of β-arylnitroolefins, followed by N-alkylation. The title compounds were characterized by 1H-NMR, EIMS and IR analysis. All the synthesized compounds were assayed as HIV-1 non-nucleoside reverse transcriptase inhibitors. A SAR study revealed that when group R1 in 5 was ortho-substituted, the resulting compounds showed better inhibitory activities against HIV-1 RT. Among the tested compounds, 5i (R1 = 2-Br, R2 = 3,5-difluorobenzyl) exhibited the highest enzyme activity, with a 88.89% inhibitory ratio against HIV-1 reverse transcriptase at the tested concentration. Further cell-based anti-HIV-1 assays showed that compound 5i exhibited a SI value of 29 with an EC50 value of 4 μM in C8166 cells. Full article
Open AccessCommunication Synthesis, ex Vivo and in Vitro Hydrolysis Study of an Indoline Derivative Designed as an Anti-Inflammatory with Reduced Gastric Ulceration Properties
Molecules 2009, 14(9), 3187-3197; doi:10.3390/molecules14093187
Received: 12 June 2009 / Revised: 7 August 2009 / Accepted: 13 August 2009 / Published: 26 August 2009
Cited by 12 | PDF Full-text (222 KB)
Abstract
The compound 1-(2,6-dichlorophenyl)indolin-2-one (1), planned as a pro-drug of diclofenac (2), was easily synthesized in 94% yield by an intramolecular reaction in the presence of coupling agent (i.e., EDC). Compound 1 showed anti-inflammatory and analgesic activity without gastro-ulcerogenic effects. The chemical
[...] Read more.
The compound 1-(2,6-dichlorophenyl)indolin-2-one (1), planned as a pro-drug of diclofenac (2), was easily synthesized in 94% yield by an intramolecular reaction in the presence of coupling agent (i.e., EDC). Compound 1 showed anti-inflammatory and analgesic activity without gastro-ulcerogenic effects. The chemical and enzymatic hydrolysis profile of the lactam derivative 1 does not indicate conversion to diclofenac (2). This compound is a new non-ulcerogenic prototype for treatment of chronic inflammatory diseases. Full article
(This article belongs to the Special Issue Advances in Heterocyclic Chemistry)
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Open AccessArticle Molecular Docking Studies and Anti−Snake Venom Metalloproteinase Activity of Thai Mango Seed Kernel Extract
Molecules 2009, 14(9), 3198-3213; doi:10.3390/molecules14093198
Received: 10 August 2009 / Revised: 21 August 2009 / Accepted: 25 August 2009 / Published: 27 August 2009
Cited by 23 | PDF Full-text (1693 KB)
Abstract
Snakebite envenomations cause severe local tissue necrosis and the venom metalloproteinases are thought to be the key toxins involved. In this study, the ethanolic extract from seed kernels of Thai mango (Mangifera indica L. cv. ‘Fahlun’) (Anacardiaceae) and its major phenolic principle
[...] Read more.
Snakebite envenomations cause severe local tissue necrosis and the venom metalloproteinases are thought to be the key toxins involved. In this study, the ethanolic extract from seed kernels of Thai mango (Mangifera indica L. cv. ‘Fahlun’) (Anacardiaceae) and its major phenolic principle (pentagalloylglucopyranose) exhibited potent and dose−dependent inhibitory effects on the caseinolytic and fibrinogenolytic activities of Malayan pit viper and Thai cobra venoms in in vitro tests. molecular docking studies revealed that the binding orientations of the phenolic principles were in the binding pockets of snake venom metalloproteinases (SVMPs). The phenolic principles could form hydrogen bonds with the three histidine residues in the conserved zinc−binding motif and could chelate the Zn2+ atom of the SVMPs, which could potentially result in inhibition of the venom enzymatic activities and thereby inhibit tissue necrosis. Full article
Open AccessArticle Vibrational Spectra Study of the Interactions Between Keggin Heteropolyanions and Amino Acids
Molecules 2009, 14(9), 3214-3221; doi:10.3390/molecules14093214
Received: 24 June 2009 / Revised: 17 August 2009 / Accepted: 19 August 2009 / Published: 27 August 2009
Cited by 12 | PDF Full-text (230 KB)
Abstract
A study of the effects of the interactions with amino acids on the vibrational spectra of Keggin heteropolyanions (NanH3-n[XM12O40]n-; n = 0,1,2,3; X = PV, SiIV, M = W
[...] Read more.
A study of the effects of the interactions with amino acids on the vibrational spectra of Keggin heteropolyanions (NanH3-n[XM12O40]n-; n = 0,1,2,3; X = PV, SiIV, M = WVI, MoVI) has been performed. Interactions occurred for all of the studied compounds leading to changes and splits in the stretching frequencies. Depending on the amino acid type, the IR bands for interbridge stretchings (M-Ob-M) and terminal stretchings (M-Od) were affected. Full article
Open AccessArticle Conjugate Addition of Indoles to α,β-Unsaturated Ketones Using a Brønsted Acid Ionic Liquid as an Efficient Catalyst
Molecules 2009, 14(9), 3222-3228; doi:10.3390/molecules14093222
Received: 6 July 2009 / Revised: 20 August 2009 / Accepted: 24 August 2009 / Published: 27 August 2009
Cited by 20 | PDF Full-text (335 KB)
Abstract
The Brønsted acid ionic liquid [PyN(CH2)4SO3H][p-CH3PhSO3] has been reported as an efficient catalyst for the Michael addition reaction of indoles to α,β-unsaturated ketones. Satisfactory results were obtained, with excellent yields
[...] Read more.
The Brønsted acid ionic liquid [PyN(CH2)4SO3H][p-CH3PhSO3] has been reported as an efficient catalyst for the Michael addition reaction of indoles to α,β-unsaturated ketones. Satisfactory results were obtained, with excellent yields and a simple experimental procedure. The catalyst could be recycled and reused up to three times without any noticeable decrease in the catalytic activity. Full article
Open AccessArticle Theoretical Studies of [2,3]-Sigmatropic Rearrangements of Allylic Selenoxides and Selenimides
Molecules 2009, 14(9), 3229-3236; doi:10.3390/molecules14093229
Received: 6 August 2009 / Revised: 24 August 2009 / Accepted: 26 August 2009 / Published: 28 August 2009
Cited by 2 | PDF Full-text (214 KB)
Abstract
Density-functional theory is used to model the endo and exo transition states for [2,3]-sigmatropic rearrangement of allylic aryl-selenoxides and -selenimides. The endo transition state is generally preferred for selenoxides if there is no substitution at the 2 position of the allyl group. Based
[...] Read more.
Density-functional theory is used to model the endo and exo transition states for [2,3]-sigmatropic rearrangement of allylic aryl-selenoxides and -selenimides. The endo transition state is generally preferred for selenoxides if there is no substitution at the 2 position of the allyl group. Based upon the relative energies of the endo and exo transition states, enantioselectivity of rearrangements is expected to be greatest for molecules with substitutions at the 1- or (E)-3- position of the allyl group. Ortho substitution of a nitro group on the ancillary selenoxide phenyl ring reduces the activation barriers, increases the difference between the endo and exo activation barriers and shifts the equilibrium toward products. Full article
(This article belongs to the Special Issue Selenium and Tellurium Chemistry)
Open AccessCommunication Antiproliferative, Cytotoxic, Antioxidant Activity and Polyphenols Contents in Leaves of Four Staphylea L. Species
Molecules 2009, 14(9), 3259-3267; doi:10.3390/molecules14093259
Received: 12 June 2009 / Revised: 13 August 2009 / Accepted: 26 August 2009 / Published: 28 August 2009
Cited by 15 | PDF Full-text (202 KB)
Abstract
Staphylea has been used for long time in Traditional Chinese Medicine (TCM) and by Native Americans in a number of therapeutical indications. The present study describes in vitro antiproliferative, cytotoxic properties (MTT and LDH test) and antioxidant activities (reduction of DPPH radical and
[...] Read more.
Staphylea has been used for long time in Traditional Chinese Medicine (TCM) and by Native Americans in a number of therapeutical indications. The present study describes in vitro antiproliferative, cytotoxic properties (MTT and LDH test) and antioxidant activities (reduction of DPPH radical and peroxynitrite radical) of Staphylea colchica Stev. (SC), S. elegans Zab. (SC), S. holocarpa Hemsl. (SH) and S. pinnata L. (SP) leave water extracts. Time- (24 and 72 h) and dose- (1-150 μg/mL) dependent effects of the above extracts were tested at the mitochondrial (MTT test) and plasma membrane level (LDH leakage) in A431 human skin carcinoma cells. Screening of these properties has shown time and dose dependent increase of harmful effects, the highest activity was observed for the SE, while the less active was the SH extract. The ED50 values for the mitochondrial and membrane damage were nearly identical for the SE and very similar for SH extract. These findings indicate simultaneous injury of both cell compartments by SE and SH extracts. The highest antioxidant potential of SE species is accompanied by the highest content of flavones/flavonols and polyphenols. Only flavonoid contents are associated with antiproliferative effects and cell membrane injury, while antioxidant properties are the result of polyphenol content. The data clearly demonstrate that individual Staphylea L. species differ, not only in the amount of biologically active compounds, but also by the extent of harmful and beneficial effects. Full article
Open AccessCommunication Carnitine Conjugate of Nipecotic Acid: A New Example of Dual Prodrug
Molecules 2009, 14(9), 3268-3274; doi:10.3390/molecules14093268
Received: 27 July 2009 / Revised: 25 August 2009 / Accepted: 27 August 2009 / Published: 31 August 2009
Cited by 6 | PDF Full-text (101 KB)
Abstract As a novel example of improved entry of poorly delivered drugs into the brain by means of nutrient conjugates, L-carnitine was conjugated to nipecotic acid and the capacity to antagonize PTZ-induced convulsions of this novel entity was evaluated. Full article
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Open AccessArticle Conversion of Natural Aldehydes from Eucalyptus citriodora, Cymbopogon citratus, and Lippia multiflora into Oximes: GC-MS and FT-IR Analysis
Molecules 2009, 14(9), 3275-3285; doi:10.3390/molecules14093275
Received: 20 July 2009 / Revised: 11 August 2009 / Accepted: 26 August 2009 / Published: 31 August 2009
Cited by 11 | PDF Full-text (338 KB)
Abstract
Three carbonyl-containing extracts of essential oils from Eucalyptus citriodora (Myrtaceae), Cymbopogon citratus (Gramineae) and Lippia multiflora (Verbenaceae) were used for the preparation of oximes. The reaction mixtures were analyzed by GC-MS and different compounds were identified on the basis of their retention times
[...] Read more.
Three carbonyl-containing extracts of essential oils from Eucalyptus citriodora (Myrtaceae), Cymbopogon citratus (Gramineae) and Lippia multiflora (Verbenaceae) were used for the preparation of oximes. The reaction mixtures were analyzed by GC-MS and different compounds were identified on the basis of their retention times and mass spectra. We observed quantitative conversion of aldehydes to their corresponding oximes with a purity of 95 to 99%. E and Z stereoisomers of the oximes were obtained and separated by GC-MS. During GC analysis, the high temperature in the injector was shown to cause partial dehydratation of oximes and the resulting nitriles were readily identified. Based on FT-IR spectroscopy, that revealed the high stability and low volatility of these compounds, the so-obtained oximes could be useful for future biological studies. Full article
Open AccessArticle Synthesis and Pharmacological Screening of Several Aroyl and Heteroaroyl Selenylacetic Acid Derivatives as Cytotoxic and Antiproliferative Agents
Molecules 2009, 14(9), 3313-3338; doi:10.3390/molecules14093313
Received: 1 July 2009 / Revised: 4 August 2009 / Accepted: 27 August 2009 / Published: 1 September 2009
Cited by 25 | PDF Full-text (825 KB)
Abstract
The synthesis and cytotoxic activity of a series of twenty six aroyl and heteroaroyl selenylacetic acid derivatives of general formula Ar-CO-Se-CH2-COOH or Heterar-CO-Se-CH2-COOH are reported. The synthesis was carried out by reaction of acyl chlorides with sodium hydrogen selenide,
[...] Read more.
The synthesis and cytotoxic activity of a series of twenty six aroyl and heteroaroyl selenylacetic acid derivatives of general formula Ar-CO-Se-CH2-COOH or Heterar-CO-Se-CH2-COOH are reported. The synthesis was carried out by reaction of acyl chlorides with sodium hydrogen selenide, prepared in situ, and this led to the formation of sodium aroylselenides that subsequently reacted with α-bromoacetic acid to produce the corresponding selenylacetic acid derivatives. All of the compounds were tested against a prostate cancer cell line (PC-3) and some of the more active compounds were assessed against a panel of four human cancer cell lines (CCRF-CEM, HTB-54, HT-29, MCF-7) and one mammary gland-derived non-malignant cell line (184B5). Some of the compounds exhibited remarkable cytotoxic and antiproliferative activities against MCF-7 and PC-3 that were higher than those of the reference compounds doxorubicin and etoposide, respectively. For example, in MCF-7 when Ar = phenyl, 3,5-dimethoxyphenyl or benzyl the TGI values were 3.69, 4.18 and 6.19 μM. On the other hand, in PC-3 these compounds showed values of 6.8, 4.0 and 2.9 μM. Furthermore, benzoylselenylacetic acid did not provoke apoptosis nor did it perturb the cell cycle in MCF-7. Full article
(This article belongs to the Special Issue Selenium and Tellurium Chemistry)
Open AccessArticle A General Synthesis of C8-Arylpurine Phosphoramidites
Molecules 2009, 14(9), 3339-3352; doi:10.3390/molecules14093339
Received: 10 July 2009 / Revised: 20 August 2009 / Accepted: 27 August 2009 / Published: 2 September 2009
Cited by 16 | PDF Full-text (265 KB)
Abstract
A general scheme for the synthesis of C8-arylpurine phosphoramidites has been developed. C8-Arylation of C8-bromo-2′-deoxyguanosine is the key step and has been achieved through the use of a Suzuki coupling. Since the coupling reaction is conducted under aqueous conditions, it is unnecessary to
[...] Read more.
A general scheme for the synthesis of C8-arylpurine phosphoramidites has been developed. C8-Arylation of C8-bromo-2′-deoxyguanosine is the key step and has been achieved through the use of a Suzuki coupling. Since the coupling reaction is conducted under aqueous conditions, it is unnecessary to protect and then deprotect the hydroxyl groups, thus saving several steps and improving overall yields. Once the C8-arylgroup is introduced, the glycosidic bond becomes very sensitive to acid catalyzed cleavage. Protection of the amino groups as the corresponding N,N-dimethylformamidine derivative improves stability of the derivatives. Synthetic C8-arylpurines were successfully used to prepare synthetic oligonucleotides. Full article
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Open AccessArticle Tris(2,4,6-trimethoxyphenyl)phosphine (TTMPP): Efficient Catalysts for the Cyanosilylation and Cyanocarbonation of Aldehydes and Ketones
Molecules 2009, 14(9), 3353-3359; doi:10.3390/molecules14093353
Received: 6 August 2009 / Revised: 25 August 2009 / Accepted: 31 August 2009 / Published: 2 September 2009
Cited by 15 | PDF Full-text (79 KB)
Abstract A variety of aldehydes and ketones were transformed to their corresponding cyanohydrin silyl ethers in good to excellent yields in the presence of 1-5 mol% of tris(2,4,6-trimethoxyphenyl)phosphine (TTMPP). Cyanohydrin carbonates were also readily prepared using 5-10 mol% of TTMPP as an organocatalyst. Full article
(This article belongs to the Special Issue Organocatalysis)
Open AccessArticle A New 4α-Methylated Sterol from a Nephthea sp. (Nephtheidae) Bornean Soft Coral
Molecules 2009, 14(9), 3360-3366; doi:10.3390/molecules14093360
Received: 20 July 2009 / Revised: 17 August 2009 / Accepted: 19 August 2009 / Published: 2 September 2009
Cited by 10 | PDF Full-text (166 KB)
Abstract A new 4α-methyl sterol, 4α-methyl-ergosta-6,8(14),22E-triene-3β-ol (1), was isolated along with cholesterol from a Nephthea sp. Bornean soft coral The structure of compound 1 was elucidated on the basis of spectroscopic analysis and comparison of the data with those of the related compounds. Full article
Open AccessCommunication Cesium Carbonate-Catalyzed α-Phenylchalcogenation of Carbonyl Compounds with Diphenyl Dichalcogenide
Molecules 2009, 14(9), 3367-3375; doi:10.3390/molecules14093367
Received: 31 July 2009 / Revised: 26 August 2009 / Accepted: 2 September 2009 / Published: 2 September 2009
Cited by 6 | PDF Full-text (247 KB)
Abstract
It was found that cesium carbonate has a unique catalytic ability on the reaction of carbonyl compounds with diphenyl diselenide to give the corresponding α-phenylseleno carbonyl compounds in moderate to good yields. Similarly, the α-phenylthiolation of carbonyl compounds with diphenyl disulfide was promoted
[...] Read more.
It was found that cesium carbonate has a unique catalytic ability on the reaction of carbonyl compounds with diphenyl diselenide to give the corresponding α-phenylseleno carbonyl compounds in moderate to good yields. Similarly, the α-phenylthiolation of carbonyl compounds with diphenyl disulfide was promoted by the cesium carbonate catalyst. Full article
(This article belongs to the Special Issue Selenium and Tellurium Chemistry)
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Open AccessArticle Preparation and Characterization of Novel Gellan Gum Hydrogels Suitable for Modified Drug Release
Molecules 2009, 14(9), 3376-3391; doi:10.3390/molecules14093376
Received: 26 June 2009 / Revised: 30 July 2009 / Accepted: 31 August 2009 / Published: 3 September 2009
Cited by 38 | PDF Full-text (476 KB)
Abstract
Innovative hydrogels obtained by physical and chemical crosslinking of deacylated Gellan gum have been characterized in terms of water uptake, rheological properties and compressibility, and the behaviour of the tested materials, according to the type of the obtained network, is thoroughly discussed. The
[...] Read more.
Innovative hydrogels obtained by physical and chemical crosslinking of deacylated Gellan gum have been characterized in terms of water uptake, rheological properties and compressibility, and the behaviour of the tested materials, according to the type of the obtained network, is thoroughly discussed. The release from the various gels of loaded model molecules of different steric hindrance was also investigated and the trend of the release profiles has been related to the structures proposed for the physical and the chemical hydrogel. Full article
(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutics)
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Open AccessArticle Identification of a Benzamide Derivative that Inhibits Stress-Induced Adrenal Corticosteroid Synthesis
Molecules 2009, 14(9), 3392-3410; doi:10.3390/molecules14093392
Received: 27 July 2009 / Revised: 14 August 2009 / Accepted: 1 September 2009 / Published: 3 September 2009
Cited by 1 | PDF Full-text (278 KB)
Abstract
Elevated serum glucocorticoid levels contribute to the progression of many diseases, including depression, Alzheimer’s disease, hypertension, and acquired immunodeficiency syndrome. Here we show that the benzamide derivative N-[2-(4-cyclopropanecarbonyl-3-methyl-piperazin-1-yl)-1-(tert-butyl-1H-indol-3-yl-methyl)-2-oxo-ethyl]-4-nitrobenzamide (SP-10) inhibits dibutyryl cyclic AMP (dbcAMP)-induced corticosteroid synthesis in a
[...] Read more.
Elevated serum glucocorticoid levels contribute to the progression of many diseases, including depression, Alzheimer’s disease, hypertension, and acquired immunodeficiency syndrome. Here we show that the benzamide derivative N-[2-(4-cyclopropanecarbonyl-3-methyl-piperazin-1-yl)-1-(tert-butyl-1H-indol-3-yl-methyl)-2-oxo-ethyl]-4-nitrobenzamide (SP-10) inhibits dibutyryl cyclic AMP (dbcAMP)-induced corticosteroid synthesis in a dose-dependent manner in Y-1 adrenal cortical mouse tumor cells, without affecting basal steroid synthesis and reduced stress-induced corticosterone increases in rats without affecting the physiological levels of the steroid in blood. SP-10 did not affect cholesterol transport and metabolism by the mitochondria but was unexpectedly found to increase 3-hydroxy-3-methylglutaryl-coenzyme A, low density lipoprotein receptor, and scavenger receptor class B type I (SR-BI) expression. However, it also markedly reduced dbcAMP-induced NBD-cholesterol uptake, suggesting that this is a compensatory mechanism aimed at maintaining cholesterol levels. SP-10 also induced a redistribution of filamentous (F-) and monomeric (G-) actin, leading to decreased actin levels in the submembrane cytoskeleton suggesting that SP-10-induced changes in actin distribution might prevent the formation of microvilli–cellular structures required for SRBI-mediated cholesterol uptake in adrenal cells. Full article
(This article belongs to the Special Issue Neuroprotective Strategies)
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Open AccessArticle Fast and Green Microwave-Assisted Conversion of Essential Oil Allylbenzenes into the Corresponding Aldehydes via Alkene Isomerization and Subsequent Potassium Permanganate Promoted Oxidative Alkene Group Cleavage
Molecules 2009, 14(9), 3411-3424; doi:10.3390/molecules14093411
Received: 12 August 2009 / Revised: 2 September 2009 / Accepted: 2 September 2009 / Published: 3 September 2009
Cited by 13 | PDF Full-text (324 KB)
Abstract
Essential oil allylbenzenes from have been converted quickly and efficiently into the corresponding benzaldehydes in good yields by a two-step “green” reaction pathway based on a solventless alkene group isomerization by KF/Al2O3 to form the corresponding 1-arylpropene and a subsequent
[...] Read more.
Essential oil allylbenzenes from have been converted quickly and efficiently into the corresponding benzaldehydes in good yields by a two-step “green” reaction pathway based on a solventless alkene group isomerization by KF/Al2O3 to form the corresponding 1-arylpropene and a subsequent solventless oxidation of the latter to the corresponding benzaldehyde by KMnO4/CuSO4·5H2O. The assistance by microwave irradiation results in very short reaction times (<15 minutes). The green conversion of eugenol (4-allyl-2-methoxyphenol) into vanillin (4-hydroxy-3-methoxybenzaldehyde) has been carried out in a similar way, requiring however two additional microwave-assisted synthetic steps for acetylation of the hydroxy group prior to the oxidation reaction, and for the final deacetylation of vanillin acetate (4-acetoxy-3-methoxybenzaldehyde) by KF/Al2O3 under solvent-free conditions, respectively. Full article
(This article belongs to the Special Issue Microwave Assisted Synthesis)
Open AccessArticle Microbial Growth and Quorum Sensing Antagonist Activities of Herbal Plants Extracts
Molecules 2009, 14(9), 3425-3435; doi:10.3390/molecules14093425
Received: 2 July 2009 / Revised: 26 July 2009 / Accepted: 5 August 2009 / Published: 3 September 2009
Cited by 49 | PDF Full-text (74 KB)
Abstract
Antimicrobial and antiquorum sensing (AQS) activities of fourteen ethanolic extracts of different parts of eight plants were screened against four Gram-positive, five Gram-negative bacteria and four fungi. Depending on the plant part extract used and the test microorganism, variable activities were recorded at
[...] Read more.
Antimicrobial and antiquorum sensing (AQS) activities of fourteen ethanolic extracts of different parts of eight plants were screened against four Gram-positive, five Gram-negative bacteria and four fungi. Depending on the plant part extract used and the test microorganism, variable activities were recorded at 3 mg per disc. Among the Grampositive bacteria tested, for example, activities of Laurus nobilis bark extract ranged between a 9.5 mm inhibition zone against Bacillus subtilis up to a 25 mm one against methicillin resistant Staphylococcus aureus. Staphylococcus aureus and Aspergillus fumigatus were the most susceptible among bacteria and fungi tested towards other plant parts. Of interest is the tangible antifungal activity of a Tecoma capensis flower extract, which is reported for the first time. However, minimum inhibitory concentrations (MIC's) for both bacteria and fungi were relatively high (0.5-3.0 mg). As for antiquorum sensing activity against Chromobacterium violaceum, superior activity (>17 mm QS inhibition) was associated with Sonchus oleraceus and Laurus nobilis extracts and weak to good activity (8-17 mm) was recorded for other plants. In conclusion, results indicate the potential of these plant extracts in treating microbial infections through cell growth inhibition or quorum sensing antagonism, which is reported for the first time, thus validating their medicinal use. Full article
Open AccessArticle The Use of MoStBioDat for Rapid Screening of Molecular Diversity
Molecules 2009, 14(9), 3436-3445; doi:10.3390/molecules14093436
Received: 24 July 2009 / Revised: 10 August 2009 / Accepted: 3 September 2009 / Published: 8 September 2009
Cited by 6 | PDF Full-text (164 KB)
Abstract
MoStBioDat is a uniform data storage and extraction system with an extensive array of tools for structural similarity measures and pattern matching which is essential to facilitate the drug discovery process. Structure-based database screening has recently become a common and efficient technique in
[...] Read more.
MoStBioDat is a uniform data storage and extraction system with an extensive array of tools for structural similarity measures and pattern matching which is essential to facilitate the drug discovery process. Structure-based database screening has recently become a common and efficient technique in early stages of the drug development, shifting the emphasis from rational drug design into the probability domain of more or less random discovery. The virtual ligand screening (VLS), an approach based on high-throughput flexible docking, samples a virtually infinite molecular diversity of chemical libraries increasing the concentration of molecules with high binding affinity. The rapid process of subsequent examination of a large number of molecules in order to optimize the molecular diversity is an attractive alternative to the traditional methods of lead discovery. This paper presents the application of the MoStBioDat package not only as a data management platform but mainly in substructure searching. In particular, examples of the applications of MoStBioDat are discussed and analyzed. Full article
(This article belongs to the Special Issue Combinatorial Chemistry)
Open AccessCommunication Physicochemical Properties and Antioxidant Activities of Luteolin-Phospholipid Complex
Molecules 2009, 14(9), 3486-3493; doi:10.3390/molecules14093486
Received: 10 July 2009 / Revised: 12 August 2009 / Accepted: 24 August 2009 / Published: 9 September 2009
Cited by 29 | PDF Full-text (246 KB)
Abstract
luteolin and phospholipid complex was prepared to improve the lipophilic properties of luteolin. The physicochemical properties of the complex were analyzed by ultraviolet-visible spectrometry (UV), infrared spectrometry (IR), X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The results showed that luteolin and phospholipid
[...] Read more.
luteolin and phospholipid complex was prepared to improve the lipophilic properties of luteolin. The physicochemical properties of the complex were analyzed by ultraviolet-visible spectrometry (UV), infrared spectrometry (IR), X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). The results showed that luteolin and phospholipid in the complex were joined by non-covalent-bonds and did not form a new compound. It was found that the complex was an effective scavenger of DPPH radicals, with an IC50 value of 28.33 μg/mL. In the Rancimat antioxidant test using lard oil as substrate, the complex also showed the strong antioxidant activity. Full article
Open AccessArticle Synthesis and Cytotoxicity of Novel Hexahydrothienocycloheptapyridazinone Derivatives
Molecules 2009, 14(9), 3494-3508; doi:10.3390/molecules14093494
Received: 17 July 2009 / Revised: 26 August 2009 / Accepted: 9 September 2009 / Published: 9 September 2009
Cited by 5 | PDF Full-text (332 KB)
Abstract
Designed as a new group of tricyclic molecules containing the thienocycloheptapyridazinone ring system, a number of 2N-substituted-hexahydrothienocycloheptapyridazinone derivatives were synthesized and their biological activity evaluated. Among the synthesized compounds, derivatives 7d and 7h were found to possess cytotoxic activity against non-small
[...] Read more.
Designed as a new group of tricyclic molecules containing the thienocycloheptapyridazinone ring system, a number of 2N-substituted-hexahydrothienocycloheptapyridazinone derivatives were synthesized and their biological activity evaluated. Among the synthesized compounds, derivatives 7d and 7h were found to possess cytotoxic activity against non-small cell lung cancer and central nervous system cancer cell lines, respectively. Full article
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Open AccessArticle Ruthenium(III) Chloride Catalyzed Acylation of Alcohols, Phenols, and Thiols in Room Temperature Ionic Liquids
Molecules 2009, 14(9), 3528-3537; doi:10.3390/molecules14093528
Received: 3 July 2009 / Revised: 10 September 2009 / Accepted: 10 September 2009 / Published: 10 September 2009
Cited by 17 | PDF Full-text (180 KB)
Abstract
Ruthenium(III) chloride-catalyzed acylation of a variety of alcohols, phenols, and thiols was achieved in high yields under mild conditions (room temperature) in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]). The ionic liquid and ruthenium catalyst can be recycled at least 10 times.
[...] Read more.
Ruthenium(III) chloride-catalyzed acylation of a variety of alcohols, phenols, and thiols was achieved in high yields under mild conditions (room temperature) in the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF6]). The ionic liquid and ruthenium catalyst can be recycled at least 10 times. Our system not only solves the basic problem of ruthenium catalyst reuse, but also avoids the use of volatile acetonitrile as solvent. Full article
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Open AccessArticle Electrochemical Reduction of Coumarins at a Film-Modified Electrode and Determination of Their Levels in Essential Oils and Traditional Chinese Herbal Medicines
Molecules 2009, 14(9), 3538-3550; doi:10.3390/molecules14093538
Received: 22 June 2009 / Revised: 26 August 2009 / Accepted: 9 September 2009 / Published: 11 September 2009
Cited by 8 | PDF Full-text (199 KB)
Abstract
The electrochemical reduction of coumarins on glassy carbon and electrodeposited metal electrodes was investigated in a Britton-Robinson buffer (pH 1.87-11.98). The effects of various factors, such as the deposition material, time, and concentration of mercury, on the precision of the analysis were explored.
[...] Read more.
The electrochemical reduction of coumarins on glassy carbon and electrodeposited metal electrodes was investigated in a Britton-Robinson buffer (pH 1.87-11.98). The effects of various factors, such as the deposition material, time, and concentration of mercury, on the precision of the analysis were explored. The possible reaction mechanism of the reduction process with regards to scan rates, peak potentials, and currents is discussed. Electroreduction was used to quantitatively determine the levels of coumarins in some essential oils and traditional Chinese herbal medicines. A comparison with high performance liquid chromatography analysis results shows good agreement. Full article
(This article belongs to the Special Issue Coumarins and Xanthones)
Open AccessArticle Microwave-Assisted Solvent-Free Acetylation of Cellulose with Acetic Anhydride in the Presence of Iodine as a Catalyst
Molecules 2009, 14(9), 3551-3566; doi:10.3390/molecules14093551
Received: 16 July 2009 / Revised: 9 September 2009 / Accepted: 11 September 2009 / Published: 11 September 2009
Cited by 44 | PDF Full-text (270 KB)
Abstract
In this work an optimization of the solvent-free acetylation of cellulose with acetic anhydride under microwave heating with iodine as a catalyst was performed. The optimized parameters included the microwave irradiation power from 300 W to 800 W, the reaction time between 5
[...] Read more.
In this work an optimization of the solvent-free acetylation of cellulose with acetic anhydride under microwave heating with iodine as a catalyst was performed. The optimized parameters included the microwave irradiation power from 300 W to 800 W, the reaction time between 5 to 40 min, the reaction temperature from 80 to 130 °C, and the amount of iodine from 1 to 15 mol%. The extent of the acetylation was measured by yield and the degree of substitution (DS), which was determined by a back-titration method. Acetylated cellulose was characterized by FT-IR, CP/MAS 13C-NMR, WRXD, and thermogravimetric analysis. The results showed that within the range of catalyst amounts studied, the DS increased as the amount of iodine used increased, however, it was barely affected by microwave output. It was also found that the reaction time and temperature had an active influence on the extent of acetylation, however, this did not mean that at the higher temperature a better acetylation of cellulose would be obtained. The optimal reaction time and temperature found in this work were 30 min and 130 °C. Full article
(This article belongs to the Special Issue Microwave Assisted Synthesis)
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Open AccessArticle Development of a High-Throughput Assay for Screening of γ-Secretase Inhibitor with Endogenous Human, Mouse or Drosophila γ-Secretase
Molecules 2009, 14(9), 3589-3599; doi:10.3390/molecules14093589
Received: 30 July 2009 / Revised: 22 August 2009 / Accepted: 31 August 2009 / Published: 14 September 2009
Cited by 7 | PDF Full-text (424 KB)
Abstract
Selective lowering of amyloid-β levels with small-molecule γ-secretase inhibitors is a promising therapeutic approach for Alzheimer’s disease. In this work, we developed a high throughput assay for screening of γ-secretase inhibitors with endogenous γ-secretase and a fluorogenic substrate. The IC50 values of
[...] Read more.
Selective lowering of amyloid-β levels with small-molecule γ-secretase inhibitors is a promising therapeutic approach for Alzheimer’s disease. In this work, we developed a high throughput assay for screening of γ-secretase inhibitors with endogenous γ-secretase and a fluorogenic substrate. The IC50 values of known γ-secretase inhibitors generated with this method were comparable with reported values obtained by other methods. The assay was optimized and applied to a small-scale screening of 1,280 compounds. The discovery of several new inhibitors warrants further investigation. This assay was also proven to be easily adopted to test compounds for drosophila and mouse γ-secretase, which could be very useful to assess compounds activity against γ-secretase from different species before the in vivo test in animal models. Full article
Open AccessArticle Synthesis of a [2.2.2] Cryptand Containing Reactive Functional Groups
Molecules 2009, 14(9), 3600-3609; doi:10.3390/molecules14093600
Received: 10 August 2009 / Revised: 3 September 2009 / Accepted: 14 September 2009 / Published: 15 September 2009
Cited by 1 | PDF Full-text (398 KB)
Abstract The functional group-containing potassium ionophore 195,245-dibromo-4,7,13,16,20,23-hexaoxa-1,10-diaza-19(1,2),24(1,2)-dibenzabicyclo[8.8.6]tetracosaphane has been synthesized. Full article
Open AccessArticle Microwave-Assisted Synthesis and Crystal Structure of Oxo(diperoxo)(4,4'-di-tert-butyl-2,2'-bipyridine)-molybdenum(VI)
Molecules 2009, 14(9), 3610-3620; doi:10.3390/molecules14093610
Received: 21 July 2009 / Revised: 3 September 2009 / Accepted: 14 September 2009 / Published: 16 September 2009
Cited by 16 | PDF Full-text (438 KB)
Abstract
The oxodiperoxo complex MoO(O2)2(tbbpy) (tbbpy = 4,4'-di-tert-butyl-2,2'- bipyridine) was isolated from the reaction of MoO2Cl2(tbbpy) in water under microwaveassisted heating at 120 ºC for 4 h. The structure of the oxodiperoxo complex was
[...] Read more.
The oxodiperoxo complex MoO(O2)2(tbbpy) (tbbpy = 4,4'-di-tert-butyl-2,2'- bipyridine) was isolated from the reaction of MoO2Cl2(tbbpy) in water under microwaveassisted heating at 120 ºC for 4 h. The structure of the oxodiperoxo complex was determined by single crystal X-ray diffraction. The MoVI centre is seven-coordinated with a geometry which strongly resembles a highly distorted bipyramid. Individual MoO(O2)2(tbbpy) complexes are interdigitated along the [010] direction to form a column. The crystal structure is formed by the close packing of the columnar-stacked complexes. Interactions between neighbouring columns are essentially of van der Waals type mediated by the need to effectively fill the available space. Full article
(This article belongs to the Special Issue Microwave Assisted Synthesis)
Open AccessArticle Adding Chemical Cross-Links to a Physical Hydrogel
Molecules 2009, 14(9), 3662-3675; doi:10.3390/molecules14093662
Received: 30 June 2009 / Revised: 27 August 2009 / Accepted: 16 September 2009 / Published: 17 September 2009
Cited by 6 | PDF Full-text (711 KB)
Abstract
Synergistic hydrogels are often encountered in polysaccharide mixtures widely used in food and biopharma products. The xanthan and konjac glucomannan pair provides one of the most studied synergistic hydrogels. Recently we showed that the junction zones stabilizing the 3D structure of this gel
[...] Read more.
Synergistic hydrogels are often encountered in polysaccharide mixtures widely used in food and biopharma products. The xanthan and konjac glucomannan pair provides one of the most studied synergistic hydrogels. Recently we showed that the junction zones stabilizing the 3D structure of this gel are present as macromolecular complexes in solution formed by the partially depolymerised polysaccharidic chains. The non-covalent interactions stabilizing the structure of the polysaccharidic complex cause the melting of the ordered structure of the complex in the solution and of the hydrogels. Introduction of chemical cross-links in the 3D structure of the synergistic hydrogel removes this behaviour, adding new features to the swelling and to the viscoelastic properties of the cured hydrogel. The use of epichlorohydrin as low molecular weight cross-linker does not impact unfavourably on the viability of NIH 3T3 fibroblasts. Full article
(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutics)
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Open AccessArticle Synthesis and Antifungal Activity of 5-Chloro-6-Phenylpyridazin-3(2H)-one Derivatives
Molecules 2009, 14(9), 3676-3687; doi:10.3390/molecules14093676
Received: 27 July 2009 / Revised: 13 September 2009 / Accepted: 16 September 2009 / Published: 18 September 2009
Cited by 12 | PDF Full-text (486 KB)
Abstract
An effective method has been developed for the preparation under mild conditions of novel pyridazine derivatives from the easily accessible starting materials mucochloric acid and benzene. All the synthesized compounds were fully characterized and some of them displayed good antifungal activities against G.
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An effective method has been developed for the preparation under mild conditions of novel pyridazine derivatives from the easily accessible starting materials mucochloric acid and benzene. All the synthesized compounds were fully characterized and some of them displayed good antifungal activities against G. zeae, F. oxysporum and C. mandshurica in preliminary antifungal activity tests. Full article
Open AccessCommunication Synthesis of Novel Asymmetric Zinc (II) Phthalocyanines Bearing Octadecyloxyl and Glucosyl Groups
Molecules 2009, 14(9), 3688-3693; doi:10.3390/molecules14093688
Received: 23 July 2009 / Revised: 31 August 2009 / Accepted: 8 September 2009 / Published: 18 September 2009
Cited by 7 | PDF Full-text (371 KB)
Abstract
A novel asymmetric zinc (II) phthalocyanine substituted by one lipophilic octadecyloxyl group and three hydrophilic glucosyl groups was synthesized. Using Q-TOF MS, the major byproducts formed during the deprotection processes were identified. An improved procedure was worked out to convert these byproducts to
[...] Read more.
A novel asymmetric zinc (II) phthalocyanine substituted by one lipophilic octadecyloxyl group and three hydrophilic glucosyl groups was synthesized. Using Q-TOF MS, the major byproducts formed during the deprotection processes were identified. An improved procedure was worked out to convert these byproducts to the desired product in quantitative yield. Full article
Open AccessArticle A New Cytotoxic 19-Nor-cardenolide from the Latex of Antiaris toxicaria
Molecules 2009, 14(9), 3694-3699; doi:10.3390/molecules14093694
Received: 22 July 2009 / Revised: 8 September 2009 / Accepted: 15 September 2009 / Published: 21 September 2009
Cited by 14 | PDF Full-text (143 KB)
Abstract
A new nor-cardenolide, named toxicarioside H (1), was isolated from the latex of Antiaris toxicaria (Pers.) Lesch (Moraceae). Its structure was elucidated on the basis of HRFAB-MS and spectroscopic techniques (IR, UV, 1D and 2D NMR). Compound 1 showed significant cytotoxicity against K562,
[...] Read more.
A new nor-cardenolide, named toxicarioside H (1), was isolated from the latex of Antiaris toxicaria (Pers.) Lesch (Moraceae). Its structure was elucidated on the basis of HRFAB-MS and spectroscopic techniques (IR, UV, 1D and 2D NMR). Compound 1 showed significant cytotoxicity against K562, SGC-7901, SMMC-7721, and HeLa cell lines in vitro by MTT method. Full article
Open AccessArticle Theoretical Study on Exciton Dynamics in Dendritic Systems: Exciton Recurrence and Migration
Molecules 2009, 14(9), 3700-3718; doi:10.3390/molecules14093700
Received: 25 August 2009 / Revised: 11 September 2009 / Accepted: 21 September 2009 / Published: 22 September 2009
Cited by 6 | PDF Full-text (922 KB)
Abstract
The optical functionalities such as exciton recurrence and migration for dendritic systems, e.g., dendrimers, are investigated using the quantum master equation (QME) approach based on the ab initio molecular orbital configuration interaction (MOCI) method, which can treat both the coherent and incoherent exciton
[...] Read more.
The optical functionalities such as exciton recurrence and migration for dendritic systems, e.g., dendrimers, are investigated using the quantum master equation (QME) approach based on the ab initio molecular orbital configuration interaction (MOCI) method, which can treat both the coherent and incoherent exciton dynamics at the first principle level. Two types of phenylacetylene dendrimers, Cayley-tree dendrimer and nanostar dendrimer with anthracene core, are examined to elucidate the features of excion recurrence and migration motions in relation to their structural dependences. It is found that the nanostar dendrimer exhibits faster exciton migration from the periphery to the core than Cayley-tree dendrimer, which alternatively exhibits exciton recurrence motion among dendron parts in case of small relaxation parameters. Such strong structural dependence of exciton dynamics demonstrates the advantage of dendritic molecular systems for future applications in nano-optical and light-harvesting devices. Full article
(This article belongs to the Special Issue Dendrimers - from Synthesis to Applications)
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Open AccessArticle Dendrimer-Capped Nanoparticles Prepared by Picosecond Laser Ablation in Liquid Environment
Molecules 2009, 14(9), 3731-3753; doi:10.3390/molecules14093731
Received: 27 August 2009 / Revised: 17 September 2009 / Accepted: 21 September 2009 / Published: 22 September 2009
Cited by 16 | PDF Full-text (1646 KB)
Abstract
Fifth generation ethylendiamine-core poly(amidoamine) (PAMAM G5) is presented as an efficient capping agent for the preparation of metal and semiconductor nanoparticles by ps laser ablation in water. In particular, we describe results obtained with the fundamental, second and third harmonic of a ps
[...] Read more.
Fifth generation ethylendiamine-core poly(amidoamine) (PAMAM G5) is presented as an efficient capping agent for the preparation of metal and semiconductor nanoparticles by ps laser ablation in water. In particular, we describe results obtained with the fundamental, second and third harmonic of a ps Nd:YAG laser and the influence of laser wavelength and pulse energy on gold particle production and subsequent photofragmentation. In this framework, the role of the dendrimer and, in particular, its interactions with gold clusters and cations are accounted. Full article
(This article belongs to the Special Issue Dendrimers - from Synthesis to Applications)
Open AccessArticle Heterocyclic Analogs of Thioflavones: Synthesis and NMR Spectroscopic Investigations
Molecules 2009, 14(9), 3814-3832; doi:10.3390/molecules14093814
Received: 3 September 2009 / Revised: 11 September 2009 / Accepted: 21 September 2009 / Published: 25 September 2009
Cited by 21 | PDF Full-text (213 KB)
Abstract
The synthesis of several hitherto unknown heterocyclic ring systems derived from thioflavone is described. Coupling of various o-haloheteroarenecarbonyl chlorides with phenylacetylene gives 1-(o-haloheteroaryl)-3-phenylprop-2-yn-1-ones, which were treated with NaSH in refluxing ethanol to yield the corresponding bi- and tricyclic annelated 2-phenylthiopyran-4-ones.
[...] Read more.
The synthesis of several hitherto unknown heterocyclic ring systems derived from thioflavone is described. Coupling of various o-haloheteroarenecarbonyl chlorides with phenylacetylene gives 1-(o-haloheteroaryl)-3-phenylprop-2-yn-1-ones, which were treated with NaSH in refluxing ethanol to yield the corresponding bi- and tricyclic annelated 2-phenylthiopyran-4-ones. Detailed NMR spectroscopic investigations of the ring systems and their precursors are presented. Full article
(This article belongs to the Special Issue Advances in Heterocyclic Chemistry)
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Open AccessCommunication Amides from Piper capense with CNS Activity – A Preliminary SAR Analysis
Molecules 2009, 14(9), 3833-3843; doi:10.3390/molecules14093833
Received: 8 September 2009 / Revised: 25 September 2009 / Accepted: 25 September 2009 / Published: 25 September 2009
Cited by 16 | PDF Full-text (322 KB)
Abstract
Piper capense L.f. (Piperaceae) is used traditionally in South Africa as a sleep inducing remedy. Bioassay-guided fractionation of the roots of P. capense led to the isolation of piperine (1) and 4,5-dihydropiperine (2), which showed moderate affinity for the benzodiazepine site on the
[...] Read more.
Piper capense L.f. (Piperaceae) is used traditionally in South Africa as a sleep inducing remedy. Bioassay-guided fractionation of the roots of P. capense led to the isolation of piperine (1) and 4,5-dihydropiperine (2), which showed moderate affinity for the benzodiazepine site on the GABAA receptor (IC50 values of 1.2 mM and 1.0 mM, respectively). The present study suggests that strict structural properties of the amides are essential for affinity. Taken together, these observations suggest that the carbon chain must contain not less than four carbons, and that a conjugated double bond, adjacent to the amide group, is necessary for binding to the receptor and that the amine part should be bulky. Full article
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Review

Jump to: Research

Open AccessReview Solid State Polyselenides and Polytellurides: A Large Variety of Se–Se and Te–Te Interactions
Molecules 2009, 14(9), 3115-3131; doi:10.3390/molecules14093115
Received: 7 July 2009 / Revised: 15 August 2009 / Accepted: 19 August 2009 / Published: 24 August 2009
Cited by 31 | PDF Full-text (1091 KB)
Abstract
A large variety of different interactions between the chalcogen atoms, Q, occur in the solid state structures of polyselenides and polytellurides, including both molecular and infinite units. The simplest motifs are classical Q22– dumbbells and nonlinear Qn2– chains
[...] Read more.
A large variety of different interactions between the chalcogen atoms, Q, occur in the solid state structures of polyselenides and polytellurides, including both molecular and infinite units. The simplest motifs are classical Q22– dumbbells and nonlinear Qn2– chains (n = 3, 4, 5, ..), e.g. found in alkali metal polychalcogenides. In addition, nonclassical so-called hypervalent motifs exist in the form of linear Q34– units or within larger units such as Q44– and Q54–. Infinitely extended Q units include zigzag, cis/trans and linear chains, as well as planar and slightly puckered layers. Several of those are susceptible to Peierls distortions, leading to the formation of both commensurate and incommensurate superstructures and anomalies in transport properties, including metal-nonmetal transitions. Full article
(This article belongs to the Special Issue Selenium and Tellurium Chemistry)
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Open AccessReview Protein Turnover in Mycobacterial Proteomics
Molecules 2009, 14(9), 3237-3258; doi:10.3390/molecules14093237
Received: 1 July 2009 / Revised: 21 August 2009 / Accepted: 26 August 2009 / Published: 28 August 2009
Cited by 8 | PDF Full-text (392 KB)
Abstract
Understanding the biology of Mycobacterium tuberculosis is one of the primary challenges in current tuberculosis research. Investigation of mycobacterial biology using the systems biology approach has deciphered much information with regard to the bacilli and tuberculosis pathogenesis. The modulation of its environment and
[...] Read more.
Understanding the biology of Mycobacterium tuberculosis is one of the primary challenges in current tuberculosis research. Investigation of mycobacterial biology using the systems biology approach has deciphered much information with regard to the bacilli and tuberculosis pathogenesis. The modulation of its environment and the ability to enter a dormant phase are the hallmarks of M. tuberculosis. Until now, proteome studies have been able to understand much about the role of various proteins, mostly in growing M. tuberculosis cells. It has been difficult to study dormant M. tuberculosis by conventional proteomic techniques with very few proteins being found to be differentially expressed. Discrepancy between proteome and transcriptome studies lead to the conclusion that a certain aspect of the mycobacterial proteome is not being explored. Analysis of protein turnover may be the answer to this dilemma. This review, while giving a gist of the proteome response of mycobacteria to various stresses, analyzes the data obtained from abundance studies versus data from protein turnover studies in M. tuberculosis. This review brings forth the point that protein turnover analysis is capable of discerning more subtle changes in protein synthesis, degradation, and secretion activities. Thus, turnover studies could be incorporated to provide a more in-depth view into the proteome, especially in dormant or persistent cells. Turnover analysis might prove helpful in drug discovery and a better understanding of the dynamic nature of the proteome of mycobacteria. Full article
(This article belongs to the Special Issue Neglected Diseases: Medicinal Chemistry and Natural Product Chemistry)
Open AccessReview Squalene Emulsions for Parenteral Vaccine and Drug Delivery
Molecules 2009, 14(9), 3286-3312; doi:10.3390/molecules14093286
Received: 13 August 2009 / Revised: 25 August 2009 / Accepted: 31 August 2009 / Published: 1 September 2009
Cited by 69 | PDF Full-text (389 KB)
Abstract
Squalene is a linear triterpene that is extensively utilized as a principal component of parenteral emulsions for drug and vaccine delivery. In this review, the chemical structure and sources of squalene are presented. Moreover, the physicochemical and biological properties of squalene-containing emulsions are
[...] Read more.
Squalene is a linear triterpene that is extensively utilized as a principal component of parenteral emulsions for drug and vaccine delivery. In this review, the chemical structure and sources of squalene are presented. Moreover, the physicochemical and biological properties of squalene-containing emulsions are evaluated in the context of parenteral formulations. Historical and current parenteral emulsion products containing squalene or squalane are discussed. The safety of squalene-based products is also addressed. Finally, analytica techniques for characterization of squalene emulsions are examined. Full article
(This article belongs to the Special Issue Triterpenes and Triterpenoids)
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Open AccessReview The Vitamin Nicotinamide: Translating Nutrition into Clinical Care
Molecules 2009, 14(9), 3446-3485; doi:10.3390/molecules14093446
Received: 17 August 2009 / Revised: 8 September 2009 / Accepted: 8 September 2009 / Published: 9 September 2009
Cited by 95 | PDF Full-text (790 KB)
Abstract
Nicotinamide, the amide form of vitamin B3 (niacin), is changed to its mononucleotide compound with the enzyme nicotinic acide/nicotinamide adenylyltransferase, and participates in the cellular energy metabolism that directly impacts normal physiology. However, nicotinamide also influences oxidative stress and modulates multiple pathways
[...] Read more.
Nicotinamide, the amide form of vitamin B3 (niacin), is changed to its mononucleotide compound with the enzyme nicotinic acide/nicotinamide adenylyltransferase, and participates in the cellular energy metabolism that directly impacts normal physiology. However, nicotinamide also influences oxidative stress and modulates multiple pathways tied to both cellular survival and death. During disorders that include immune system dysfunction, diabetes, and aging-related diseases, nicotinamide is a robust cytoprotectant that blocks cellular inflammatory cell activation, early apoptotic phosphatidylserine exposure, and late nuclear DNA degradation. Nicotinamide relies upon unique cellular pathways that involve forkhead transcription factors, sirtuins, protein kinase B (Akt), Bad, caspases, and poly (ADP-ribose) polymerase that may offer a fine line with determining cellular longevity, cell survival, and unwanted cancer progression. If one is cognizant of the these considerations, it becomes evident that nicotinamide holds great potential for multiple disease entities, but the development of new therapeutic strategies rests heavily upon the elucidation of the novel cellular pathways that nicotinamide closely governs. Full article
(This article belongs to the Special Issue Vitamins)
Open AccessReview Mouse Models Targeting Selenocysteine tRNA Expression for Elucidating the Role of Selenoproteins in Health and Development
Molecules 2009, 14(9), 3509-3527; doi:10.3390/molecules14093509
Received: 17 August 2009 / Revised: 3 September 2009 / Accepted: 7 September 2009 / Published: 10 September 2009
Cited by 21 | PDF Full-text (328 KB)
Abstract
Selenium (Se) deficiency has been known for many years to be associated with disease, impaired growth and a variety of other metabolic disorders in mammals. Only recently has the major role that Se-containing proteins, designated selenoproteins, play in many aspects of health and
[...] Read more.
Selenium (Se) deficiency has been known for many years to be associated with disease, impaired growth and a variety of other metabolic disorders in mammals. Only recently has the major role that Se-containing proteins, designated selenoproteins, play in many aspects of health and development begun to emerge. Se is incorporated into protein by way of the Se-containing amino acid, selenocysteine (Sec). The synthesis of selenoproteins is dependent on Sec tRNA for insertion of Sec, the 21st amino acid in the genetic code, into protein. We have taken advantage of this dependency to modulate the expression of Sec tRNA that in turn modulates the expression of selenoproteins by generating transgenic, conditional knockout, transgenic/standard knockout and transgenic/conditional knockout mouse models, all of which involve the Sec tRNA gene, to elucidate the intracellular roles of this protein class. Full article
(This article belongs to the Special Issue Selenium and Tellurium Chemistry)
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Open AccessReview Chemistry of the M (M=Fe, Ca, Ba)-Se-H2O Systems at 25 °C
Molecules 2009, 14(9), 3567-3588; doi:10.3390/molecules14093567
Received: 28 July 2009 / Revised: 18 August 2009 / Accepted: 11 September 2009 / Published: 14 September 2009
Cited by 4 | PDF Full-text (856 KB)
Abstract
The chemistry of the M (M=Fe, Ca, Ba)-Se-H2O systems at 25 °C is reviewed based on our previous papers. In this paper, the phase equilibria in the Fe(III)-Se(IV)-H2O, Ca-Se(IV,VI)-H2O and Ba-Se(IV,VI)-H2O systems at 25 °C
[...] Read more.
The chemistry of the M (M=Fe, Ca, Ba)-Se-H2O systems at 25 °C is reviewed based on our previous papers. In this paper, the phase equilibria in the Fe(III)-Se(IV)-H2O, Ca-Se(IV,VI)-H2O and Ba-Se(IV,VI)-H2O systems at 25 °C are discussed. Then, the three-stage process for removal of selenium from industrial waste water [Se(IV,VI) < 1,500 mg/L] containing sulfuric acid was introduced. This seems to be a promising process for selenium removal from acidic sulfate waste water containing high concentration levels of selenium to below 0.1 mg/L. Full article
(This article belongs to the Special Issue Selenium and Tellurium Chemistry)
Open AccessReview Medicinal Chemistry of Annonaceous Acetogenins: Design, Synthesis, and Biological Evaluation of Novel Analogues
Molecules 2009, 14(9), 3621-3661; doi:10.3390/molecules14093621
Received: 4 August 2009 / Revised: 31 August 2009 / Accepted: 11 September 2009 / Published: 17 September 2009
Cited by 52 | PDF Full-text (2839 KB)
Abstract
Most Annonaceous acetogenins are characterized by between one and three THF ring(s) with one or two flanking hydroxyl group(s) in the center of a C32/34 fatty acid, and the terminal carboxylic acid is combined with a 2-propanol unit to form an α,β-unsaturated γ-lactone.
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Most Annonaceous acetogenins are characterized by between one and three THF ring(s) with one or two flanking hydroxyl group(s) in the center of a C32/34 fatty acid, and the terminal carboxylic acid is combined with a 2-propanol unit to form an α,β-unsaturated γ-lactone. While many studies have addressed the properties and synthesis of natural acetogenins due to their attractive biological activities and unique structural features, a number of analogues have also been described. This review covers the design, synthesis, and biological evaluation of acetogenin analogues. Full article
(This article belongs to the Special Issue Acetogenins: Extraction, Synthesis and Biological Properties)
Open AccessReview Carbosilane and Carbosiloxane Dendrimers
Molecules 2009, 14(9), 3719-3730; doi:10.3390/molecules14093719
Received: 1 September 2009 / Revised: 10 September 2009 / Accepted: 15 September 2009 / Published: 22 September 2009
Cited by 6 | PDF Full-text (247 KB)
Abstract
This review focuses on novel carbosilane dendrimers containing branches with Si-C and Si-O-C bonds. Introduction of organic moieties into the dendrimers is performed by hydrosilation of carbon-carbon double/triple bonds. Versatile organic or organometallic moieties are introduced onto the peripheral regions of dendrimers by
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This review focuses on novel carbosilane dendrimers containing branches with Si-C and Si-O-C bonds. Introduction of organic moieties into the dendrimers is performed by hydrosilation of carbon-carbon double/triple bonds. Versatile organic or organometallic moieties are introduced onto the peripheral regions of dendrimers by coupling and complexation reactions, which clearly demonstrates their potential for variation. Full article
(This article belongs to the Special Issue Dendrimers - from Synthesis to Applications)
Open AccessReview Nasal Delivery of High Molecular Weight Drugs
Molecules 2009, 14(9), 3754-3779; doi:10.3390/molecules14093754
Received: 21 July 2009 / Revised: 14 September 2009 / Accepted: 17 September 2009 / Published: 23 September 2009
Cited by 53 | PDF Full-text (495 KB)
Abstract
Nasal drug delivery may be used for either local or systemic effects. Low molecular weight drugs with are rapidly absorbed through nasal mucosa. The main reasons for this are the high permeability, fairly wide absorption area, porous and thin endothelial basement membrane of
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Nasal drug delivery may be used for either local or systemic effects. Low molecular weight drugs with are rapidly absorbed through nasal mucosa. The main reasons for this are the high permeability, fairly wide absorption area, porous and thin endothelial basement membrane of the nasal epithelium. Despite the many advantages of the nasal route, limitations such as the high molecular weight (HMW) of drugs may impede drug absorption through the nasal mucosa. Recent studies have focused particularly on the nasal application of HMW therapeutic agents such as peptide-protein drugs and vaccines intended for systemic effects. Due to their hydrophilic structure, the nasal bioavailability of peptide and protein drugs is normally less than 1%. Besides their weak mucosal membrane permeability and enzymatic degradation in nasal mucosa, these drugs are rapidly cleared from the nasal cavity after administration because of mucociliary clearance. There are many approaches for increasing the residence time of drug formulations in the nasal cavity resulting in enhanced drug absorption. In this review article, nasal route and transport mechanisms across the nasal mucosa will be briefly presented. In the second part, current studies regarding the nasal application of macromolecular drugs and vaccines with nanoand micro-particulate carrier systems will be summarised. Full article
(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutics)
Open AccessReview On the Chemical Stabilities of Ionic Liquids
Molecules 2009, 14(9), 3780-3813; doi:10.3390/molecules14093780
Received: 1 July 2009 / Revised: 16 September 2009 / Accepted: 18 September 2009 / Published: 25 September 2009
Cited by 195 | PDF Full-text (365 KB)
Abstract
Ionic liquids are novel solvents of interest as greener alternatives to conventional organic solvents aimed at facilitating sustainable chemistry. As a consequence of their unusual physical properties, reusability, and eco-friendly nature, ionic liquids have attracted the attention of organic chemists. Numerous reports have
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Ionic liquids are novel solvents of interest as greener alternatives to conventional organic solvents aimed at facilitating sustainable chemistry. As a consequence of their unusual physical properties, reusability, and eco-friendly nature, ionic liquids have attracted the attention of organic chemists. Numerous reports have revealed that many catalysts and reagents were supported in the ionic liquid phase, resulting in enhanced reactivity and selectivity in various important reaction transformations. However, synthetic chemists cannot ignore the stability data and intermolecular interactions, or even reactions that are directly applicable to organic reactions in ionic liquids. It is becoming evident from the increasing number of reports on use of ionic liquids as solvents, catalysts, and reagents in organic synthesis that they are not totally inert under many reaction conditions. While in some cases, their unexpected reactivity has proven fortuitous and in others, it is imperative that when selecting an ionic liquid for a particular synthetic application, attention must be paid to its compatibility with the reaction conditions. Even though, more than 200 room temperature ionic liquids are known, only a few reports have commented their effects on reaction mechanisms or rate/stability. Therefore, rather than attempting to give a comprehensive overview of ionic liquid chemistry, this review focuses on the non-innocent nature of ionic liquids, with a decided emphasis to clearly illuminate the ability of ionic liquids to affect the mechanistic aspects of some organic reactions thereby affecting and promoting the yield and selectivity. Full article
(This article belongs to the Special Issue Ionic Liquids)

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