Next Issue
Volume 15, January
Previous Issue
Volume 14, November
 
 
molecules-logo

Journal Browser

Journal Browser

Molecules, Volume 14, Issue 12 (December 2009) – 42 articles , Pages 4804-5388

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Reader to open them.
Order results
Result details
Section
Select all
Export citation of selected articles as:

Editorial

Jump to: Research, Review

110 KiB  
Editorial
Discovery of Artemisinin (Qinghaosu)
by Fulong Liao
Molecules 2009, 14(12), 5362-5366; https://doi.org/10.3390/molecules14125362 - 21 Dec 2009
Cited by 45 | Viewed by 17034
Abstract
Artemisinin (Qinghaosu), a new antimalarial drug, was discovered in China in the early 1970s. The discovery of artemisinin is attributed to You-You Tu, at that time a middle-aged phytochemist working in the Institute of Chinese Materia Medica, China Academy of Traditional Chinese Medicine. [...] Read more.
Artemisinin (Qinghaosu), a new antimalarial drug, was discovered in China in the early 1970s. The discovery of artemisinin is attributed to You-You Tu, at that time a middle-aged phytochemist working in the Institute of Chinese Materia Medica, China Academy of Traditional Chinese Medicine. The following paragraph provides a brief summary of her discovery. [...] Full article

Research

Jump to: Editorial, Review

477 KiB  
Article
New Cucurbitane Triterpenoids and Steroidal Glycoside from Momordica charantia
by Jie-Qing Liu, Jian-Chao Chen, Cui-Fang Wang and Ming-Hua Qiu
Molecules 2009, 14(12), 4804-4813; https://doi.org/10.3390/molecules14124804 - 25 Nov 2009
Cited by 45 | Viewed by 14260
Abstract
Three new cucurbitane triterpenoids 1–3 and one new steroidal glycoside 4, were isolated together with ten known compounds from Momordica charantia. The structures of new compounds were determined to be 19(R)-n-butanoxy-5β,19-epoxycucurbita-6,23-diene-3β,25-diol 3-O- [...] Read more.
Three new cucurbitane triterpenoids 1–3 and one new steroidal glycoside 4, were isolated together with ten known compounds from Momordica charantia. The structures of new compounds were determined to be 19(R)-n-butanoxy-5β,19-epoxycucurbita-6,23-diene-3β,25-diol 3-O-β-glucopyranoside (1), 23-O-β-allopyranosylecucurbita-5,24-dien-7α,3β,22(R),23(S)-tetraol 3-O-β-allopyranoside. (2), 23(R),24(S),25-trihydroxycucurbit-5-ene 3-O-{[β-glucopyranosyl(1→6)]-O-β-glucopyranosyl}-25-O-β-glucopyranoside (3), and 24(R)-stigmastan-3β,5α,6β-triol-25-ene 3-O-β-glucopyranoside (4), respectively. Their structures were elucidated by the combination of mass spectrometry (MS), one and two-dimensional NMR experiments and chemical reactions. Full article
Show Figures

Figure 1

280 KiB  
Article
Synthesis and Study of Novel Coumarin Derivatives Potentially Utilizable as Memory Media
by Radoslav Flašík, Henrieta Stankovičová, Anton Gáplovský and Jana Donovalová
Molecules 2009, 14(12), 4838-4848; https://doi.org/10.3390/molecules14124838 - 25 Nov 2009
Cited by 36 | Viewed by 10978
Abstract
Novel coumarin derivatives, 2-oxo-2H-chromenecarbaldehyde hydrazones were prepared by reaction of substituted 2-oxo-2H-chromenecarbaldehydes with N-aminoimides in ethanol in the presence of 4-toluenesulfonic acid as catalyst. The photochromic and thermochromic properties of the prepared compounds were investigated. Full article
Show Figures

Graphical abstract

565 KiB  
Article
Regioselective Synthesis of New 2-(E)-Cyano(thiazolidin-2-ylidene)thiazoles
by Mehdi Bakavoli, Hamid Beyzaie, Mohammad Rahimizadeh, Hossein Eshghi and Reza Takjoo
Molecules 2009, 14(12), 4849-4857; https://doi.org/10.3390/molecules14114849 - 25 Nov 2009
Cited by 11 | Viewed by 8714
Abstract
Cyclocondensation of 2-[bis(methylthio)methylene]malononitrile (1) and cysteamine (2) afforded 2-(thiazolidin-2-ylidene)malononitrile (3). This compound on treatment with NaSH gave the corresponding thioamide derivative 4a in a regioselective manner on the basis of its single crystal X-ray diffraction analysis. Reaction of this compound with several α-bromocarbonyl [...] Read more.
Cyclocondensation of 2-[bis(methylthio)methylene]malononitrile (1) and cysteamine (2) afforded 2-(thiazolidin-2-ylidene)malononitrile (3). This compound on treatment with NaSH gave the corresponding thioamide derivative 4a in a regioselective manner on the basis of its single crystal X-ray diffraction analysis. Reaction of this compound with several α-bromocarbonyl compounds gave new 2-(E)-cyano(thiazolidin-2-ylidene)thiazoles 5a-g. Full article
Show Figures

Figure 1

153 KiB  
Communication
A Facile Synthesis of 2,4-Disubstituted Thiazoles Using MnO2
by Yan-Bo Yu, Hong-Liang Chen, Li-Yi Wang, Xin-Zheng Chen and Bin Fu
Molecules 2009, 14(12), 4858-4865; https://doi.org/10.3390/molecules14124858 - 26 Nov 2009
Cited by 19 | Viewed by 10461
Abstract
Structurally diverse thiazoles with electron-donating and electron-withdrawing groups were conveniently synthesized through manganese dioxide (MnO2) oxidation of the corresponding thiazolines. The effect of substitution at the 2- and 4-positions was investigated. The desired thiazoles with aryl or vinyl substitutions at the [...] Read more.
Structurally diverse thiazoles with electron-donating and electron-withdrawing groups were conveniently synthesized through manganese dioxide (MnO2) oxidation of the corresponding thiazolines. The effect of substitution at the 2- and 4-positions was investigated. The desired thiazoles with aryl or vinyl substitutions at the 2- or 4-position can be obtained in good to excellent yields. Full article
Show Figures

Figure 1

405 KiB  
Article
Synthesis, Structural Studies and Antitumoral Evaluation of C-6 Alkyl and Alkenyl Side Chain Pyrimidine Derivatives S
by Svjetlana Krištafor, Tatjana Gazivoda Kraljević, Damjan Makuc, Janez Plavec, Lidija Šuman, Marijeta Kralj and Silvana Raić-Malić
Molecules 2009, 14(12), 4866-4879; https://doi.org/10.3390/molecules14124866 - 27 Nov 2009
Cited by 6 | Viewed by 9976
Abstract
The synthetic route for introduction of fluorophenylalkyl (compounds 5, 7, 14 and 15) and fluorophenylalkenyl (compounds 4E and 13) side chains at C-6 of the pyrimidine nucleus involved the lithiation of the pyrimidine derivatives 1, 2 and 11 and subsequent nucleophilic addition or [...] Read more.
The synthetic route for introduction of fluorophenylalkyl (compounds 5, 7, 14 and 15) and fluorophenylalkenyl (compounds 4E and 13) side chains at C-6 of the pyrimidine nucleus involved the lithiation of the pyrimidine derivatives 1, 2 and 11 and subsequent nucleophilic addition or substitution reactions of the organolithium intermediate thus obtained with 2-fluorophenylacetone, 4-fluoroacetophenone or ethyl 4-fluorobenzoate as electrophiles. The structures of novel compounds were confirmed by 1H-, 19F- and 13C-NMR and MS. Compounds 8 and 10 containing unsaturated fluorophenylalkyl side chains showed better inhibitory effect than their saturated fluorophenylalkylated pyrimidine counterparts 7 and 9. A conformational study based on NOE enhancements showed the importance of the double bond and substitution in the side chain for the conformational preferences in relation to inhibitory activity. Among all tested compounds, C-5 furyl (12) and phenyl (13 and 15) substituted pyrimidine derivatives showed significant cytostatic activities against all tested tumor cell lines. Full article
Show Figures

Graphical abstract

59 KiB  
Article
Novel Bisquaternary Oximes—Reactivation of Acetylcholinesterase and Butyrylcholinesterase Inhibited by Paraoxon
by Kamil Kuca, Lucie Musilova, Jiri Palecek, Vladimir Cirkva, Martin Paar, Kamil Musilek, Martina Hrabinova, Miroslav Pohanka, Jana Zdarova Karasova and Daniel Jun
Molecules 2009, 14(12), 4915-4921; https://doi.org/10.3390/molecules14124915 - 01 Dec 2009
Cited by 19 | Viewed by 10043
Abstract
Four novel bisquaternary aldoxime cholinesterase reactivators differing in their chemical structure were prepared. Afterwards, their biological activity was evaluated for their ability to reactivate acetylcholinesterase (AChE; EC 3.1.1.7) and butyrylcholinesterase (BuChE; EC 3.1.1.8) inhibited by paraoxon. Their reactivation activity was compared with standard [...] Read more.
Four novel bisquaternary aldoxime cholinesterase reactivators differing in their chemical structure were prepared. Afterwards, their biological activity was evaluated for their ability to reactivate acetylcholinesterase (AChE; EC 3.1.1.7) and butyrylcholinesterase (BuChE; EC 3.1.1.8) inhibited by paraoxon. Their reactivation activity was compared with standard reactivators—pralidoxime, obidoxime and HI-6—which are clinically used at present. As it resulted, none of the prepared compounds surpassed obidoxime, which is considered to be the most potent compound if used for reactivation of AChE inhibited by paraoxon. In case of BuChE reactivation, two compounds (K053 and K068) achieved similar results as obidoxime. Full article
Show Figures

Figure 1

205 KiB  
Article
Phenolic Compound Profiles in Berry Skins from Nine Red Wine Grape Cultivars in Northwest China
by Zan-Min Jin, Jian-Jun He, He-Qiong Bi, Xiang-Yun Cui and Chang-Qing Duan
Molecules 2009, 14(12), 4922-4935; https://doi.org/10.3390/molecules14124922 - 01 Dec 2009
Cited by 61 | Viewed by 11775
Abstract
Phenolic compound profiles were investigated by HPLC-MS in two consecutive years to assess genotypic variation in berry skins of nine red Vitis vinifera cultivars. The results showed that the types and levels of phenolic compounds greatly varied with cultivar. Common wine grape cultivars [...] Read more.
Phenolic compound profiles were investigated by HPLC-MS in two consecutive years to assess genotypic variation in berry skins of nine red Vitis vinifera cultivars. The results showed that the types and levels of phenolic compounds greatly varied with cultivar. Common wine grape cultivars such as Syrah, Cabernet Sauvignon, Cabernet Gernischt and Merlot contained more types of anthocyanins, flavonols, flavan-3-ols, stilbenes and phenolic acids than Gamay, Yan73, Pinot Noir, Zinfandel and Мускат Розовый. Yan 73 and Pinot Noir had abundant anthocyanins, but only a few nonanthocyanin phenolic compounds. Gamay, Zinfandel and Мускат Розовый contained only a few anthocyanins and flavonols. For a grape cultivar, the ratio of one anthocyanin content to total anthocyanin content did not change greatly from one year to the next, unlike for non-anthocyanins. Cluster analysis showed that except for Syrah and Yan 73, the phenolic profiles in the tested grape cultivars had no significant year-to-year variations. Full article
Show Figures

Figure 1

244 KiB  
Article
Synthesis and Phytotoxic Activity of New Pyridones Derived from 4-Hydroxy-6-Methylpyridin-2(1H)-one
by Antonio Jacinto Demuner, Vania Maria Moreira Valente, Luiz Cláudio Almeida Barbosa, Akshat Rathi, Timothy J. Donohoe and Amber L. Thompson
Molecules 2009, 14(12), 4973-4986; https://doi.org/10.3390/molecules14124973 - 01 Dec 2009
Cited by 32 | Viewed by 12449
Abstract
Commercial dehydroacetic acid was converted into 4-hydroxy-6-methylpyridin-2(1H)-one (3), which was then condensed with several aliphatic aldehydes to produce seven new title compounds in variable yields (35–92%). Reaction of 3 with α,β-unsaturated aldehydes resulted in the formation of condensed pyran derivatives 4g' [...] Read more.
Commercial dehydroacetic acid was converted into 4-hydroxy-6-methylpyridin-2(1H)-one (3), which was then condensed with several aliphatic aldehydes to produce seven new title compounds in variable yields (35–92%). Reaction of 3 with α,β-unsaturated aldehydes resulted in the formation of condensed pyran derivatives 4g' and 4h'. A mechanism is proposed to explain the formation of such compounds. The effects of all methylpyridin-2(1H)-one derivatives on the development of the dicotyledonous species Ipomoea grandifolia and Cucumis sativus and the monocotyledonous species Sorghum bicolor were evaluated. At the dose of 6.7 × 10-8 mol a.i./g substrate the compounds showed some phytotoxic selectivity, being more active against the dicotyledonous species. These compounds can be used as lead structures for the development of more active phytotoxic products. Full article
Show Figures

Figure 1

769 KiB  
Article
Hepatoprotective Potential of Extracts from Seeds of Areca catechu and Nutgalls of Quercus infectoria
by Pimolpan Pithayanukul, Saruth Nithitanakool and Rapepol Bavovada
Molecules 2009, 14(12), 4987-5000; https://doi.org/10.3390/molecules14124987 - 01 Dec 2009
Cited by 71 | Viewed by 12450
Abstract
Aqueous extracts from seeds of Areca catechu L. (Arecaceae) (AC) and nutgalls of Quercus infectoria Oliv. (Fagaceae) (QI) were investigated for their hepatoprotective potential by studying their antioxidant capacity using four different methods, by determining their in vitro anti−inflammatory activity against 5-lipoxygenase, and [...] Read more.
Aqueous extracts from seeds of Areca catechu L. (Arecaceae) (AC) and nutgalls of Quercus infectoria Oliv. (Fagaceae) (QI) were investigated for their hepatoprotective potential by studying their antioxidant capacity using four different methods, by determining their in vitro anti−inflammatory activity against 5-lipoxygenase, and by evaluating their hepatoprotective potential against liver injury induced by carbon tetrachloride (CCl4) in rats. AC and QI extracts exhibited potent antioxidant and anti-inflammatory activities. Treatment of rats with AC and QI extracts reversed oxidative damage in hepatic tissues induced by CCl4. It is suggested that extracts rich in either condensed or hydrolysable tannins and known for their potent antioxidant and anti-inflammatory activities, may potentially confer protection against oxidative stress−induced liver injury. These data should contribute to evidence-based traditional medicines for anti-inflammatory and hepatoprotective effects of both extracts. Full article
Show Figures

Figure 1

278 KiB  
Article
18-Crown-6 and Dibenzo-18-crown-6 Assisted Extraction of Cesium from Water into Room Temperature Ionic Liquids and Its Correlation with Stability Constants for Cesium Complexes
by Andrey Grigoryevich Vendilo, Dmitry Ivanovich Djigailo, Svetlana Valeryevna Smirnova, Irina Ivanovna Torocheshnikova, Konstantin Ivanovich Popov, Vladimir Georgyevich Krasovsky and Igor Vladimirovich Pletnev
Molecules 2009, 14(12), 5001-5016; https://doi.org/10.3390/molecules14125001 - 02 Dec 2009
Cited by 30 | Viewed by 13245
Abstract
The pH-profiles of the extraction of Cs+ into four conventional (1-butyl-3-methylimidazolium hexafluorophosphate and bis[trifluoromethyl)sulphonyl]imides of 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-(2-ethylhexyl)-3- methylimidazolium) and two novel (trioctylmethylammonium salicylate and tetrahexylammonium dihexylsulfosuccinate) room temperature ionic liquids have been determined both in the absence and in the [...] Read more.
The pH-profiles of the extraction of Cs+ into four conventional (1-butyl-3-methylimidazolium hexafluorophosphate and bis[trifluoromethyl)sulphonyl]imides of 1-butyl-3-methylimidazolium, 1-hexyl-3-methylimidazolium, and 1-(2-ethylhexyl)-3- methylimidazolium) and two novel (trioctylmethylammonium salicylate and tetrahexylammonium dihexylsulfosuccinate) room temperature ionic liquids have been determined both in the absence and in the presence of crown ether (18-crown-6 or dibenzo-18-crown-6). The pH-profiles of distribution ratio of crown ethers have been established in the same conditions. The relationship of cesium extraction efficiency both with the stability of its complexes with crown ethers and crown ethers’ distribution ratio has been clarified. Full article
(This article belongs to the Collection Ionic Liquids)
Show Figures

Graphical abstract

452 KiB  
Article
Effects of α-Melanocortin Enantiomers on Acetaminophen-Induced Hepatotoxicity in CBA Mice
by Petra Turčić, Mirna Bradamante, Karlo Houra, Nikola Štambuk, Tomislav Kelava, Paško Konjevoda, Saša Kazazić, Dražen Vikić-Topić and Biserka Pokrić
Molecules 2009, 14(12), 5017-5026; https://doi.org/10.3390/molecules14125017 - 02 Dec 2009
Cited by 10 | Viewed by 10907
Abstract
Proteins and peptides in mammals are based exclusively on L-amino acids. Recent investigations show that D-amino acids exhibit physiological effects in vivo, despite of their very small quantities. We have investigated the hepatoprotective effects of the Land D-enantiomers of α-melanocortin peptide (α-MSH). [...] Read more.
Proteins and peptides in mammals are based exclusively on L-amino acids. Recent investigations show that D-amino acids exhibit physiological effects in vivo, despite of their very small quantities. We have investigated the hepatoprotective effects of the Land D-enantiomers of α-melanocortin peptide (α-MSH). The results showed that peptideenantiomerism is related to the protective effects of melanocortin peptides in vivo. L-α-MSH exhibited potent hepatoprotective effect in the experimental model of acetaminophen induced hepatotoxicity in male CBA mice, while its D-mirror image was inefficient. Furthermore, the antibody to the L-peptide did not recognize the D-structure. The results indicate that the opposite peptide configuration may be used to modulate its function and metabolism in vivo and in vitro. Full article
(This article belongs to the Special Issue Prodrugs)
Show Figures

Graphical abstract

550 KiB  
Article
Dissolution of Microcrystalline Cellulose in Phosphoric Acid—Molecular Changes and Kinetics
by Junhua Zhang, Jingqiang Zhang, Lu Lin, Tianming Chen, Jun Zhang, Shijie Liu, Zhenjiang Li and Pingkai Ouyang
Molecules 2009, 14(12), 5027-5041; https://doi.org/10.3390/molecules14125027 - 04 Dec 2009
Cited by 95 | Viewed by 15004
Abstract
In this study, we aimed to dissolve microcrystalline cellulose (MCC) with phosphoric acid to obtain high-quality fermentable saccharides. MCC was directly dissolved in phosphoric acid (the concentration was 83%) for 10 hours at temperatures of 30, 50, and 70 °C. The structural changes [...] Read more.
In this study, we aimed to dissolve microcrystalline cellulose (MCC) with phosphoric acid to obtain high-quality fermentable saccharides. MCC was directly dissolved in phosphoric acid (the concentration was 83%) for 10 hours at temperatures of 30, 50, and 70 °C. The structural changes of MCC were determined in detail with X-ray powder diffraction, solid-state cross-polarization magic angle spinning 13C-NMR, and X-ray photoelectron spectroscopy. The kinetics of MCC decrystallization during treatment with phosphoric acid was also compared at 30, 50, and 70 °C. With the assumption of first order kinetics, the Arrhenius parameters of K, A0 and Ea were calculated. The rate constants of decrystallization reaction (K) were 0.06, 0.17, and 0.12 h-1 respectively. The pre-exponential factor (A0) was 1.2 × 106 h-1, and the activation energy (Ea) was 42.4 kJ/mol. Full article
Show Figures

Graphical abstract

179 KiB  
Article
Synthesis and Antitumor Activities of Phenanthrene-Based Alkaloids
by Songtao Li, Li Han, Liang Sun, Dan Zheng, Jiang Liu, Yingbo Fu, Xueshi Huang and Zhanyou Wang
Molecules 2009, 14(12), 5042-5053; https://doi.org/10.3390/molecules14125042 - 07 Dec 2009
Cited by 12 | Viewed by 10569
Abstract
A series of phenanthrene-based tylophorine derivatives (PBTs) were synthesized and their cytotoxic activities against the H460 human large-cell lung carcinoma cell line were evaluated. Among these compounds, N-(3-hydroxy-2,6,7-tri-methoxyphenanthr-9-ylmethyl)-L-prolinol (5a), and N-(3-hydroxy-2,6,7-trimethoxy-phenanthr-9-ylmethyl)-L-valinol (9) exhibited good activities, with IC [...] Read more.
A series of phenanthrene-based tylophorine derivatives (PBTs) were synthesized and their cytotoxic activities against the H460 human large-cell lung carcinoma cell line were evaluated. Among these compounds, N-(3-hydroxy-2,6,7-tri-methoxyphenanthr-9-ylmethyl)-L-prolinol (5a), and N-(3-hydroxy-2,6,7-trimethoxy-phenanthr-9-ylmethyl)-L-valinol (9) exhibited good activities, with IC50 values of 11.6 and 6.1 mM, respectively. Full article
Show Figures

Scheme 1

145 KiB  
Article
Antimalarial Activity of Ultra-Short Peptides
by Lemuel Pérez-Picaso, Benjamín Velasco-Bejarano, A. Berenice Aguilar-Guadarrama, Rocío Argotte-Ramos and María Yolanda Rios
Molecules 2009, 14(12), 5103-5114; https://doi.org/10.3390/molecules14125103 - 08 Dec 2009
Cited by 15 | Viewed by 9904
Abstract
Ultra-short peptides 1-9 were designed and synthesized with phenylalanine, ornithine and proline amino acid residues and their effect on antimalarial activity was analyzed. On the basis of the IC50 data for these compounds, the effects of nature, polarity, and amino acid sequence [...] Read more.
Ultra-short peptides 1-9 were designed and synthesized with phenylalanine, ornithine and proline amino acid residues and their effect on antimalarial activity was analyzed. On the basis of the IC50 data for these compounds, the effects of nature, polarity, and amino acid sequence on Plasmodium berghei schizont cultures were analyzed too. Tetrapeptides Phe-Orn-Phe-Orn (4) and Lys-Phe-Phe-Orn (5) showed a very important activity with IC50 values of 3.31 and 2.57 μM, respectively. These two tetrapeptides are candidates for subsequent in vivo assays and SARS investigations. Full article
432 KiB  
Article
Calpain Inhibition Reduces Axolemmal Leakage in Traumatic Axonal Injury
by Endre Czeiter, András Büki, Péter Bukovics, Orsolya Farkas, József Pál, Erzsébet Kövesdi, Tamás Dóczi and János Sándor
Molecules 2009, 14(12), 5115-5123; https://doi.org/10.3390/molecules14125115 - 09 Dec 2009
Cited by 14 | Viewed by 11939
Abstract
Calcium-induced, calpain-mediated proteolysis (CMSP) has recently been implicated to the pathogenesis of diffuse (traumatic) axonal injury (TAI). Some studies suggested that subaxolemmal CMSP may contribute to axolemmal permeability (AP) alterations observed in TAI. Seeking direct evidence for this premise we investigated whether subaxolemmal [...] Read more.
Calcium-induced, calpain-mediated proteolysis (CMSP) has recently been implicated to the pathogenesis of diffuse (traumatic) axonal injury (TAI). Some studies suggested that subaxolemmal CMSP may contribute to axolemmal permeability (AP) alterations observed in TAI. Seeking direct evidence for this premise we investigated whether subaxolemmal CMSP may contribute to axolemmal permeability alterations (APA) and pre-injury calpain-inhibition could reduce AP in a rat model of TAI. Horseradish peroxidase (HRP, a tracer that accumulates in axons with APA) was administered one hour prior to injury into the lateral ventricle; 30 min preinjury a single tail vein bolus injection of 30 mg/kg MDL-28170 (a calpain inhibitor) or its vehicle was applied in Wistar rats exposed to impact acceleration brain injury. Histological detection of traumatically injured axonal segments accumulating HRP and statistical analysis revealed that pre-injury administration of the calpain inhibitor MDL-28170 significantly reduced the average length of HRP-labeled axonal segments. The axono-protective effect of pre-injury calpain inhibition recently demonstrated with classical immunohistochemical markers of TAI was further corroborated in this experiment; significant reduction of the length of labeled axons in the drug-treated rats implicate CMSP in the progression of altered AP in TAI. Full article
(This article belongs to the Special Issue Neuroprotective Strategies)
Show Figures

Figure 1

240 KiB  
Article
Synthesis of Chiral 1,4-Disubstituted-1,2,3-Triazole Derivatives from Amino Acids
by Michael Klein, Karin Krainz, Itedale Namro Redwan, Peter Dinér and Morten Grøtli
Molecules 2009, 14(12), 5124-5143; https://doi.org/10.3390/molecules14125124 - 09 Dec 2009
Cited by 14 | Viewed by 12965
Abstract
A versatile method for the synthesis of chiral 1,4-disubstituted-1,2,3-triazole derivatives starting from easily accessible naturally occurring D-or L-amino acids as chiral synthons is described. The amino acids were converted into azido alcohols, followed by copper catalyzed [3+2] cycloaddition reactions between the azido alcohols [...] Read more.
A versatile method for the synthesis of chiral 1,4-disubstituted-1,2,3-triazole derivatives starting from easily accessible naturally occurring D-or L-amino acids as chiral synthons is described. The amino acids were converted into azido alcohols, followed by copper catalyzed [3+2] cycloaddition reactions between the azido alcohols and methyl propiolate and subsequent ester aminolysis with primary and secondary amines furnished the target compounds, which were obtained in excellent yields with no racemization. Docking of selected target compounds shows that the chiral 1,4-disubstituted-1,2,3-triazoles derivatives has the potential of mimicking the binding mode of known purine analogues. Full article
Show Figures

Figure 1

137 KiB  
Article
A New 2-(2-Phenylethyl)Chromone from Chinese Eaglewood
by Hao-Fu Dai, Jun Liu, Yan-Bo Zeng, Zhuang Han, Hui Wang and Wen-Li Mei
Molecules 2009, 14(12), 5165-5168; https://doi.org/10.3390/molecules14125165 - 09 Dec 2009
Cited by 44 | Viewed by 12069
Abstract
A new 2-(2-phenylethyl)chromone, 5,6,7,8-tetrahydroxy-2-(3-hydroxy-4-methoxyphenethyl)-5,6,7,8-tetrahydro-4H-chromen-4-one (1) was isolated from the Chinese eaglewood [Aquilaria sinensis (Lour.) Gilg]. Its structure was established by detailed MS and NMR spectroscopic analysis, as well as comparison with literature data. Full article
Show Figures

Figure 1

416 KiB  
Communication
Highly Efficient and Reusable Copper-Catalyzed N-Arylation of Nitrogen-Containing Heterocycles with Aryl Halides
by A Young Kim, Hyun Ju Lee, Ji Chan Park, Hyunju Kang, Haesik Yang, Hyunjoon Song and Kang Hyun Park
Molecules 2009, 14(12), 5169-5178; https://doi.org/10.3390/molecules14125169 - 10 Dec 2009
Cited by 58 | Viewed by 11539
Abstract
CuO/AB was found to be a simple and efficient catalyst for the N-arylation of a variety of nitrogen-containing heterocycles, giving the products in excellent yields. Full article
(This article belongs to the Special Issue Advances in Heteroaromatic Chemistry)
Show Figures

Figure 1

377 KiB  
Article
Pore Forming Properties of Cecropin-Melittin Hybrid Peptide in a Natural Membrane
by Alberto Milani, Mascia Benedusi, Marco Aquila and Giorgio Rispoli
Molecules 2009, 14(12), 5179-5188; https://doi.org/10.3390/molecules14125179 - 11 Dec 2009
Cited by 25 | Viewed by 10566
Abstract
The pore forming properties of synthetic cecropin-melittin hybrid peptide (Acetyl-KWKLFKKIGAVLKVL-CONH2; CM15) were investigated by using photoreceptor rod outer segments (OS) isolated from frog retinae obtained by using the whole-cell configuration of the patch-clamp technique. CM15 was applied (and removed) to [...] Read more.
The pore forming properties of synthetic cecropin-melittin hybrid peptide (Acetyl-KWKLFKKIGAVLKVL-CONH2; CM15) were investigated by using photoreceptor rod outer segments (OS) isolated from frog retinae obtained by using the whole-cell configuration of the patch-clamp technique. CM15 was applied (and removed) to (from) the OS in ~50 ms with a computer-controlled microperfusion system. Once the main OS endogenous conductance was blocked with light, the OS membrane resistance was ≥1 GΩ, allowing high resolution, low-noise recordings. Different to alamethicines, CM15 produced voltage-independent membrane permeabilisation, repetitive peptide application caused a progressive permeabilisation increase, and no single-channel events were detected at low peptide concentrations. Collectively, these results indicate a toroidal mechanism of pore formation by CM15. Full article
(This article belongs to the Special Issue Molecular Diversity Feature Papers)
Show Figures

Figure 1

427 KiB  
Article
Synthesis and Evaluation of in Vitro Biological Activity of 4-Substituted Arylpiperazine Derivatives of 1,7,8,9-Tetrachloro-10,10-dimethoxy-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione
by Jerzy Kossakowski, Magdalena Pakosinska-Parys, Marta Struga, Izabela Dybala, Anna E. Koziol, Paolo La Colla, Laura Ester Marongiu, Cristina Ibba, David Collu and Roberta Loddo
Molecules 2009, 14(12), 5189-5202; https://doi.org/10.3390/molecules14125189 - 11 Dec 2009
Cited by 17 | Viewed by 12578
Abstract
A series of twenty arylpiperazine derivatives of 1,7,8,9-tetrachloro-10,10-dimethoxy-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione have been prepared. These derivatives were tested in vitro with the aim of identifying novel lead compounds active against emergent and re-emergent human and cattle infectious diseases (AIDS, hepatitis B and C, tuberculosis, [...] Read more.
A series of twenty arylpiperazine derivatives of 1,7,8,9-tetrachloro-10,10-dimethoxy-4-azatricyclo[5.2.1.02,6]dec-8-ene-3,5-dione have been prepared. These derivatives were tested in vitro with the aim of identifying novel lead compounds active against emergent and re-emergent human and cattle infectious diseases (AIDS, hepatitis B and C, tuberculosis, bovine viral diarrhea). In particular, these compounds were evaluated in vitro against representatives of different virus classes, such as a HIV-1 (Retrovirus), a HBV (Hepadnavirus) and the single-stranded RNA+ viruses Yellow fever virus (YFV) and Bovine viral diarrhea virus (BVDV), both belonging to the Flaviridae. Compounds 2c, 2g and 3d showed a modest activity against CVB-2. The molecular structures of the starting imide 1 and one of propyl-piperazine derivatives, 3b, have been determined by an X-ray crystallography study. Full article
Show Figures

Graphical abstract

264 KiB  
Article
Synthesis and Antimicrobial Activity of Some Pyridinium Salts
by Vildan Alptüzün, Sülünay Parlar, Hüseyin Taşlı and Ercin Erciyas
Molecules 2009, 14(12), 5203-5215; https://doi.org/10.3390/molecules14125203 - 14 Dec 2009
Cited by 45 | Viewed by 9023
Abstract
Some substituted benzylidenehydrazinylpyridinium derivatives bearing benzyl, ethylphenyl and propylphenyl groups on the pyridinium nitrogen were synthesized and screened for possible antibacterial and antifungal activities against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans using the microdilution method. Antimicrobial test results [...] Read more.
Some substituted benzylidenehydrazinylpyridinium derivatives bearing benzyl, ethylphenyl and propylphenyl groups on the pyridinium nitrogen were synthesized and screened for possible antibacterial and antifungal activities against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans using the microdilution method. Antimicrobial test results indicated that compounds containing a 3-phenylpropyl chain displayed the highest antimicrobial activity against Staphylococcus aureus and the compound 3d was the most active in the series against all tested bacteria and fungi strains. Full article
Show Figures

Figure 1

236 KiB  
Article
A Striking Exception to the Chelate Model for Acyclic Diastereocontrol: Efficient Access to a Versatile Propargyl Alcohol for Chemical Synthesis
by Sami F. Tlais, Ronald J. Clark and Gregory B. Dudley
Molecules 2009, 14(12), 5216-5222; https://doi.org/10.3390/molecules14125216 - 15 Dec 2009
Cited by 5 | Viewed by 10204
Abstract
The four-step, asymmetric synthesis of a chiral propargyl alcohol 1 from (R)-pantolactone is described. A key feature of the synthesis is a diastereoselective acetylide addition to a chiral α-alkoxy-aldehyde 7, in which unusual Felkin selectivity is observed, despite the potential [...] Read more.
The four-step, asymmetric synthesis of a chiral propargyl alcohol 1 from (R)-pantolactone is described. A key feature of the synthesis is a diastereoselective acetylide addition to a chiral α-alkoxy-aldehyde 7, in which unusual Felkin selectivity is observed, despite the potential for chelation control. Crystalline propargyl alcohol 1 is valuable for complex molecule synthesis, and is easy to prepare in multi-gram quantities and high diastereomeric purity. Full article
(This article belongs to the Special Issue Asymmetric Synthesis)
Show Figures

Figure 1

176 KiB  
Article
Generation of 500-Member Library of 10-Alkyl-2-R1,3-R2-4,10-Dihydrobenzo[4,5]imidazo[1,2-α]pyrimidin-4-ones
by Svetlana M. Sirko, Nikolay Yu. Gorobets, Vladimir I. Musatov and Sergey M. Desenko
Molecules 2009, 14(12), 5223-5234; https://doi.org/10.3390/molecules14125223 - 15 Dec 2009
Cited by 9 | Viewed by 9091
Abstract
Representative benzimidazopyrimidinones were previously reported to be intercalating antitumor agents. In this work, we used 2-substituted 4,10-dihydrobenzo [4,5]imidazo[1,2-α]pyriminin-4-ones for their diversification by regioselective alkylation. Under the conditions established, the alkylation gave 10-alkyl derivatives which permitted the parallel generation of a 500-member [...] Read more.
Representative benzimidazopyrimidinones were previously reported to be intercalating antitumor agents. In this work, we used 2-substituted 4,10-dihydrobenzo [4,5]imidazo[1,2-α]pyriminin-4-ones for their diversification by regioselective alkylation. Under the conditions established, the alkylation gave 10-alkyl derivatives which permitted the parallel generation of a 500-member library of the title compounds. Full article
(This article belongs to the Special Issue Molecular Diversity Feature Papers)
Show Figures

Figure 1

331 KiB  
Communication
MALDI-TOF MS Profiling of Annonaceous Acetogenins in Annona muricata Products for Human Consumption
by Pierre Champy, Vincent Guérineau and Olivier Laprévote
Molecules 2009, 14(12), 5235-5246; https://doi.org/10.3390/molecules14125235 - 15 Dec 2009
Cited by 43 | Viewed by 12342
Abstract
Annonaceous acetogenins are proposed as environmental neurotoxicants consumed through medicinal and alimentary habits and responsible for atypical parkinsonian syndromes observed in tropical areas. Potential sources of exposure still have to be determined, as, to date, only a few batches of products for human [...] Read more.
Annonaceous acetogenins are proposed as environmental neurotoxicants consumed through medicinal and alimentary habits and responsible for atypical parkinsonian syndromes observed in tropical areas. Potential sources of exposure still have to be determined, as, to date, only a few batches of products for human consumption were searched for these compounds. To assess the presence of acetogenins, we propose a fast, sensitive and accurate method of screening, using MALDI-TOF MS, with minimal sample preparation. Development of the technique is discussed. Its application to leaves of herbal tea, pulp and bottled nectar of Annona muricata is presented. Full article
(This article belongs to the Special Issue Acetogenins: Extraction, Synthesis and Biological Properties)
Show Figures

Figure 1

394 KiB  
Article
1-Arylsulfonyl-2-(Pyridylmethylsulfinyl) Benzimidazoles as New Proton Pump Inhibitor Prodrugs
by Jai Moo Shin, George Sachs, Young-moon Cho and Michael Garst
Molecules 2009, 14(12), 5247-5280; https://doi.org/10.3390/molecules14125247 - 15 Dec 2009
Cited by 11 | Viewed by 9807
Abstract
New arylsulfonyl proton pump inhibitor (PPI) prodrug forms were synthesized. These prodrugs provided longer residence time of an effective PPI plasma concentration, resulting in better gastric acid inhibition. Full article
(This article belongs to the Special Issue Prodrugs)
Show Figures

Figure 1

209 KiB  
Article
Chemical Constituents from the Stems of Diospyros maritima
by Chi-I Chang, Chiy-Rong Chen, Hsi-Lin Chiu, Chao-Lin Kuo and Yueh-Hsiung Kuo
Molecules 2009, 14(12), 5281-5288; https://doi.org/10.3390/molecules14125281 - 15 Dec 2009
Cited by 6 | Viewed by 9383
Abstract
A new phenolic, bis(6-hydroxy-2,3,4-trimethoxylphen-1-yl)methane (1) and a new butanedioate, butylmethyl succinate (2), along with twenty-nine known compounds including one naphthoquinone derivative, two chromanones, eight benzenoids, one lignan, one tocopherol, and sixteen triterpenoids were isolated from the stems of Diospyros [...] Read more.
A new phenolic, bis(6-hydroxy-2,3,4-trimethoxylphen-1-yl)methane (1) and a new butanedioate, butylmethyl succinate (2), along with twenty-nine known compounds including one naphthoquinone derivative, two chromanones, eight benzenoids, one lignan, one tocopherol, and sixteen triterpenoids were isolated from the stems of Diospyros maritima. epi-Isoshinanolone (3) was isolated in pure form for the first time. In addition, 5,7-dihydroxy-2-methylchomanone (4) was isolated from a natural source for the first time. Their structures were established on the basis of spectroscopic data as well as direct comparison with authentic samples. Full article
Show Figures

Figure 1

123 KiB  
Article
Germacrene D, A Common Sesquiterpene in the Genus Bursera (Burseraceae)
by Koji Noge and Judith X. Becerra
Molecules 2009, 14(12), 5289-5297; https://doi.org/10.3390/molecules14125289 - 15 Dec 2009
Cited by 44 | Viewed by 11401
Abstract
The volatile components of the leaves of five Bursera species, B. copallifera, B. exselsa, B. mirandae, B. ruticola and B. fagaroides var. purpusii were determined by gas chromatography–mass spectrometry (GC–MS). Germacrene D was one of the predominant components (15.1–56.2%) of [...] Read more.
The volatile components of the leaves of five Bursera species, B. copallifera, B. exselsa, B. mirandae, B. ruticola and B. fagaroides var. purpusii were determined by gas chromatography–mass spectrometry (GC–MS). Germacrene D was one of the predominant components (15.1–56.2%) of all of these species. Germacrene D has also been found in other Bursera species and some species of Commiphora, the sister group of Bursera, suggesting that the production of germacrene D might be an ancient trait in the genus Bursera. Full article
197 KiB  
Article
Protecting-Group-Free Synthesis of 2-Deoxy-Aza-Sugars
by Emma Marie Dangerfield, Catherine Heather Plunkett, Bridget Louise Stocker and Mattie Simon Maria Timmer
Molecules 2009, 14(12), 5298-5307; https://doi.org/10.3390/molecules14125298 - 16 Dec 2009
Cited by 25 | Viewed by 12896
Abstract
The protecting-group-free asymmetric synthesis of 1,2,4-trideoxy-1,4-imino-L-xylitol is readily achieved in five steps from 2-deoxy-D-ribose and with an overall yield of 48%. Key in this synthesis is the application of our recently developed Vasella-reductive amination and carbamate annulation methodologies to the synthesis of 2-deoxy-aza-sugars. [...] Read more.
The protecting-group-free asymmetric synthesis of 1,2,4-trideoxy-1,4-imino-L-xylitol is readily achieved in five steps from 2-deoxy-D-ribose and with an overall yield of 48%. Key in this synthesis is the application of our recently developed Vasella-reductive amination and carbamate annulation methodologies to the synthesis of 2-deoxy-aza-sugars. The carbamate annulation occurred with excellent yield and diastereoselectively (>20:1 d.r.), in favour of the 3,4-cis isomer. Full article
(This article belongs to the Special Issue Asymmetric Synthesis)
Show Figures

Figure 1

150 KiB  
Article
A Chalcone Glycoside from the Fruits of Sorbus commixta Hedl.
by Lok Ranjan Bhatt, Moon Sung Bae, Bo Mi Kim, Gi-Su Oh and Kyu Yun Chai
Molecules 2009, 14(12), 5323-5327; https://doi.org/10.3390/molecules14125323 - 16 Dec 2009
Cited by 22 | Viewed by 11353
Abstract
Sorbus commixta Hedl. (Rosaceae) has been traditionally used in oriental countries for the treatment of asthma and other bronchial disorders. In this study, a chalcone glycoside was isolated from the ethyl acetate extract of the fruits of this plant. The compound was identified [...] Read more.
Sorbus commixta Hedl. (Rosaceae) has been traditionally used in oriental countries for the treatment of asthma and other bronchial disorders. In this study, a chalcone glycoside was isolated from the ethyl acetate extract of the fruits of this plant. The compound was identified as neosakuranin based on the spectroscopic analysis and comparion with literature data. This is the first report of isolation of neosakuranin from Sorbus commixta. Full article
Show Figures

Graphical abstract

424 KiB  
Article
Cytotoxic Activity of Curcumin towards CCRF-CEM Leukemia Cells and Its Effect on DNA Damage
by Yu Kong, Wei Ma, Xia Liu, Yuangang Zu, Yujie Fu, Nan Wu, Lu Liang, Liping Yao and Thomas Efferth
Molecules 2009, 14(12), 5328-5338; https://doi.org/10.3390/molecules14125328 - 17 Dec 2009
Cited by 36 | Viewed by 14536
Abstract
The cytotoxic activity of curcumin towards CCRF-CEM human T-cell leukemia cells was measured by the MTT assay. Tumor cells were more sensitive to the cytotoxic activity of curcumin or curcumin-Cu (II)compared to normal cells, and the IC50 ofcurcumin towards CCRF-CEM cells was [...] Read more.
The cytotoxic activity of curcumin towards CCRF-CEM human T-cell leukemia cells was measured by the MTT assay. Tumor cells were more sensitive to the cytotoxic activity of curcumin or curcumin-Cu (II)compared to normal cells, and the IC50 ofcurcumin towards CCRF-CEM cells was 8.68 µM, and that ofcurcumin-Cu (II) was 8.14 µM. The cell cycle distribution of curcumin-treated CCRF-CEM cells was analyzed by flow cytometry. DNA damage induced by oxidants such as curcumin-Cu (II) ions is considered as one of the main causes of cell inactivation. Therefore, we analyzed the effect of curcumin on DNA damage by agarose gel electrophoresis and atomic force microscopy (AFM). Gel electrophoresis analyses showed that curcumin or Cu (II) alone failed to cause DNA damage in pBR322 plasmid DNA as compared with the normal plasmid. However, DNA plasmids were mostly damaged after treatment with curcumin of different concentrations in the presence of Cu (II). Two forms were observed by means of AFM: closed circular plasmids and linear plasmids. DNA damage induced by a combination of curcumin and Cu (II) was also found by agarose gel electrophoresis, which was applied as control method to verify the results obtained by AFM. Full article
Show Figures

Figure 1

498 KiB  
Article
Synthesis and Biological Evaluation of Novel 1-Alkyltryptophan Analogs as Potential Antitumor Agents
by Ting Sun, Zhao-Long Li, Hua Tian, Shih-Chen Wang and Jiong Cai
Molecules 2009, 14(12), 5339-5348; https://doi.org/10.3390/molecules14125339 - 18 Dec 2009
Cited by 8 | Viewed by 9917
Abstract
To seek novel antitumor agents, we designed and synthesized new 1-tryptophan analogs based on tryptophan catabolism. 1-Alkyltryptophan analogues including 1-ethyltryptophan (1-ET), 1-propyltryptophan (1-PT), 1-isopropyltryptophan (1-isoPT) and 1-butyltryptophan (1-BT) were synthesized from tryptophan. We examined whether those compounds had the antiproliferative effects on SGC7901 [...] Read more.
To seek novel antitumor agents, we designed and synthesized new 1-tryptophan analogs based on tryptophan catabolism. 1-Alkyltryptophan analogues including 1-ethyltryptophan (1-ET), 1-propyltryptophan (1-PT), 1-isopropyltryptophan (1-isoPT) and 1-butyltryptophan (1-BT) were synthesized from tryptophan. We examined whether those compounds had the antiproliferative effects on SGC7901 and HeLa cells line by using MTT assay in vitro, respectively. Compared to tryptophan, all targeted compounds efficiently inhibited proliferation of two cancer cell lines at 2 mmol/L for 48 hours. Among these tryptophan analogs, 1-BT showed the most powerful cytotoxicity against SGC7901 and HeLa cells at 1 mmol/L and 2 mmol/L concentration. These data suggest that some specific tryptophan analogs could be developed as potential anti-neoplastic agents. Full article
Show Figures

Figure 1

488 KiB  
Article
Correlation between Antioxidant Activities and Phenolic Contents of Radix Angelicae Sinensis (Danggui)
by Xican Li, Xiaoting Wu and Ling Huang
Molecules 2009, 14(12), 5349-5361; https://doi.org/10.3390/molecules14125349 - 21 Dec 2009
Cited by 197 | Viewed by 15901
Abstract
Radix Angelicae Sinensisis (RAS) is one of the most popular traditional Chinese herbal medicines. In the present study, six RAS extracts (i.e., phenolic extract PE, petroleum ether extract PEE, ethyl acetate extract EAE, absolute ethanol extract AEE, 95% ethanol extract 95 [...] Read more.
Radix Angelicae Sinensisis (RAS) is one of the most popular traditional Chinese herbal medicines. In the present study, six RAS extracts (i.e., phenolic extract PE, petroleum ether extract PEE, ethyl acetate extract EAE, absolute ethanol extract AEE, 95% ethanol extract 95 EE, and water extract WE) were prepared and their antioxidant activities measured by DPPH (1,1-diphenyl-2-picrylhydrazyl radical), ABTS [2,2′-azino-bis(3- ethylbenzothiazoline-6-sulfonic acid diammonium salt)], Reducing power, •O2– and lipid peroxidation assays. In general, PE, PEE and EAE had relatively high antioxidant activity, followed by AEE with moderate activity, as compared with 95 EE and WE that had low activity. Their phenolic contents (including total phenolic, ferulic acid, caffeic acid, same as below) were then determined by HPLC or spectrophotometry. The sequence of phenolic contents was roughly identical with that of antioxidant activity. When the values of 1/IC50 of various antioxidant assays were used to evaluate the level of antioxidant of the RAS extracts, (plot between 1/IC50 values and phenolic contents), the correlation coefficient (R) ranged from 0.642 to 0.941, with an average value of 0.839. Significant positive correlations demonstrated that the antioxidant effects of RAS might generally be considered a result of the presence of the phenolic compounds, especially ferulic acid and caffeic acid. Full article
Show Figures

Figure 1

192 KiB  
Article
New Conjugated Benzothiazole-N-oxides: Synthesis and Biological Activity
by Peter Gajdoš, Peter Magdolen, Pavol Zahradník and Pavlína Foltínová
Molecules 2009, 14(12), 5382-5388; https://doi.org/10.3390/molecules14125382 - 23 Dec 2009
Cited by 14 | Viewed by 9098
Abstract
Eleven new 2-styrylbenzothiazole-N-oxides have been prepared by aldol – type condensation reactions between 2-methylbenzothiazole–N-oxide and para-substituted benzaldehydes. Compounds with cyclic amino substituents showed typical push-pull molecule properties. Four compounds were tested against various bacterial strains as well as [...] Read more.
Eleven new 2-styrylbenzothiazole-N-oxides have been prepared by aldol – type condensation reactions between 2-methylbenzothiazole–N-oxide and para-substituted benzaldehydes. Compounds with cyclic amino substituents showed typical push-pull molecule properties. Four compounds were tested against various bacterial strains as well as the protozoan Euglena gracilis as model microorganisms. Unlike previously prepared analogous benzothiazolium salts, only weak activity was recorded. Full article
Show Figures

Figure 1

Review

Jump to: Editorial, Research

352 KiB  
Review
Molecular Iodine-Mediated Cyclization of Tethered Heteroatom-Containing Alkenyl or Alkynyl Systems
by Malose Jack Mphahlele
Molecules 2009, 14(12), 4814-4837; https://doi.org/10.3390/molecules14124814 - 25 Nov 2009
Cited by 129 | Viewed by 13658
Abstract
Molecular iodine has established itself as a readily available and easy-to-handle electrophilic and oxidizing reagent used in various organic transformations. In this review attention is focused on the use of molecular iodine in promoting cyclization (iodocyclization and cyclodehydroiodination) of tethered heteroatom-containing alkenyl or [...] Read more.
Molecular iodine has established itself as a readily available and easy-to-handle electrophilic and oxidizing reagent used in various organic transformations. In this review attention is focused on the use of molecular iodine in promoting cyclization (iodocyclization and cyclodehydroiodination) of tethered heteroatom-containing alkenyl or alkynyl systems. Full article
(This article belongs to the Special Issue Organic Iodine Chemistry)
Show Figures

Graphical abstract

335 KiB  
Review
Selenium Utilization Strategy by Microalgae
by Hiroya Araie and Yoshihiro Shiraiwa
Molecules 2009, 14(12), 4880-4891; https://doi.org/10.3390/molecules14124880 - 30 Nov 2009
Cited by 79 | Viewed by 13154
Abstract
The diversity of selenoproteins raises the question of why so many life forms require selenium. Selenoproteins are found in bacteria, archaea, and many eukaryotes. In photosynthetic microorganisms, the essential requirement for selenium has been reported in 33 species belonging to six phyla, although [...] Read more.
The diversity of selenoproteins raises the question of why so many life forms require selenium. Selenoproteins are found in bacteria, archaea, and many eukaryotes. In photosynthetic microorganisms, the essential requirement for selenium has been reported in 33 species belonging to six phyla, although its biochemical significance is still unclear. According to genome databases, 20 species are defined as selenoprotein-producing organisms, including five photosynthetic organisms. In a marine coccolithophorid, Emiliania huxleyi (Haptophyta), we recently found unique characteristics of selenium utilization and novel selenoproteins using 75Se-tracer experiments. In E. huxleyi, selenite, not selenate, is the main substrate used and its uptake is driven by an ATP-dependent highaffinity, active transport system. Selenite is immediately metabolized to low-molecular mass compounds and partly converted to at least six selenoproteins, named EhSEP1–6. The most (EhSEP2) and second-most abundant selenoproteins (EhSEP1) are disulfide isomerase (PDI) homologous protein and thioredoxin reductase (TR) 1, respectively. Involvement of selenium in PDI is unique in this organism, while TR1 is also found in other organisms. In this review, we summarize physiological, biochemical, and molecular aspects of selenium utilization by microalgae and discuss their strategy of selenium utilization. Full article
(This article belongs to the Special Issue Selenium and Tellurium Chemistry)
Show Figures

Figure 1

754 KiB  
Review
Phospholipids: Key Players in Apoptosis and Immune Regulation
by Ricardo A. Chaurio, Christina Janko, Luis E. Muñoz, Benjamin Frey, Martin Herrmann and Udo S. Gaipl
Molecules 2009, 14(12), 4892-4914; https://doi.org/10.3390/molecules14124892 - 30 Nov 2009
Cited by 122 | Viewed by 18846
Abstract
Phosphatidylserine (PS), a phospholipid predominantly found in the inner leaflet of eukaryotic cellular membranes, plays important roles in many biological processes. During apoptosis, the asymmetric distribution of phospholipids of the plasma membrane gets lost and PS is translocated to the outer leaflet of [...] Read more.
Phosphatidylserine (PS), a phospholipid predominantly found in the inner leaflet of eukaryotic cellular membranes, plays important roles in many biological processes. During apoptosis, the asymmetric distribution of phospholipids of the plasma membrane gets lost and PS is translocated to the outer leaflet of the plasma membrane. There, PS acts as one major “eat me” signal that ensures efficient recognition and uptake of apoptotic cells by phagocytes. PS recognition of activated phagocytes induces the secretion of anti-inflammatory cytokines like interleukin-10 and transforming grow factor-beta. Deficiencies in the clearance of apoptotic cells result in the occurrence of secondarily necrotic cells. The latter have lost the membrane integrity and release immune activating danger signals, which may induce inflammatory responses. Accumulation of dead cells containing nuclear autoantigens in sites of immune selection may provide survival signals for autoreactive B-cells. The production of antibodies against nuclear structures determines the initiation of chronic autoimmunity in systemic lupus erythematosus. Since PS on apoptotic cells is an important modulator of the immune response, natural occurring ligands for PS like annexinA5 have profound effects on immune responses against dead and dying cells, including tumour cells. In this review we will focus on the role of PS exposure in the clearance process of dead cells and its implications in clinical situations where apoptosis plays a relevant role, like in cancer, chronic autoimmunity, and infections. Relevance of other phospholipids during the apoptosis process is also discussed. Full article
(This article belongs to the Special Issue Phospholipids)
Show Figures

Graphical abstract

532 KiB  
Review
Microwave Multicomponent Synthesis
by Helmut M. Hügel
Molecules 2009, 14(12), 4936-4972; https://doi.org/10.3390/molecules14124936 - 01 Dec 2009
Cited by 120 | Viewed by 14429
Abstract
In the manner that very important research is often performed by multidisciplinary research teams, the applications of multicomponent reactions involving the combination of multiple starting materials with different functional groups leading to the higher efficiency and environmentally friendly construction of multifunctional/complex target molecules [...] Read more.
In the manner that very important research is often performed by multidisciplinary research teams, the applications of multicomponent reactions involving the combination of multiple starting materials with different functional groups leading to the higher efficiency and environmentally friendly construction of multifunctional/complex target molecules is growing in importance. This review will explore the advances and advantages in microwave multicomponent synthesis (MMS) that have been achieved over the last five years. Full article
(This article belongs to the Special Issue Microwave Assisted Synthesis)
Show Figures

Figure 1

283 KiB  
Review
Neuroprotection by Radical Avoidance: Search for Suitable Agents
by Rüdiger Hardeland
Molecules 2009, 14(12), 5054-5102; https://doi.org/10.3390/molecules14125054 - 07 Dec 2009
Cited by 51 | Viewed by 16737
Abstract
Neurodegeneration is frequently associated with damage by free radicals. However, increases in reactive oxygen and nitrogen species, which may ultimately lead to neuronal cell death, do not necessarily reflect its primary cause, but can be a consequence of otherwise induced cellular dysfunction. Detrimental [...] Read more.
Neurodegeneration is frequently associated with damage by free radicals. However, increases in reactive oxygen and nitrogen species, which may ultimately lead to neuronal cell death, do not necessarily reflect its primary cause, but can be a consequence of otherwise induced cellular dysfunction. Detrimental processes which promote free radical formation are initiated, e.g., by disturbances in calcium homeostasis, mitochondrial malfunction, and an age-related decline in the circadian oscillator system. Free radicals generated at high rates under pathophysiological conditions are insufficiently detoxified by scavengers. Interventions at the primary causes of dysfunction, which avoid secondary rises in radical formation, may be more efficient. The aim of such approaches should be to prevent calcium overload, to reduce mitochondrial electron dissipation, to support electron transport capacity, and to avoid circadian perturbations. l-Theanine and several amphiphilic nitrones are capable of counteracting excitotoxicity and/or mitochondrial radical formation. Resveratrol seems to promote mitochondrial biogenesis. Mitochondrial effects of leptin include attenuation of electron leakage. Melatonin combines all the requirements mentioned, additionally regulates anti- and pro-oxidant enzymes and is, with few exceptions, very well tolerated. In this review, the perspectives, problems and limits of drugs are compared which may be suitable for reducing the formation of free radicals. Full article
(This article belongs to the Special Issue Neuroprotective Strategies)
Show Figures

Figure 1

319 KiB  
Review
The Chemical Composition and Biological Properties of Coconut (Cocos nucifera L.) Water
by Jean W. H. Yong, Liya Ge, Yan Fei Ng and Swee Ngin Tan
Molecules 2009, 14(12), 5144-5164; https://doi.org/10.3390/molecules14125144 - 09 Dec 2009
Cited by 462 | Viewed by 95452
Abstract
Coconut water (coconut liquid endosperm), with its many applications, is one of the world’s most versatile natural product. This refreshing beverage is consumed worldwide as it is nutritious and beneficial for health. There is increasing scientific evidence that supports the role of coconut [...] Read more.
Coconut water (coconut liquid endosperm), with its many applications, is one of the world’s most versatile natural product. This refreshing beverage is consumed worldwide as it is nutritious and beneficial for health. There is increasing scientific evidence that supports the role of coconut water in health and medicinal applications. Coconut water is traditionally used as a growth supplement in plant tissue culture/micropropagation. The wide applications of coconut water can be justified by its unique chemical composition of sugars, vitamins, minerals, amino acids and phytohormones. This review attempts to summarise and evaluate the chemical composition and biological properties of coconut water. Full article
(This article belongs to the Special Issue Phytochemicals with Signaling, Medicinal and Therapeutic Properties)
Show Figures

Figure 1

358 KiB  
Review
Molecular Iodine—An Expedient Reagent for Oxidative Aromatization Reactions of α,β-Unsaturated Cyclic Compounds
by Malose Jack Mphahlele
Molecules 2009, 14(12), 5308-5322; https://doi.org/10.3390/molecules14125308 - 16 Dec 2009
Cited by 58 | Viewed by 14987
Abstract
Prompted by the scant attention paid by published literature reviews to the applications of molecular iodine in oxidative aromatization reactions, we decided to review methods developed to-date involving iodine as an oxidant to promote aromatization of α,β-unsaturated cyclic compounds. Full article
(This article belongs to the Special Issue Organic Iodine Chemistry)
Show Figures

Figure 1

322 KiB  
Review
Role of Phosphatidyl-Serine in Bone Repair and Its Technological Exploitation
by Antonio Merolli and Matteo Santin
Molecules 2009, 14(12), 5367-5381; https://doi.org/10.3390/molecules14125367 - 22 Dec 2009
Cited by 41 | Viewed by 11498
Abstract
In the 1970s, morphological evidence collected by electron microscopy linked mineral deposition (“calcification” or “mineralization”) in newly-forming bone to membrane-encapsulated particles of a diameter of approximately 100 nm (50–200 nm) that were called “matrix vesiscles”. As the characterisation of these vesicles progressed towards [...] Read more.
In the 1970s, morphological evidence collected by electron microscopy linked mineral deposition (“calcification” or “mineralization”) in newly-forming bone to membrane-encapsulated particles of a diameter of approximately 100 nm (50–200 nm) that were called “matrix vesiscles”. As the characterisation of these vesicles progressed towards their biochemical composition, the role of lipids in the biomineralization process appeared to be crucial. In particular, a group of cell-membrane phospholipids were identified as major players in the crystal formation process. Indeed, in the 1980s it became clear that phosphatidylserine, together with proteins of the annexin family, was among the most important molecules in binding calcium ions and that this phospholipid was involved in the regulation of the early stages of mineralization in vivo. During the same period of time, the number of surgical implantations of orthopaedic, dental and maxilo-facial devices requiring full integration with the treated bone prompted the study of new functionalisation molecules able to establish a stable bonding with the mineral phase of the host tissue. In the late 1990s studies started that aimed at exploiting the potential of calcium-binding phospholipids and, in particular, of the phosphatidylserine as functionalisation molecules to improve the osteointegration of artificial implants. Later, papers have been published that show the potential of the phophatidylserine and phosphatidylserine-mimicking coating technology to promote calcification both in vitro and in vivo. The promising results support the future clinical application of these novel osteointegrative biomaterials. Full article
(This article belongs to the Special Issue Phospholipids)
Show Figures

Figure 1

Previous Issue
Next Issue
Back to TopTop