Next Issue
Previous Issue

E-Mail Alert

Add your e-mail address to receive forthcoming issues of this journal:

Journal Browser

Journal Browser

Table of Contents

Molecules, Volume 14, Issue 8 (August 2009), Pages 2684-3114

  • 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 Readerexternal link to open them.
View options order results:
result details:
Displaying articles 1-33
Export citation of selected articles as:
Open AccessArticle Production of β-Maltooligosaccharides of α- and δ-Tocopherols by Klebsiella pneumoniae and Cyclodextrin Glucanotransferase as Anti-Allergic Agents
Molecules 2009, 14(8), 3106-3114; https://doi.org/10.3390/molecules14083106
Received: 14 July 2009 / Revised: 19 August 2009 / Accepted: 20 August 2009 / Published: 20 August 2009
Cited by 9 | PDF Full-text (139 KB) | HTML Full-text | XML Full-text
Abstract
The glycosylation of α- and δ-tocopherols using Klebsiella pneumoniae and cyclodextrin glucanotransferase (CGTase) was investigated. K. pneumoniae converted α- and δ-tocopherols into the corresponding β-glucosides in 10 and 8% yield, respectively. CGTase glycosylated α-tocopheryl β-glucoside to α-tocopheryl β-maltoside (51%) and α-tocopheryl β-maltotrioside (35%).
[...] Read more.
The glycosylation of α- and δ-tocopherols using Klebsiella pneumoniae and cyclodextrin glucanotransferase (CGTase) was investigated. K. pneumoniae converted α- and δ-tocopherols into the corresponding β-glucosides in 10 and 8% yield, respectively. CGTase glycosylated α-tocopheryl β-glucoside to α-tocopheryl β-maltoside (51%) and α-tocopheryl β-maltotrioside (35%). On the other hand, δ-tocopheryl β-glucoside was converted into the corresponding β-maltoside (45%) and β-maltotrioside (29%) by CGTase. The β-glucoside of α-tocopherol, and β-glucoside and β-maltoside of δ-tocopherol showed inhibitory effects on IgE antibody production and on histamine release from rat peritoneal mast cells. Full article
(This article belongs to the Special Issue Vitamins)
Figures

Figure 1

Open AccessArticle Evolution of the Yields and Composition of Essential Oil from Portuguese Myrtle (Myrtus comunis L.) through the Vegetative Cycle
Molecules 2009, 14(8), 3094-3105; https://doi.org/10.3390/molecules14083094
Received: 28 July 2009 / Revised: 13 August 2009 / Accepted: 18 August 2009 / Published: 20 August 2009
Cited by 30 | PDF Full-text (230 KB) | HTML Full-text | XML Full-text
Abstract
The chemical composition of the essential oil of Portuguese myrtle was determined at different developmental stages of the plant: pre-flowering, flowering, unripe and ripe berries. The oil was extracted separately by Clevenger distillation from leaves, branches and berries. The yields vary from 0.33%
[...] Read more.
The chemical composition of the essential oil of Portuguese myrtle was determined at different developmental stages of the plant: pre-flowering, flowering, unripe and ripe berries. The oil was extracted separately by Clevenger distillation from leaves, branches and berries. The yields vary from 0.33% to 0.74% for leaves, 0.02% to 0.19% for branches, and 0.11% to 0.23% for berries. The highest yields were obtained for the leaves in October, and for the berries in September; branches show similar values in the months of June, July and September, and the samples collected in May and October produced very little amount of oil. Altogether, September seems to be the month with the best yields for the three parts of the plant. The essential oils were analyzed by GC and GC/MS, and a total of thirty five components were identified. The major components were limonene+1,8-cineole [25.9% (berries)–39.5% (leaves)], myrtenyl acetate [6.6% (berries)–24.8% (leaves)], α-pinene [9.7% (berries)–21.5% (leaves)], and linalool [6.2% (leaves)–36.5% (berries)]. Portuguese myrtle belongs to the group of myrtles which are characterized by the presence of myrtenyl acetate as one of the major components. Full article
Figures

Figure 1

Open AccessReview Synthesis of Heteroaromatic Compounds by Oxidative Aromatization Using an Activated Carbon/Molecular Oxygen System
Molecules 2009, 14(8), 3073-3093; https://doi.org/10.3390/molecules14083073
Received: 6 July 2009 / Revised: 31 July 2009 / Accepted: 10 August 2009 / Published: 14 August 2009
Cited by 25 | PDF Full-text (532 KB) | HTML Full-text | XML Full-text
Abstract
A variety of heteroaromatic compounds, such as substituted pyridines, pyrazoles, indoles, 2-substituted imidazoles, 2-substituted imidazoles, 2-arylbenzazoles and pyrimidin-2(1H)-ones are synthesized by oxidative aromatization using the activated carbon and molecular oxygen system. Mechanistic study focused on the role of activated carbon in
[...] Read more.
A variety of heteroaromatic compounds, such as substituted pyridines, pyrazoles, indoles, 2-substituted imidazoles, 2-substituted imidazoles, 2-arylbenzazoles and pyrimidin-2(1H)-ones are synthesized by oxidative aromatization using the activated carbon and molecular oxygen system. Mechanistic study focused on the role of activated carbon in the synthesis of 2-arylbenzazoles is also discussed. In the final section, we will disclose the efficient synthesis of substituted 9,10-anthracenes via oxidative aromatization. Full article
(This article belongs to the Special Issue Advances in Heteroaromatic Chemistry)
Figures

Figure 1

Open AccessReview Plant-Derived Antimalarial Agents: New Leads and Efficient Phytomedicines. Part II. Non-Alkaloidal Natural Products
Molecules 2009, 14(8), 3037-3072; https://doi.org/10.3390/molecules14083037
Received: 9 July 2009 / Revised: 7 August 2009 / Accepted: 13 August 2009 / Published: 13 August 2009
Cited by 107 | PDF Full-text (520 KB) | HTML Full-text | XML Full-text
Abstract
Malaria is still the most destructive and dangerous parasitic infection in many tropical and subtropical countries. The burden of this disease is getting worse, mainly due to the increasing resistance of Plasmodium falciparum against the widely available antimalarial drugs. There is an urgent
[...] Read more.
Malaria is still the most destructive and dangerous parasitic infection in many tropical and subtropical countries. The burden of this disease is getting worse, mainly due to the increasing resistance of Plasmodium falciparum against the widely available antimalarial drugs. There is an urgent need for new, more affordable and accessible antimalarial agents possessing original modes of action. Natural products have played a dominant role in the discovery of leads for the development of drugs to treat human diseases, and this fact anticipates that new antimalarial leads may certainly emerge from tropical plant sources. This present review covers most of the recently-published non-alkaloidal natural compounds from plants with antiplasmodial and antimalarial properties, belonging to the classes of terpenes, limonoids, flavonoids, chromones, xanthones, anthraquinones, miscellaneous and related compounds, besides the majority of papers describing antiplasmodial crude extracts published in the last five years not reviewed before. In addition, some perspectives and remarks on the development of new drugs and phytomedicines for malaria are succinctly discussed. Full article
(This article belongs to the Special Issue Neglected Diseases: Medicinal Chemistry and Natural Product Chemistry)
Figures

Graphical abstract

Open AccessArticle Asymmetric Friedel-Crafts Alkylation of Indole with Chalcones Catalyzed by Chiral Phosphoric Acids
Molecules 2009, 14(8), 3030-3036; https://doi.org/10.3390/molecules14083030
Received: 22 July 2009 / Revised: 6 August 2009 / Accepted: 10 August 2009 / Published: 13 August 2009
Cited by 22 | PDF Full-text (292 KB) | HTML Full-text | XML Full-text
Abstract
The reaction of indole with chalcones, to give Michael-type adducts, was found to occur with good efficiency (up to 98% yield) and moderate enantioselectivity (up to 52% e.e.) in the presence of a chiral BINOL-based phosphoric acid. Furthermore, the alkylation products can be
[...] Read more.
The reaction of indole with chalcones, to give Michael-type adducts, was found to occur with good efficiency (up to 98% yield) and moderate enantioselectivity (up to 52% e.e.) in the presence of a chiral BINOL-based phosphoric acid. Furthermore, the alkylation products can be obtained in much higher e.e.s after one only crystallization. Full article
(This article belongs to the Special Issue Asymmetric Synthesis)
Figures

Graphical abstract

Open AccessArticle Coupling Reactions of α-Bromocarboxylate with Non-Aromatic N-Heterocycles
Molecules 2009, 14(8), 3019-3029; https://doi.org/10.3390/molecules14083019
Received: 20 July 2009 / Revised: 30 July 2009 / Accepted: 12 August 2009 / Published: 13 August 2009
Cited by 3 | PDF Full-text (293 KB) | HTML Full-text | XML Full-text
Abstract
The conditions for the C-N bond forming reaction (C-N coupling reaction) between α-bromocarboxylate and nitrogen-containing non-aromatic heterocyclic rings under heterogeneous copper(I) oxide catalysis are investigated in this paper. All the generated compounds were fully characterized by IR, NMR and MS spectroscopy. Ab initio
[...] Read more.
The conditions for the C-N bond forming reaction (C-N coupling reaction) between α-bromocarboxylate and nitrogen-containing non-aromatic heterocyclic rings under heterogeneous copper(I) oxide catalysis are investigated in this paper. All the generated compounds were fully characterized by IR, NMR and MS spectroscopy. Ab initio/DFT calculations of partial charges on nitrogen atoms in all the discussed heterocycles and on C(2) of carboxylate under applied conditions were predicted. These in silico results correlate relatively with the experimental observations. Full article
(This article belongs to the Special Issue Heck Coupling)
Figures

Figure 1

Open AccessCorrection Correction: Meulenberg, E. P. Phenolics: Occurrence and Immunochemical Detection in Environment and Food. Molecules 2009, 14, 439-473
Molecules 2009, 14(8), 3018; https://doi.org/10.3390/molecules140803018
Received: 3 August 2009 / Published: 13 August 2009
PDF Full-text (15 KB) | HTML Full-text | XML Full-text
Abstract
In the original published version of this paper [1], there are two repeated refs. 134 in the reference list.[...] Full article
Open AccessArticle Structural Characterization of Calcium Alginate Matrices by Means of Mechanical and Release Tests
Molecules 2009, 14(8), 3003-3017; https://doi.org/10.3390/molecules14083003
Received: 25 June 2009 / Revised: 4 August 2009 / Accepted: 10 August 2009 / Published: 12 August 2009
Cited by 13 | PDF Full-text (234 KB) | HTML Full-text | XML Full-text
Abstract
In this paper we have concentrated on the characterization of calcium alginate hydrogels loaded with a model drug (myoglobin) by means of a mechanical approach; in addition, release tests of myoglobin from alginate hydrogels were performed. At a fixed temperature, relaxation tests (mechanical
[...] Read more.
In this paper we have concentrated on the characterization of calcium alginate hydrogels loaded with a model drug (myoglobin) by means of a mechanical approach; in addition, release tests of myoglobin from alginate hydrogels were performed. At a fixed temperature, relaxation tests (mechanical study) were carried out on matrices constituted by different polymer concentrations. The interpretation of the relaxation behavior of the different matrices was conducted using the generalized Maxwell model; as a result of this investigation it was possible to conclude that for polymer concentrations greater than 0.5 g/ 100 mL the matrices behaved as solid materials. In addition, it was observed that the mechanical properties of the matrices increased with polymer concentration. With regard to the release tests, the diffusion coefficient of myoglobin in the matrix in relation to polymer concentrations was determined. The mechanical and release data where then analyzed by Flory’s theory and by a modified free-volume theory, respectively, to estimate the network mesh size ξ. The comparison between the mesh sizes obtained by the two approaches showed a satisfactory agreement for polymer concentrations greater than 0.5 g/100 mL. It should be noted that the approach proposed here to determine the polymeric network meshes is absolutely general and can be advantageously applied to the characterization of other similar polymeric systems. Full article
(This article belongs to the Special Issue Macromolecules Applied to Pharmaceutics)
Figures

Graphical abstract

Open AccessArticle Synthesis and Theoretical Study of Molecularly Imprinted Nanospheres for Recognition of Tocopherols
Molecules 2009, 14(8), 2985-3002; https://doi.org/10.3390/molecules14082985
Received: 13 June 2009 / Revised: 5 August 2009 / Accepted: 11 August 2009 / Published: 12 August 2009
Cited by 30 | PDF Full-text (737 KB) | HTML Full-text | XML Full-text
Abstract
Molecular imprinting is a technology that facilitates the production of artificial receptors toward compounds of interest. The molecularly imprinted polymers act as artificial antibodies, artificial receptors, or artificial enzymes with the added benefit over their biological counterparts of being highly durable. In this
[...] Read more.
Molecular imprinting is a technology that facilitates the production of artificial receptors toward compounds of interest. The molecularly imprinted polymers act as artificial antibodies, artificial receptors, or artificial enzymes with the added benefit over their biological counterparts of being highly durable. In this study, we prepared molecularly imprinted polymers for the purpose of binding specifically to tocopherol (vitamin E) and its derivative, tocopherol acetate. Binding of the imprinted polymers to the template was found to be two times greater than that of the control, non-imprinted polymers, when using only 10 mg of polymers. Optimization of the rebinding solvent indicated that ethanol-water at a molar ratio of 6:4 (v/v) was the best solvent system as it enhanced the rebinding performance of the imprinted polymers toward both tocopherol and tocopherol acetate with a binding capacity of approximately 2 mg/g of polymer. Furthermore, imprinted nanospheres against tocopherol was successfully prepared by precipitation polymerization with ethanol-water at a molar ratio of 8:2 (v/v) as the optimal rebinding solvent. Computer simulation was also performed to provide mechanistic insights on the binding mode of template-monomer complexes. Such polymers show high potential for industrial and medical applications, particularly for selective separation of tocopherol and derivatives. Full article
Figures

Graphical abstract

Open AccessArticle Azolyacetones as Precursors to Indoles and Naphthofurans Facilitated by Microwave Irradiation with Simultaneous Cooling
Molecules 2009, 14(8), 2976-2984; https://doi.org/10.3390/molecules14082976
Received: 8 July 2009 / Revised: 30 July 2009 / Accepted: 5 August 2009 / Published: 11 August 2009
Cited by 6 | PDF Full-text (129 KB) | HTML Full-text | XML Full-text | Correction | Supplementary Files
Abstract
Phthalimide reacted with phenacyl bromide under microwave irradiation to yield phenacyl isoindolidene-1,3-dione (3b), while 3a reacted with phenylhydrazine to yield the phenylhydrazone 4 that was readily converted into indoylphthalimide 8. Similarly N-benzotriazolylacetone (6a) reacted with phenyl hydrazine to yield the phenylhydrazone 7a
[...] Read more.
Phthalimide reacted with phenacyl bromide under microwave irradiation to yield phenacyl isoindolidene-1,3-dione (3b), while 3a reacted with phenylhydrazine to yield the phenylhydrazone 4 that was readily converted into indoylphthalimide 8. Similarly N-benzotriazolylacetone (6a) reacted with phenyl hydrazine to yield the phenylhydrazone 7a that was converted into indoylbenzotriazole 9. Treatment of 8 with hydrazine hydrate afforded a mixture of phthalhydrazide 10 and 3-amino-2-methylindole (11). Reacting enaminone 13 with naphthoquinone (14) afforded the aryl naphthofuran 17. The possibility of the formation of the aldehyde 18 was excluded based on HMQC, which revealed that the carbonyl carbon is not linked to any hydrogen. Full article
Figures

Graphical abstract

Open AccessReview Chemical and Biological Characterization of Oleanane Triterpenoids from Soy
Molecules 2009, 14(8), 2959-2975; https://doi.org/10.3390/molecules14082959
Received: 24 June 2009 / Revised: 21 July 2009 / Accepted: 6 August 2009 / Published: 10 August 2009
Cited by 34 | PDF Full-text (564 KB) | HTML Full-text | XML Full-text
Abstract
Soyasaponins are a group of complex and structural diverse oleanane triterpenoids found in soy (Glycine max) and other legumes. They are primarily classified into two main groups − group A and B − based on the attachment of sugar moieties at
[...] Read more.
Soyasaponins are a group of complex and structural diverse oleanane triterpenoids found in soy (Glycine max) and other legumes. They are primarily classified into two main groups − group A and B − based on the attachment of sugar moieties at positions C-3 and C-22 of the ring structures. Group A soyasaponins are bidesmosidic, while group B soyasaponins are monodesmosidic. Group B soyasaponins are further classified into two subcategories known as 2,3-dihydro-2,5-dihydroxy-6 -methyl-4H-pyran-4-one (DDMP) and non-DDMP conjugated molecules. The preparation and purification of soyasaponin molecules is complicated by the presence of bioactive soy isoflavones, which often overlap with soyasaponin in polarity and must removed from extracts before biological assessment. Soyasaponin extracts, aglycones of group A and B and individual group B soyasaponins such as soyasaponin I have been reported to posses specific bioactive properties, such as in vitro anti-cancer properties by modulating the cell cycle and inducing apoptosis. The isolation, chemical characterization and detection strategies by HPLC and HPLC-MS are reviewed, along with the reported bioactive effects of soyasaponin extracts and individual molecules in cultured cancer cell experiments. Full article
(This article belongs to the Special Issue Triterpenes and Triterpenoids 2013)
Figures

Figure 1

Open AccessArticle Antioxidant Activity of Some Plant Extracts Towards Xanthine Oxidase, Lipoxygenase and Tyrosinase
Molecules 2009, 14(8), 2947-2958; https://doi.org/10.3390/molecules14082947
Received: 22 May 2009 / Revised: 9 July 2009 / Accepted: 22 July 2009 / Published: 10 August 2009
Cited by 43 | PDF Full-text (225 KB) | HTML Full-text | XML Full-text
Abstract
Natural products have the potential to be developed into new drugs for the treatment of various diseases. The aim of the present study was to screen the antioxidant activities of some common edible fruits, garden plants and medicinal plants indigenous to Taiwan. This
[...] Read more.
Natural products have the potential to be developed into new drugs for the treatment of various diseases. The aim of the present study was to screen the antioxidant activities of some common edible fruits, garden plants and medicinal plants indigenous to Taiwan. This was performed by assessing the activities of lipoxygenase, xanthine oxidase and tyrosinase following incubation with extracts from these plants. A further aim was to use HPLC-DAD and tyrosinase to chromatographically identify the antioxidative constituents obtained from an extract exhibiting strong antioxidative properties. The acetone extracts of 27 cultivated plant species from Taiwan were tested for antioxidant activities towards xanthine oxidase, tyrosinase and lipoxygenase using spectrophotometric assays. Koelreuteria henryi, Prunus campanulata, and Rhodiola rosea showed the highest xanthine oxidase inhibitory activities. Camellia sinensis, Rhodiola rosea, and Koelreuteria henryi exhibited good tyrosinase inhibitory activities and potent anti-lipoxygenase activities. As Koelreuteria henryi had notable significant inhibitory activities towards xanthine oxidase, tyrosinase, and lipoxygenase, it was further tested with tyrosinase and HPLC-DAD. The results from this part of the study revealed that the more powerful the antioxidant capability of the extracted component, the greater the decrease in peak height obtained after reacting with tyrosinase. Additional studies are warranted to further characterize the compounds responsible for the antioxidant properties of the examined extracts. Full article
Figures

Figure 1

Open AccessArticle Catalytic Epoxidation of a Technical Mixture of Methyl Oleate and Methyl Linoleate in Ionic Liquids Using MoO(O2)2•2QOH (QOH = 8-quinilinol) as Catalyst and NaHCO3 as co-Catalyst
Molecules 2009, 14(8), 2935-2946; https://doi.org/10.3390/molecules14082935
Received: 2 July 2009 / Revised: 3 August 2009 / Accepted: 5 August 2009 / Published: 10 August 2009
Cited by 20 | PDF Full-text (271 KB) | HTML Full-text | XML Full-text
Abstract
The oxo-diperoxo molybdenum(VI) complex MoO(O2)2•2QOH (QOH = 8-quinilinol) was prepared and characterized by elemental analysis, IR and UV-Vis spectra. The ionic liquids (ILs) [bmim][BF4], [hydemim][BF4], and [bmim][PF6] were characterized by 1H-NMR and
[...] Read more.
The oxo-diperoxo molybdenum(VI) complex MoO(O2)2•2QOH (QOH = 8-quinilinol) was prepared and characterized by elemental analysis, IR and UV-Vis spectra. The ionic liquids (ILs) [bmim][BF4], [hydemim][BF4], and [bmim][PF6] were characterized by 1H-NMR and UV-Vis spectra. The epoxidation of a technical mixture of methyl oleate and methyl linoleate with H2O2, in [bmim][BF4], [hydemim][BF4] and [bmim][PF6], catalyzed by MoO(O2)2•2QOH (QOH = 8-quinilinol) and with NaHCO3 as co-catalyst has been studied for the first time. It was found that high conversions of methyl oleate and methyl linoleate to their respective oxidation products, as well as the total selectivity of their oxidation products to oxirane in [hydemim][BF4] were obtained. Also, the IL phases containing the Mo(VI) catalyst can be readily recycled by washing with diethyl ether and drying, and the Mo(VI) catalyst can be reused at least five times. Full article
(This article belongs to the collection Ionic Liquids)
Figures

Figure 1

Open AccessCommunication Screening for γ-Nonalactone in the Headspace of Freshly Cooked Non-Scented Rice Using SPME/GC-O and SPME/GC-MS
Molecules 2009, 14(8), 2927-2934; https://doi.org/10.3390/molecules14082927
Received: 22 June 2009 / Revised: 13 July 2009 / Accepted: 27 July 2009 / Published: 10 August 2009
Cited by 5 | PDF Full-text (267 KB) | HTML Full-text | XML Full-text
Abstract
The determination of γ-nonalactone as one of the important odor-active compounds in freshly cooked non-scented rice is reported. It was evaluated by gas chromatography-olfactometry (GC-O) analysis and identified by gas chromatography-mass spectrometry (GC-MS) analysis in the headspace above the freshly cooked non-scented rice
[...] Read more.
The determination of γ-nonalactone as one of the important odor-active compounds in freshly cooked non-scented rice is reported. It was evaluated by gas chromatography-olfactometry (GC-O) analysis and identified by gas chromatography-mass spectrometry (GC-MS) analysis in the headspace above the freshly cooked non-scented rice samples extracted by using a modified headspace solid-phase microextraction (SPME) method. This component had a mass spectrum with a characteristic ion peak at m/z 85 (100%) and a linear retention index (RI) of 2,023 on a DB Wax column, consistent with those of an authentic sample of γ-nonalactone. The odor characterization of a strong, sweet, coconut-like aroma of this compound was also validated by GC-O comparison with the authentic compound. Full article
Figures

Figure 1

Open AccessArticle Cross-Cyclotrimerization with Two Nitriles as a Synthetic Pathway to Unsymmetrically 3,3’-Disubstituted bis(Tetrahydroisoquinolines)
Molecules 2009, 14(8), 2918-2926; https://doi.org/10.3390/molecules14082918
Received: 10 July 2009 / Revised: 31 July 2009 / Accepted: 3 August 2009 / Published: 10 August 2009
Cited by 14 | PDF Full-text (233 KB) | HTML Full-text | XML Full-text
Abstract
Microwave assisted CpCo(CO)2 catalyzed cross-cyclotrimerizations of 1,7,9,15-hexadecatetrayne with two different nitriles to give unsymmetrically substituted bis(tetrahydroisoquinolines) was studied. The reaction proceeded with a range of alkyl and aryl nitriles with reasonable isolated yields. Full article
(This article belongs to the Special Issue Microwave Assisted Synthesis)
Figures

Graphical abstract

Back to Top