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Heterocyclic compounds, in particular oxygen-containing heterocyclic compounds, are of special interest to medicinal chemists because of their unusual biological properties. In the present study, the highly conjugated nitrogen heterocyclic scaffold comprised of flavone derivative with metal acetates to form metal chelates of the type [MIIL(OAc)2], flavone analogues (L); M=Co2+, Zn2+, Cu2+ and Ni2+. The above title compounds were characterized using composition analysis o fCHN and spectroscopic techniques. Based on spectroscopic and analytical measurements confirmed that square planar arrangements for the Co2+, Zn2+, Cu2+ and Ni2+ complexes. Antimicrobial efficacy of prepared complexes were assessed against A.flavus, A.niger, B.subtilis, E. coli, C. albicans and S.aureus. The anti-mycobacterial (H37Rv) efficacy of flavone analogues and its complexes were screened using MABA approach and compared with standard. The acetylcholinesterase (AChE) inhibitory effect of the ligand was examined to find out the therapeutic efficiency of compound in the treatment of neurodegenerative disorders. The synthesized ligand exhibited selective inhibition (AChE & BuChe) values (IC50:0.20(flavone analogue), 2.41 (Rivastigmine) and 3.01 µM (Galantamine), respectively. Further, the in vitro ant-inflammatory efficiency of metal chelates were performed with the help of egg albumin method. The α-glucosidase inhibition activity was also carried out for the prepared metal complexes.

A new flavone called juncione and known flavone derivatives cynaroside and jaceosidin were isolated from the aerial part of Artemisia juncea Kar. & Kir. The structure 5,6,4′-trihydroxy-3′,5′-dimethoxyflavone 7-O-β-D-glucopyranoside was established for juncione based on IR, UV, PMR, and 13C NMR spectral data and HSQC and HMBC experiments.

A series of novel flavone derivatives were designed, synthesized, and evaluated for their H3 R inhibitory activity. The results showed that four compounds exhibited significant anti-H3 R activity. Molecular docking experiments indicated that a salt bridge, hydrogen-bonding, and hydrophobic interactions all contributed to interactions between inhibitors and H3 R.

Seventeen new flavone derivatives substituted at the 4&prime, OH position were designed, synthesized and evaluated for their anticancer and antibacterial activities. Among them, compounds 3, 4, 6f, 6e, 6b, 6c and 6k demonstrated the most potent antiproliferative activities against a human erythroleukemia cell line (HEL) and a prostate cancer cell line (PC3). The results also showed that the IC50 value of compounds 3, 4, 6f, 6e, 6b, 6c and 6k were close to that of the anticancer drug cisplatin (DDP) and lower than that of apigenin. All of the derivatives did not present antibacterial activities. The structure&ndash, activity relationships evaluation showed that the configuration of methyl amino acid might affect their biological activities.

Our work in the area of carbon-monoxide-releasing molecules led to the synthesis and crystallization of new flavone derivatives as intermediates. Herein we report the first crystal structure of the title compound, C16H12O3, a hydroxy-substituted flavone where the 2-phenyl group has been replaced by a p-tolyl group. The introduction of the 3-hydroxy group allows the formation of intermolecular O—H...O=C hydrogen bonds, used to build centrosymmetric R 2 2(10) ring motifs in the crystal.

Three new flavone derivatives, paranicflavones A–C (1–3), together with three known similar compounds (4–6), were isolated from their roots and stems of Tiandeng tobacco. Their structures were elucidated by spectroscopic methods, including extensive 1H and 13C NMR techniques. Additionally, compounds 1–6 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities, and compound 2 exhibited anti-TMV activity with inhibition rate of 35.8%, which is higher than that of positive control, ningnanmycin.

The benzyl-substituted flavone compounds are rare in nature, while some of which have interesting biological activities. The total synthesis of benzyl-substituted flavone derivatives via the acidic rearrangement of benzyl groups in flavone benzyl ethers, and the complicated regioselectivity of the rearrangement were reported. The regioselectivity was proposed to be determined by the steric hindrance as well as the ease of electrophilic substitution reaction for benzyl cations at different positions of corresponding debenzylated flavone compounds.

Prioritization of compounds using inverse docking approach is limited owing to potential drawbacks in its scoring functions. Classically, molecules ranked by best or lowest binding energies and clustering methods have been considered as probable hits. Mining probable hits from an inverse docking approach is very complicated given the closely related protein targets and the chemically similar ligand data set. To overcome this problem, we present here a computational approach using receptor-centric and ligand-centric methods to infer the reliability of the inverse docking approach and to recognize probable hits. This knowledge-driven approach takes advantage of experimentally identified inhibitors against a particular protein target of interest to delineate shape and molecular field properties and use a multilayer perceptron model to predict the biological activity of the test molecules. The approach was validated using flavone derivatives possessing inhibitory activities against principal antimalarial molecular targets of fatty acid biosynthetic pathway, FabG, FabI and FabZ, respectively. We propose that probable hits can be retrieved by comparing the rank list of docking, quantitative-structure activity relationship and multilayer perceptron models. Copyright © 2014 John Wiley & Sons, Ltd.

Two new acylated flavone C-glycosides, 6''-O-(2'''-methylbutyryl)isoswertisin (1) and 6''-O-(2'''-methylbutyryl)isoswertiajaponin (2), together with four known acylated flavone C-glycosides, were isolated for the first time from the whole plants of Hemistepta lyrata (Compositae). Their structures were elucidated on the basis of chemical and spectroscopic methods including HR-ESI-MS, ESI-MS, UV, IR, and 1D and 2D NMR spectral techniques.

Two new glycosides, 1,6-di-O-syringoyl-β-d-glucopyranose (1) and quercetin 3-O-[(3-O-syringoyl-α-l-rhamnopyranosyl)-(1 → 6)-β-d-glucopyranoside] (2), along with seven known compounds were isolated from the MeOH extract of Leonurus japonicus. The structures of these compounds were elucidated by spectral analysis.

A synthetic precursor cis-[RuIICl2(dmso)4] is complexed separately with 3-(4-benzyloxyphenyl)-1-(2-hydroxylphenyl)-prop-2-en-1-one (L1H) and 2-(4-benzyloxyphenyl)-3hydroxy-chromen-4-one (L2H). The resulting complexes are assigned the composition fac-[RuCl(S-dmso)3(L1)] 1 and fac-[RuCl(S-dmso)3(L2)] 2 using elemental analyses, FAB mass data and spectroscopic (IR, 1H NMR, UV–Vis, emission) spectral properties. The X-ray diffraction analysis shows that complexes self-associate through non-covalent interactions and provide 1D and 2D supramolecular structures. These complexes are assayed for their cytotoxicity studies on Dalton Lymphoma cell lines.

In this paper, a simple and novel synthesis of baicalein is described. This transformation features the novel synthesis of helilandin B and a different way to demethylate. The overall yield of 59% is acceptable.

An expeditious synthesis of three polyoxygenated flavones mosloflavone, negletein and baicalein. starting from crysin, an easily available flavone, by a bromination/methoxylation procedure is reported The convergent synthesis exploits a base induced Wesley-Moser type rearrangement (C) 2009 Elsevier Ltd All rights reserved

We establish useful models that relate experimentally measured biological activities of compounds to their molecular structure. The pED50 feeding inhibition on Spodoptera litura species exhibited by aurones, chromones, 3-coumarones and flavones is analyzed in this work through the hypothesis encompassed in the Quantitative Structure?Activity Relationships (QSAR) Theory. This constitutes a first necessary computationally based step during the design of more bio-friendly repellents that could lead to insights for improving the insecticidal activities of the investigated compounds.After optimizing the molecular structure of each furane and pyrane benzoderivative with the semiempirical molecular orbitals method PM3, more than a thousand of constitutional, topological, geometrical and electronic descriptors are calculated and multiparametric linear regression models are established on the antifeedant potencies. The feature selection method employed in this study is the Replacement Method, which has proven to be successful in previous analyzes. We establish the QSAR both for the complete molecular set of compounds and also for each chemical class, so that acceptably describing the variation of the inhibitory activities from the knowledge of their structure and thus achieving useful predictive results. The main interest of developing trustful QSAR models is that these enable the prediction of compounds having no experimentally measured activities for any reason. Therefore, the structure?activity relationships are further employed for investigating the antifeedant activity on previously synthesized 2-,7-substituted benzopyranes, which do not pose any measured values on the biological expression. One of them, 2-(α-naphtyl)-4H-1-benzopyran-4-one, results in a promising structure to be experimentally analyzed as it has predicted pED50=1.162. Fil: Duchowicz, Pablo Román. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: Goodarzi, Mohammad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: Ocsachoque, Marco Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas ; Argentina Fil: Romanelli, Gustavo Pablo. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas ; Argentina Fil: Ortiz, Erlinda del Valle. Universidad Nacional de Catamarca. Facultad de Tecnologia y Ciencias Aplicadas; Argentina. Comision Nacional de Investigacion Cientifica y Tecnologica; Chile Fil: Autino, Juan C.. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; Argentina Fil: Bennardi, Daniel Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; Argentina Fil: Ruiz, Diego Manuel. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Catedra de Quimica Organica; Argentina Fil: Castro, Eduardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina

A new acylated flavone glycoside, echioidinin 2'-O-beta-D-(2''-O-acetyl)glucopyranoside (1) along with the three known flavonoids, 5,6,7,8,5'-pentamethoxy-3',4'-methylenedioxyflavone (2), 5,2',6'-trihydroxy-7-methoxyflavone (3), and kaempferol 7,4'-dimethyl ether 3-O-beta-D-glucopyranoside (4), were isolated from the roots of Colebrookea oppositifolia. The structure of compound 1 was elucidated by extensive spectral and chemical studies.

Two new steroidal saponins and two known flavonoid glycosides were isolated from the fruits of Tribulus terrestris. Their structures were assigned by spectroscopic analysis and chemical reaction as 26-O-beta-D-glucopyranosyl-(25R)-5 alpha-furostan-12-one-3beta,22 alpha,26-triol-3-O-beta-D-glucopyranosyl (1 --2)-beta-D-glucopyranosyl(1 --4)-beta-D-galactopyranoside (1), 26-O-beta-D-glucopyranosyl-(25S)-5 alpha-furostan-22-methoxy-2 alpha,3beta,26-triol-3-O-beta-D-glucopyranosyl(1 --2)-beta-D-glucopyranosyl(1 --4)-beta-D-galactopyranoside (2), kaempferol-3-gentiobioside (3), and isorhamnetin-3-gentiobioside (4).

Quantitative structure–activity relationship (QSAR) has been established for 32 oxime- and methyloxime-containing flavone and isoflavone derivatives having antiproliferative activity. Multiple linear regressions were used to generate the relationship between biological activity and calculated descriptors. Model with good statistical qualities was developed using the software VLIFE MDS 2.0. Validation of the model was done by cross-validation, randomization, and external test set prediction. On the basis of the QSAR model, we designed a new series of compounds and calculated the activity and found that the compounds were more potent than the existing compounds. QSAR studies of flavone and isoflavone derivatives. The negative coefficient of SdOi indicated that its increase is detrimental to antiproliferative activity. The positive coefficient of QMDMg showed that the magnitude of dipole is responsible for the activity.

Two new flavonoids, compounds 1 and 2, together with seven known flavonoids, were isolated from Galium verum L. Their structures were elucidated as diosmetin 7-O-alpha-l-rhamnopyranosyl-(1-2)-[beta-d-xylopyranosyl-(1-6)]-beta-d-glucopyranoside (1) and 3,5,7,3',4',3'',5'',7'',3''',4'''-decahydroxyl-[8-CH(2)-8'']-biflavone (2) by chemical methods and spectroscopic analyses. Compounds 3 and 4 were isolated from the genus Galium for the first time.

The synthesis and biological activity of a new series of 2-{3-[substituted benzylamino-methyl)-phenyl]-4H-benzopyrane-4-one (IVa-e) and N-substituted benzyl-N-[3-(4-oxo-4H-benzopyrane-2-yl)benzyl]-3-phenyl-acrylamide (Va-e) derivatives are reported. The synthesized compounds were tested in vitro for antifungal and antibacterial activities. Compound IVa showed the best antifungal activity compared with miconazole (CAS 22916-47-8). Compound IVc indicated the best antibacterial activity compared with the control drug ampicillin (CAS 69-53-4).

The and chemical shifts of eleven flavone derivatives were completely determined by basic 1D and 2D NMR experiments. Nineteen flavone derivatives including the above eleven derivatives were examined for anti-oxidative effects using the 1,1-diphenyl-2-picryl-hydrazyl assay and Caenorhabditis elegans. In order to understand the relationships between the structures of flavone derivatives and their anti-oxidative activities, a Comparative Molecular Field Analysis was performed. 먿♸娈

A novel flavonoid, [2-(3,4-dihydroxy-phenyl)-3,5,7-trihydroxy-4-oxo-4H-chromen-8-yl]-[8-hydroxy-7-(E-4-hydroxy-3-methyl-but-2-enyl)-2,2-dimethyl-chroman-5-yl]-acetic acid methyl ester (10), trivially named sabian, along with 11 known compounds, have been isolated from the stems and leaves of Sabiayunnanensis. Their structures were established on the basis of spectral analysis.

In a chemical investigation on the flavone composition of Leonurus heterophyllus a new flavonoside has been isolated. By means of physico-chemical evidences and spectral analysis its structure has been established as quercetin-3-O-[3-(4-hydroxy-3,5-dimethoxybenzyl)-alpha-L-rhamnopyranosyl]-(1--6)-beta-D-galactopyranoside (1).

The 'H and 1 3 C chemical shifts of flavone and its five derivatives were determined completely using the basic ID and 2D NMR experiments and molecular modeling. Of the six compounds used for our experiments, the NMR dataof three compounds were published previously, but we found that the data of two compounds included wrong assignments. Therefore, we report the corrected data and the complete assignments of NMR data of the other three compounds.

The twigs of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis yielded 16 compounds. Two novel diprenylated chalcones: 3,5′-di-(2-hydroxy-3-methylbut-3-enyl)-4,2′,4′-trihydroxychalcone, 3, 4-(2,2-dimethylpyrano)-3′-(2-hydroxy-3-methylbut-3-enyl)-2′,4′-dihydroxychalcone and the known stipulin were isolated from both species. 3-(2-Hydroxy-3-methylbut-3-enyl)-5′-(3,3-dimethylallyl)-4,2′,4′-trihydroxychalcone and the known compounds: 4-hydroxylonchocarpin, kanzonol B, bartericins A, B, C and 3′-(2-hydroxy -3-methylbut-3-enyl)-4,2′,4′-trihydroxychalcone were isolated from D. barteri while the known compounds: gancaonin Q, paratocarpins C, F, and lupeol were obtained from Dorstenia angusticornis . β-Sitosterol and its β- d -glucopyranoside were isolated from both species. Structures of these secondary metabolites were established using spectroscopic analysis, especially, NMR spectra in conjunction with 2D experiments, COSY, HMQC and HMBC.

Six new acylated flavone C-glycosides, 2''-O-(2'''-methylbutyryl)isoswertisin (1), 3''-O-(2'"-methylbutyryl)isoswertisin (2), 2''-O-(2'"-methylbutyryl)vitexin (3), 2''-O-(2'"-methylbutyryl)orientin (4), 2''-O-(3'",4'"-dimethoxybenzoyl)vitexin (5), and 2''-O-(3'",4'"-dimethoxybenzoyl)orientin (6), and the known flavone C-glycoside, isoswertisin, were isolated from the flowers of Trollius ledebouri. The structures of 1-6 were elucidated by spectroscopic methods.

The New Zealand tree Quintinia acutifolia has yielded four biflavonoids, the new 2,3,2'',3''-tetrahydroochnaflavone (3), and its 7,7''-di-O-methyl derivative (1). The rare 7-O-methyl-2,3,2'',3''-tetrahydroochnaflavone (2) and 2'',3''-dihydroochnaflavone (4), both previously identified only from members of the Ochnaceae, were also isolated. Structures were determined by spectroscopic methods. This is the first report of biflavonoids from the Grossulariaceae.

The reactions of iodoflavone with 3-methyl-3-hydroxybut-1-yne and 3-methylbut-3-en-2-yne are described and the antimicrobial and cytotoxic activities of the obtained compounds have been tested. The molecular structures of 6-(3-hydroxy-3-methylbut-1-ynyl)-flavone (1a) and 6-(3-methylbut-3-en-1-ynyl) flavone (1b) have been determined by X-ray crystallography. The planar configuration of the two compounds has been attributed to intramolecular hydrogen bond interactions. In 1a, the presence of the hydroxyl group determines a dimeric arrangement of the molecules. In both compounds in the crystal state, molecular stacking has been observed.

Five new prenylflavonoids, artocommunols CA (1), CB (2), CC (3), CD (4), and CE (5), were isolated from the cortex of the roots of Artocarpus communis, along with the known compound cyclomorusin. The structures of 1-5 were determined by spectral methods.

In this study, it is aimed to investigate the synthesis and the calcium antagonistic activity of some flavone derivatives which contain the 1,4-dihydropyridine ring system at the A ring of the flavone nucleus. For this purpose we first synthesized 6-formylflavone and then twelve 1,4-dihydropyridine derivatives were synthesized by the reaction of 6-formylflavone with alkylacetoacetates, acetoacetanilide and methyl or ethyl aminocrotonate. Conformational analysis was performed for compound 3a. The calcium antagonistic activity of compound 2a was examined using nifedipine as the reference compound.

Solution phase combinatorial synthesis of flavone derivatives and evaluation of their affinity for the central benzodiazepine receptors is described. The libraries preparation is simple and provides a convenient method for rapid compound generation and screening. Thirty one new compounds were obtained of which the most promising, as high affinity benzodiazepine receptor ligands, were 6-bromo-3'-fluoroflavone; 6,3'-dichloroflavone; 6-bromo-3'-chloroflavone and 6-chloro-3'-bromoflavone.

New 2′-hydroxychalcone and flavone derivatives have been synthesised. Their [1H] and [13C] NMR spectra were assigned by the application of COSY and HETCOR experiments and allowed the discussion of some structural aspects. It was shown on the basis of NOE experiments some configurational and conformational features of both type of compounds.

Six flavone derivatives were studied. Previously reported NMR data of three of these derivatives were corrected and the NMR data for the other three derivatives not studied previously were completely assigned on the basis of the basic 1D and 2D NMR experiments and molecular modeling.

Purpose. A QSAR study based on electrotopological state (E-state) indices was conducted for a series of flavone HIV-1 integrase inhibitors to guide drug design. Methods. E-state indices formulated to encode electronic and topological information for each skeletal atom in a molecule (Kier and Hall Pharm. Res. 7:801–807 (1990)) were calculated using the Molconn-X program, and partial least squares (PLS) multivariate regression was used to derive QSAR models. Results. Predictive models with correlation coefficients (r2) of 0.98 (3 PLS components) and 0.99 (5 PLS components) and corresponding cross-validated correlation coefficients (c.v. r2) of 0.51 and 0.73, were obtained for inhibition of cleavage and integration, respectively, with one molecule omitted from the analysis. Conclusions. E-state indices at C6, C3′, C5′, C5, and O4 were found to be more important for prediction of activity than those for any of the other 12 flavone skeletal atoms that are common to the molecules in the data set.

published in Advance ACS Abstracts, November 1, 1995. 0095-233819511635-1034$09.00/0 0 ing various combinations of molecular descriptors. The structures of the flavone derivatives used in this study are shown in Figure 1. A total of 34 descriptors were generated for each flavone derivative. The descriptor pool contained topological and electronic descriptors. The topological descriptors that were calculated include valence connectivity indexes6 0f”’5xv, Wiener number Wand path numbers7 pO-plo, Balaban indexs J, Harary indexes9 HI -&, and molecular topological indexi0 MTI. The electronic descriptors include hardness indexes’ ’ (absolute hardness r, relative hardness qr), energy of the highest occupied molecular orbital E(HOMO), and energy of the lowest unoccupied molecular orbital E(LUMO), topological resonance energy indices’ (topological resonance energy TRE and topological resonance energy per electron TRE(PE)), and the sum of the charges of the atoms located in the chromone moiety

A number of free radical generating systems were used to investigate the antioxidant properties and structure-activity relationships of a series of monohydroxylated and dihydrox­ylated flavones. Ortho-dihydroxylated flavones showed the highest inhibitory activity on en­ zymic and non-enzymic microsomal lipid peroxidation as well as on peroxyl radical scaveng­ing. Most flavones were weak scavengers of hydroxyl radical, while ortho-dihydroxylated flavones interacted with superoxide anion generated by an enzymic system or by human neutrophils. This series of compounds did not exert cytotoxic effects on these cells. Scaveng­ing of superoxide and peroxyl radicals may determ ine the antioxidant properties of these active flavones.

Two new flavone derivatives (1 and 2) were isolated from the aerial parts of Macrothelypteris torresiana, along with four known flavonoids: protoapigenin, apigenin, kaempferol and quercetin. The structures were determined on the basis of spectroscopic data. Compound 1 showed weak cytotoxic activity against human tumour cell lines HepG₂ , MCF₇ and K562.

Flavone and 10 hydroxy and glucoside flavone derivatives were synthesised. They were tested for their analgesic effect in mice employing acetic acid-induced writhing and tail immersion methods. Subcutaneously all the tested compounds exhibited significant analgesic activity with varying potencies in both assay models. The activity of flavone and its 5-; 7-; 2'-; 5,7- and 7,8-hydroxy derivatives apparently involves an opiate-like mechanism, since their activity was reversed by naloxone pretreatment. It is suggested that flavonoid substances may utilise more than one mechanism in eliciting analgesia.

The present work deals with the chemometric modeling of antioxidant molecules belonging to the class of flavone derivatives employing the quantitative structure-activity relationship (QSAR) technique. A QSAR model was initially built based on the Fujita-Ban method with the training set molecules. Due to the inability of the Fujita-Ban type model to predict satisfactorily the activity of the test set molecules, further QSAR models were built using different chemometric tools (genetic function approximation, genetic partial least squares) with additional descriptors viz., topological, structural, spatial and quantum chemical ones. The statistically significant models thus developed suggest that hydroxy and methoxy substituents at certain specified positions of the A and B rings of the flavone moiety chiefly influence the antioxidant activity of these molecules.

Three new flavonol triglycosides, kaempferol-3-O-alpha-L-rhamnopyranosyl-(1 -> 6)-beta-D-glucopyranosyl-(1 -> 3)-beta-D-glucopyranoside (1), quercetin-3-O-alpha-L-rhamnopyranosyl-(1 -> 6)-beta-D-glucopyranosyl-(1 -> 3)-beta-D-glucopyranoside (2), quercetin-3-O-alpha-L-rhamnopyranosyl-(1 -> 6)-beta-D-glucopyranosyl-(1 -> 2)-beta-D-glucopyranoside (3), together with the two known flavonol glycosides, kaempferol-3-O-alpha-L-rhamnopyranosyl-(1 -> 6)-beta-D-glucopyranoside and kaempferol-3-O-alpha-L-rhamnopyranosyl-(1 -> 6)-beta-D-glucopyranosyl-(1 -> 2)-beta-D-glucopyranoside, were isolated from the aerial parts of Derris trifoliata. Their structures were determined on the basis of chemical and spectroscopic analyses.

An aldol condensation and an Algar-Flynn-Oyamada oxidative cyclization were key steps in the direct synthesis of chrysosplenol D, an efflux pump inhibitor that can potentiate the activity of commercially important antibiotics and antimalarials.

We performed a predictive analysis based on quantitative structure–activity relationships (QSAR) of an important property of flavonoids, which is the inhibition (IC50) of aldose reductase (AR). The importance of AR inhibition is that it prevents cataract formation in diabetic patients. The best linear model constructed from 55 molecular structures incorporated six molecular descriptors, selected from more than a thousand geometrical, topological, quantum-mechanical, and electronic types of descriptors. As a practical application, we used the obtained QSAR model to predict the AR inhibitory effect of newly synthesized flavonoids that present 2-, 7-substitutions in the benzopyrane backbone50) of aldose reductase (AR). The importance of AR inhibition is that it prevents cataract formation in diabetic patients. The best linear model constructed from 55 molecular structures incorporated six molecular descriptors, selected from more than a thousand geometrical, topological, quantum-mechanical, and electronic types of descriptors. As a practical application, we used the obtained QSAR model to predict the AR inhibitory effect of newly synthesized flavonoids that present 2-, 7-substitutions in the benzopyrane backbone Fil: Mercader, Andrew Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: Duchowicz, Pablo Román. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: Fernández, Francisco Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: Castro, Eduardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentina Fil: Bennardi, Daniel Oscar. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Cátedra de Química Orgánica; Argentina Fil: Autino, Juan Carlos. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Cátedra de Química Orgánica; Argentina Fil: Romanelli, Gustavo Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Agrarias y Forestales. Departamento de Ciencias Exactas. Cátedra de Química Orgánica; Argentina

Two new compounds, alternanthin B (1) and N-trans-feruloyl-3,5-dimethoxytyramine (2), along with four known compounds (3-6) were isolated from the aerial parts of Alternanthera philoxeroides. Their structures were elucidated on the basis of spectroscopic methods. The antitumor activity of the isolated compounds was also evaluated.

Three new C-glycosylflavones, named 5,7,4'-trihydroxy-6-methoxy-8-C-[beta-D-xylopyranosyl- (1 --2)]-beta-D-glucopyranosyl flavonoside (1), 5,7,4'-trihydroxy-8-methoxy-6-C-[beta-D-xylopyranosyl-(1 --2)]-beta-D-glucopyranosyl flavonoside (2), and 5,3',4'-trihydroxy-7,8-dimethoxy-6-C-[beta-D-xylopyranosyl-(1 --2)]-beta-D-glucopyranosyl flavonoside (3), along with two known compounds 5,4'-dihydroxy-7-methoxy-6-C-glucopyranosyl-flavonoside (4), 3-methoxy-4-hydroxymethyl benzoate (5) were isolated from 70% acetone extract of Corallodiscus flabellata. Their structures were identified on the basis of spectroscopic techniques and chemical methods.

A new chromone named as 5,4′-dihydroxy-7-methyl 3-benzyl chromone (1) along with three known flavonoid compounds as unsubstituted flavone, kaempferol-3-o-rhamnoside and quercetin-3-o-arabinoside have been isolated from the leaves of Cassia nodosa. Their structures have been established by means of chemical and spectral evidences (IR, UV, 1H-NMR, 13C-NMR and mass spectra).

From the roots of Sophora flavescens collected in Taiwan, four new prenylflavonoids, sophoraflavanone K (1), sophoraflavanone L (2), 8-lavandulylkaempferol (3), and cyclokuraridin (4), a new arylbenzofuran, 2-(2,4-dihydroxy-5-prenylphenyl)-5,6-methylenedioxybenzofuran (5), and a new prenyldibenzoyl derivative, sophoradione (6), were isolated. The structures of 1-6 were determined by spectroscopic data analysis. Compounds 2-6 were evaluated for cytotoxic activity against the KB epidermoid carcinoma cell line.