Dimeric alkaloids and flavonoids from Aristolochia ridicula

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

An LC-DAD Fingerprinting Method for Alkaloids, Flavonoids and Styrylpyrones from Cryptocarya mandioccana

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

High-Performance Liquid Chromatographic Quantification of Flavonoids in Eriocaulaceae Species and Their Antimicrobial Activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mutagenicity of Flavonoids Assayed by Bacterial Reverse Mutation (Ames) Test

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Preparative separation of flavonoids from the medicinal plant Davilla elliptica St. Hill. by high-speed counter-current chromatography

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Xanthones and flavonoids from Leiothrix curvifolia and Leiothrix flavescens

8-Carboxymethyl-1,6-dihydroxy-3,5-dimethoxyxanthone 8-carboxymethyl-1,5,6-trihydroxy-3-methoxyxanthone and 8-carboxy-methyl-1,3,5,6-tetrahydroxyxanthone were isolated from the capitula of Leiothrix curvifolia and Leiothrix flavescens and characterized by spectroscopic methods, mainly 1D and 2D NMR experiments, as well as by electrospray mass spectrometry. Eight known flavonoids were also isolated and they were identified by 1D and 2D NMR experiments and comparison with literature data. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Bioactive pyrones and flavonoids from Cryptocarya ashersoniana seedlings

The bioassay directed fractionation of the EtOH extract from leaves of Cryptocarya ashersoniana seedlings led to the isolation of two flavonol glucosides: iso-quercitrin and hyperin, which exhibited free radical scavenging activity towards DPPH (IC50 34.4 muM and 32.7 muM, respectively) and were compared to standard compounds rutin (IC50 27.0 muM) and catechin (IC50 41.4 muM). Investigation of extracts from the seedlings roots and stems afforded one antifungal styrylpyrone: goniothalamine, and two dihydropyrones: 6-propyl-5,6-dihydro-2-pyrone and the new 6-[(4'-ethyl-9'-oxabicyclo[3.3.1]non-6'-en-3'-yl)methyl]-5,6-dihydro-2H-pyran-2-one, which had its structure determined by detailed analysis of MS and NMR data, including 2D experiments.

Flavonoids and lignans from Virola surinamensis twigs and their in vitro activity against Trypanosoma cruzi

Dichloromethane extracts from twigs of Virola surinamensis (Myristicaceae) showed in vitro trypanosomicidal activity against trypomastigote form of Trypanosoma cruzi. The extract, fractionated by preparative circular chromatography and preparative high-performance liquid chromatography yielded two steroids, two lignans, five flavonoids, and one polyketide. Among the isolated compounds, the lignans presented the highest trypanosomicidal activity.

Use of on-line liquid chromatography-nuclear magnetic resonance spectroscopy for the rapid investigation of flavonoids from Sorocea bomplandii

This paper reports the identification of di- and triglycosylated flavonoids from Sorocea bomplandii (Moraceae) by liquid chromatography coupled on-line to nuclear magnetic resonance (LC-NMR). These glycosylated flavonoids may be used as a taxonomic marker in future work. (C) 2002 Elsevier B.V. B.V All rights reserved.

Flavonoids and isoflavonoids from Gynerium sagittatum

Four flavonoids namely (2R,3R)-2,3-trans-7,4 '-dimethoxydihydroflavonol, (2R,3S,4S)-2,3-trans-3,4-cis-7,4'-dimethoxy-3,4-flavandiol, 6-hydroxy-7,4 '-dimethoxyflavone, 6,7,4 '-trimethoxyflavone, along with the known isoflavonoids ferreirin, dihydrocajanin, dalbergioidin, dihydrobiochanin A and biochanin A and other I I known compounds were isolated from the roots of Gynerium sagittatum. The structural characterization of these compounds was carried out via one- and two-dimensional NMR experiments in combination with ESI-MS. Finally a quantitative analysis of the isoflavones of the methanolic extract was performed by LC-ESI-MS. The high quantity of isoflavonoids found in G. sagittatum makes this plant a good natural source of isoflavonoids. (c) 2007 Elsevier Ltd. All rights reserved.

Neolignans, styrylpyrones and flavonoids from an Aniba species

The trunk wood and barks from an Aniba species contain four esters of benzoic acid with cinnamyl alcohol, five benzofuran neolignans, licarin-A, burchellin, cis-burchellin, burchellin-rearranged and cis-burchellin-rearranged, one tetrahydrofuran neolignan, aristolignin, three bicyclooctane guianin-type neolignans, (7S, 8S, 1'R, 5'R)-4-hydroxy-3,3'-dimethoxy-4',6'-dioxo-8.1', 7.5'-neolignan-Delta: 1,3,5,2',8' and the new (7S, 8S, 1'R, 4'R, 5'S)-4'-hydroxy-3,4,3'-trimethoxy-6'-oxo-8.1', 7.5'-neolignan-Delta: 1,3,5,2',8' and (7S, 8S, 1'R, 4'R, 5'S)-4,4'-dihydroxy-3,3'-dimethoxy-6'-oxo-8.1', 7.5'-neolignan-Delta: 1,3,5,2',8', one new bicyclooctane canellin-type neolignan (7S, 8S, 1'S, 4'R, 5'R, 6'S)-4',6'-dihydroxy-3,4-dimethoxy-3'-oxo-8.1', 7.5'-neolignan-Delta: 1,3,5,8', two styrylpyrones, 4-methoxy-6-(11,12-dimethoxy-trans-styryl)-2-pyrone and 6-(11,12-methylenedioxy-trans-styryl)-4-methoxy-2-pyrone, two styrylpyrone dimers: 4'-methoxy-8-(11,12-dimethoxyphenyl)-7-[6-(4-methoxy-2-pyronyl)-6-(E)-styryl-1'-oxabicyclo[4,2,0]octa-4'-en-2'-one and the new 11,12-dimethoxyphenyl-7,7'-di-[6-(4-methoxy-2-pyronyl)]-cyclobutane and six flavonoids, 3,5-dihydroxy-7,4'-dimethoxyflavone, 5-hydroxy-3,7,4'-trimethoxyflavone, 3,5,4'-trihydroxy-7-methoxyflavone, 2,3-dihydro-5-hydroxy-7,4'-dimethoxyflavone, 2,3-dihydro-3,5-dihydroxy-7-methoxyflavone, 2,3-dihydro-3,5-dihydroxy-7,4'-dimethoxyflavone and a new flavan, 6,7,3',4',5'-pentamethoxyflavan. (C) 1997 Elsevier B.V. Ltd.

Flavonoids from Iryanthera sagotiana

Leaves and inflorescences of Iryanthera sagotiana were found to contain three known dihydrochalcones, two flavonol rhamnosides, four flavanonol rhamnosides, one dihydrocoumaric acid, besides the new 3,'3'''-bis-2',4',6'-trihydroxy-4-methoxydihydrochalcone and 4',6'-dihydroxy-4-methoxydihydrochalcone-2'-O-beta-D-glucopyranoside. (C) 1997 Elsevier B.V. Ltd.

Chemical composition of flavonoids and styrylpyrones and the genetic variability of isozymes in natural populations of Cryptocarya mandioccana Meisner (Lauraceae)

The chemical composition of leaves of 57 trees of Cryptocarya mandioccana from three populations of southeastern Brazil was investigated through HPLC, assaying six flavonoids, seven styrylpyrones, and seven unidentified compounds. From 51 of the former trees, genotypes were obtained from 40 polymorphic loci of 19 isozymes. Cluster analyses of the phytochemical and genetical variation revealed that trees exhibited four chemotypes and five clusters from isozymes, respectively. Discriminant analyses from selected variables of the isozymic and chemical data sets were performed, respectively, in relation to the four chemotypes and the five isozyme clusters. The classification of individuals presented respective error estimates of 9.16% and 13.57%, indicating that the genetic data could explain the clusters from chernotypes and vice versa at acceptable error levels. Linear regressions with Dummy variable showed significant association of locus Skdh-2 with quercetin-3-O-beta-D-glucopyranoside and cryptofolione, indicating that its alleles would be responsible for the chemotype variation between individuals. (c) 2006 Elsevier Ltd. All rights reserved.

Planifolin, a new naphthopyranone dimer and flavonoids from Paepalanthus planifolius

A new naphthopyranone dimer (I) named planifolin was isolated from a methylene chloride extract of the capitula of Paepalanthus planifolius. The structure of 1 has been determined by chemical and spectroscopic means. In addition, a known dihydronaphthopyranone glycoside and seven known flavonoids were isolated from an ethanolic extract of the leaves of P. planifolius.

Dimorphandra mollis: an alternative as a source of flavonoids with antioxidant action

Dimorphandra mollis: An Alternative as a Source of Flavonoids with Antioxidant Action. Dimorphandra molls fruits are rich in flavonoids rutin and quercetin, which are compounds with high antioxidant activity and can be used to prevent diseases caused by free radicals. The aim of this study was to obtain an extract rich in flavonoids from fruits of D. mollis. The extract was analyzed using the methods of determination by spectrophotometry and high performance liquid chromatography. The presence of rutin and quercetin was identified in the extract, which showed a total flavonoids content of 33.71 To. The extract also showed antioxidant activity as scanvanger of DPPH and ABTS radicals. It was possible to conclude that D. mollis fruits are a rich source of flavonoids with antioxidant action.