Antifungal constituents from roots of Virola surinamensis

Chromatographic fractionation of the dichloromethane extract from roots of Virola surinamensis yielded two new natural products, 3-epi-juruenolide C and 2'-hydroxy-7,4'-dimethoxyisoflavone, as well as various known steroids, lignans, isoflavones, flavonoids and diarylpropanes. of these, alpha,2'-dihydroxy-4,3'-dimethoxydihydrochal biochanin A and 2'-hydroxy-7,4'-dimethoxyisoflavone displayed antifungal activity against Cladosporium cladosporioides at a minimum amount of 5 mu g, whereas 7-hydroxyflavanone and 7-hydroxy-4'-methoxyisoflavone exhibited an antifungal activity 10-fold higher than the positive control Nystatin. (C) 1999 Elsevier B.V. Ltd. All rights reserved.

Preparative isolation of a novel flavonoid from an infusion of Byrsonima basiloba leaves by high-speed counter-current chromatography

A method for the isolation of three compounds from the infusion of leaves of Byrsonima basiloba A. Juss. by high-speed counter-current chromatography (HSCCC) was developed. This technique led to the separation of a novel compound, quercetin 3-O-alpha-L-rhamnopyranosyl-(1 -> 3)-O-[alpha-L-rhamnopyranosyl-(1 -> 6)]-beta-D-allopyranoside, and two known compounds quercetin3-O-(X-L-rhamnopyranosyl-(1 -> 6)-beta-D-galactopyranoside and (+)-catechin in 4 h with purities of over 92%. The structures of the compounds were determined by one- and two-dimensional NMR spectroscopy and HPLC.

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.

Chemical evolution in the Asteraceae. The Oxidation-Reduction mechanism and production of secondary metabolites

This work describes the application of partial least squares (PLS) regression to variables that represent the oxidation data of several types of secondary metabolite isolated from the family Asteraceae. The oxidation states were calculated for each carbon atom of the involved compounds after these had been matched with their biogenetic precursor. The states of oxidation variations were named oxidation steps. This methodology represents a new approach to inspect the oxidative changes in taxa. Partial least square (PLS) regression was used to inspect the relationships among terpenoids, cournarins, polyacetylenes, and flavonoids from a data base containing approximately 27,000 botanical entries. The results show an interdependence between the average oxidation states of each class of secondary metabolite at tribe and sub tribe levels.

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.

Pharmacological and toxicological studies of Drimys angustifolia Miers. (Winteraceae)

Drimys angustifolia Miers. (Winteraceae) is a Brazilian medicinal plant used as analgesic, antiulcer and anti-inflammatory without studies to assure its efficacy and safety Leaf and stem bark extracts were evaluated to determine the antiulcer, analgesic, antiinflammatory and antioxidant activities. Preliminary toxic effects and qualitative phytochemical profile were also performed. The antiulcer activity was detected in both extracts. Administration of the leaf extract at 250 mg/kg inhibited total lesion area by 76.50% (p < 0.01 in ethanol/HCl method), while carbenoxolone at 250 mg/kg reduced lesions by 69.48%. Stem bark extract (250 mg/kg) inhibited lesion by 81.42%, while carbenoxolone by 74.10%. Similar effects were observed in the ethanol-induced ulcer method, but no activity was observed in piroxican model. The effects involve nitric oxide in gastric protection, since the L-NAME treatment reversed the protection given by the extracts. Antioxidant effects suggest an involvement against oxidative stress. In the pain (writhing, tail-flick and hot-plate tests) and inflammation (carrageenan-induced paw edema) models, the extracts did not present any effect. The phytochemical studies demonstrated that both extracts contain flavonoids, saponins, glycosilated triterpenoids, fixed acids, cyanogenic glycosides, quinones, tannins, xanthone and steroidal aglycones. Toxicological studies showed that the extracts are safe at the effective antiulcer doses. (c) 2006 Elsevier B.V.. 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.

Pharmacokinetic Study of Nobiletin and Tangeretin in Rat Serum by High-Performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry

Nobiletin (NOB) and tangeretin (TAN), two of the main polymethoxylated flavones (PMFs) in citrus, influence a number of key biological pathways in mammalian cells. Although the impacts of NOB and TAN on glucose homeostasis and cholesterol regulation have been investigated in human clinical trials, much information is still lacking about the metabolism and oral bioavailability of these compounds in animals. In this study, NOB and TAN were administered to rats by gavage and intraperitoneal (ip) injection, and the blood serum concentrations of these compounds and their main metabolites were monitored by high-performance liquid chromatography-electrospray ionization-mass spectrometry (HPLC-ESI-MS). In addition to the administered compounds, two metabolites of TAN and eight metabolites of NOB were detected and measured over 24 h. With identical oral doses, nearly 10-fold higher absorption of NOB occurred compared to TAN. For both compounds, maximum levels of glucuronidated metabolites occurred in the blood serum at later time points (similar to 5-8 h) compared to the earlier T(max) a values for NOB and TAN. In most cases the glucuronides occurred at substantially higher concentrations than the aglycone metabolites. Low levels of NOB and TAN and their metabolites were detectable in rat blood serum even at 24 h after treatment.

Preparation and thermal characterization of inclusion complex of Brazilian green propolis and hydroxypropyl-beta-cyclodextrin

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Organic and conventional fertilisation procedures on the nitrate, antioxidants and pesticide content in parts of vegetables

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

Anti-ulcerogenic and analgesic activities of the leaves of Wilbrandia ebracteata in mice

Wilbrandia ebracteata (Cogn.) Cogn. is a medicinal plant belonging to the Cucurbitaceae family used popularly as an antiulcer and analgesic medicine. The hydromethanol extract of leaves was investigated to determine its anti-ulcerogenic (ethanol and indomethacin induced gastric damage) and analgesic (writhing and tail-flick tests) activities in mice (efficacy), its acute toxicity (safety), and its phytochemistry (quality control). Oral administration of leaf extract at a dose of 1000 mg/kg body wt. significantly reduced 73.3% of the total area of lesion in ethanol-induced gastric damage, but was inactive in an indomethacin-induced gastric damage test. The hydromethanol extract was also inactive in both analgesic tests. Oral administration of the leaf extract did not produce mortality in mice, while the LD50 value of the roots was 22.10 mg/kg body wt. in female mice and 58.31 mg/kg body wt. in male mice. Leaves of W. ebracteata reacted positively for steroids, flavonols, flavanones, saponins, tannins and xanthones and negative for other compounds, including cucurbitacins. Leaf extract of W. ebracteata was active as an anti-ulcerogenic, probably through increasing gastric defensive factors, and flavonoids might be the main constituent responsible for this activity.

Structural basis for inhibition of cyclin-dependent kinase 9 by flavopiridol

Flavopiridol has been shown to potently inhibit CDK1 and 2 (cyclin-dependent kinases 1 and 2) and most recently it has been found that it also inhibits CDK9. The complex CDK9-cyclin T1 controls the elongation phase of transcription by RNA polymerase II. The present work describes a molecular model for the binary complex CDK9-flavopiridol. This structural model indicates that the inhibitor strongly binds to the ATP-binding pocket of CDK9 and the structural comparison of the complex CDK2-flavopiridol correlates the structural differences with differences in inhibition of these CDKs by flavopiridol. This structure opens the possibility of testing new inhibitor families, in addition to new substituents for the already known leading structures such as flavones and adenine derivatives. © 2002 Elsevier Science (USA). All rights reserved.

Flavonoids and arbutin from Turnera diffusa

The infusion of the aerial parts of Turnera diffusa was phytochemically examined. Chromatographic procedures led to the isolation of a new flavone glycoside, five known flavonoids and p-arbutin. Structures were determined by 1D- and 2D NMR experiments, as well as ES-MS and UV spectra.

Chemical constituents from the infusion of Zollernia ilicifolia vog. and comparison with Maytenus species

The new flavonoid glycoside kaempferol-3-O-α-L-rhamnopyranosyl(1→2)-O-[α-L- rhamnopyranosyl(1→6)]-O-β-D-galactopyranoside-7-O-α-L- rhamnopyranoside was isolated together with (S)-zierin from the leaves of Zollernia ilicifolia (Fabaceae), a medicinal plant used as analgesic and antiulcerogenic effects in Brazilian Tropical Atlantic Rain Forest. The structures were established on the basis of 1H, 13C NMR and 2D NMR (COSY, HMBC, HMQC), UV, MS and IV spectra. The infusion of Zollernia ilicifolia was qualitatively compared to the infusion of the espinheiras-santas (Maytenus aquifolium and Maytenus ilicifolia) by HPLC-DAD.