In vitro Trypanocidal Activity of Phenolic Derivatives from Peperomia obtusifolia

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

Flavonas, lignanas e terpeno de Piper umbellata (Piperaceae)

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

Aromatic compounds from three Brazilian Lauraceae species

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

Alkamides and phenethyl derivatives from Aristolochia gehrtii

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

Solution infrared spectroscopy investigation of copper (II) azide-complexes.

The structure of the two azide-complexes, [Cu(N-3)(2)(N,N-diEten)](2) and [Cu(N-3)(2)(tmeen)](2), N,N-diEten=N,N-diethylethylenediamine; tmeen=N,N,N',N'-tetramethyethylenediamine in solutions of acetonitrile, acetone, tetrahydrofuran, chloroform and dichloromethane, were investigated by infrared spectroscopy. The data show that the complex [Cu(N-3)(2)(N,N-diEten)](2) mantains its structure in solution, while that for [Cu(N-3)(2)(tmeen)](2) is modified.

Lipophyllic antioxidants from Iryanthera juruensis fruits

The phytochemical investigation of the hexane extract of I,:Iryanthera juruensis (Myristicaceae) fruits led to the isolation of two tocotrienols and four lignans which exhibited antioxidant activity towards beta -carotene on TLC autographic assay. Two inactive quinones and three omega -arylalkanoic acids were also isolated. The isolates were investigated for their redox properties using cyclic voltammetry. The structure elucidation of the new compounds tone tocotrienol. one quinone and three w-arylalkanoic acids) was based on analysis of spectroscopic data, (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Stereoselective synthesis of 8,9-licarinediols

The total synthesis of 8,9-licarinediols was selectively carried out from licarin A, previously obtained by oxidative coupling of (E)-isoeugenol. The corresponding enantiomerically pure (+)- and(-)-licarin A ester derivatives were subjected to Sharpless oxidation to yield the asymmetric C-8, C-9 dihydroxylation products, whose absolute configurations were established by means of the CD and NMR spectroscopic analyses of their Mosher ester derivatives. (C) 2000 Elsevier B.V. Ltd. All rights reserved.

Diterpene esters of aristolochic acids from Aristolochia pubescens

From the acetone and ethanol extracts of the tubercula of Aristolochia pubescens, two diterpene esters of aristolochic acids were isolated, together with 23 known compounds. The structures of the compounds were determined on the basis of spectroscopic analysis. (C) 2003 Elsevier Ltd. All rights reserved.

Screening and HPLC methods for carotenoids in sweetpotato, cassava and maize for plant breeding trials

Analytical methods for sweetpotato, cassava and maize were developed. In orange and salmon-fleshed sweetpotatoes, (all-E)-beta-carotene predominated and results of spectrophotometric screening and HPLC quantification did not differ significantly. In yellow-fleshed sweetpotato and cassava, however, spectrophotometric screening overestimated the HPLC values because of the presence of several minor carotenoids. Aside from (all-E)-beta-carotene, Z-isomers were present in cassava in appreciable amounts. For both crops, extraction with acetone or tetrahydrofuran: methanol. (1: 1), using a mortar and pestle or a Polytron homogenizer, gave equivalent results. Rehydration of dry maize at room temperature for 30 min or at 85 degrees C for 5, 10 or 15 min gave equivalent results. Concentrations obtained with the C18 and C30 columns did not differ significantly for zeaxanthin, lutein, beta-cryptoxanthin and beta-carotene in the all-E-configuration, but their Z-isomers were difficult to locate in the chromatogram obtained with the C30 column. Extraction with tetrahydrofuran:methanol (1:1) gave significantly lower results for zeaxanthin and lutein. (c) 2005 Elsevier Ltd. All rights reserved.

Insecticidal activity of chemical constituents from Aristolochia pubescens against Anticarsia gemmatalis larvae

Acetone and ethanol extracts of the tubercula and several compounds isolated from Aristolochia pubescens (Willd) were bioassayed on velvebean caterpillars, Anticarsia gemmatalis (Hubner), for evaluation of the insecticidal activities. of the extracts subjected to bioassay, the acetone extract showed the highest activity. (-)-Cubebin did not show activity against soybean caterpillars, whereas aristolochic acid and ent-kaur-15-en-17-ol increased the larval period. These compounds, and (+)-eudesmin and (+)-sesamin, reduced the viability of this period, giving rise to malformed adults. These extracts and compounds are therefore potential botanical insecticide agents for the control of velvetbean caterpillars in soybean crops. (C) 2003 Society of Chemical Industry.

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.

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.

Butanolides as a common feature of Iryanthera lancifolia and Virola surinamensis

A comparative phytochemical study between pericarps of Iryanthera lancifolia and Virola surinamensis showed that the first one contains a new pair of epimeric 2-alkenyl-gamma-lactones, besides an aryltetralinic lignan and one tocotrienol, while the second species contains the lignans, galgravin and veraguensin, seven juruenolides: juruenolides C, D, F, G and epi-juruenolides D, F, G, together with three pairs of epimeric aliphatic 2-alkenyl-gamma-lactones. Juruenolide F, epi-juruenolides D, F, G and the 2-alkenyl-gamma-lactones are new natural compounds. (C) 1998 Elsevier B.V. Ltd. All rights reserved.

Rearranged (4 -> 2)-abeo-clerodane and clerodane diterpenes from Aristolochia chamissonis

From stems of Aristolochia chamissonis Duch., five new diterpenes, one rearranged (4 --> 2)-abeo-clerodane and four ent-clerodanes, were isolated. Their structures were determined to be (+)-(4 --> 2)-abeo-kolavelool-3-oic acid, (-)-13-epi-2-oxokolavelool, (-)-2 beta-hydroxykolavelool, (-)-2 beta-hydroperoxykolavelool and (+)- 13-epi-2 alpha-hydroxykolavelool. In addition, lignans, sesquiterpenes, steroids and two known ent-clerodane diterpenes were isolated. (C) 1998 Elsevier B.V. Ltd. All rights reserved.

2,3-Dihydrobenzofuran neolignans from Aristolochia pubescens

From a hexane extract of stems and roots of Aristolochia pubescens, the new neolignans (2S,3S,1'R,2'R)- and (2S,3S, 1'S,2'R)-2,3-dihydro-5-(1',2'-dihydroxypropyl)-2-(4-hydroxy-3-methylbenzofuran) and (2S,3S,1'R,2'R)- and (2S,3S,1'S,2'R)-2,3-dihydro-5-(1',2'-dihydroxypropyl)-2-(3,4-dimethoxyphenyl)-7-methoxy-3-methyl-benzofuran were isolated, together with the known neolignan licarin A, and its bisnor-neolignan aldehyde and acid derivatives. In addition, sitosterol, 8R,9R-oxide-beta-caryophyllene, kobusone, ent-kauran-16 alpha, 17-diol, vanillin, vanillic acid, (+)-sesamin, (+)eudesmin, and (-)-cubebin were isolated. The structures of the new compounds have been elucidated by spectroscopic methods and by chemical transformation using Mosher's acid chloride. (C) 1999 Elsevier B.V. Ltd. All rights reserved.