Mário Geraldo de Carvalho

Cytotoxic activities against Ehrlich carcinoma and human K562 leukaemia of alkaloids and flavonoid from two Solanum Species

Diversas especies do genero Solanum apresentam glicoalcaloides e flavonoides com grande variedade de atividades biologicas. O flavonoide tiliroside (1), uma fracao rica em glicoalcaloides denominada GB e o glicoalcaloide solasonina (2) foram obtidos dos tricomas de galhos jovens e frutos de Solanum crinitum Lam e o alcaloide estereoidal solasodina (3), extraido das partes aereas de S. jabrense Agra & M. Nee, tiveram sua atividade citotoxica avaliada frente a celulas do carcinoma de Ehrlich e da leucemia humana K562. O efeito antiproliferativo destas substâncias mostrou comportamento dose-dependente apos avaliacao atraves do metodo do MTT, para ambos os casos. Os resultados indicaram atividade citotoxica para 1, GB e 2, com IC50 = 69,50 mM, 19,5 mg mL-1 e 74,20 mM, respectivamente, quando ensaiadas frente ao carcinoma de Ehrlich, e IC50 = 118,40 mM, 13,65 mg mL-1, 60,35 mM e 76,92 mM para 1, GB, 2 e 2a (derivado peracetilado da solasonina) frente a leucemia K562. A baixa atividade da aglicona solasodina (3) indicou a importância da presenca dos acucares na estrutura do glicoalcaloide e permitiu postular a substância 2, presente na fracao rica em glicoalcaloides (GB), como um dos principios ativos. Alem disso, os resultados mostraram a possibilidade de biomonitoramento atraves do ensaio do MTT na busca de metabolitos com atividade citotoxica.

Isoflavanone dimers hexaspermone A, B and C from Ouratea hexasperma

Abstract The three new isoflavanone dimers 5-hydroxy-4′,7-dimethoxy-2,3-trans-isoflavanone-(2→2″)-5″-hydroxy-4‴,7″-dimethoxy-2″,3″-trans-isoflavanone, 5-hydroxy-4′,7-dimethoxy-2,3-trans-isoflavanone-(2→2″)-4‴-hydroxy-5″,7″-dimethoxy-2″,3″-trans-isoflavanone and 5-hydroxy-4′,7-dimethoxy-2,3-trans-isoflavanone-(2→2″)-4‴,5″-dihydroxy-7″-methoxy-2″,3″-trans-isoflavanone were isolated from Ouratea hexasperma, together with the known 5,7,4′-trimethoxyisoflavone, a mixture of aliphatic esters and a mixture of aliphatic acids.

Ocorrência de flavonas, flavonóis e seus glicosídeos em espécies do gênero Solanum (Solanaceae)

During the last decades several flavonoids of Solanum species have been isolated. This review describes the flavones, flavonols and their glycosides presently known as constituents of Solanum species.

A flavone dimer from Ouratea hexasperma

Abstract From the leaves of Ouratea hexasperma , the flavone dimer 4′,5,7-trihydroxyflavone-(6→8″)-4‴,5″-dihydroxy-7″-methoxyflavone was isolated in addition to methyl myoinositol. The structures were established by various analyses including 2D-NMR spectroscopy.

Chemical Constituents from Himatanthus articulata

Chemical investigation of Himatanthus articulata (Vahl) Woodson led to the isolation of stigmasterol, sitosterol, cycloartenol, a-amyrin-3b-O-cinnamoyl, b-amyrin-3b-O-cinnamoyl, lupeol-3b-O-cinnamoyl, a-amirin-3b-O-acetyl, b-amirin-3b-O-acetyl, lupeol-3b-O-acetyl, ursolic acid, methylmyoinositol, 1b-O-b-D-glucopyranosylplumeric acid, plumeride-1b-O-b-D-glucopyranosyl, plumericin and isoplumericin. Spectroscopic analysis (IR, 1H, 13C-NMR and MS) were used for the identification of these compounds and some derivatives.

Triterpenos isolados de Eschweilera longipes miers (Lecythidaceae)

The phytochemical studies of Eschweilera longipes have led to the identification of ten triterpenoids: fridelin, fridelinol, a-amirin, b-amirin, 3b-O-cinamoyl-a-amirin, 3b-O-cinamoyl-b-amirin, a-amirenone, b-amirenone, 3-a-hidroxi-lupeol, 3-a-hidroxi-taraxasterol, along with b-sitosterol, stigmasterol, a -tocopherol and tocotrienol. The structures of these compounds were identified by analysis of IR, 1H and 13C NMR data and comparison with values of literature.

New Biflavonoid and Other Constituents from Luxemburgia nobilis (EICHL)

O fracionamento cromatografico dos extratos orgânicos das folhas e galhos de Luxemburgia nobilis (Ochnaceae) forneceu o sitosterol, sitosterol-3-O- βD-glicopiranosil, friedelina, friedelinol, a mistura dos triterpenos lupeol, α-amirina e β-amirina, rutina, epicatequina, uma mistura de duas chalconas, isoliquiritigenina e 3’-hidroxiisoliquiritigenina, duas biflavonas conhecidas, amentoflavona e robustaflavona alem de uma biflavona nova, 5,7,4’-triidroxiflavona-(3’-O-4”’)-5”,7”diidroxiflavanona. As estruturas foram definidas atraves dos dados espectrometricos incluindo experimentos bidimensionais de RMN das substâncias naturais e dos derivados metilados e acetilados da biflavona nova. Chromatographic fractionation of the organic extracts from the leaves and branches of Luxemburgia nobilis (Ochnaceae) afforded sitosterol, sitosterol-3-O- βD-glucopyranoside, friedelin, friedelinol, a mixture of triterpenes lupeol, α-amyrin and β-amyrin, rutin, epicatechin, a mixture of two chalcones, 2,4,3’,4’-tetrahydroxychalcone and 2,4,4’-trihydroxychalcone, two known biflavones, amentoflavone and robustaflavone along with a new biflavonoid, 5,7,4’-trihydroxyflavone-(3’-O4’”)-5”,7”-dihydroxyflavanone. The structures were established from spectral data, including 2DNMR experiments of the natural substances and of the acetyl and methyl ether derivatives of the new biflavone.

Cordiachromes from Auxemma oncocalyx

Abstract Further cordiachromes, rel -10 α ,11 β -epoxy-11α-ethoxy-8α-hydroxy-2-methoxy-8aβ-methyl-5,6,7,8,8a,9,10aβ-octahydro-1,4-anthracendione, 6-formyl-2-methoxy-9-methyl-7,8-dihydro-1,4-phenanthrendione, rel -8 α ,11 α ;9 α ,11 α -diepoxy-1,4-dihydroxy-2-methoxy-8aβ-methyl-5,6,7,8,8a,9,10,10aβ-octahydro-10-anthracenone, rel -9 α ,11 α -epoxy-1,4,8α-trihydroxy-2-methoxy-8aβ-methyl-5,6,7,8,8a,9,10,10aβ-octahydro-10-anthracenone, rel -2″-methoxy-7″-methyl-1″,4″-naphtalendione-(6″→5)-tetrahydropyran-(2-eq→ O →2ax)-tetrahydropyran-(5′→6‴)- 2‴-methoxy-7‴-methyl-1‴,4‴-naphthalendione, together with the known, allantoin, sitosterol and 3 β - O -d-glucopyranosylsitosterol, have been isolated from Auxemma oncocalyx . Their structures were determined from spectral data, including 2D NMR experiments.

Ácido ent-16alfa,17-diidroxicauran-19-óico isolado de Ouratea semiserrata e os desafios estereoquímicos dos carbonos quirais C-4 e C-16

Phytochemical investigation of the leaves and branches of a specimen of Ouratea semiserrata led to the isolation and characterization of ent-16a,17-dihydroxykauran-19-oic acid, along with other natural products. This diterpenoid and its derivatives were used to unambiguous 1H and 13C chemical shifts assignments and to indicate some mistake data described in the literature as consequence mainly of the stereochemicals of the chiral carbons C-4 and C-16. The HRMS spectra were also analysed.

Diterpenos, triterpenos e esteróides das flores de Wedelia paludosa

Phytochemical investigation of the flowers of Wedelia paludosa afforded two diterpenes, ent-kaur-16-en-19-oic acid and ent-kaur-9(11),16-dien-19-oic acid, three acylated triterpenes, 3b-O-hexa-decanoylolean-12-en-28-oic acid, 3b-O-pentadecanoylolean-12-en-28-oic acid and 3b-O-tetradecanoylolean-12-en-28-oic acid, and three steroids, stigmasterol, 3b-O-b-D-glycopyranosyl sitosterol and 3b-O-b-D-glycopyrano-sylstigmasterol. The substances were identified by their spectral data.