Flavonoids of Lavoisiera, Microlicia and Trembleya (Melastomataceae) and their taxonomic meaning

Leaves of species of three closely related genera of Melastomataceae, Lavoisiera, Miciolicia and Trembleya were analyzed for their flavonoid composition. A total of 116 compounds were obtained, comprising 69 flavonol and 47 flavone glycosides. The common occurrence of flavones, including 6-oxygenated derivatives, characterize Lavoisiera (which often yielded methoxylated flavonols and flavones). Flavonols predominate in species of Miciolicia. The flavonoid patterns of Trembleya are rather confusing, some species being akin to Lavoisiera, others to Microlicia. UPGMA analysis using the flavonoid aglycones as characters and the samples analyzed as OTUs gives no complete resolution for the three genera, but provides clusters combining exclusively or preferentially species of either Lavoisiera and Microlicia. Species of Trembleya emerge from the phenogram interspersed among species of the other genera, The data suggest the recognition of Lavoisiera and Microlicia and the lumping of species of Trembleya with either of these genera. If greater flavone diversity is viewed as indicative of further evolutionary advancement, shrubby habits in Microliceae (Lavoisiera and Trembleya,a) should be regarded as derived from herbaceous ones ((Microlicia): (C) 2001 Elsevier Science Ltd. All rights reserved.29771172

Antiproliferative activity of methanol extracts of four species of Croton on different human cell lines

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Several species of Croton have been described with biological activities, mainly due to diterpenes, alkaloids and/or other secondary metabolites. These activities account for the traditional use of Croton species to treat certain diseases in South America, Asia and Western Africa. The crude methanol extracts obtained from leaves and steam bark of Croton dichrous Mull. Arg., C. erythroxyloides Baill., C. myrianthus Mull. Arg. and C. splendidus Mart. ex Colla were tested for antiproliferative activity against ten human cancer cell lines. Chemical analyses of all extracts were carried out by GC/MS and HPLC/MS/MS. The leaf extract obtained from C. erythroxyloides showed potent activity against PC-3 (prostate) and OVCAR-3 (ovary) cell lines. Lupeol is suggested to be involved in such activity. Tiliroside, an acyl-glycosilated flavonoid ubiquitous in all tested extracts, seems to play an important role in the observed moderate activity of most extracts against the leukemia K562 cell lineage.234662667Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [07/02518-6

Antiproliferative activity and constituents of leaf extracts of Croton sphaerogynus Baill. (Euphorbiaceae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Several Croton species have been used in traditional medicine and contain substances active against cancer, such as diterpenoids and alkaloids. Croton sphaerogynus is a shrub from the Atlantic Rain Forest in southeastern Brazil. The main goal of this study was to characterize the main constituents of the leaf extracts of C. sphaerogynus and evaluate their in vitro antiproliferative activity against tumor cell lines. Hexane, dichloromethane and methanol extracts of leaves were analyzed by GC/MS and evaluated for their in vitro antiproliferative activity on the cell lines 786-0 (kidney), HT-29 (colon), 1(562 (leukemia), NCI-ADR/RES (drug resistant ovary), NCI-H460 (lung), MCF-7 (mammary), PC-3 (prostate), OVCAR-3 (ovary), U251 (glioma) and UACC-62 (melanoma). Relevant constituents in dichloromethane and hexane extracts were abietane, podocarpane and clerodane type furano diterpenes. Dicloromethane and hexane extracts exhibited activity against NCI-H460 (GI(50) 0.26 mu g/mL and 0.33 mu g/mL, respectively) and K562 (GI(50) 0.60 mu g/mL and <0.25 mu g/mL, respectively). Taking into account all cell lines tested, the dichloromethane extract was shown to have higher activity (mean log GI(50) 0.86) than hexane and methanol extracts (mean log GI(50) 1.26 and 1.49, respectively). The antiproliferative activity observed in the present work is probably accounted for by the abietane and/or podocarpane diterpenes. (C) 2013 Elsevier B.V. All rights reserved.50661665Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP