Contribuição ao conhecimento químico de Croton pedicellatus Kunth

Abstract

The present work describes for the first time the chemical investigation from leaves of Croton pedicellatus Kunth. (Euphorbiaceae), a shrub, native to South America and popularly known as “velame”, name given to several Croton species. The ethanol extract from leaves was subjected to classical chromatographic procedures including high performance liquid chromatography (HPLC), resulting in the isolation of 15 secondary metabolites: two sesquiterpenes known as blumenol A and roseosídeo; five clerodane furan diterpenes: 12,20:15,16-diepoxy-3-hydroxy-7,20-dioxocleroda-13(16),14-dien-18,2-olide; methyl-12,20: 15,16-diepoxy-2,8-dihydroxy-3-acetoxy-7,20-dioxocleroda-13(16),14-dien-18-oate; methyl-12.20:15,16-diepoxy-2-hydroxy-3-acetoxy-7,20-dioxocleroda-13 (16),14-dien-18-oate; methyl-12,20:15,16-diepoxy-3,8- dihydroxy-2-acetoxy-7,20 -dioxocleroda-13(16),14-dien-18-oate; methyl-12,20:15,16-diepoxy-3-hydroxy-2-acetoxy-7,20-dioxocleroda-13(16),14-dien-18-oate, and six flavonoids: alpinumisoflavone, kaempferol, quercetin-3-glucoside, Kaempferol-3-β-D-(6-trans-p-coumaroyl)glucopyranoside (tiliroside), kaempferol-3-β-D-(6-trans-pcoumaroyl)galactopyranoside and kaempferol-3’-methoxy-3-β-D-(6-trans-pcoumaroyl)glucopyranoside, besides the steroids β-sitosterol and its derivative 3-glucosylated. The structure determination of all secondary metabolites isolated was performed by spectrometric techniques such as hydrogen-1 and carbon-13 nuclear magnetic resonance (1H NMR and 13C one/two- dimensional), infrared spectrometry (IR), high resolution mass spectrometry and comparison with literature data.