Estudo químico de Luehea speciosa e Ocotea costulatum

Abstract

The present thesis describes the chemical study of two plant species. The ethanolic extract from the wood of Luehea speciosa Willd (Tiliaceae), collected in the Amazon region was fractionated by chromatografic technique. This yielded friedelin (Ls-1w), a mixture of β-sitosterol, stigmasterol and 24-methylcholesterol (Ls-2W), (1S, 5S, 2R, 6R)-2,6-di(3,4,5-trimethoxyphenyl)-3,7- dioxabicyclo |3,3,0| octane (Ls-3w) and 8-hydroxy-6,7-dimethoxy- 3-methyl-isocoumarin (Ls-4w). These compounds have already been described in the literature. The ethanolic extract from the trunk wood of Ocotea costulatum (Lauraceae), collected in the Amazon region was fractionated by chromatografic technique. This afforded a benzodioxanic neolignan: rel-(7R, 8R) - ∆8'-5'-methoxy-3,4,5- trimethoxy-7.0.3',8.0.4' - lignan (oc-1w) and two bicyclo octanoid neolignans: rel-(1R, 3S, 4R, 5S, 6S, 7R)-1-allyl-4- h y d r o x y - 7 - m e t h y l - 3 , 5 - d i m e t h o x y - ( 3 ' , 4 ' - m e t h y l e n e d i o x y - 5 ' - methoxyphenyl) - 8 - oxobicyclo|3,2,1| octane (Oc-2w) and rel- (1S, 4R, 5S, 6S, 7R)-1-allyl-4-hydroxy-7-methyl-3,5-dimethoxy- 6(3',4'-methylenedioxy-5'-methoxyphenyl)-8-oxobicyclo |3,2,1| oct-2-ene (Oc-3w). The compound Oc-3w is a new one. The molecular structures of these compounds were determinea by usual spectrometric techniques (IR, MS, 1H NMR and 13NMR). The structural elucidations involved longrange coupling constant analysis in the 1H NMR spectra and chemical shifts in the 13C NMR spectra. The chemical profile of the families Tiliaceae and Elaeocarpaceae was made by the search in chemical literature