Metabólitos especiais isolados de Luxemburgia octandra (Ochnaceae), Laseguea erecta (Apocynaceae), do látex de Parahancornia amapa (Apocynaceae) e de Solanum crinitum (Solanaceae)

Abstract

The analysis of the fractions from the chromatographic fractionation of lhe extracts from Luxemburgia ocrandra (Ochnaceae), latex from Parahancomia amapa (Apocynaceae), Lasegue erecra (Apocynaceae) and from Solanum crinitum (Solanaceae) led to the isolation of some chemical constituents which belong to different classes of special metabolites. From the branches of L. octandra were isolated sitosterol, stigmasterol, lupeol, betulinic acid, chalcone, isoliquiritigenin (2,4,4'trihydroxychalcone), 3,4,3',4'-tetrahydroxychalcone, a mixture of two Cglucopiranosylflavone, 8-C-glucopiranosilluteolin and 8-C-glucopiranosyl-7-methylluteolin, and two biflavoooids, 2",3"-dihydroochnaflavone [5,7,4'-trihydroxychalcone(4'-0-3"')-2",4"-dihydroxychalcone. From the latex of P. amapa were isolated three phenylethanoids, comoside [4-hydroxy-4-(2-0 -P-D-glycopiranosyl-ethylene) cyclohexadienone ), 2-p-hydroxyphenylethanol and 2-( 4-hydroxy-3-methoxyphenyl)ethanol and a mixture of acyl esters of lupool, a-amyrio and P-amyrin. From the wood of L. erecla were isolated scopoletin, the lignoid pinoresinol and the saponin digitoxigenin. Toe steroidal alcaloid solasonin and the flavonoid tiliroside [3-0-(β-D-glucopiranosyl-6'-coumaroil)-kanferol) were isolated, respectively, from the fruits and from the tricomes of S. crinilum. The structures were determined by IR, MS and 1H and 13C NMR spectra analysis. Besides the identification of the new bichalcone, named luxenchalcone, new derivatives, luxenchalcone-trimethylether, luxenchalcone-permethylether, luxenchalcone-peracetylester, tetraacetyl-comoside and peracetylsolasonine were also prepared. Toe general toxicity was eralvated against Artemia salina. Toe anti-helmintic activity of extracts from L. octandra was also studied. Furthermore, the cytotoxic activity against Ehrlich carcinoma and K 562 human leukemia of solasonine, total glycoalkaloids, tiliroside, luxencbalcone and its derivatives was carrie<I onl Finally, the total glycoalkaloids and solasonine were also teste<! for alelopathic activity and were found to be quite active.