Characterization and biological properties of Pouteria torta extracts: a preliminary study

Abstract

Rev. Bras. Farmacogn. Braz J. Pharmacogn. 15(3):jul/set. 2005 Finally, the ethanol extract was partitioned using Hexane: CHCl 3 : CH 3 CN: H 2 O (2:1: 3.4:1) (Duarte et al., 2000) yielding three fractions. The yields of crude extracts and fractions are presented in Figure 1. Brine shrimp lethality test (BST) All fractions were tested for brine shrimp lethality. The assay was performed basically according to the simplifi ed Meyer's method (Meyer et al., 1982). Briefl y, brine shrimp, Artemia salina L. encysted eggs (Maramar) were incubated in artifi cial seawater at 28 o C. Samples were dissolved in 200 L of DMSO plus 20 mL of artifi cial seawater. Serial dilutions (triplicate) were prepared in the same solution. Metanauplii (10 units) was added to each set of tubes containing samples and the cultures further incubated for 24 h. Controls containing DMSO were included on each set of experiments. Potassium dichromate was used as reference standard. LD 50 (after 24 h) were calculated by Probit analysis. Chemical constituents of hexane extract Hexane extract (5 g) was chromatographed over silica gel, by using hexane: ethyl acetate: methanol gradient. After analysis by TLC, the obtained 24 fractions were gathered in 8 groups. Group 1 (93 mg) furnished a hydrocarbon mixture. Group 3 (50 mg) was extracted by acetone, furnishing 25 mg of amorphous white solid characterized as long chain esters mixture. Groups 5, 6, 7 and 8 (503 mg) were extracted by acetone: methanol (1:1) furnishing 82 mg (1.2 %) of a white amorphous solid (Pt1). Groups 2 and 4 were found to be very complex mixtures and were not studied at this time. RESULTS AND DISCUSSION