ANALYSIS OF THE NON-RUBBER CONSTITUENTS OF LATEX FROM <em>ALSTONIA</em> <em>ANGUSTILOBA</em>

Abstract

latex samples of four Alstonia angustiloba (pulai) trees from two different locations were analysed. The total solids contents of the samples varied from 28 to 36%. On average, the solids portion consisted of 81% resins, 11% rubber and 8% residue. No large variation was observed in the composition of latex between the trees. The pulai latex was also found to be quantitatively similar in composition to that of jelutong. Separation of the acetone solubles of the resin fraction by column chromatography (silica, hexane:ethy l acetate) gave two major fractions. Structural elucidation of these fractions revealed that the resin of pulai latex consisted of four main compounds, viz lupeol acetate as a major component (25% dry weight), lupeol (15%), α-amyrin and its acetate (15%) and a trace amount of (3-amyrin acetate.