ISOLATION, PURIFICATION AND IDENTIFICATION OF CHEMICAL CONSTITUENTS FROM ELATERIOSPERMUM TAPOS

Elateriospermum tapos, known as perah tree of the family Euphorbiaceae, is a monoecious canopy species found in Southeast Asian tropical rainforests. In Malaysia, the species is abundant in lowland forests throughout the country especially in northern parts of Peninsular Malaysia. The tree is easily recognized by the reddish pink foliage during a leaf flush. The timber from the tree is hard and heavy and is used for construction and firewood. Fruits and seeds are consumed by native communities though too much of it at one time has been known to induce dizziness. The bark, leaves and fruit stalks exude copious, white and sticky latex which is used for treating cracked sole of the foot (Chai et al. 1989). Not much is known about the chemical constituents except for the presence of hydrocyanic acid in the leaves and seeds, and triterpenes such as β-amyrin palmitate, germanicol palmitate, β-amyrin acetate, germanicol acetate, ψ -taraxasterol acetate and lupeol acetate in the bark (Chow & Quon 1970). During the course of our chemical studies of Malaysian medicinal plants, we investigated the perah tree collected from the forest reserve of Forest Research Institute Malaysia (FRIM). In this paper, we report on the isolation, purification and identification of 16 compounds obtained from the leaves and wood of E. tapos. Fresh leaves and wood were separately extracted by repeated soaking in methanol at room temperature, and the methanolic extracts were suspended in water and successively extracted with tert-butyl methyl ether and ethyl acetate for the first and diethyl ether for the second. The resulting fractions tert-butyl methyl ether soluble portion, ethyl acetate soluble portion and water-soluble portion of the leaves and the water-soluble portion of the wood were each subjected to a combination of column chromatography employing Diaion HP20-SS, Sephadex LH-20, MCI gel CHP 20P, Chromatorex ODS, Toyopearl HW-40F and silica gel which led to the isolation of two flavan-3-ols, four condensed tannins, one biflavone, two cyanogenic glucosides, two aromatic glucosides, one phenylpropane, one glycerol derivative, one megastigmane, and two glycosides of secondary alcohol (Figure 1). These compounds were identified on the basis of spectroscopic and elemental analyses and comparison of their 1 H- and 13 C-NMR data with literature values or authentic samples. The two flavan-3-ols were identified as (1) catechin (Nonaka et al. 1983a) and (2) gallocatechin