Phytochemical and biological studies on goniothalamus spp. in Borneo

Abstract

Goniothalamus spp. are widely distributed is the island of Borneo. About 40 species of Goniothalamus have been recorded in Borneo. Goniothalamus spp. are widely used in traditional medicinal practices in Borneo especially in treating diarrhea, fever, skin diseases, antidotes and most commonly used as postparturation aids and as abortifacient. Some of the species are also being used as natural insecticide. Several Goniothalamus spp. commonly found in Borneo especially the endemic species have been studied in order to isolate biologically active compounds. The studies involved solvent extraction and partition; isolation and purification by various chromatographic methods; structural elucidation by various spectroscopic methods and biological assay using established protocols. Some of the species studied includes Goniothalamus andersonii, G. borneensis, G. clemensii, G. dolichocarpus, G. fasciculantus, G. gigantifolius, G. longistipites, G. macrophyllus, G. roseus, G. stenopetalus and G. velutinus. Phytochemical studies on these species resulted in the isolation of various styryl-lactones and alkaloids. Cytotoxic styryl-lactones and their derivatives that have been isolated in almost all Goniothalamus spp. studied are characteristic compounds of this useful genus. Some of the more important styryl-lactones derivatives isolated includes goniothalamin, 5-acetoxygoniothalamin, goniodiol, 5-hydroxygoniothalamin, dehydrogoniothalamin, goniotriol, goniofufurones, goniofupyrones, goniothalenol, goniotharvensin and cardiobutanolide. Some of the spesies studied such as G. borneensis, G. gigantifolius, G. macrophyllus, G. roseus and G. stenophyllus gave various styryl-lactones and their derivatives while some others such as G. clemensii, G. longistipites and G. stenopetaluss only gave goniothalamin, goniothalamin oxide and 5-acetoxygoniothalamin. All the isolated styryl-lactones and their derivatives showed interesting biological activity especially cytotoxicity on various human tumour cell lines. The distributions of alkaloids in this genus are rather limited and only isolated from several species studied. Alkaloids have been isolated from G. boornennsis, G. gigantifolius, G. stenophyllus and G. velutinus. The alkaloids produced by many Goniothalamus species are notably aporphines and are biologically active. Some of the alkaloids isolated include goniothalactam, goniopedaline, aristololactam AII, aristololactam BII and velutinam. G. velutinus produced almost all the mentioned alkaloids Interestingly G. velutinus being used by some of the ethnics in Borneo in the treatment of tumour and all the mentioned alkaloids isolated from G. velutinus showed certain degree of cytotoxicity on various human cell lines.