ACACIA GUM EXUDATES FROM SOMALIA AND TANZANIA - THE ACACIA-SENEGAL COMPLEX

Analytical data are presented for the polysaccharide and proteinaceous components of the gum exudates from three Somalian Acacia spp. viz. Acacia sp.nov. (Fagg & Styles 85) and A. cheilanthifolia Chiov. (members of the A. senegal complex) and A. leucospira Brenan. In addition, data are given for a Tanzanian specimen of gum arabic and, for comparative purposes, for a reference specimen of Sudanese gum arabic from A. senegal (L.) Willd. The gum from A, leucospira is dextrorotatory and has a low rhamnose, high uronic acid and high methoxyl content; it therefore has affinities to the sources of commercial gum talha (A. seyal Del. and relatives). In contrast, the gums from A. cheilanthifolia and Acacia sp. nov. are laevorotatory and of special interest as they provide the first opportunity to study positively identified members of the A. senegal complex backed by properly documented herbarium voucher specimens. Although undoubtedly closely related species,their chemical and spectroscopic data indicate that their gum exudates, and that from the Tanzanian sample, are analytically and structurally distinct from that of A. senegal (L.) Willd. © 1990.