GEOGRAPHICAL VARIATION IN THE MAJOR COMPOUNDS OF ALOE FEROX LEAF EXUDATE

Geographical variation in fresh Aloe ferox leaf exudate of which the d ried product is commercially known as Cape Aloes, was investigated thr oughout the natural distribution range of the species. The composition of the major compounds is remarkably invariable, with aloeresin A, al oesin, and aloin (both epimers A and B) contributing between 70% and 9 7% of total dry weight, in a ratio of approximately 4:3:2, respectivel y. Minor compounds are less evenly distributed, with aloinoside A and aloinoside B more frequent in the western parts of the distribution ar ea and aloeresin C and 5-hydroxyaloin A generally present in small qua ntities throughout the distribution area. The aloin content of the exu date is clearly related to provenance but there are no distinct geogra phical discontinuities. The selection of high-yielding provenances, wi th total aloin levels above 25%, is recommended for commercial cultiva tion.