Leaf compounds in potential plantation species of Aloe in Kenya

Abstract

Many Aloe species are valued for the healing properties associated with the leaf tissues, a factor that has led to over-exploitation of natural populations and endangerment of some local Kenyan species. While trade in native, wild aloe stocks has been banned by a presidential declaration, depletion continues, indicating the need to grow these plants as a field crop. The chemical profiles of 3 Aloe species growing in Kenya and widely used medicinally were evaluated along with Aloe vera L. Burm. F. to determine if any of these species could provide the much needed leaf extracts and exudates. Reversed phase HPLC was used to separate and quantitatively estimate the aloe leaf compounds aloenin, aloesin (aloeresin B), aloeresin D, barbaloin, nataloe-einodin-7-O-glucoside, and 2′-O-p-coumaroyl aloenin. The methanol extracts of leaves from Aloe macrosiphon Baker was similar to those of Aloe vera for barbaloin, aloesin, and alocresin-D. Methanol extracts of leaves from Aloe ruspoliana Baker and Aloe ukambensis Reynolds had quite different chemical profiles from Aloe vera and from each other.