Bioactive compounds isolated from Aloe ferox:: A plant traditionally used for the treatment of sexually transmitted infections in the Eastern Cape, South Africa

Aloe ferox Mill. is one of the plants used for the treatment of sexually transmitted infections (STIs) in the Eastern Cape province of South Africa. Different extracts of the plant were investigated for their antimicrobial constituents. This led to the isolation of three known compounds, namely, 1,8-dihydroxy-3-hydroxymethyl-9,10-anthracenedione (1, aloe-emodin), 1,8-dihydroxy-3-methyl-9,10-anthracenedione (2, chrysophanol), and 10-C-beta-D-glucopyranosyl- 1,8-dihydroxy-3-hydroxymethyl-9-anthracenone (3, aloin A). The structures of the compounds were determined by chemical and spectroscopic studies. The antibacterial activity of the compounds (1-3) was demonstrated using the microplate dilution method.