Comparative Chemical Studies on the Leaves of Sarto Aloe Species of Ethiopia
No Thumbnail Available
Date
1990-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa Universty
Abstract
Chemical investigations on the leaves of A. berhana Reynolds, A.
rivae Oaker, A. megalacantha Baker and A. pulcherdma ined. resulted
in the isolation of a total of nine compounds, the structures of which
were established by spectroscopic means as well as chemical degradation
to known compounds and compaidLson, in some cases, with authentic
samples. Chrysophanol and P -Sitosterol were isolated from all four
species. Furthermore, A. berhana afforded a novel pre-anthraquinone
(tentatively given the trivial name berhanone), protocatechuic acid
(a biologically important aromatic acid rare from a natural source),
barbaloin (the major active constituent of the officially recognised
commercial aloes responsible for the- use of the plant as purgative)
and aloe-emodin. A. rivae and A. megalacantha yielded aloe-emodin,
berhanone, barbaloin and aloinoside (a constituent of the commercially
important Cape and Socotrine aloes). A. pulcherima afforded nataloin
(major constituent of the commercial Natal aloes) add 7-hydroxybarbaloin
(the characteristic substance of the commercially important Curacao aloes
in the European Pharmacopoeia).
A further comparative chemical screening on the presence of the commercially
important compound, barbaloin, in the loaves of some Aloe species by
means of HPLC and TLC analyses revealed that this glucoside is the major
constituent of A, berhana Reynolds, A. rivae Baker, A. megalacantha Baker,
A* calidophylla Reynolds, /\. secundiflore Engler, A. mcloughlinii Christian,
and A. otalensis Baker, Barbaloin was, however, not detected in the
leaves of A. pulcherimn.
Description
Keywords
Leaves of Sarto Aloe