Chemistry & Pharmacology
Dr. Carl Albrecht holds up a molecule - a
unique triterpenoid glucoside.
The chemistry of Sutherlandia was studied
by Prof. Ben-Erik van Wyk and Dr. Carl Albrecht. Four known key
compounds contribute to the efficacy of this medicinal plant : the
non-protein amino acid L-canavanine;
pinitol; GABA ; and asparagine.
In addition a novel triterpenoid glucoside has been isolated and
The published biological activities of these compounds
appear to validate some of the traditional uses of the plant, and
further support the use of the plant as a quality-of-life tonic
in cancer and AIDS patients.
Microchemical tests in laboratories indicated the
presence of tannins but no alkaloids, cardiac glycosides, saponins
or anthraquinone derivatives. Free amino acids are reported as common
constituents of Sutherlandia frutescens.1
TLC - Sutherlandia frutescens
Thin layer chromatography on silica gel using as
solvent a mixture of toluene:diethyl ether:1.75M acetic acid
(1:1:1). Reference compound cineole (0,1% in chloroform).
Rf values of major compounds: 0, 50 (yellow-green);
0, 63 (purple); 0, 91 (purple);
cineole: 0, 81 (blue-purple)
Sutherlandia frutescens - microscopical features 2
Studies using 50% ethanol extracts of fresh flowers of Sutherlandia
frutescens found no antitumour activity against CA-Lewis lung, Leuk-L1210
or Sarcoma 180 (solid) tumours in the mouse. Similar extracts, assayed
for cytotoxicity against CA-9KB cell lines, at a concentration of
20.0 mcg/ml, proved inactive.6
No in vitro antimicrobial activity against Pseudomonas
aeruginosa, Candida albicans or Mycobacterium smegmatis was observed
in the concentrations used for disc assays in our laboratories.
Some activity was recorded against Staphylococcus aureus.
Research into anticancer and immunomodulatory
activity of this species is
currently in progress. The results appear promising.
L-Canavanine is known to occur in high levels in certain seeds.
What is unusual is that significant levels of this compound are
found in Sutherlandia leaves. This potent non-protein amino acid
is an L-arginine antagonist with documented antiviral, anti-bacterial,
anti-fungal and anticancer activities. An average of 2.2 mg of L-canavanine
per dry gram of leaf material of Sutherlandia was found. L-Canavanine
is a potent L-arginine antagonist that has patented anticancer (Swaffar,
1995; Crooks, 1994.) and antiviral activity, including against influenza
virus and retroviruses (Green, 1988.). L-Canavanine is also a selective
inhibitor of inducible nitric oxide synthase and therefore has possible
application in the treatment of septic shock and chronic inflammation
(Anfossi, G. et al. 1999; Levy, B. et al. 1999).
The non-protein amino acid canavanine has been
detected in the seeds of this species but not in other
Pinitol, a known anti-diabetic agent (Narayanan, 1987), has been
isolated from Sutherlandia leaves, and quantitative work is in progress.
A US Patent (Ostlund, 1996) suggests that pinitol may have clinical
application in treating the wasting in cancer and AIDS patients.
GABA was isolated from dry Sutherlandia leaves in levels up
to 14 mg/g dry weight. This inhibitory neurotransmitter could account
for the use of the plant for anxiety and stress, and for the improvement
in mood and well-being experienced by many patients.
Novel Triterpenoid Glucoside
A novel triterpenoid glucoside has been isolated and characterized,
and is one of the key compounds used in the selection of raw material
for propagation. This compound has promising biological activities,
but this is still the subject of ongoing research.
Preliminary scientific research, published peer-reviewed scientific
research, and clinical experience suggests that key phyto chemicals
in select chemotypes of Sutherlandia varieties are:
- anti-viral, anti-fungal and anti-bacterial
- inhibitors of Tumor Necrosis Factor (TNF). Excess production
of TNF is known to drive the wasting process in cancer, TB and