ABSTRACT in curing and healing some human maladies

ABSTRACT

Medicinal
plants contain bioactive compounds or plant metabolites that serve an important
therapeutic role in curing and healing some human maladies such as microbial
diseases. Some of these bioactive compounds exhibit especially good
antimicrobial effects upon pathogenic agents that have become a major public
health problem around the world causing death and upsurge of resistance to
drugs commonly used.

Plant
metabolites such as flavonoids have been reported to display antimicrobial
properties against some microbe strains whereas genus the Tephrosia is known to be rich in flavonoids. In the search to
isolate from medicinal plants the compounds that exhibit antimicrobial effects,
Tephrosia hildebrandtii aerial part
was phytochemically analyzed.

The
phytochemical investigation on this plant material led to the isolation of five
flavones derivatives, a sterol, a triterpene and a carotenoid. Five of the
isolated compounds were new and their structures were established using a
combination of techniques including NMR, UV and MS.

Both
the MeOH/CH2Cl2 (1:1 v/v) crude extract and the isolated
compounds were tested for antimicrobial activity against Escherichia coli (gram negative bacterium), Bacillus cereus (gram positive bacterium) and Candida albicans (fungus). The crude extract, compound (90) and compound (91) showed significant activity against Escherichia coli with ZI values of 15, 18 and 15 mm respectively
and MIC values of 2.50, 0.25 and 0.50 mg/mL respectively. The crude extract and
compound (90) also exhibited good
activity against Candida albicans
with ZI values of 18 and 21 mm respectively and MIC values of 2.50 and 0.25
mg/mL respectively while compounds (94),
(95) and (96) showed a moderate activity with ZI values of 13, 14 and 14 mm
respectively and MIC values of 0.50, 0.50 and 0.50 mg/mL respectively. Compound
(90) and the mixture of compounds (92,
93) showed good activities against Bacillus
cereus with ZI values of 14 and 17 mm respectively and MIC values of 0.50
and 0.25 mg/mL respectively while the crude extract and compound (91) were moderately active with ZI
values of 11 and 11 mm respectively and MIC values of 5.00 and 0.50 mg/mL
respectively.

Pyrazoline
and guanidine derivatives of compound (94)
have been prepared on the treatment with guanidine hydrochloride and hydrazine
hydrate in presence of alkali respectively. structures