Four pentacyclic triterpenoids with antifungal and antibacterial activity from Curtisia dentata (Burm.f) C.A. Sm. leaves.
BACKGROUND
Curtisia dentata is used in southern Africa to treat various diseases of bacterial and fungal origin in humans and animals to such a degree that the species is vulnerable and declining [Dold, A.R., Cocks, M.L., 2001. Traditional veterinary medicine in the Alice district of the Eastern Cape Province, South Africa. South African Journal of Science 97, 375-379]. Preliminary studies indicated good activity against Candida albicans.


OBJECTIVE
The phytochemistry and antimicrobial activity of this plant species has not been extensively investigated, and a closer examination of the compounds responsible for antimicrobial activity was warranted.


METHODS
Broth microdilution assay and bioautography were used to evaluate antibacterial and antifungal activity in Curtisia dentata leaf extracts and fractions. Bioassay-directed fractionation using column chromatography yielded four compounds characterised by spectroscopic methods.


RESULTS
Lupeol (1), betulinic acid (2), ursolic acid (3) and 2alpha-hydroxyursolic acid (4) were isolated from Curtisia dentata leaves. Betulinic acid, ursolic acid and 2alpha-hydroxyursolic acid appreciably inhibited fungal growth with MIC values ranging from 8 to 63mug/mL.


CONCLUSIONS
The isolation of four antibacterial and antifungal triterpenoids is reported for the first time from Curtisia dentata. This study provides information on the antimicrobial compounds of this species, as well as a preliminary rationale for the use in traditional South African medicine.
Shai
L J
LJ
Phytomedicine Programme, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria, Private Bag X04, Onderstepoort, 0110 Pretoria, South Africa.
McGaw
L J
LJ
Aderogba
M A
MA
Mdee
L K
LK
Eloff
J N
JN
D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D000935:Antifungal Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D029767:Cornaceae / Q000737:chemistry*; D016488:Medicine, African Traditional; D008826:Microbial Sensitivity Tests / Q000379:methods; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology*; D018515:Plant Leaves; D013019:South Africa; D014315:Triterpenes / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D010936:Plant Extracts; D014315:Triterpenes