TITLE:
New Hemisynthetic Oleanane Saponin with Antimicrobial Activities
AUTHORS:
Cyrille Ngoufack Tagousop, Jean-De-Dieu Tamokou, Leonel Donald Tsamo Feugap, Dominique Harakat, Laurence Voutquenne-Nazabadioko, David Ngnokam
KEYWORDS:
Saponin, Acetylation, Methylation, Antimicrobial Activities
JOURNAL NAME:
Advances in Biological Chemistry,
Vol.11 No.1,
January
14,
2021
ABSTRACT: A new hemisynthetic oleanane saponin: 4',2",3",4",6"-penta-O-acetyl-6'-O- methyl-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucuronopyranosyl
oleanolic acid (2) was obtained after acetylation and methylation reaction on 3-O-β-D- glucopyranosyl-(1→2)-β-D-glucuronopyranosyl oleanolic acid (1). Its structure was established by extensive analysis of 1D-(1H, 13C),
2D-(COSY, HSQC and HMBC) NMR data in conjunction with mass spectrometry (HR- TOFESIMS).
The evaluation of antimicrobial activities using microdilution method showed
that, reaction product (2) presented
the lowest values of MIC against E. coli (MIC = 16 μg/mL), S. aureus (MIC = 8 μg/mL), C. tropicalis (MIC = 16 μg/mL) C. albicans (MIC = 8 μg/mL) compare to the substrate (1) against the same microbial
strains: E. coli (MIC = 32 μg/mL), S. aureus (MIC = 16 μg/mL), C. tropicalis (MIC = 32 μg/mL), C. albicans (MIC = 16 μg/mL). These results indicate that, acetylation
and methylation reactions of compound 1 increase its antimicrobial
activities against the tested microorganisms.