摘要：Antifungal activity of
Monotheca
buxifolia methanolic extract and its various fractions were assessed against
Macrophomina
phaseolina, a soil-borne fungal pathogen of more than 500 vegetal species as well as rare and emerging opportunistic human pathogen. Different concentrations of methanolic extract (3.125 to 200 mg mL
−1) inhibited fungal biomass by 39–45%. Isolated
n-hexane, chloroform and ethyl acetate fractions suppressed fungal biomass by 32–52%, 29–50% and 29–35%, respectively. Triterpenes lupeol and lupeol acetate
(1,
2) were isolated from n-hexane while betulin, β-sitosterol, β-amyrin, oleanolic acid (
3–6) were isolated from chloroform fraction. Vanillic acid, protocatechuic acid
, kaempferol and quercetin
(7–10) were isolated from the ethyl acetate fraction and identified using various spectroscopic techniques namely mass spectroscopy and NMR. Antifungal activity of different concentrations (0.0312 to 2 mg mL
−1) of the isolated compounds was evaluated and compared with the activity of a broad spectrum fungicide mancozeb. Different concentrations of mencozeb reduced fungal biomass by 83–85%. Among the isolated compounds lupeol acetate
(2) was found the highest antifungal against
M.
phaseolina followed by betulin
(3), vanillic acid (
7), protocatechuic acid
(8), β-amyrin (
5) and oleanolic acid
(6) resulting in 79–81%, 77–79%, 74–79%, 67–72%, 68–71% and 68–71%, respectively. Rest of the compounds also showed considerable antifungal activity and reduced
M.
phaseolina biomass by 41–64%.
