A new ursane-type triterpene oxoglucopyranoside from Crossopteryx febrifuga

Abstract A new saponin, 3- O -β- d -3-oxo-glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid ( 1 ), was isolated from the methanol extract of stem bark of Crossopteryx febrifuga together with the known 3β- d -glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid ( 2 ), shanzhiside methyl ester ( 3 ), shanzhiside ( 4 ), β-sitosterol ( 5 ), β-sitosterol-3- O -β- d -glucopyranoside ( 6 ), ursa-12,20(30)-diene-27,28-dioic acid ( 7 ), hederagenin ( 8 ), and oleanolic acid ( 9 ). The structures were established by comprehensive interpretation of their spectral data 1D- ( 1 H and 13 C), 2D-NMR ( 1 H- 1 H COSY, HMQC, HMBC), spectroscopic, and electrospray ionisation time-of-flight mass spectrometry analysis. The isolated compounds and extracts were screened for their antibacterial properties. Although the EtOAc and n -BuOH extracts exhibited considerable antibacterial activity against Pseudomonas aeruginosa with minimum inhibitory concentration (MIC) value of 32 μg/mL, compounds 2 and 8 showed moderate activity against Enterococcus faecalis with MIC values of 256 and 128 μg/mL, respectively. The new compound ( 1 ) exhibited a moderate antibacterial activity against Staphylococcus aureus with an MIC value of 512 μg/mL.