ABSTRACT
A new saponin, 3-O-ß-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 3ß-d-glucopyranosyl-ursa-12,20(30)-diene-27,28-dioic acid (2), shanzhiside methyl ester (3), shanzhiside (4), ß-sitosterol (5), ß-sitosterol-3-O-ß-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- (1H and 13C), 2D-NMR (1H-1H 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.
Subject(s)
Glucosides/isolation & purification , Rubiaceae/chemistry , Triterpenes/isolation & purification , Bacteria/drug effects , Carbohydrate Conformation , Carbon-13 Magnetic Resonance Spectroscopy , Glucosides/chemistry , Glucosides/pharmacology , Microbial Sensitivity Tests , Proton Magnetic Resonance Spectroscopy , Triterpenes/chemistry , Triterpenes/pharmacologyABSTRACT
Preparations of Crossopteryx febrifuga (Afzel.) Benth. (Rubiaceae) are widely used in Northern Nigeria in the therapeutic management of trypanosomiasis, malaria and painful inflammatory disorders. Previous studies have shown that the methanolic stem bark extract of Crossopteryx febrifuga possesses significant analgesic and anti-inflammatory properties possibly mediated via Non-selective inhibition of cyclo-oxygenase pathways. In the present study, the methanolic stem bark extract of Crossopteryx febrifuga was evaluated against ethanol- and piroxicam-induced ulceration in rats. Histopathological studies of the rat stomach tissues were also carried out in order to determine its safety profile on the gastrointestinal tract (git). The extract (25, 50 and100 mg extract/kg body weight) significantly (P<0.05) and dose-dependently reduced ulcer index induced by ethanol (24 - 92%) and piroxicam (81.81- 98.60%). Histopathology of the rat stomach tissues from control and extract-treated groups at 25 mg/kg body weight extract showed mild inflammation characterized by infiltration of inflammatory cells, while the extract treated groups at 50 and 100mg/kg body weight and 200 mg misoprostol/kg body weight group showed no obvious lesions. These results showed that the extract had no deleterious effects and was cytoprotective on the gastrointestinal tract (git). It can thus be developed as a safe alternative to conventional non-steroidal anti-inflammatory drugs (NSAIDs) for the management of painful inflammatory disorders.