A new anti-inflammatory triterpene saponin isolated from Anabasis setifera

A bio-guided fractionation of Anabasis setifera Moq. (Chenopodiaceae) for anti-inflammatory activity was carried out using carrageenin rat paw edema model in rats. On the basis of percent edema inhibition after 3 h of carrageenin injection, n-butanol fraction showed promising activity through a significant (p < 0.05) decrease in paw volume by 85.6 % from control using indomethacin as reference standard. Moreover, the n-butanol fraction significantly (p < 0.05) decreased PGE(2) and TNF-alpha in the exudates of rat paw edema. Chemical investigation of n-butanol fraction afforded alpha-amyrin 3-O-glucopyranoside (1), patuletin 7-O-glucopyranoside (2), myricitrin (3) and a new oleanane triterpene saponin derivative (4), sophradiol 3-O-alpha-l-C-1(4)-rhamnopyranosyl-(1'''-> 4'')-O-beta-d-C-4(1)-galactopyranosyl (1''-> 6')-O-beta-d-C-4(1)-glucopyranoside. The structure of the new compound was determined by comprehensive analyses of their 1D and 2D NMR, mass spectral data and comparison with previously known analogs. Only compound 4 revealed a significant (p < 0.05) inhibition of cyclooxygenase 1 and 2 (COX) activities.