Cycloartane-type glycosides from Astragalus brachycalyx FISCHER and their effects on cytokine release and hemolysis

WOS: 000414229300014Two new tridesmosidic cycloartane-type triterpene glycosides (1 and 2) were isolated from the methanolic extract of the roots of Astragalus brachycalyx FISCHER (A. brachycalyx) along with ten (3-12) known cycloartanetype triterpene glycosides. Structures of the new compounds were established as 3-O-beta-D-xylopyranosyl-6-O-beta-Dglucopyranosyl- 16-O-beta-D-glucopyranosyl-3 beta, 6a, 16 beta, 24(S)-25-pentahydroxycycloartane (1), 3-O-[a-L-arabinopyranosyl-(1. 2)-beta-D-xylopyranosyl]-6-O-beta-D-glucopyranosyl-16-O-beta-D-glucopyranosyl-3 beta, 6 alpha, 16 beta, 24(S)-25-pentahydroxycycloartane (2), by using 1D and 2D-NMR techniques and mass spectrometry. In vitro immunomodulatory effects and hemolytic activities of the new saponins (1 and 2) and acetylated form of 1 (1a) were studied together with the BuOH and MeOH extracts of Astragalus brachycalyx. The results have proven that tridesmosidic Astragalus cycloartanes are noteworthy immunomodulatory compounds via induction of cytokine production, namely IL-2 and IFN-gamma. The test compounds also resulted slight hemolysis at very high doses substantiating a safer profile compared to the positive control QS-21.Ege University Research FoundationEge University [15-FBE-001]The authors gratefully acknowledge to the financial support of Ege University Research Foundation (15-FBE-001) for the finical support and thank Prof. Dr. Ali Asghar Maassoumi for the identification of the plant material, and special thanks to NMR operators of both Ege University and Prince Sattam bin Abdulaziz University namely Salih Gunnaz and Anzarul Haque, respectively