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

Publication date: September 2017 Source:Phytochemistry Letters, Volume 21 Author(s): Behnaz Aslanipour, Derya Gülcemal, Ayşe Nalbantsoy, Hasan Yusufoglu, Erdal Bedir Two 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 cycloartane-type triterpene glycosides. Structures of the new compounds were established as 3-O-β-d-xylopyranosyl-6-O-β-d-glucopyranosyl-16-O-β-d-glucopyranosyl-3β,6α,16β,24(S)-25-pentahydroxycycloartane (1), 3-O-[α-l-arabinopyranosyl-(1→2)-β-d-xylopyranosyl]-6-O-β-d-glucopyranosyl-16-O-β-d-glucopyranosyl-3β,6α,16β,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-γ. The test compounds also resulted slight hemolysis at very high doses substantiating a safer profile compared to the positive control QS-21. Graphical abstract
Source: Phytochemistry Letters - Category: Chemistry Source Type: research