Flavoniods from aerial parts of Astragalus hoantchy

Four new flavonoids, astragaisoflavans A–D (1–4), along with thirteen known ones (5–17) were isolated from the aerial parts of Astragalus hoantchy. Their structures were established by the extensive spectroscopic analyses including one- and two-dimensional NMR, HRESIMS, IR, and UV results. The absolute configurations of 1–4 were deduced based on circular dichroism. Compounds 1–3 all possessed a rare modified A-ring and compound 4 was a dimeric isoflavan. Compound 5 was first identified from genus Astragalus and 6–17 were found from A. hoantchy for the first time. Compound 1 and 4 were evaluated for their antifungal activity against Alternaria solani (a phytopathogenic fungus), with the result that 1 failed to exhibit significant antifungal activity at the testing concentration of 100 μg/mL and the IC50 value of 4 was 173.3 μg/mL.

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