Seladoeflavones G‐I, Three New flavonoids from Selaginella doederleinii Hieron.

Abstract Three new flavonoids, seladoeflavones G‐I ( 1 – 3 ), together with six known flavonoids, involvenflavone E ( 4 ), involvenflavone F ( 5 ), unciflavone F ( 6 ), 3‐[5,7‐dihydroxy‐2‐(4‐methoxy‐phenyl)‐4‐oxo‐4 H ‐chromen‐8‐yl]‐4‐methoxy‐ benzoic acid ( 7 ), naringenin ( 8 ), and eriodictyol ( 9 ) were isolated from the petroleum ether and the ethyl acetate fractions of the whole herbs of Selaginella doederleinii . The structures of new flavonoids were established by 1D NMR ( 1 H, 13 C and DEPT), 2D NMR (HMBC, 1 H‐ 1 H COSY and HSQC), HRMS and electronic circular dichroism (ECD). Compounds 1 – 7 are apigenin or naringin derivatives with aryl substituents at the C‐8 or C‐3′ positions, in which the new compounds 1 and 2 were identified as S configuration. In addition, compounds 4 and 5 exhibited strong cytotoxicity against human laryngeal cancer cells (Hep‐2 and Fadu) with IC 50 values in the range of 1.41‐3.22 μg/mL. The results of this study could enrich the flavonoids diversity and be regarded as some further insight into the chemotaxonomic diversity of natural products in Selaginella .