Two new serratene triterpenes from club moss cultivars

Two new serratene triterpenes, 14α,21β-dihydroxyserrat-3β-yl acetate and 3α,21β-dihydroxyserrat-14-en-23-oic acid, together with eight known compounds were isolated from two club moss cultivars, Phlegmariurus carinatus (Desv.) Ching and Phlegmariurus nummulariifolius (Blume) Ching. 14α,21β-Ddihydroxyserrat-3β-yl acetate (1) was isolated from P. carinatus, and 3α,21β-dihydroxyserrat-14-en-23-oic acid (2), an undescribed carboxylic group at C-23 position of the serratene triterpenoids, was isolated from P. nummulariifolius. The structures of these new compounds were elucidated by using HR-ESIMS, UV, IR, 1D (¹H and ¹³C NMR spectra), 2D NMR spectra, experimental ECD spectrometry and the single-crystal X-ray analysis. Biological evaluation of 14α,21β-dihydroxyserrat-3β-yl acetate (1) and lycoclavanol (8) revealed moderate cytotoxic activity on three tumor cell lines (HepG2, A549 and HuCCA-1) whereas 3α,21β-dihydroxyserrat-14-en-23-oic acid (2) showed strong inhibitory effect on HuCCA-1 cells with the IC₅₀ of 4.72 µM.