A Novel Steroid Derivative and A New Steroidal Saponin from Endophytic Fungus Xylaria Sp.

Two new steroids, (24 R)-22, 23-dihydroxy-ergosta-4,6,8(14)-trien-3-one 23-β-D-glucopyranoside (1), and xylarester (2), together with 16 known compounds were isolated from the extract of endophytic Xylaria sp. solid culture. Their structures were elucidated by spectroscopic methods. Compound 2 has an unprecedent ergosta skeleton with a six-membered lactonic group in A ring. The X-ray single crystal diffraction data of 4,7-dihydroxy-13-tetradeca-2,5,8-trienolide (4) were also reported for the first time. The antibacterial, anti-acetylcholinesterase, nitric oxide inhibition and cytotoxic activities of 1–3 were investigated. Compound 1 showed cytotoxicity to MCF-7 with the ratio of inhibition at 72 % for a concentration at 40 μM.