Chemical investigation of the stems of Fritillaria unibracteata P.K. Hsiao & K.C. Hsia resulted in the isolation of nine compounds, by means of silica gel column chromatography, and preparative HPLC. Based on spectroscopic and chemical evidence, these compounds were identified as: 27-hydroxychlorogenone (1), sieboldogenin (2), (3β, 25S)-spirost-5-ene-3,17,27-triol (3), laxogenin (4), tigogenone (5), cerevisterol (6), ergosterol peroxide (7), stigmaterol (8), and β-sitosterol (9). Compound 1 was a new compound, and compounds 2-9 were isolated from the stems of Fritillaria unibracteata for the first time. The inhibitory effects of compounds 1−9 on A549 cells were determined using the MTT method. The results show that compound 6 exhibits moderate inhibitory activity with an IC50 value of (14.16 ± 1.11) μmol/L.

As a medicinal and edible fungus, Inonotus obliquus has a long history of folk application in Russia, Japan, and Northeast China. It is rich in terpenoids, steroids, polysaccharides, phenols, alkaloids, etc, and exhibits pharmacological activities including anti-tumor, hypoglycemic, anti-inflammatory, antioxidant, and lipid-lowering effects. Among these, lanostane-type tetracyclic triterpenes represent its characteristic constituents. This review systematically summarizes the research progress on the chemical components isolated and identified from I. obliquus and their pharmacological activities in recent years. The structures of terpenoids, steroids, and phenolic compounds are compiled and illustrated, with a particular focus on the skeletal types and structural characteristics of lanostane-type tetracyclic triterpenes. This work aims to provide some reference for the further investigation and comprehensive development and utilization of I. obliquus.