The steroid constituents in the 75% ethanol extract of Cyanotis arachnoidea and their anti-HSV-1 activities in vitro were investigated in this study. The ethyl acetate fraction of the extract was isolated and purified using silica gel, ODS, Sephadex LH-20 column chromatography, and semi-preparative HPLC. Structural identification was conducted based on spectroscopic data. Ten steroid compounds were isolated and identified, namely makisterone A 3-acetate(1), makisterone A 2-acetate(2), makisterone A(3), ajugasterone C 2-acetate(4), ajugasterone C(5), 20-hydroxyecdysone 2-acetate(6), 20-hydroxyecdysone 3-acetate(7), podecdysone C(8), rubrosterone(9), and poststerone(10). Compounds 1 and 2 are new steroid compounds. The anti-HSV-1 activities of compounds 1-10 were evaluated using the CPE inhibition method. Vero cells were used in the experiment, with acyclovir as the positive control. The results showed that compounds 9 and 10 showed anti-HSV-1 activity, with EC_(50) values of 83.11 and 103.62 μg·mL~(-1), respectively.
Keywords: Cyanotis arachnoidea; HSV-1; chemical constituent; structural identification.