Chemical constituents of Pileostegia viburnoides var. glabrescens

The phytochemical studies of traditional Chinese medicinal plant Pileostegia viburnoides var. glabrescens have led to the isolation and identification of 31 compounds, including ten coumarins: umbelliferone, 7,8-dihydroxycoumarin, hydrangetin, scopoletin, 6,7-dihydroxy-8-methoxycoumarin, skimmin, fraxin, 7-O-β-D-glucopyranosyl-8-methoxybenzopyranone, 8'-epi-cleomiscosin A, aquillochin, six triterpenes: friedelin, canophyllal, friedelinol, β-amyrin, β-glutinol, 3β-acetoxy-12α-hydroxyolean-28, 13-olide, four steroids: β-sitosterol, daucosterol, 3β, 6β-stigmast-4-en-3, 6-diol, gramisterol, along with 1, 8-dihydroxyanthraquinone, alboside II, loganin, sweroside, syringin, erythreo-syringoylglycerol 4-O-β-D-glucoside, n-butyl-β-D-fructopyranoside, 5-hydromethyl-2-furan carboxaldehyde, vincosamide. Structures of two new compounds remain to be further confirmed. The crystal structure of n-butyl-β-D-fructopyranoside was determined for the first time. Except for canophyllal, the others were obtained from the genus of Pileostegia for the first time and all compounds were obtained from P. viburnoides var. glabrescens for the first time.