Analyses of phytosterols and free radical scavengers in the bulbs of Ornithogalum cuspidatum Bertol.

Abstract

The gas chromatography-mass spectrometry (GC-MS) analyses of the methanol (MeOH) extract of the bulbs of Ornithogalum cuspidatum led to the identification of thirteen phytosterols, namely cholesterol, 3,5-didehydro-stigmastan-6,22-diene, 4,4-dimethyl-5 alpha-cholest-7-en-3-one, 4 beta-methylcholesterol, 5-cholestene-3 beta,7 beta-diol, campesterol, cholest-4-ene-3,6-dione, stigmast-4-en-3-one, stigmasta-3,5-dien-7-one, stigmasterol, Delta 5-ergostenol, beta-sitosterol, gamma-sitosterol The free radical scavenging activity of the MeOH extract, and its solid-phase extraction fractions were assessed by the 2,2-diphenyl-1-picryl hydrazyl (DPPH) assay, and the 40% MeOH-water fraction showed the highest degree of free radical scavenging property (RC(50) 8.87 x 10(-2) mg/mL), compared to that of the positive controls Trolox(R) and quercetin 3.07 x 10(-3) and 2.78 x 10(-4) mg/mL, respectively. The 40% MeOH-water fraction also had the highest level of total phenolics content.