Triterpenes in Traditional and Supercritical-Fluid Extracts of Morus alba Leaf and Stem Bark

Abstract

Our objectives were to establish a GC method capable of quantitative analysis of terpenoids without derivatisation and to examine the amount of beta-sitosterol extracted from Morus alba L. leaf and stem bark by use of traditional organic solvent extraction and supercritical-fluid extraction (SFE). To measure beta-sitosterol content without derivatization, GC-FID was used with 5-alpha-cholestan-3-one as internal standard. To identify terpenoid constituents, GC-MS was used; beta-sitosterol, phytol, lanost-7-en-3-on, alpha-amyrin, beta-amyrin, and lupeol were identified. We established that for Morus leaf the best SFE method for beta-sitosterol was pilot scale SFE; the beta-sitosterol content of this extract was higher than that of the hexane solvent extract. Among analytical SFE conditions, 200 bar for 90 min and 300 bar for 60 min resulted in extraction of the most beta-sitosterol. For mulberry stem bark, solvent extraction with hexane and SFE at 400 bar and 40 degrees C for 60 min proved the best methods.