Extraction technology and identification of procyanidins from Episperm of Sorghumseed

In this study, procyanidins were extracted and determined from the episperm of Sorghumseed harvested in Heilongjiang Province. Extraction conditions were optimized by orthorhombic analysis. Column chromatography and gel (Sephadex LH-20) chromatography were conducted for further separation and purification. The resulting purified and separated extracts were identified by using ESI-MS. Among the four extraction factors concerned, including temperature, ratio of material/solution, extraction time and pH value, temperature was the most significant that affected the extraction rate, followed by the ratio of material/solution. Molecular weights of various procyanidins extracted were measured by ESI-MS. The optimized extraction condition was to extract at temperature 80℃ for 1.5 h at pH 4, and with a 1∶20 material/solution ratio. In the material studied, oligomers, no larger than pentamers, were the major procyanidins presented in the Episperm of Sorghumseed.