Study On The Antioxidant Activity Of Ulva Pertusa Extracts

As a kind of large ocean economic green alga, Ulva pertusa is abundant in China,containing both high nutritional and pharmaceutical value. Recently, the industrializedseedling production and manual cultivation technology of Ulva pertusa has been welldeveloped, but study about its biological activity is still in the initial stage, far less thanthe pace of Aquaculture cultivation, especially its antioxidation feature has yet to bepromoted.Based on Ulva pertusa, indicated by its antioxidation eliminating free radical, thisresearch selected, separated, and identified antioxidants in Ulva pertusa, wishing toapply achievement of its antioxidation into natural antioxidant, curing medicines. Themain results are as follows:With ultrasound technique, crude ingredients in Ulva pertusa was extracted, thenexamined influence of temperature, solid-to-liquid ratio, concentration of ethanol, timeto soluble solid material, through series of single factor test and orthogonal test,extraction condition was optimized. Results showed that the best extraction system is:temperature60℃, solid-to-liquid ratio1:25, concentration of ethanol60%, time ofultrasound2h. Under this circumstance, extraction rate of soluble solid matter in Ulvapertusa is11.81%, RSD is0.53%, indicating that results is highly accurate andreliable.By way of liquid-liquid extraction, indicated by elimination of ABTS free radicals,hydroxyl free radical, DPPH free radical, crude extraction of Ulva pertusa was studied.Results showed that extraction by normal butanol has better antioxidation. Then D101macroporous resin was adopted for further purification, eluded with ethanol in differentconcentration. Elution part was examined with antioxidation ability. Finally, SR-50possessing higher antioxidation ability was selected for further research. In order toobtain purer product, the study employed medium pressure liquid chromatography forthe first time to purify SR-50systematically. Under most suitable elutioncondition(chloroform:methanol=94:6), SR-50-I was obtained, then according toantioxidation analysis, the ability of elimination of ABTS free radical, hydroxyl freeradical, DPPH free radical were much stronger than that of SR-50. which means purityof antioxidation in sample purified was enhanced.Combined with Ultraviolet Spectrum Analysis, Conventional color reaction andLC-MS, purified constituent SR-50-I was identified, and preliminarily conclude thatSR-50-I contains catechol, epicatechin, morin.They are expected to be identified asquality control indedx of Ulva pertusa antioxidant ingredient.