The Study On The Extraction Of Rosmarinic Acid From Perillae And The Antioxidant Ability Of The Perillae Extract

Folium Perillae, widely spread in China, was in the list of stuffs, which were both medicine and food, announced by the China Ministry of Health, and contained many kinds of bio-active substances. One of these substances was rosmarinic acid, which had very strong antioxidant ability. In this paper, the optimum extracting condition of rosmarinic acid (RosA) from Perillae leaves and the antioxidant ability of the extract were studied.Firstly, condition of extraction with ethyl-acetate were determined as extracting 3 times and the ratio of extract to solvent 5:3 (v/v). With the single-factor experiments, soaking conditions of hot water were reached as follow: temperature of the water 100 C, soaking time 30min, ratio of water to material 30:1 (v/w). With the orthodox experiments, the optimum extracting condition was determined. It was concluded that hot water soaking, with the soaking rate(water to material) 40:l(v/w), soaking temperature 100 C, soaking time 45minutes and the ratio of extract to solution 5:3(v/v), was the best extracting method. Under this condition, the extracting rate of RosA could reach 0.983%. After dried under vacuum, the Perillae extract was collected. The qualitative analysis by HPLC showed that it contained RosA, and the quantitative analysis with FeSO4 method showed that the concentration of RosA in Perillae extract was 37.49%(w/w).Secondly, the antioxidant actvities of Perillae extract was studied. The extract showed stronger inhibiting ability of per-oxidation in liposome induced by Fe2+, scavenging ability on hydroxyl radical ( OH), inhibiting ability of the haemolysis induced by H2O2 and inhibiting ability of the LPO formation in the homogenate of rat liver in vitro than ascorbic acid. However the Perillae extract showed slightly lower reducing power, scavenging ability on superoxide radical ( O2-) in vitro than ascorbic acid, and lower inhibiting ability of the oxidization of 2'-deoxyribose than sulfuourea.RosA was a substance stable to light and heat. Then, the relation between the structure of RosA and antioxidant ability and its mechanism was analyzed in theory.