Composition of the essential oil and petroleum ether extract of Lycium chinense Miller fruits and antioxidant activity of its several extracts

The essential oil and petroleum ether extract from the fruits of Lycium chinense Mill. (Solanaceae), were analyzed by gas chromatography-mass spectrometry (GC-MS). Out of 42 peaks, 40 components, which constituted 99.81%, were identified in the oil. The oil was dominated by acid and esters which accounted for 66.61 and 8.43%, respectively. The major constituents were hexadecanoic acid methyl ester (4.92%), hexadecanoic acid ethyl ester (9.92 %), ethyl linoleate (3.45%), tetradecanoic acid (3.72%) and hexadecanoic acid (62.89%). Forty components, which constitute 99.50 %, were identified in the petroleum ether extract. The major components of petroleum ether extract were hexadecanoic acid (17.43%), hexadecanoic acid ethyl ester (9.51%), hexadecanoic acid methyl ester (3.72 %), ethyl linoleate (10.26%), and phytol (3.58%). The petroleum ether extract components were identified for the first time. The identity of constituents of essential oil and petroleum ether extract was confirmed on the basis of retention time and mass and supplemented library.Extracts of different polarity from fruits of L. chinense were investigated for their antioxidant activity. Two different bioassays were used, namely scavenging of the diphenylpicrylhydrazyl (DPPH) radical method and the other reducing power of Fe3+ method. The total phenolic content was quantified of each extract as well. Butanol, ethyl acetate and methanolic extracts contributed to the strongest antioxidant activity. The fruit extracts of medicinal plant (L. chinense) has potential as a natural antioxidant and thus inhibit unwanted oxidation process.   Key words: Lycium chinense, Solanaceae, fruits, essential oil, petroleum ether extract, gas chromatography-mass spectrometry (GC-MS), antioxidant activity.