Studies On The Cytotoxic And Antiviral Constituents Of Wikstroemia Indica (L.)C.A.Mey.

The cytotoxic and antiviral constituents of Wikstroemia indica (L.) C. A. Mey. were studied in this thesis with bioassay-guided analysis and isolation method.The cytotoxicity of the ethanol extract, fractions and different hour's aqueous extracts from W. indica were tested by cytopathic effect reduction assay and MTT assay. As a result, there were few differences of cytotoxicity among the different hour's aqueous extracts, and their CC₅₀ were all between 125μg/mL and 250μg/mL. The petroleum ether fraction from the ethanol extract had the greatest cytotoxicity against Vero cells with CC₅₀ value of 3.1μg/mL and against HeLa cells with CC₅₀ value of 10μg/mL, respectively. Other two lower polar subfractions WIE-1 and WIE-2 which were fractionized from the ethyl acetate fraction were also found to be cytotoxic against Veto cells with CC₅₀ value of 70μg/mL and 18.75μg/mL, and against HeLa cells with CC₅₀ value of 83.3μg/mL and 66.7μg/mLThen, the petroleum ether fraction, WIE-1 and WIE-2 subfractions were analyzed by GC-MS. Their components were identified to be unsaturated bicyclic alkanes, fatty acid methyl ethers and steroids, and the fatty acid methyl ethers were the most. In the petroleum ether fraction, the amount of fatty acid methyl esters was about 68.42%. And as the main components of the fatty acid methyl esters, palmiti acid methyl ester, oleic acid methyl ester, 9,12-octadecadienoic acid methyl ester and octadecanoic acid methyl ester took the amounts of 10.95%, 8.59%, 3.71% and 5.03% respectively from the petroleum ether fraction. According to the GC-MS results with the toxicity results of the petroleum ether fraction, WIE-1 and WIE-2 subfractions, it can be suggested that the fatty acid methyl esters might be the toxin of W. indica. Besides, the constituents of the ethanol extract, fractions and different hour's aqueous extracts were also analyzed and compared by HPLC.The chemical constituents of the ethyl acetate fraction of W. indica were isolated. Seven pure compounds were obtained. They were elucidated by spectroscopic analysis and compared with published datas to be daphnoretin (1), di-n-butyl phthalate (2),β-sitosterol (3), methyl-p-hydroxybenzoate (4), methyl-2,4,6-trihydroxybenzoate (5), genkwanin (6) and sikokianin (7). Di-n-butyl phthalate (2), methyl-p-hydroxybenzoate (4) and methyl-2,4,6-trihydroxybenzoate (5) were obtained from Yhymelaeaceae for the first time. And daphnoretin (1) showed obvious in vitro anti-RSV activity with IC₅₀ value of 7.81μg/mL and SI value of 32.01.In summary, the cytotoxic constituents of W. indica mainly existed in the low polarity fraction, and it was suggested to be long chain fatty acids and esters. Besides, daphnoretin as an effective anti-RSV constituent was obtained.