Studies On The Chemical Constituents And Bioactivities Of Leaves Of Morus Nigra L. In Xinjiang

In this paper,the biological activity of ethanol extract of mulberry leaves,the chemical constituents of ethyl acetate extract and the bioactivities of the isolated compounds were studied in vitro.1.To study the biological activities of ethanol extract from leaves of Morus nigra L.in Xinjiang,the crude powder of dry leaves was extracted with 80%ethanol at 30?.The extract was dissolved and suspended in H₂O,and partitioned with petroleum ether,ethyl acetate and n-butanol successively and then concentrated to dry.The petroleum ether phase,ethyl acetate phase,n-butanol phase and water phase were obtained respectively.The anti-tumor activity of the extracts was studied on Hela cells by MTT assay,the antioxidant activity of the extracts was evaluated by DPPH free radicals,and the hypoglycemic activity of the extracts was investigated by?-glucosidase inhibition model in vitro.The anti-tumor ability was from strong to weak:ethyl acetate>n-butanol>water phase,and the antioxidant capacity from strong to weak was:ethyl acetate phase>n-butanol phase>petroleum ether phase>water phase,the hypoglycemic ability was as follows:ethyl acetate phase>n-butanol>water phase>petroleum ether phase.The results showed the ethyl acetate phase had good antitumor,antioxidant and hypoglycemic bioactivities compared with other three parts of ethanol extract from leaves of Morus nigra L..2.Eleven compounds were separated from ethyl acetate extract of ethanol extract of mulberry leaves by TLC and kinds of column chromatography.The compounds were identified by modern methods such as NMR,UV,IR and HPLC-MS.The eleven compounds were identified by comparing the literature as:Benzyl3-hydroxy-2-O-?-glucopyranosyloxybenzoate?1?,Benzyl 2-?-glucopyranosyloxybenzoate?2?,2-??-D-Glucopyranosyloxy?-benzylbenzoate?3?,Methyl 2-O-?-D-glucopyranosylbenzoate?4?,Caffeic acid ethylester?5?,Dibutylphthalate?6?,?3S,5R,6S,7E?-3,5,6-trihydroxy-7-megastigmen-9-one?7?,?-?-Loliolide?8?,9,16-dioxo-10,12,14-octadeca-trienoic acid?9?,9,16-dioxo-10,12,14-octadeca-trienoic acid methyl ester?10?,quercetin-3-O-?-D-glucopyranoside?11?.And compound 1 was identified as a new compound,compound 10 was identified as a new natural product.What's more,compound 2-9 was isolated from Morus nigra L.for the first time.3.The antioxidant activity of these 11 compounds was evaluated by DPPH free radical scavenging rate and the hypoglycemic activity of these compounds was investigated by inhibition model of?-glucosidase in vitro.It was found that compounds 5 and 11 showed moderate antioxidant activities compared with positive control,and compound 2 exhibited hypoglycemic activity with IC₅₀ value of 0.056 mg/mL.