Twenty terpenoids, including a new triterpenoid ( 1 ) and a new monoterpenoid ( 20 ), were isolated from the branches and leaves of Pyrus pashia . The structures of two new compounds were determined to be 2α, 3β, 27-trihydroxyolean-12-en-28-oic acid ( 1 ) and (4α)-3-(5,5-dimethyltetrahydrofuranyl)-1-buten-3-ol 3- O -β- d -glucopyranoside ( 20 ) on the basis of spectroscopic analysis (IR, HRESIMS, 1D and 2D NMR) and chemical method. Some of the isolated compounds were evaluated for their cytotoxic activity against a panel of human cancer cell lines by MTT assay, using cisplatin as a positive control. Compound 14 exhibited cytotoxic activities against A549 (IC 50 = 19.18 ± 4.26 μM), Hela (IC 50 = 12.56 ± 3.89 μM), SGC7901 (IC 50 = 10.48 ± 1.95 μM) and NHI-1975 (IC 50 = 7.38 ± 2.31 μM) cell lines as well as compound 12 displayed cytotoxic activities against A549 (IC 50 = 14.71 ± 1.47 μM) and Hela (IC 50 = 12.22 ± 1.88 μM) cell lines.
Pyrus pashia flowers are used as edible and medicinal materials in Yunnan Province, China. The antioxidant activities of 85% ethanolic extract of P. pashia flowers and derived soluble fractions were evaluated for the first time using four different test systems. The total phenolic and total flavonoid contents of each fraction were also determined. It was found that the ethyl acetate fraction exhibited the strongest antioxidant effect. An investigation of this flower's chemical constituents was carried out and led to the isolation of a new phenolic glycoside, 4- O - Z -coumaroylarbutin ( 1 ), along with twenty-seven other phenolic compounds ( 2 – 28 ). Hydroquinone ( 13 ) showed the highest content and powerful activity, which implied that the compound plays an important role in the antioxidant activity of this flower. Thus, P. pashia flowers could serve as a valuable natural antioxidant source for potential application in functional foods.
危险品化学品经营许可证（带存储）