Chemistry of Natural Compounds Department, National Research Centre, Dokki, 12622 Cairo, Egypt.
Carbohydr Res. 2011 Jan 3;346(1):64-7. doi: 10.1016/j.carres.2010.11.007. Epub 2010 Dec 3.
Investigation of the aqueous alcoholic extract of Pyruscalleryana Decne. leaves led to the isolation of two new phenolic acids glycosides, namely protocatechuoylcalleryanin-3-O-β-glucopyranoside (1) and 3'-hydroxybenzyl-4-hydroxybenzoate-4'-O-β-glucopyranoside (2), together with nine known compounds among them lanceoloside A and methylgallate, which have been isolated for the first time from the genus Pyrus. Structures of the isolated compounds were established by spectroscopic analysis, including UV, IR, HRESI-MS, and 1D/2D NMR. The total extract and some isolated compounds were determined against DPPH (2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazinyl radical, for their free radical scavenging activity, the total alcoholic extract showed strong antioxidant activity while the two new compounds showed weak antioxidant activity.
对梨叶的水醇提取物进行研究，分离得到了两种新的酚酸糖苷，即原儿茶酸咖啡酰基-β-吡喃葡萄糖苷（1）和 3'-羟基苯甲基-4-羟基苯甲酸-4'-O-β-吡喃葡萄糖苷（2），此外还分离得到了 9 种已知化合物，其中包括柳醇 A 和没食子酸甲酯，这两种化合物均为首次从梨属植物中分离得到。通过光谱分析，包括 UV、IR、HRESI-MS 和 1D/2D NMR，确定了分离得到的化合物的结构。总提取物和一些分离得到的化合物对 DPPH（2,2-二苯基-1-（2,4,6-三硝基苯基）肼基自由基）的自由基清除活性进行了测定，结果表明，总醇提物具有很强的抗氧化活性，而两种新化合物则表现出较弱的抗氧化活性。
