不同提取方法对海桐果皮多糖理化性质及生物活性的影响

Effects of Different Extraction Methods on The Physicochemical Properties and Biological Activity of Polysaccharides from The Pericarp of Pittosporum tobira

为研究不同提取方法对海桐果皮多糖理化性质与活性的影响,通过复合酶法和热水浸提法提取海桐果皮多糖,并比较不同方法提取的海桐果皮多糖的理化性质及抗氧化、止血等生物活性。采用紫外光谱、红外光谱、酸水解等方法测定海桐果皮多糖的理化性质,并检测1,1-二苯基-2-三硝基苯肼自由基(DPPH·)、2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐自由基(ABTS^(+)·)、羟基自由基(·OH)清除率和总还原能力4个指标,综合评价海桐果皮多糖的抗氧化能力;采用凝血4项检测评价海桐果皮多糖体外凝血活性。结果表明:两种方法提取的海桐果皮多糖均是由鼠李糖、阿拉伯糖、半乳糖、葡萄糖、木糖、甘露糖组成的含有半乳糖醛酸的杂多糖,但单糖的相对摩尔比例有明显差异。两种方法提取的海桐果皮多糖对DPPH·、ABTS^(+)·和·OH均具有较好清除能力,还显示出一定还原能力,热水浸提法提取的海桐果皮多糖抗氧化活性较高;两种方法提取的海桐果皮多糖均显著缩短了活化部分凝血酶时间(P<0.001),显著增加了纤维蛋白原含量(P<0.05),表明其止血活性是通过内源性凝血途径和提高纤维蛋白原含量实现的。不同方法提取的海桐果皮多糖的红外光谱、单糖组成和体外抗氧化活性有差异,复合酶法提取的海桐果皮多糖具有较高的提取率和纯度,热水浸提法提取的海桐果皮多糖体外抗氧化活性更好。

To investigate the effects of different extraction methods on the physicochemical properties and activities of polysaccharides form the pericarp of Pittosporum tobira,polysaccharides were extracted by complex enzyme method and hot water extraction method,and the effects of different extraction methods on the physicochemical properties and biological activities of the pericarp of Pittosporum tobira polysaccharides,such as antioxidant and hemostatic activities,were compared.The physicochemical properties of the pericarp of Pittosporum tobira polysaccharides were determined through UV,IR,acidic hydrolysis and so on.The antioxidant activity of the polysaccharides was evaluated by measuring the scavenging rate of 1,1-diphenyl-2-trinitrophenylhydrazine radical(DPPH·),the scavenging rate of 2,2-diazobium bis(3-ethyl-benzothiazole-6-sulfonic acid)ammonium salt radical(ABTS^(+)·),the scavenging rate of hydroxyl radical(·OH)and the total reducing power.And the anticoagulant activity of polysaccharides in vitro was evaluated by four coagulation tests.The results showed that the two kinds of polysaccharides prepared by different methods were heteropolysaccharides containing uronic acid,which were composed of rhamnose,arabinose,galactose,glucose,xylose,mannose and galacturonic acid,but there were significant differences in the relative molar ratios of monosaccharides.These two kinds of polysaccharides had good scavenging capacity for DPPH·,ABTS^(+)·and·OH,and also showed corresponding reduction ability,and the polysaccharides prepared by hot water extraction method had higher antioxidant activity.They both significantly shortened APTT(P<0.001),and could significantly increase FIB(P<0.05),indicating that their hemostatic activity was achieved through endogenous coagulation pathway and increasing fibrinogen content.There were difference in infrared spectrum,monosaccharide composition and antioxidant activity in vitro of the pericarp of Pittosporum tobira polysaccharides between two extraction methods.The polysaccharides derived from the complex enzyme method exhibited higher extraction rate and purity,while those from the hot water extraction method exerted superior antioxidant activity in vitro.The experimental results laid a theoretical foundation for the development and application of polysaccharides from the pericarp of Pittosporum tobira in the fields of fresh-keeping and health care.