Preliminary Study On Standards And Antioxidant Effect Of Urtica Cannabina L.in Xinjiang

Urtica cannabina L.,a perennial herb of the nettle family,is rich in resources in Xinjiang and distributed throughout Xinjiang.U.cannabina L.has a long history of medicinal use and has many effects.Literature research found that the polysaccharide content in U.cannabina L.was high and had good biological activity.In recent years,polysaccharides of many plants have been widely used as natural antioxidants,but so far there have been no reports on the antioxidant properties of U.cannabina L.polysaccharides.There is little research on U.cannabina L.at home and abroad,and the medicinal material still stays in the category of folk medicinal use,lacks quality control,cannot meet the needs of preparation production and clinical use,and affects the efficacy of medicine.The quality control of medicinal materials is an indispensable part of their clinical efficacy,and it is also a problem that must be solved before the innovation and development of medicinal materials.At present,only the 2010 edition of the "Xinjiang Uygur Autonomous Region Uygur Medicinal Materials Standards" includes U.cannabina L.,and only trait identification and microscopic identification,while the establishment of quality standards for Chinese medicinal materials generally includes trait identification,microscopic identification,thin layer identification,inspection and content determination,and the quality standards of this medicinal materials need to be further improved.Therefore,in this study,10 batches of U.cannabina L.collected from different regions of Xinjiang were selected as the research object,and the extraction process of the polysaccharides of the medicinal herb was optimized,and the antioxidant effect of the crude polysaccharide extract was studied.On the basis of the "Xinjiang Uygur Autonomous Region Uygur Medicinal Materials Standards" the contents of identifications,inspection items and content determination items were added,and the quality standards of the medicinal materials were initially improved.The main research contents are as follows:1.Design orthogonal test to optimize the extraction process of U.cannabina L.polysaccharide,and obtain the best extraction process: extraction temperature 100 °C,material-liquid ratio 1:12(g/m L),extraction time 2 h,extraction times are 3 times.The crude polysaccharides of U.cannabina L.from different origins were extracted under optimal extraction conditions,and the polysaccharide content was determined.The antioxidant effect of crude polysaccharides of U.cannabina L.from different origins was studied by DPPH radical scavenging capacity assay,ABTS radical scavenging capacity determination and total reducing power determination,and the results showed that the crude polysaccharide of U.cannabina L.had good antioxidant capacity,but there were differences between different origins.2.Carry out preliminary quality control of U.cannabina L.medicinal materials,and improve the local quality standards of the medicinal materials.The Chinese Pharmacopoeia methods of the 2020 edition was used to identify and routinely check 10 batches of medicinal materials;The content of chlorogenic acid and polysaccharides in 10 batches of medicinal materials was determined by taking chlorogenic acid and polysaccharide components as the index components of the content determination items.A variety of identification methods are used to comprehensively identify U.cannabina L.,which can achieve the purpose of identifying the medicinal material;It is preliminarily proposed that the moisture content in U.cannabina L.medicinal materials shall not exceed 10.00%,the total ash shall not exceed17.00%,the acid insoluble ash shall not be higher than 3.00%,the water-soluble extract shall not be less than 18.00%,the chlorogenic acid content shall not be less than 0.25 mg/g,and the polysaccharide content shall not be less than 14.00 mg/g.