Structure and Activity Relationship of Antioxidant Flavonoids from Leaves of Paulownia tomentosa var.tomentosa
Paulownia tomentosa var.tomentosa(Scrophulariaceae)is a deciduous tree,indigenous to China,widely distributed in Eastern Asia and used in construction and papermaking industry,as well as in traditional medicine to treat cough,bronchitis,phlegm,hemorrhoid,asthma,high blood pressure,and bacterial diarrhea.To date,we have not found any published data on the chemical profile of P.tomentosa var.tomentosa in the literature.In this study,phytochemical investigation on leaves of the title plant led to the isolation of different classes of flavonoids,including two flavan-3-ols,(+)-catechin(1)and(-)-epicatechin(2),a flavanone,naringenin(3),a flavanonol,taxifolin (4),two flavones,apigenin (5)and luteolin(6),and two flavonols,kaempferol (7)and quercetin(8),and their structures were elucidated on the basis of physichemical and spectroscopicai evidence (NMR and MS).Among the isolates,compounds 1,2,3,4,6,7and 8 were the first time found their occourence in genus of Paulownia.The antioxidant activity of the crude extracts,soluble fractions and isolated flavonoids were evaluated by DPPH free radical-scavenging assay.Results suggested that EtOAc and H2O participated fractions and flavonoids 1,2,4,6,7 and 8 showed significantly high antioxidant potential compared with α-tocopherol and BHT,which were used as controls.
Paulownia tomentosa var. Tomentosa Steud flavonoids isolation NMR
CHUANLING SI XIAOJUAN DENG ZHONG LIU
Tianjin Key Lab of Pulp and Paper,Tianjin University of Science & Technology,Tianjin 300457,China;Ke Tianjin Key Lab of Pulp and Paper,Tianjin University of Science & Technology,Tianjin 300457,China
国际会议
第二届国际造纸与环境学术会议(The Second International Papermaking & Environment Conference)
天津
英文
263-266
2008-05-14（万方平台首次上网日期，不代表论文的发表时间）