Studies On The Constituents And Biological Activities Of Nelumbo Nucifera Gaertn. And Dioscorea Panthaica Prain Et Burk.

Heye is the dried leaf of perennial herbage Nelumbo nucifera Gaertn which belongs to the genus Nelumbo of family Nymphaeaceae. It distributes widelyin Hunan, Hubei, Zhejiang and Jiangsu provinces of China. It is bitter taste and neutral in nature according to the record of Chinese Materia Medica, and it has the functions of dissipating dampness, raising lucid yang and cooling blood to stop bleeding. In order to use and develop this drug further, the chemical constituents and the biological activities of the partial compounds were screened. In addition, the distribution, living environment, medical efficacy, chemical constituent and pharmacological action about the genus Nelumbo plants were summarized. Our research results are as follows.Thirty-two compounds were isolated from the 70% ethanol extract of the leaves of Nelumbo nucifera Gaertn by using the modern chromatographic techniques. The structures of twenty-seven ones (HY-1-HY-27) were identified by the physico-chemical properties and modern spectral techniques, including IR,1H NMR, 13C NMR, HMQC, HMBC, EI-MS, and ESI-MS. They contained fourteen flavonoids, two alkaloids, two steroids, two steroid glycosides, three sterols, one phenol and two megastigmane glucosides. These compounds were identified as follows:10-octacosanol (HY-1),β-sitosterol (HY-2),1-undecanol (HY-3),1-eicosanol (HY-4), daucosterol (HY-5),6'-Hydroxy-4,4'-dimethoxychalcone (HY-6),3,7,8-trimethoxy- Chinese Academy of Medical Science and Peking Union Medical College 1-hydroxy-xanthone (HY-7), Rhamnetin-3-O-glucopyranoside (HY-8), chrysoeriol 7-O-β-D-glucoside (HY-9), quercetin 3-O-β-D-glucopyranoside (HY-10), quercitrin-3-O-α-L-rhamnopyranosyl (HY-11), hyperoside (HY-12), quercetin 3-O-rutinoside (HY-13), astragalin (HY-14), isorhamnetin-3-O-α-L-rhamnopyranosyl-(1→6)-[α-D-lyxopyranosyl-(1→2)-β-D-glucopyranoside] (HY-15), isorhamnetin-3-O-α-D-lyxopyranosyl-(1→2)-β-D-glucopyranoside (HY-16), isorhamnetin-3-O-β-D-glucopyranoside (HY-17), isorhamnetin-3-0-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (HY-18), quercetin (HY-19), kaempferol (HY-20), dehydronu-ciferine (HY-21), roemerine (HY-22), stigmast-7-en-3-O-β-D-glucopyranoside (HY-23),stigmast-7-en-3β-ol (HY-24), benzene-1,2-diol (HY-25), alangionoside L (HY-26), icariside B2 (HY-27). Among these compounds, six were isolated from the Nelumbo nucifera Gaertn for the first time and four were isolated from the leaves of Nelumbo nucifera Gaertn.In addition, lipase inhibition, AChE inhibition,A-beta aggregation and hiap-paggregation activities of seventeen compounds were researched. The results in-dicated that 6'-hydroxy-4,4'-dimethoxychalcone (HY-6),rhamnetin-3-O-β-D-gluc-opyranoside (HY-8),querc-etin-3-O-β-D-glucopyranoside (HY-11),quercitrin,qu-ercetin-3-O-rutinoside (HY-13),isorhamnetin-3-O-α-L-rharnnopyranosyl-(1→6)-[α-D-lyxopyranosyl-(1→2)-β-D-glucop-yranoside] (HY-15) showed activities in b-eta amyloid(1-42) inhibition activity with A-beta aggregation method.In summary, the chemical constituents and biological activities were systematical studied in this thesis. These provided the theoretical basis and scientific reference for further study, development and application of Nelumbo nucifera Gaertn. Dioscorea panthaica Prain et Burk., a plant from Dioscoreaceae, is distributed only in China, widely in Sichuan, Guizhou, Hunan and Yunnan provinces. The rhizomes of the plant are medicinal parts that are effective in gas expulsion, heat clearing, and detoxification. They are used as traditional Chinese medicine for the treatment of gastric diseases, bone injuries, and rheumatic arthritis. Dioscorea panthaica is also the essential herbal resource of diaoxinxuekang for the treatment of cardiovascular diseases. In order to use and develop this drug further, the chemical constituents and the biological activities of the partial compounds were screened. In addition, the distribution, living environment, medical efficacy, chemical constituent and pharmacological action about Dioscorea panthaica were summarized. Our research results are as follows.Sixteen compounds were isolated from the extract of the dried rhizomes ofDioscorea panthaica by using the modern chromatographic techniques. The structures of fourteen ones (HY-1～HY-14) were identified by the physico-chemical properties and modern spectral techniques, including UV, IR,1H NMR,13C NMR, HMQC, HMBC, NOESY and ESI-MS. They contained thirteen steroidal saponin compounds. These compounds were identified as follows:β-sitosterol (HSY-1), trillin (HSY-2), dioscin (HSY-3), gracillin (HSY-4),3-O-[α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl]-26-O-β-D-glucopyranosyl-25(R)-furosta-5,20(22)-dien-3β,26-di ol (HSY-5), dioscoreside I (HSY-6), pregnadienolone 3-O-β-chacotriside (HSY-7), pseudoprotodioscin (HSY-8), peudoprotogracillin (HSY-9), dioscoreside E (HSY-10), 3-O-[α-L-rhamnopyranosyl-(1→4)-β-D-glucopyranosyl]-26-O-β-D-glucopyranosyl-2 5(R)-furosta-5,22(23)-dien-3β,20α,26-triol (HSY-11),3-O-[β-D-glucopyranosyl-(1→3)-O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl]-26-O-β-D-glucopyranos yl-20(R)-methoxyl-25(R)-furosta-5,22(23)-dien-3β,26-diol (HSY-12),3-O-[α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl]-26-O-β-D-glucopyranosyl-20,22-seco-25(R)-furosta-5-ene-20,22-dione-3β,26-diol (HSY-13),3-O-[α-L-rhamnopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl]-26-O-β-D-glucopyranosyl-20,22-seco-25(R)-furosta-5-ene-20,22-dione-3β,26-diol (HSY-14). Among these compounds, HSY-11, HSY-12 and HSY-13 were new compounds, HSY-9 was isolated from the Dioscorea panthaicafor the first time.In addition, the inhibitory activities of the saponins against a-glucosidase were investigated. The results indicated that gracillin(HSY-4),3-O-[α-L-rhamno-pyranosy-(1→2)-β-D-glucopyranosyl]-26-O-β-D-glucopyranosyl-25(R)-furosta-5,20 (22)-dien-3(3,26-diol (HSY-5) and pregnadienolone 3-O-β-chacotriside (HSY-7) were found to exhibit potent activities.In summary, the chemical constituents and biological activities were systematical studied in this thesis. These provided the theoretical basis and scientific reference for further study, development and application of Dioscorea panthaica Prain et Burk.