Two cyclopeptides,heterophyllin A and B,have been isolated from the roots of Pseudostellaria heterophylla.Their structures were elucidated by chemical, spectroscopic,and enzymatic methods.
In addition to 2-deoxycrustecdysone(1),we isolated and identi- fied two new natural moulting hormones-2-deoxy-3-epicrustecdysone(2)and 2-deoxycrustecdysone-3-O-β-D-glucopyranoside(3)from the roots of Tino- spora capi...In addition to 2-deoxycrustecdysone(1),we isolated and identi- fied two new natural moulting hormones-2-deoxy-3-epicrustecdysone(2)and 2-deoxycrustecdysone-3-O-β-D-glucopyranoside(3)from the roots of Tino- spora capillipes,it is the first time to get ecdysteroids from this genus.展开更多
Phytochemical investigation of the roots of Ligularia nelumbifolia afforded three new sinapyl alcohol derivatives together with two other novel constituents.Their structures were elucidated by high field 1D and 2D NMR...Phytochemical investigation of the roots of Ligularia nelumbifolia afforded three new sinapyl alcohol derivatives together with two other novel constituents.Their structures were elucidated by high field 1D and 2D NMR techniques and chemical transformations.展开更多
Two new oligopeptides, Asterin A and B, have been isolated from the roots of Aster tataricus L. f., and their structures were elucidated on the basis of spectroscop- ic, chemical and enzymatic methods.
Two new alkaloids namely tuberostemoninal and tuberostemoamide as minor components were isolated from the roots of Stemona tubeross.Their structures were determined by various 2D NMR and other spectra and finally conf...Two new alkaloids namely tuberostemoninal and tuberostemoamide as minor components were isolated from the roots of Stemona tubeross.Their structures were determined by various 2D NMR and other spectra and finally confirmed by X-ray analysis.展开更多
We extend a theorem of Ivanev and Saff to show that for the Hermite-Pade interpolant at the roots of unity to a function meromorphic in the unit disc, its leading coefficients vanish if and only if the corresponding i...We extend a theorem of Ivanev and Saff to show that for the Hermite-Pade interpolant at the roots of unity to a function meromorphic in the unit disc, its leading coefficients vanish if and only if the corresponding interpolani to a related function vanishes at given points outside the unit disc. The result is then extended to simultaneous Hermite-Pade interpolation to a finite set of functions.展开更多
CASSAVA - an edible starchy tuberous root found throughout Sub-Saharan Africa - is more than a staple food for Pedro Tomo. As the owner of a small agro-food factory in Maputo Province in north Mozambique, Tomo has ma...CASSAVA - an edible starchy tuberous root found throughout Sub-Saharan Africa - is more than a staple food for Pedro Tomo. As the owner of a small agro-food factory in Maputo Province in north Mozambique, Tomo has made cassava transformation the core of his current business model. His initiative began this August.展开更多
For several weeks in September, a wave of demonstrations against the United States, and Western countries in general, swept the Muslim world. The initial cause for the anger was a trailer of a film deriding the Prophe...For several weeks in September, a wave of demonstrations against the United States, and Western countries in general, swept the Muslim world. The initial cause for the anger was a trailer of a film deriding the Prophet Muhammad. Qin Tian, a researcher with the China Institutes of Contemporary International Relations, believes though the demonstrations are widespread, people should stay mindful of the Middle East＇s diversity. His views follow：展开更多
The present phytochenucal study was undertaken to investigate the chemical constituents of the 95%EtOH extract of the dried roots of Rehmannia glutinosa.The compounds were isolated and purified by Diaion HP-20,Toyopea...The present phytochenucal study was undertaken to investigate the chemical constituents of the 95%EtOH extract of the dried roots of Rehmannia glutinosa.The compounds were isolated and purified by Diaion HP-20,Toyopearl HW-40,silica gel column chromatography and preparative HPLC,and the structures were identified on展开更多
文摘Two cyclopeptides,heterophyllin A and B,have been isolated from the roots of Pseudostellaria heterophylla.Their structures were elucidated by chemical, spectroscopic,and enzymatic methods.
文摘In addition to 2-deoxycrustecdysone(1),we isolated and identi- fied two new natural moulting hormones-2-deoxy-3-epicrustecdysone(2)and 2-deoxycrustecdysone-3-O-β-D-glucopyranoside(3)from the roots of Tino- spora capillipes,it is the first time to get ecdysteroids from this genus.
基金①This work was supported by the National Natural Science Foundation of China and the doctoral programmc from State Education Commission of China.
文摘Phytochemical investigation of the roots of Ligularia nelumbifolia afforded three new sinapyl alcohol derivatives together with two other novel constituents.Their structures were elucidated by high field 1D and 2D NMR techniques and chemical transformations.
基金This work was supported by the National Science Foundation.
文摘Two new oligopeptides, Asterin A and B, have been isolated from the roots of Aster tataricus L. f., and their structures were elucidated on the basis of spectroscop- ic, chemical and enzymatic methods.
文摘Two new alkaloids namely tuberostemoninal and tuberostemoamide as minor components were isolated from the roots of Stemona tubeross.Their structures were determined by various 2D NMR and other spectra and finally confirmed by X-ray analysis.
文摘We extend a theorem of Ivanev and Saff to show that for the Hermite-Pade interpolant at the roots of unity to a function meromorphic in the unit disc, its leading coefficients vanish if and only if the corresponding interpolani to a related function vanishes at given points outside the unit disc. The result is then extended to simultaneous Hermite-Pade interpolation to a finite set of functions.
文摘CASSAVA - an edible starchy tuberous root found throughout Sub-Saharan Africa - is more than a staple food for Pedro Tomo. As the owner of a small agro-food factory in Maputo Province in north Mozambique, Tomo has made cassava transformation the core of his current business model. His initiative began this August.
文摘For several weeks in September, a wave of demonstrations against the United States, and Western countries in general, swept the Muslim world. The initial cause for the anger was a trailer of a film deriding the Prophet Muhammad. Qin Tian, a researcher with the China Institutes of Contemporary International Relations, believes though the demonstrations are widespread, people should stay mindful of the Middle East＇s diversity. His views follow：
文摘The present phytochenucal study was undertaken to investigate the chemical constituents of the 95%EtOH extract of the dried roots of Rehmannia glutinosa.The compounds were isolated and purified by Diaion HP-20,Toyopearl HW-40,silica gel column chromatography and preparative HPLC,and the structures were identified on
