The phytochemical investigation on the ethanolic extracts of the barks of Taxus yunnanensis (Taxaceae) led to the isolation of two new neo-lignans, named taxuyunins A (1) and B (2), a-long with the known diterpenolign...The phytochemical investigation on the ethanolic extracts of the barks of Taxus yunnanensis (Taxaceae) led to the isolation of two new neo-lignans, named taxuyunins A (1) and B (2), a-long with the known diterpenolignan, brevitaxin (3). Their structures were elucidated on the basis of spectroscopic and chemical evidences. Compound 1 is a neo-lignan xyloside while compound 2 belongs to the rare neo-lignan possessing a ramified C3 side chain.展开更多
The invasive plant Eupatorium adenophorum Spreng has caused great economic loss in China, and is gravely threatening the native biodiversity and ecosystem. The plant has been phytochemically investigated for the defen...The invasive plant Eupatorium adenophorum Spreng has caused great economic loss in China, and is gravely threatening the native biodiversity and ecosystem. The plant has been phytochemically investigated for the defen- sive chemical substances in its leaves. Three active sesquiterpenoids were isolated and identified, which include a new sesquiterpenoid （1）, and two known sesquiterpenoids （2, 3）. Their structures were established by spectroscopic studies such as 1D- and 2D-NMR and MS analyses. Meanwhile, the antifeedant activities of these compounds against two generalist plant-feeding insects, Helicoverpa armigera and Spodoptera exigua, were carried out. Com- pound 1 showed significant antifeedant activity against S. exigua with ECs0 = 7.46 μg/cm^2, while compounds 2 and 3 were more active against H. armigera （EC50=2.57 and 3.04 μg/cm^2 respectively）. These findings suggest a de- fensive role of sesquiterpenoids in E. adenophorum against herbivores.展开更多
Further investigation on the aerial parts of Isodon enanderianus afforded a novel asymmetric ent kauranoid dimer, enanderinanin J (1). The structure of the dimer was elucidated by means of spectroscopic m...Further investigation on the aerial parts of Isodon enanderianus afforded a novel asymmetric ent kauranoid dimer, enanderinanin J (1). The structure of the dimer was elucidated by means of spectroscopic methods (including 2D NMR techniques). Enanderinanin J was a dimer of xerophilusin A and probably formed by cycloaddition.展开更多
基金Project supported by the National Natural Science Foundation of China(No.3950081),the Young Academic and Technical Leader Raising Foundation of Yunnan Province(awarded to Hong-Jie Zhang),and the Special Supported Bioscience and Biotechnique Foundation of
文摘The phytochemical investigation on the ethanolic extracts of the barks of Taxus yunnanensis (Taxaceae) led to the isolation of two new neo-lignans, named taxuyunins A (1) and B (2), a-long with the known diterpenolignan, brevitaxin (3). Their structures were elucidated on the basis of spectroscopic and chemical evidences. Compound 1 is a neo-lignan xyloside while compound 2 belongs to the rare neo-lignan possessing a ramified C3 side chain.
文摘The invasive plant Eupatorium adenophorum Spreng has caused great economic loss in China, and is gravely threatening the native biodiversity and ecosystem. The plant has been phytochemically investigated for the defen- sive chemical substances in its leaves. Three active sesquiterpenoids were isolated and identified, which include a new sesquiterpenoid （1）, and two known sesquiterpenoids （2, 3）. Their structures were established by spectroscopic studies such as 1D- and 2D-NMR and MS analyses. Meanwhile, the antifeedant activities of these compounds against two generalist plant-feeding insects, Helicoverpa armigera and Spodoptera exigua, were carried out. Com- pound 1 showed significant antifeedant activity against S. exigua with ECs0 = 7.46 μg/cm^2, while compounds 2 and 3 were more active against H. armigera （EC50=2.57 and 3.04 μg/cm^2 respectively）. These findings suggest a de- fensive role of sesquiterpenoids in E. adenophorum against herbivores.
文摘Further investigation on the aerial parts of Isodon enanderianus afforded a novel asymmetric ent kauranoid dimer, enanderinanin J (1). The structure of the dimer was elucidated by means of spectroscopic methods (including 2D NMR techniques). Enanderinanin J was a dimer of xerophilusin A and probably formed by cycloaddition.
