Three new triterpenes, 3β,21α-dihydroxylupen-18（19）-en （1）, 3β,25-dihydroxytirucalla- 7,23（24）-dien （2）, and 21α-hydroxy-19α-hydrogentaraxastero1-20（30）-en （3） were obtained from an ethyl acetate extr...Three new triterpenes, 3β,21α-dihydroxylupen-18（19）-en （1）, 3β,25-dihydroxytirucalla- 7,23（24）-dien （2）, and 21α-hydroxy-19α-hydrogentaraxastero1-20（30）-en （3） were obtained from an ethyl acetate extract of the whole plant of Siyekucai （Ixeris chinensis）. The structures of 1-3 were determined by spectroscopic methods （EIMS, IR, 1D and 2D NMR）.展开更多
A novel series of pyrido[ 1,2-e]purin-4（3H）-one derivatives containing polar substituents on 5＇-position were designed and prepared as potential PDE5 inhibitors. This paper reports the synthetic routes, 1H-NMR data...A novel series of pyrido[ 1,2-e]purin-4（3H）-one derivatives containing polar substituents on 5＇-position were designed and prepared as potential PDE5 inhibitors. This paper reports the synthetic routes, 1H-NMR data, and the PDE5 inhibitory activities of the target compounds. The polar piperazinyl group contained （on 5＇-position） compound, 3B2, showed the highest activity among the tested derivatives but less potency than sildenafil 1.展开更多
文摘Three new triterpenes, 3β,21α-dihydroxylupen-18（19）-en （1）, 3β,25-dihydroxytirucalla- 7,23（24）-dien （2）, and 21α-hydroxy-19α-hydrogentaraxastero1-20（30）-en （3） were obtained from an ethyl acetate extract of the whole plant of Siyekucai （Ixeris chinensis）. The structures of 1-3 were determined by spectroscopic methods （EIMS, IR, 1D and 2D NMR）.
文摘A novel series of pyrido[ 1,2-e]purin-4（3H）-one derivatives containing polar substituents on 5＇-position were designed and prepared as potential PDE5 inhibitors. This paper reports the synthetic routes, 1H-NMR data, and the PDE5 inhibitory activities of the target compounds. The polar piperazinyl group contained （on 5＇-position） compound, 3B2, showed the highest activity among the tested derivatives but less potency than sildenafil 1.
