Density functional theory （DFT） was applied to study the ground state geometries and isomerization processes of 1,1＇-binaphthalene-8,8＇-diol. Three isomers, denoted as ISO1, ISO2, and ISO3, were found, distinguish...Density functional theory （DFT） was applied to study the ground state geometries and isomerization processes of 1,1＇-binaphthalene-8,8＇-diol. Three isomers, denoted as ISO1, ISO2, and ISO3, were found, distinguished by different orientations of the OH groups, and each OH-orientational isomer has R- and S-enantiomer. The conformational stabilities of these isomers were investigated by tracking the energy change with respect to the ring-to-ring torsion. The inter-conversions between the three OH-orientational S-isomers were found to have quite low barriers owing to the nearly free rotation of OH groups around the O-C single bonds. The S-R enantiomerization of ISO1 and ISO2 can take place through the ring-ring torsion around the C1-C1/ single bond, either in the anti-rotation manner or in the syn-rotation manner. The barriers of the anti routes are lower than those of the corresponding syn routes by 87.95 and 75.04 kJ/mol. For the S-R enantiomerization of ISO3, only the anti route was found. The barriers for the anti route enantiomerizations of ISO1, ISO2, and ISO3 are 119.61, 120.43, and 121.59 kJ/mol, respectively. A parallel reaction mechanism via three anti enantiomerization routes was proposed for the racemization of 1,1＇-binaphthalene-8,8＇-diol.展开更多
ObjectiveTo investigate the effects of friedelin (terpenoid) and 8-hydroxyisocapnolactone-2-3-diol (coumarin) with concentration 10 μM, 30 μM, and 100 μM on inhibiting mast cells (MCs) degranulation....ObjectiveTo investigate the effects of friedelin (terpenoid) and 8-hydroxyisocapnolactone-2-3-diol (coumarin) with concentration 10 μM, 30 μM, and 100 μM on inhibiting mast cells (MCs) degranulation.MethodsThe investigation was performed in vitro by administering each compound into rat peritoneal MCs and rat basophilic leukemia-2H3 cells followed by activation with 50 μg/mL of compound 48/80 or 1 μM of ionomycin. The concentration of histamine released from each group was measured by a high-performance liquid chromatography-fluorometry system with post-column derivatization using o-phthalaldehyde.Results8-Hydroxyisocapnolactone-2-3-diol inhibited degranulation of compound 48/80 activated-rat peritoneal MCs with the histamine release percentages of 74.57%, 72.21% and 51.79% when the 10 μM, 30 μM and 100 μM concentrations were used, respectively. Where as about 81% histamine was released by the control group. Degranulation inhibition ability was also observed in ionomycin-activated rat basophilic leukemia-2H3 cells. In contrast, friedelin failed to inhibit degranulation in either cell type. The inhibition of 8-hydroxyisocapnolactone-2-3-diol was not related to the depletion of histamine synthesis as implied by the total histamine measurement.ConclusionsThese results exhibit the promising of 8-hydroxyisocapnolactone-2-3-diol is a potential parent structure for developing a MCs stabilizer.展开更多
A new tetrahydrophenanthrene named henryin A(1) was isolated from the leaves of Chloranthus henryi.Its structure was determined to be(S)-4,6,9-trimethyl-5,6,7,8-tetrahydrophenanthrene-1,2-diol on the basis of IR,MS,1D...A new tetrahydrophenanthrene named henryin A(1) was isolated from the leaves of Chloranthus henryi.Its structure was determined to be(S)-4,6,9-trimethyl-5,6,7,8-tetrahydrophenanthrene-1,2-diol on the basis of IR,MS,1D and 2D NMR spectral.展开更多
A new diterpenoid was isolated from the bark of Larix olgensis Henry var. koreana Nakai. Its structure was elucidated as 5S, 9S, 10R-labda-8 (17), 13-diene-6a, 15-diol l by spectroscopic methods.
文摘Density functional theory （DFT） was applied to study the ground state geometries and isomerization processes of 1,1＇-binaphthalene-8,8＇-diol. Three isomers, denoted as ISO1, ISO2, and ISO3, were found, distinguished by different orientations of the OH groups, and each OH-orientational isomer has R- and S-enantiomer. The conformational stabilities of these isomers were investigated by tracking the energy change with respect to the ring-to-ring torsion. The inter-conversions between the three OH-orientational S-isomers were found to have quite low barriers owing to the nearly free rotation of OH groups around the O-C single bonds. The S-R enantiomerization of ISO1 and ISO2 can take place through the ring-ring torsion around the C1-C1/ single bond, either in the anti-rotation manner or in the syn-rotation manner. The barriers of the anti routes are lower than those of the corresponding syn routes by 87.95 and 75.04 kJ/mol. For the S-R enantiomerization of ISO3, only the anti route was found. The barriers for the anti route enantiomerizations of ISO1, ISO2, and ISO3 are 119.61, 120.43, and 121.59 kJ/mol, respectively. A parallel reaction mechanism via three anti enantiomerization routes was proposed for the racemization of 1,1＇-binaphthalene-8,8＇-diol.
文摘ObjectiveTo investigate the effects of friedelin (terpenoid) and 8-hydroxyisocapnolactone-2-3-diol (coumarin) with concentration 10 μM, 30 μM, and 100 μM on inhibiting mast cells (MCs) degranulation.MethodsThe investigation was performed in vitro by administering each compound into rat peritoneal MCs and rat basophilic leukemia-2H3 cells followed by activation with 50 μg/mL of compound 48/80 or 1 μM of ionomycin. The concentration of histamine released from each group was measured by a high-performance liquid chromatography-fluorometry system with post-column derivatization using o-phthalaldehyde.Results8-Hydroxyisocapnolactone-2-3-diol inhibited degranulation of compound 48/80 activated-rat peritoneal MCs with the histamine release percentages of 74.57%, 72.21% and 51.79% when the 10 μM, 30 μM and 100 μM concentrations were used, respectively. Where as about 81% histamine was released by the control group. Degranulation inhibition ability was also observed in ionomycin-activated rat basophilic leukemia-2H3 cells. In contrast, friedelin failed to inhibit degranulation in either cell type. The inhibition of 8-hydroxyisocapnolactone-2-3-diol was not related to the depletion of histamine synthesis as implied by the total histamine measurement.ConclusionsThese results exhibit the promising of 8-hydroxyisocapnolactone-2-3-diol is a potential parent structure for developing a MCs stabilizer.
基金the National Natural Science Foundation of China(No.20462004) for financial support
文摘A new tetrahydrophenanthrene named henryin A(1) was isolated from the leaves of Chloranthus henryi.Its structure was determined to be(S)-4,6,9-trimethyl-5,6,7,8-tetrahydrophenanthrene-1,2-diol on the basis of IR,MS,1D and 2D NMR spectral.
文摘A new diterpenoid was isolated from the bark of Larix olgensis Henry var. koreana Nakai. Its structure was elucidated as 5S, 9S, 10R-labda-8 (17), 13-diene-6a, 15-diol l by spectroscopic methods.
