Time resolved laser spectroscopy and GC/MS were used to investigate the primary processes and the side reactions occurring in benzophenone and chlorothioxanthone/amine systems used as photoinitiators of radical polyme...Time resolved laser spectroscopy and GC/MS were used to investigate the primary processes and the side reactions occurring in benzophenone and chlorothioxanthone/amine systems used as photoinitiators of radical polymerization. The discrepancy observed between the experimental data and the expected behaviour is accounted for by detrimental chemical reaction involving the ketone triplet state, the ketyl radical and the amine-derived radical.展开更多
Structural elucidation (automatic determination of the structure of amolecule from its spectra) is frequently hampered by combinatorial explosion when trying to assemblethe identified substructures. We devised a new m...Structural elucidation (automatic determination of the structure of amolecule from its spectra) is frequently hampered by combinatorial explosion when trying to assemblethe identified substructures. We devised a new method which can avoid this pitfall by a systematicexamination of allowed ^(13)C chemical shifts ranges for all substructures chemically possible andcombined with a progressive pruning thanks to neighbouring relationships appearing from 2D NMR. Thismethod is explained by a detailed example.展开更多
The quantitative relationship between relative electrophoretic mobility in capillary electrophoresis for a series of 31 closely related alkylpyridines and their molecular structures was studied by using CODESSA. Acco...The quantitative relationship between relative electrophoretic mobility in capillary electrophoresis for a series of 31 closely related alkylpyridines and their molecular structures was studied by using CODESSA. According to the t test on the results, we found that the three most important descriptors affecting the mobility are the relative number of rings ( NR ), Min e n attraction for a C—N bond ( MEN ) and average complementary information index (ACIC) . With these structure descriptors a good three parameter linear model was developed to correlate the mobility of these compounds with their structures. This model can not only correctly predict the migration behavior of these compounds, but also find the structural factors which are responsible for the migration behavior of these compounds, thus can help to explain the separation mechanism of these compounds. The method used in this work can also be extended to the mobility structure relationship research of other compounds.展开更多
For Histone Deacetylase (HDAC) Inhibitor, four 3D-QSAR models for four types of different activities,were constructed. The cross-validated q 2 value of CoMFA Model 1 is 0.624 and the noncross-validated r 2 value is ...For Histone Deacetylase (HDAC) Inhibitor, four 3D-QSAR models for four types of different activities,were constructed. The cross-validated q 2 value of CoMFA Model 1 is 0.624 and the noncross-validated r 2 value is 0.939. The cross-validated q 2 value of Model 2 for training set is 0.652 and the noncross-validated r 2 value is 0.963. The cross-validated q 2 value for Model 3 is 0.713,with noncross-validated r 2 value 0.947. The cross-validated q 2 value for Model 4 is 0.566 with noncross-validated r 2 value 0.959. Their predicted abilities were validated by different test sets which did not include in training set. Then the relationship between substituents and activities was analyzed by using these models and the main influence elements in different positions (positions 8 and 14) were found. The polar donor electron group of position 8 could increase the activity of inhibition of HDAC,because it could form chelation with the catalytic Zn. Suitable bulk and positive groups at position 14 are favorable to anti-HDAC activity. These models could well interpret the relationship between inhibition activity and apicidin structure affording us important information for structure-based drug design.展开更多
文摘Time resolved laser spectroscopy and GC/MS were used to investigate the primary processes and the side reactions occurring in benzophenone and chlorothioxanthone/amine systems used as photoinitiators of radical polymerization. The discrepancy observed between the experimental data and the expected behaviour is accounted for by detrimental chemical reaction involving the ketone triplet state, the ketyl radical and the amine-derived radical.
文摘Structural elucidation (automatic determination of the structure of amolecule from its spectra) is frequently hampered by combinatorial explosion when trying to assemblethe identified substructures. We devised a new method which can avoid this pitfall by a systematicexamination of allowed ^(13)C chemical shifts ranges for all substructures chemically possible andcombined with a progressive pruning thanks to neighbouring relationships appearing from 2D NMR. Thismethod is explained by a detailed example.
文摘The quantitative relationship between relative electrophoretic mobility in capillary electrophoresis for a series of 31 closely related alkylpyridines and their molecular structures was studied by using CODESSA. According to the t test on the results, we found that the three most important descriptors affecting the mobility are the relative number of rings ( NR ), Min e n attraction for a C—N bond ( MEN ) and average complementary information index (ACIC) . With these structure descriptors a good three parameter linear model was developed to correlate the mobility of these compounds with their structures. This model can not only correctly predict the migration behavior of these compounds, but also find the structural factors which are responsible for the migration behavior of these compounds, thus can help to explain the separation mechanism of these compounds. The method used in this work can also be extended to the mobility structure relationship research of other compounds.
基金ProjectsupportedbytheMinisterofScienceandTechnologyofChina (No .2 0 0 2AA2 3 10 11) ,theNationalNaturalScienceFoundationofChina (No .2 0 0 73 0 5 8) ,theScienceandTechnologyCommitteeofShanghai (No .0 2DJ14 0 13 ) ,ChineseAcademyofSciences NationalCentero
文摘For Histone Deacetylase (HDAC) Inhibitor, four 3D-QSAR models for four types of different activities,were constructed. The cross-validated q 2 value of CoMFA Model 1 is 0.624 and the noncross-validated r 2 value is 0.939. The cross-validated q 2 value of Model 2 for training set is 0.652 and the noncross-validated r 2 value is 0.963. The cross-validated q 2 value for Model 3 is 0.713,with noncross-validated r 2 value 0.947. The cross-validated q 2 value for Model 4 is 0.566 with noncross-validated r 2 value 0.959. Their predicted abilities were validated by different test sets which did not include in training set. Then the relationship between substituents and activities was analyzed by using these models and the main influence elements in different positions (positions 8 and 14) were found. The polar donor electron group of position 8 could increase the activity of inhibition of HDAC,because it could form chelation with the catalytic Zn. Suitable bulk and positive groups at position 14 are favorable to anti-HDAC activity. These models could well interpret the relationship between inhibition activity and apicidin structure affording us important information for structure-based drug design.
