{"title":"用量子化学方法研究了甲壳素对自由基的清除作用。","authors":"H Y Zhang","doi":"","DOIUrl":null,"url":null,"abstract":"<p><strong>Aim: </strong>To study whether the xanthonoid structure can enhance the ability of chinonin to scavenge free radicals and to understand the sequence of activity of chinonin hydroxyls.</p><p><strong>Methods: </strong>Semiempirical quantum chemistry method AM1 was employed to calculate delta HOF values, the differences between heat of formations of mother molecule and its free radicals, and spin density distribution of different states of chinonin. delta HOF values were used as theoretical indices to measure scavenging activity of chinonin on free radicals and effects of structure on delta HOF values were investigated.</p><p><strong>Results: </strong>delta HOF values of different phenolics were calculated to be 139.09 kJ.mol-1 (O5-H6), 141.46 kJ.mol-1 (O4-H5), 185.14 kJ.mol-1 (O2-H2) and 195.71 kJ.mol-1 (O1-H1). Spin density distribution of free radicals were obtained as well.</p><p><strong>Conclusion: </strong>Xanthonoid structure of chinonin made ring C to display high passive effect on ring B, which reduced scavenging activity of phenolics of ring B on free radicals. The sequence of activities of chinonin hydroxyls was O5-H6 > O4-H5 > O2-H2 > O1-H1.</p>","PeriodicalId":24002,"journal":{"name":"Zhongguo yao li xue bao = Acta pharmacologica Sinica","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"1999-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Scavenging effect of chinonin on free radicals studied with quantum chemistry.\",\"authors\":\"H Y Zhang\",\"doi\":\"\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p><strong>Aim: </strong>To study whether the xanthonoid structure can enhance the ability of chinonin to scavenge free radicals and to understand the sequence of activity of chinonin hydroxyls.</p><p><strong>Methods: </strong>Semiempirical quantum chemistry method AM1 was employed to calculate delta HOF values, the differences between heat of formations of mother molecule and its free radicals, and spin density distribution of different states of chinonin. delta HOF values were used as theoretical indices to measure scavenging activity of chinonin on free radicals and effects of structure on delta HOF values were investigated.</p><p><strong>Results: </strong>delta HOF values of different phenolics were calculated to be 139.09 kJ.mol-1 (O5-H6), 141.46 kJ.mol-1 (O4-H5), 185.14 kJ.mol-1 (O2-H2) and 195.71 kJ.mol-1 (O1-H1). Spin density distribution of free radicals were obtained as well.</p><p><strong>Conclusion: </strong>Xanthonoid structure of chinonin made ring C to display high passive effect on ring B, which reduced scavenging activity of phenolics of ring B on free radicals. The sequence of activities of chinonin hydroxyls was O5-H6 > O4-H5 > O2-H2 > O1-H1.</p>\",\"PeriodicalId\":24002,\"journal\":{\"name\":\"Zhongguo yao li xue bao = Acta pharmacologica Sinica\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1999-06-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Zhongguo yao li xue bao = Acta pharmacologica Sinica\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Zhongguo yao li xue bao = Acta pharmacologica Sinica","FirstCategoryId":"1085","ListUrlMain":"","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Scavenging effect of chinonin on free radicals studied with quantum chemistry.
Aim: To study whether the xanthonoid structure can enhance the ability of chinonin to scavenge free radicals and to understand the sequence of activity of chinonin hydroxyls.
Methods: Semiempirical quantum chemistry method AM1 was employed to calculate delta HOF values, the differences between heat of formations of mother molecule and its free radicals, and spin density distribution of different states of chinonin. delta HOF values were used as theoretical indices to measure scavenging activity of chinonin on free radicals and effects of structure on delta HOF values were investigated.
Results: delta HOF values of different phenolics were calculated to be 139.09 kJ.mol-1 (O5-H6), 141.46 kJ.mol-1 (O4-H5), 185.14 kJ.mol-1 (O2-H2) and 195.71 kJ.mol-1 (O1-H1). Spin density distribution of free radicals were obtained as well.
Conclusion: Xanthonoid structure of chinonin made ring C to display high passive effect on ring B, which reduced scavenging activity of phenolics of ring B on free radicals. The sequence of activities of chinonin hydroxyls was O5-H6 > O4-H5 > O2-H2 > O1-H1.
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