以焦脱镁叶绿酸-α甲酯(MPP-α)为起始原料,在对其E-环羰基进行保护的前提下,经焦脱镁叶绿酸-α(Times new Rman)甲酯与1-乙基丙基溴化镁进行Grignard反应;所生成新的卟吩仲醇再经脱保护、脱水和氧化等诸多反应,将3-位仲羟基转化成碳碳...以焦脱镁叶绿酸-α甲酯(MPP-α)为起始原料,在对其E-环羰基进行保护的前提下,经焦脱镁叶绿酸-α(Times new Rman)甲酯与1-乙基丙基溴化镁进行Grignard反应;所生成新的卟吩仲醇再经脱保护、脱水和氧化等诸多反应,将3-位仲羟基转化成碳碳双键和羰基,其碳氧双键再行Grignard反应并脱水成烯,完成一些未见报道的3-位烷基取代的焦脱镁叶绿酸衍生物的合成.其化学结构均经UV, IR,1HNMR及元素分析予以证实.展开更多
目的探讨联苯双酯(DDB)对中波紫外线(UVB)的防护作用及其相关机制研究,为临床应用提供理论依据。方法 DDB和维生素C对照检测五味子甲素衍生物DDB对超氧阴离子(O_2^-)的清除率。MTT法测定DDB、UVB对人永生化角质形成细胞(Ha Ca T)、人真...目的探讨联苯双酯(DDB)对中波紫外线(UVB)的防护作用及其相关机制研究,为临床应用提供理论依据。方法 DDB和维生素C对照检测五味子甲素衍生物DDB对超氧阴离子(O_2^-)的清除率。MTT法测定DDB、UVB对人永生化角质形成细胞(Ha Ca T)、人真皮成纤维细胞(FB)生长的影响及DDB对UVB的防护作用。通过Giemsa染色,从形态学上观察DDB对UVB损伤的防护作用。激光共聚焦观察活性氧簇(ROS)及检测其荧光强度。结果实验结果表明,相同浓度DDB具有强的清除O_2^-的能力;DDB对Ha Ca T、Fb细胞无毒性且可防护UVB损伤。Giemsa染色后,形态学上发现DDB可以明显抑制细胞的凋亡。DDB可抑制Ha Ca T细胞外ROS的生成。结论五味子甲素衍生物DDB对UVB有明显的防护作用,DDB作用机制是通过其抗氧化活性抑制UVB辐射引起的氧化应激及细胞凋亡等,起到紫外线防护作用,有望开发成为有效的抗氧化剂和紫外防护产品。展开更多
A gas chromatographic method was established for the separation of positional isomers of chlorobenzoic acid.Being derived,(o,m,p)chlorobenzoic acids were well separated with a HP5 capillary column.The oxid...A gas chromatographic method was established for the separation of positional isomers of chlorobenzoic acid.Being derived,(o,m,p)chlorobenzoic acids were well separated with a HP5 capillary column.The oxidation products of chlorotoluene were quantified using the internal standard method,with recoveries over 96%.展开更多
A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative ...A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative of methyl oleate.Trimethylsilylation reaction was introduced to further improve methyl oleate oxidation stability and lubricity after epoxidation and open-ring reactions.The order of effectiveness of acid binding agent was N,N-diisopropylethylamine(DIEA) > pyridine > diethylamine > triethylamine,and the effects of various parameters on the trimethylsilylation reaction as well as on the silicon-oxygen bond stability and reaction yield were studied.A maximum yield of 34.54%was achieved at hydroxyl/trimethyl chlorosilane/DIEA molar ratio of1:1.25:1,reaction temperature 40℃,reaction time 1.5 h.展开更多
文摘以焦脱镁叶绿酸-α甲酯(MPP-α)为起始原料,在对其E-环羰基进行保护的前提下,经焦脱镁叶绿酸-α(Times new Rman)甲酯与1-乙基丙基溴化镁进行Grignard反应;所生成新的卟吩仲醇再经脱保护、脱水和氧化等诸多反应,将3-位仲羟基转化成碳碳双键和羰基,其碳氧双键再行Grignard反应并脱水成烯,完成一些未见报道的3-位烷基取代的焦脱镁叶绿酸衍生物的合成.其化学结构均经UV, IR,1HNMR及元素分析予以证实.
文摘目的探讨联苯双酯(DDB)对中波紫外线(UVB)的防护作用及其相关机制研究,为临床应用提供理论依据。方法 DDB和维生素C对照检测五味子甲素衍生物DDB对超氧阴离子(O_2^-)的清除率。MTT法测定DDB、UVB对人永生化角质形成细胞(Ha Ca T)、人真皮成纤维细胞(FB)生长的影响及DDB对UVB的防护作用。通过Giemsa染色,从形态学上观察DDB对UVB损伤的防护作用。激光共聚焦观察活性氧簇(ROS)及检测其荧光强度。结果实验结果表明,相同浓度DDB具有强的清除O_2^-的能力;DDB对Ha Ca T、Fb细胞无毒性且可防护UVB损伤。Giemsa染色后,形态学上发现DDB可以明显抑制细胞的凋亡。DDB可抑制Ha Ca T细胞外ROS的生成。结论五味子甲素衍生物DDB对UVB有明显的防护作用,DDB作用机制是通过其抗氧化活性抑制UVB辐射引起的氧化应激及细胞凋亡等,起到紫外线防护作用,有望开发成为有效的抗氧化剂和紫外防护产品。
文摘A gas chromatographic method was established for the separation of positional isomers of chlorobenzoic acid.Being derived,(o,m,p)chlorobenzoic acids were well separated with a HP5 capillary column.The oxidation products of chlorotoluene were quantified using the internal standard method,with recoveries over 96%.
基金Supported by the National Natural Science Foundation of China(21306088)National Key Technologies R&D Program of China(2015BAD15B07)+1 种基金State Key Laboratory of Chemical Engineering(SKL-Ch E-13A01,Tsinghua University,China)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD,China)
文摘A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative of methyl oleate.Trimethylsilylation reaction was introduced to further improve methyl oleate oxidation stability and lubricity after epoxidation and open-ring reactions.The order of effectiveness of acid binding agent was N,N-diisopropylethylamine(DIEA) > pyridine > diethylamine > triethylamine,and the effects of various parameters on the trimethylsilylation reaction as well as on the silicon-oxygen bond stability and reaction yield were studied.A maximum yield of 34.54%was achieved at hydroxyl/trimethyl chlorosilane/DIEA molar ratio of1:1.25:1,reaction temperature 40℃,reaction time 1.5 h.