NMR Studies on Interactions between Diperoxovanadate and N-Substituted Picolinamide

为了探讨有机配体上取代基团对反应平衡的影响,在模拟生理条件下(0.15mol/LNaCl溶液),应用多核(1H,13C和51V)多维(COSY和DOSY)NMR以及变温技术等谱学方法研究双过氧钒配合物[OV(O2)2(D2O)]-/[OV(O2)2(HOD)]-与N-取代皮考啉酰胺的相互作用.它们反应性从强到弱的顺序为:N-甲基-皮考啉酰胺≈N-(2-羟乙基)-皮考啉酰胺>N-乙基-皮考啉酰胺>N-丙基-皮考啉酰胺,这说明了皮考啉酰胺N上取代基的电子效应影响反应.竞争配位导致一系列新的7配位的过氧钒物种生成,而利用上述谱学方法则有助于揭示此类相互作用体系的反应过程和配位机制.To understand the substituting effects of organic ligands on the reaction equilibrium, the interac- tions between diperoxovanadate complex [OV(O2)2(D2O)]-/[OV(O2)2(HOD)]- and a series of N-substituted picolinamide ligands in solution were explored using multinuclear (1H, 13C, and 51V) magnetic resonance, COSY, DOSY, and variable temperature NMR in 0.15 mol/L NaCl ionic medium for mimicking the physio- logical conditions. The order of reactive capability of the picolinamide-like ligands with [OV(O2)2(D2O)]-/ [OV(O2)2(HOD)]? is as follows: N-methylpicolinamide ≈ N-(2-hydroxyethyl)picolinamide > N-ethyl- picolinamide>N-propylpicolinamide. The substituting group influences the reactivity by an electron effect. Competitive coordination interactions result in a series of new seven-coordinated peroxovanadate species [OV(O2)2L]-(L=N-substituted picolinamide).973子课题(No.2003CB716005);; 国家自然科学基金(No.20772027);; 湖南省自然科学基金(No.06JJ30004);; 中国博士后科学基金(No.20070410805);; 卫生部(福建省)卫生教育联合攻关计划(No.3502Z20051027);; 厦门市重大疾病攻关研究基金(No.Wkj2005-2-019);; 固体表面物理化学国家重点实验室开放基金;; 湖南科技大学博士基金(No.E-55107)资助项目

Theoretical Study on Intramolecular Proton Transfer Reaction in 2-(2-Mercaptophenyl)benzoxazole

在b3lyP/6-31g(d,P)水平上研究了2-(2-巯苯基)苯并噁唑气态中五种异构体(E1,E2,E3,E4和k)在气态中的稳定性及其在基态下的质子转移,同时结合极化连续介质模型(PCM)研究了水、二甲亚砜、乙腈、乙醇、苯胺和环己烷等对2-(2-巯苯基)苯并噁唑溶剂化作用的影响.研究结果表明,醇式异构体E1为2-(2-巯苯基)苯并噁唑的优势构型;在E1向k(酮式异构体)转变过程中,存在一个较小的能垒;当考虑零点振动能(zPVE)后,逆向能垒消失.在溶液中,随着溶剂极性的增强,醇式异构体E1与k之间的反应平衡向k方向移动,在非极性溶剂环己烷中,E1为优势构型,而在强极性水溶液中,k为优势构型。The tautomers(E1,E2,E3,E4,and K) and the ground state intramolecular proton transfer reaction of 2-(2-mercaptophenyl)benzoxazole were studied at the B3LYP/6-31G(d,p) level.The effect of solvent(water,dimethylsulfoxide,acetonitrile,ethanol,aniline,and cyclohexane) was studied at the B3LYP/6-31G(d,p) level,using the polarizable continuum model.The results of density functional calculations indicate that the enol form E1 is the most stable tautomer at the ground state.In these solvents there is an equilibrium for 2-(2-mercaptophenyl)benzoxazole in the ground state between E1 and K,and the equilibrium shifts toward the tautomer K as the polarity of the solvent increases.E1 is the preferential conformation in cyclohexane,but K is the more stable tautomer in water.国家自然科学基金(Nos.20772027;20803020);973子课题(No.2003CB716005);中国博士后科学基金(No.20070410805)资助项

NMR Studies on Interactions between Diperoxovanadate Complex and 3-Substituted Pyridines

为探讨有机配体上取代基团对反应平衡的影响,在模拟生理条件下(0.15mol/LNaCl溶液),应用多核(1H、13C和51V)多维(DOSY)以及变温NMR技术研究双过氧钒配合物[OV(O2)2(D2O)]-/[OV(O2)2(HOD)]-(简写为dpV)与3-取代吡啶的相互作用,并首次报道了一些物种的NMR化学位移.dpV与有机配体的反应性从强到弱的顺序为:吡啶>烟酸根>烟酸甲酰胺≈烟酸甲酯,这说明吡啶环上取代基影响反应平衡.竞争配位导致一系列新的6配位的过氧钒物种生成.密度泛函计算结果合理地解释了实验结果,并表明溶剂化效应在反应中起重要作用.To understand the substituting group effects of organic ligands on the reaction equilibrium, the interactions between a diperoxovanadate complex [OV(O2)2(D2O)]-/[OV(O2)2(HOD)]- (abbr. dpV) and a series of 3-substituted pyridines in solution were explored using multinuclear (1H, 13C, and 51V) magnetic resonance, DOSY, and variable temperature NMR in 0.15 mol/L NaCl ionic medium for mimicking the physiological condition. Some direct NMR data were given for the first time. The reactivity among the 3-substituted pyridines towards dpV takes the order of pyridine>nicotinate>N-methyl nicotinamide≈ methyl nicotinate. The competitive coordination results in the formation of a series of new six-coordinated peroxovanadate species [OV(O2)2L]n- (L=3-substituted pyridines, n=1 or 2). The results of density func-tional calculations provided a reasonable explanation of the relative reactivity of the 3-substituted pyridines. Solvation effects play an important role in these reactions.国家自然科学基金(Nos.20772027,20803020);; 973子课题(No.2003CB716005);; 湖南省自然科学基金(No.06JJ30004);; 中国博士后科学基金(No.20070410805);; 湖南省教育厅青年项目(No.06B028);; 固体表面物理化学国家重点实验室资助项目;; 湖南科技大学博士基金(No.E-55107)资助项

NMR and Theoretical Study on Interactions between Diperoxovanadate Complex and Substituted Pyridines

为探讨有机配体上取代基团对反应平衡的影响,在模拟生理条件下(0.15mol/L NaCl溶液),应用多核(1H,13C和51V)多维(DOSY)以及变温NMR技术研究双过氧钒配合物[OV(O2)2(D2O)]-/[OV(O2)2(HOD)]-(简写为bpV)与取代吡啶的相互作用.bpV与有机配体的反应性从强到弱的顺序为:皮考林酸根>异烟酸根>异烟酸甲酯>皮考林甲酯,这说明吡啶环上同一位置上的不同取代基团和同一取代基团在不同位置上都影响反应平衡,竞争配位导致一系列新的6配位(配体为异烟酸根和异烟酸甲酯)或7配位(配体为皮考林酸根和皮考林甲酯)的过氧钒物种[OV(O2)2L]n-(L=取代吡啶,n=1或2)生成,密度泛函计算结果较合理地解释了实验结果,并表明溶剂化在反应中起重要作用.To understand the substitution group effects of organic ligands on the reaction equilibrium,the interactions between diperoxovanadate complex [OV(O2)2(D2O)]-/[OV(O2)2(HOD)]-(abbr. bpV) and a series of substituted pyridines were explored using multinuclear(1H,13C,and 51V) magnetic resonance,DOSY,and variable temperature NMR in 0.15 mol/L NaCl ionic medium for mimicking the physiological condition. The reactivity order among the substituted pyridines and bpV is picolinate>isonicotinate> methyl isonicotinate>methyl picolinate. The competitive coordination results in the formation of a series of new six-coordinated(isonicotinate and methyl isonicotinate) or seven-coordinated(picolinate and methyl picolinate) peroxovanadate species [OV(O2)2L]n-(L=substituted pyridines,n=1 or 2). Both the different substitution groups at the same position and the same groups at the different substitution position affect these reactions. The results of density functional calculations provide someway a reasonable explanation for the relative reactivity of the substituted pyridines. Solvation effects play an important role in these reactions.国家自然科学基金(Nos.20772027,20803020);; 973子课题(No.2003CB716005);; 湖南省自然科学基金(No.06JJ30004);; 中国博士后科学基金(No.20070410805);; 湖南省教育厅青年项目(No.06B028);; 固体表面物理化学国家重点实验室资助项目;; 湖南科技大学博士基金(No.E-55107)资助项目

NMR Studies on Interactions between Diperoxovanadate and Imidazole-like Ligands

为探讨咪唑环上取代基团对反应平衡的影响,在模拟生理条件(0.15 mol·L~(-1)NaCl溶液)下,应用多核(~1H、~(13)C和~(51)V)、扩散排序谱(DOSY)以及变温NMR等谱学技术研究双过氧钒配合物NH_4[OV(O_2)_2{2-(2'-Pyri-dine)- [midazole}]·4H_2O(简写为bpV(Imi-Py))和咪唑类配体(咪唑、2-甲基-咪唑、4-甲基-咪唑和组氨酸)的相互作用,其从强到弱的顺序为咪唑≈4-甲基-咪唑>2-甲基-咪唑>组氨酸.研究结果表明,咪唑环上取代基团空间位阻对反应平衡产生较大影响,同时竞争配位的结果导致新的6配位过氧物种[OV(O_2)_2L]~-(L为咪唑类配体)的生成,当配体为4-甲基-咪唑和组氨酸时,生成的则是一对异构体.To understand the substituting effects of imidazole ring on the reaction equilibrium,the interactions between diperoxovanadate complex NH_4[OV(O_2)_2{2-(2'-Pyridine)-Imidazole}]·4H_2O (abbr.bpV(Imi-Py)) and a series of imidazole-like ligands (imidazole,2-methyl-imidazole,4-methyl-imidazole,and histidine) in solution were explored using multinuclear (~1H,~(13)C,and ~(51)V) magnetic resonance,diffusion ordered spectroscopy (DOSY),and variable temperature NMR in 0.15 mol·L~(-1) NaCl ionic medium for mimicking the physiological conditions.The experimental results indicated that the activities of bpV(Imi-Py) and organic ligands were as follows:imidazole≈4-methyl-imidazole>2-methyl- imidazole>histidine.The stedc effect of the organic ligands affects the reaction equilibrium.At the same time,new six- coordinated peroxovanadate species [OV(O_2)_2L]-(L=imidazole-like ligands) were formed due to the competitive coordination between 2-(2'-pyridyl)-imidazole and the imidazole-like ligands.When the ligand was 4-methyl- imidazole or histidine,a pair of isomers was formed.国家自然科学基金(20772027);; 973子课题(2003CB716005);; 湖南省自然科学基金(06JJ30004);; 中国博士后科学基金(20070410805);; 湖南省教育厅青年项目(068028);; 卫生部(福建省)卫生教育联合攻关计划(3502220051027);; 厦门市重大疾病攻关研究基金(Wkj2005-2-019);; 固体表面物理化学国家重点实验室开放基金和湖南科技大学博士基金(E55107)资

NMR Studies on Interactions between Diperoxovanadate and 1-Ethyl-1H-Imidazole

为探讨过氧钒配合物中有机配体对反应平衡的影响,在模拟生理条件下(0.15MOl·l-1nACl溶液),应用多核(1H、13C和51V)多维(COSy和HSQC)核磁共振(nMr)以及变温技术等谱学方法研究双过氧钒配合物[OV(O2)2l]-(l=d2O或HOd,与之配位的过氧钒物种简写为bPV)和[OV(O2)2ll′]n{-n=1-2,ll′=3-羟基-皮考啉酸根(3-OH-PIC),2-(2′-吡啶)-咪唑(Py-IM),1,10-邻菲啰啉(PHEn),与它们配位的含钒物种分别简写为bPV(3-OH-PIC)、bPV(Py-IM)和bPV(PHEn)}与n-乙基咪唑(n-ET-IM)的相互作用.实验结果表明,n-ET-IM与4种双过氧钒配合物反应性从强到弱的顺序为bPV>bPV(3-OH-PIC)>bPV(Py-IM)>bPV(PHEn).研究表明,金属中心上配体的配位能力、空间位阻和分子量等因素都对反应平衡产生较大的影响,同时竞争配位的结果导致新的6配位过氧物种[OV(O2)2(n-ET-IM)]-的生成.利用上述谱学方法有助于揭示此类相互作用体系的反应过程和配位方式.To understand the effects of organic ligands on the reaction equilibrium, interactions between a series of diperoxovanadate complexes [OV(O2)2L]- (L=D2O or HOD, the corresponding peroxovanadate species (bpV)) and [OV (O2)2LL′]n-{n=1-2; LL′ =3-hydroxyl-picolinate (3-OH-pic), 2-(2′-pyridine)-imidazole (py-im), 1,10-phenanthroline (phen), the corresponding peroxovanadate species bpV(3-OH-pic), bpV(py-im), and bpV(phen)}and 1-ethyl-1H-imidazole (N- Et-im) in solution were explored using multinuclear (1H, 13C, and 51V) magnetic resonance, COSY (correlated spectroscopy), HSQC (heteronuclear single quantum coherence) and variable temperature nuclear magnetic responance (NMR) using 0.15 mol·L-1 NaCl ionic medium to mimic physiological conditions.Experimental results indicated that the reactivity of these four complexes with 1-ethyl-1H-imidazole decreased as follows: bpV>bpV(3-OH-pic)>bpV(py-im)> bpV(phen).The coordinating ability, the steric effect, and the molecular weight of these organic ligands affected the reaction equilibrium.A new six-coordinated peroxovanadate species [OV(O2)2(N-Et-im)]- was formed because of competitive coordination.国家自然科学基金(20772027;20803020);中国博士后科学基金(20070410805);卫生部科学研究基金-福建省卫生教育联合攻关计划(WKJ2008-2-036);厦门市重大疾病攻关研究基金(3502Z20051027)资助项目---

NMR studies on interactions between diperoxovanadate and N-substituted picolinamide

To understand the substituting effects of organic ligands on the reaction equilibrium, the interactions between diperoxovanadate complex [OV(O-2)(2)(D2O)(-)/[OV(O-2)(2)(HOD)](-) and a series of N-substituted picolinamide ligands in solution were explored using multinuclear (H-1, C-13, and V-51) magnetic resonance, COSY, DOSY, and variable temperature NMR in 0.15 mol/L NaCl ionic medium for mimicking the physiological conditions. The order of reactive capability of the picolinamide-like ligands with [OV(O-2)(2)(D2O)](-)/[OV(O-2)(2)(HOD)](-) is as follows: N-methylpicolinamide approximate to N-(2-hydroxyethyl)picolinamide > N-ethylpicolinamide>N-propylpicolinamide. The substituting group influences the reactivity by an electron effect. Competitive coordination interactions result in a series of new seven-coordinated peroxovanadate species [OV(O-2)(2)L](-) (L=N-substituted picolinamide)

NMR studies on interactions between diperoxovanadate complexes and 1-methylimidazole

To understand the effects of organic ligands of the diperoxovanadate complexes on the reaction equilibrium, the interactions between a series of diperoxovanadate complexes [OV(O-2)(2)LL '](n-) [n=1 similar to 3; LL '=oxalate, abbr. oxa; picolinate, abbr. pic; 2,2 '-bipyridine, abbr. bipy; and 1,10-phenanthroline, abbr. phen. The corresponding peroxovanadate species abbreviate bpV(oxa), bpV(pic), bpV(bipy), and bpV(phen)] and I-methylimidazole (abbr. N-Me-Im) in solution were explored using multinuclear (H-1, C-13, and V-51) magnetic resonance, COSY, and variable temperature NMR in 0.15 mol/L NaCl ionic medium for mimicking the physiological conditions. The experimental results indicated the activity order of these four complexes with I-methylimidazole as follows: bpV(oxa)> bpV(pic)> bpV(bipy)> bpV(phen). Both the coordinating capability and the steric effect of the organic ligands affect the reaction equilibrium. At the same time, a new six-coordinated peroxovanadate species [OV(O-2)(2)(N-Me-Im)](-) is formed due to the competitive coordination

NMR Studies on Interactions between Diperoxovanadate and 1-Ethyl-1H-Imidazole

To understand the effects of organic ligands on the reaction equilibrium, interactions between a series of diperoxovanadate complexes [OV(O-2)(2)L](-) (L=D2O or HOD, the corresponding peroxovanadate species (bpV)) and [OV (O-2)(2)LL'](n-) {n=1-2; LL' =3-hydroxyl-picolinate (3-OH-pic), 2-(2'-pyridine)-imidazole (py-im), 1,10-phenanthroline (phen), the corresponding peroxovanadate species bpV(3-OH-pic), bpV(py-im), and bpV(phen)} and 1-ethyl-1H-imidazole (N-Et-im) in solution were explored using multinuclear (H-1, C-13, and V-51) magnetic resonance, COSY (con-elated spectroscopy), HSQC (heteronuclear single quantum coherence) and variable temperature nuclear magnetic responance (NMR) using 0.15 mol.L-1 NaCl ionic medium to mimic physiological conditions. Experimental results indicated that the reactivity of these four complexes with 1-ethyl-1H-imidazole decreased as follows: bpV > bpV(3-OH-pic)> bpV(py-im)> bpV(phen). The coordinating ability, the steric effect, and the molecular weight of these organic ligands affected the reaction equilibrium. A new six-coordinated peroxovanadate species [OV(O-2)(2)(N-Et-im)](-) was formed because of competitive coordination.National Natural Science Foundation of China [20772027, 20803020]; China Postdoctoral Science Foundation [20070410805]; Science Research Foundation of Ministry of Health & United Fujian Provincial Health ; Education Project for Tackling the Key Research [WKJ2008-2-036]; Health and Science and Technology of Xiamen, China [3502Z20051027

Effect of hOGG1 gene polymorphisms on urinary 8-OHdG levelin occupational chromate exposed population

目的评价铬酸盐职业接触对机体遗传损伤的影响,分析8-羟基鸟嘌呤DNA糖苷酶(hOGG1)基因多态性与铬酸盐致遗传损伤的关联。方法采用判断抽样方法,以136名铬酸盐作业工人为接触组,以156名无铬酸盐及其他职业病危害因素接触人员为对照组,采用电感耦合等离子体-质谱法测定2组人群周围血全血铬水平,以酶联免疫吸附试验测定尿8-羟基-脱氧鸟苷(8-OHdG)水平,采用基质辅助激光解析电离飞行时间质谱法对hOGG1基因4个单核苷酸多态性位点进行分型检测。结果接触组人群全血铬和尿8-OHdG水平均高于对照组(中位数:3.41 vs 0.90&mu;g/L,6.02 vs 4.72&mu;g/g肌酐,P&lt;0.01)。对于研究对象(接触组和对照组人群),校正年龄、体质指数、性别、吸烟、饮酒等混杂因素后,铬酸盐接触可能为尿8-OHdG水平升高的危险因素(P&lt;0.05);隐性模型下hOGG1的rs293796和rs13096551均为尿8-OHdG水平升高的危险因素(P&lt;0.05)。对于接触组人群,校正年龄、体质指数、性别、吸烟、饮酒等混杂因素后,hOGG1的rs293796加性模型、隐性模型和rs13096551隐性模型均为尿8-OHdG水平升高的危险因素(P&lt;0.05),rs3219008显性模型为尿8-OHdG水平升高的保护因素(P&lt;0.05);但经Bonferroni多重检验校正后,仅rs293796隐性模型仍为接触组人群尿8-OHdG水平升高的危险因素(P&lt;0.001),且与铬酸盐接触存在有统计学意义的交互作用(P</p