氮杂环荧光试剂2-(11H-苯[a]咔唑)乙基氯甲酸酯对胺类化合物标记及质谱鉴定

含氮类荧光试剂2-(11H-苯[a]咔唑)乙基氯甲酸酯(BCEC-Cl)经柱前衍生处理后,采用荧光检测及柱后在线质谱鉴定对食品中胺类化合物进行了测定。标记反应在pH9的硼酸缓冲液中进行,3min后获得稳定的荧光产物。衍生物于λex=279nm激发条件下产生强烈荧光,其发射波长在λem=380nm处。产物的分离在EclipseXDB-C8色谱柱(150mm×4.6mm,5μm)上进行,采用梯度洗脱对12种脂肪胺衍生物进行了优化分离。采用大气压化学电离源(APCISource)正离子模式进行在线的柱后质谱鉴定,实现了多种脂肪胺衍生物的快速、准确测定。建立的方法具有良好的重现性,回归系数大于0.9996,检出限为1.8~14fmol。     

2-(11H-苯[a]咔唑)-乙酸在脂肪胺的高效液相色谱分离及质谱鉴定中的应用

采用新型荧光衍生试剂2-(11H-苯[a]咔唑)-乙酸(BCA)进行柱前衍生并经荧光检测对脂肪胺进行高效液相色谱(HPLC)分离和质谱定性.衍生物荧光激发和发射波长为λex=285 nm,λem=384 nm.60 ℃下在乙腈溶剂中用N-乙基-N′-[(3-二甲氨基)丙基]碳二亚胺盐酸盐(EDC)作催化剂, 衍生反应15 min后获得稳定的荧光产物.在Hypersil BDS C18 (4.0 mm×200 mm, 10 μm) 色谱柱上, 采用梯度洗脱对12种脂肪胺衍生物进行了优化分离.采用大气压化学电离源(APCI Source)正离子模式进行质谱定性, 实现了各种脂肪胺衍生物的快速、准确测定.脂肪胺的线性回归系数不小于0.999 8 , 检出限(S/N=3)为5.73 ～31.3 fmol.     

EASC荧光标记和LC-APCI-MS检测环境水样中游离脂肪胺

采用新型荧光标记试剂10-乙基吖啶酮-2-磺酰氯(EASC)作为柱前衍生试剂, 在Hypersil BDS C18反相色谱柱上(4.6 mm×200 mm, 10 μm i.d.), 采用梯度洗脱在20 min内实现了12种EASC-脂肪胺衍生物的快速基线分离. 最佳检测波长为λex/λem=270 nm/430 nm. EASC与常用的Dansyl-Cl相比具有更强的光致发光特性(紫外和荧光): 紫外吸收强度之比为3.2∶1, 相对荧光强度之比为30.0∶1~105.4∶1, 荧光量子效率之比为43.0∶1. 通过荧光检测及离子阱大气压化学电离源的正离子模式获得了胺类组分的准确定量和相应的柱后质谱鉴定. 质谱灵敏度之比为1.6∶1~6.2∶1. 建立的方法对环境水样中脂肪胺类化合物的测定具有快速、准确和重现性良好等优点, 回归系数大于0.9995, 检出限为4.0~12.7 fmol.     

咔唑-9-乙基氯甲酸酯柱前衍生胺类化合物高效液相色谱分离

采用一种新的氯甲酸酯类荧光衍生试剂咔唑-9-乙基氯甲酸酯进行柱前衍生胺类化合物并通过荧光检测的方法进行高效液相色谱(HPLC)分析。衍生物的荧光激发和发射波长为λcr／λcrs=293/365nm。色谱柱：Hypersil BDS C18柱，柱温：35℃；流速：l mL/min；流动相A为水/乙腈(20／80，V／V)，流动相B为乙腈/水(95／5，V／V)。衍生试剂用量(mol)是胺类化合物总量的3～4倍时，衍生化产率最大且恒定。该方法具有检测灵敏度高，衍生化反应简单、快速、不受样品基质盐分的干扰，尤其适合天然生物样品，食品及饲料中的胺类化合物的分析。     

2-(11H-苯[a]咔唑)乙基氯甲酸酯柱前衍生化用于氨基酸的高效液相色谱分析

利用新型荧光试剂2-(11H-苯[a]咔唑)乙基氯甲酸酯(BCEC-Cl)作为柱前衍生化试剂,在HypersilBDS C18(200mm×4.6mm,5μm)反相色谱柱上,采用梯度洗脱对20种氨基酸衍生物进行了分离检测。在乙腈与Na2B4O7缓冲液中,室温下BCEC-Cl与氨基酸反应5min可实现完全衍生。检测的激发和发射波长分别为λex=279nm,λem=380nm。采用柱后质谱电喷雾离子源(ESI source)正离子模式,实现了水解牛血清白蛋白中氨基酸和油菜蜂花粉中氨基酸的定性定量检测。荧光定性检测的线性回归系数均大于0.9990,检出限为1.49~19.74fmol(S/N=3)。     

氯甲酸2-(9-咔唑)乙基酯柱前衍生化HPLC法用于环境水中脂肪胺测定

利用一种新型的衍生化试剂氯甲酸2-(9-咔唑)乙基酯柱前衍生10种脂肪胺,建立了脂肪胺类化合物的梯度洗脱高效液相色谱分离分析方法,在紫外254nm条件下检测,线性检测范围为50-500μmol／L,检出(S／N=3)为9．5—25μmol／L;对海水及河水中脂肪胺的试验结果表明,建立的方法快速、灵敏度高,可以满足环境检测等方面的需要。     

柱前衍生-高效液相色谱分离测定及质谱鉴定脂肪胺

采用新型荧光衍生试剂2-(2-苯基-1-氢-菲[9,10-d]咪唑)-乙酸(PPIA)进行柱前衍生,经荧光检测实现了脂肪胺的高效液相色谱(HPLC)分离测定及柱后质谱鉴定。60℃下在乙腈溶剂中用N-乙基-N′-[(3-二甲氨基)丙基]碳二亚胺盐酸盐(EDC)做缩合剂,衍生反应15min可获得稳定的荧光产物。脂肪胺衍生物荧光检测波长为380nm(激发波长为260nm)。在EclipseXDB-C8色谱柱上,采用梯度洗脱对12种脂肪胺衍生物进行了优化分离,测定了造纸厂废水、大鼠端脑和酸奶中脂肪胺的含量。经柱后在线质谱大气压化学电离源(APCISource)正离子模式实现了各种脂肪胺衍生物的质谱鉴定,借助对活性中间体的质谱解析确定了衍生反应的反应机理。该方法具有良好的重现性和回收率,多数脂肪胺的线性回归系数大于0.9996;检出限为3.1~18fmol(S/N=3∶1)。     

新型荧光衍生试剂用于脂肪胺的反相高效液相色谱-荧光检测分析

利用新型荧光试剂4-(1H-菲并[9,10-d]咪唑-2-)苯甲酸(PIBA)进行柱前衍生并经荧光检测对脂肪胺进行了高效液相色谱(HPLC)分离和在线质谱定性。激发和发射波长分别为ex=261nm,em=443nm。80℃下在吡啶溶剂中用N-乙基-N’-[(3-二甲氨基)丙基]碳二亚胺盐酸盐(EDC)做催化剂,衍生反应10min后获得稳定的荧光产物。在EclipseXDB-C8色谱柱(4.6150mm,5mm)上,梯度洗脱对12种游离脂肪胺衍生物进行了优化分离。采用大气压化学电离源(APCI)正离子模式,实现了各种脂肪胺衍生物的测定。多数脂肪胺的线性回归系数大于0.9999,检测限为10.5～53.4fmol。     

顺序一锅法合成5,6,8-三氢-吡喃并[3′,4′:4,5]噻吩并[2,3-d]嘧啶-4(3H)-酮衍生物

采用顺序一锅法,以4,5,7-三氢-吡喃并[4,3-d]噻吩基三苯基膦亚胺、芳基异氰酸酯和胺类化合物为原料,合成了19个结构新颖的5,6,8-三氢吡喃并[3′,4′:4,5]噻吩并[2,3-d]嘧啶-4(3H)-酮衍生物.该方法具有条件温和、操作简便、收率高等特点.所得化合物的结构用1H NMR,IR和MS等手段进行了表征,此外还通过X射线单晶衍射分析法进一步确证了化合物3-(4-氯苯基)-2-二乙胺基-5,6,8-三氢-吡喃并[3′,4′:4,5]噻吩并[2,3-d]嘧啶-4(3H)-酮(4a)的结构.     

顺序一锅法合成5,6,8-三氢-吡喃并[3’,4’:4,5]噻吩并[2,3-d]嘧啶-4(3H)-酮衍生物

采用顺序一锅法,以4,5,7-三氢-吡喃并[4,3-d]噻吩基三苯基膦亚胺、芳基异氰酸酯和胺类化合物为原料,合成了19个结构新颖的5,6,8-三氢-吡喃并[3’,4’:4,5]噻吩并[2,3-d]嘧啶-4(3H)-酮衍生物.该方法具有条件温和、操作简便、收率高等特点.所得化合物的结构用1H NMR,IR和MS等手段进行了表征,此外还通过X射线单晶衍射分析法进一步确证了化合物3-(4-氯苯基)-2-二乙胺基-5,6,8-三氢-吡喃并[3’,4’:4,5]噻吩并[2,3-d]嘧啶-4(3H)-酮(4a)的结构.     

7-[2-hydroxyethyl] cephalosporanic acid derivatives

The preparation of $\text{cis}$ and $\text{trans}$ 7-[2-hydroxyethyl] cephalosporanic acid salts, as well as their corresponding O-sulfate analogs, is described. A very useful method for preparing large quantities of 7-oxocephalosporanates from 7-ACA is also described.     

2-Substituted 7-amino-1,2,4-triazolo[1,5-a]-[1,3,5]triazines

3-Substituted 5-amino-1-guanyl-1,2,4-triazoles have been obtained which, on reaction with orthoformic ester or 100% formic acid, form 2-substituted 7-amino-1,2,4-triazolo[1,5-a]-[1,3,5]triazines.     

Synthetic and structural studies of [6]-, [7]- and [10]metacyclophanes

A new preparative sequence from 2,3-polymethylene-2-cyclopentenone 5 to 2,6-polymethylenebromobenzenes 3 (n = 6, 7, 10) and 2,6-polymethylenephenyllithiums 6 has been found. The reaction of 6 with various electrophiles produces a number of new compounds to disclose the unique reactivity of the aryl C-Li moiety surrounded by the polymethylene chain. Photolysis of 3a and 3b provides transannular products 8, 10 and 11, all arising from the proximity between the aromatic bromine and the aliphatic hydrogen intraannularly opposed to be removed as HBr. Spectrometric study gives quantitative data of the dependence of the molecular geometry upon the chain length and the aromatic substituents. The energy barriers ΔG_c^≠ of the conformational flipping are 17·4 kcal/mol (T_c 76·5°) for [6]metacyclophane (7a), 11·5 kcal/mol (T_c ?28°) for [7]metacyclophane (7b), ·8 kcal/mol for [10]metacyclophane (7c). The lower-energy process of the aliphatic chain in [6]metacyclophane derivatives is the pseudorotation with substituent-dependent barrier ΔG_c^≠ 11·1 kcal/mol (T_c ?31·5°) for 7a, 12·4 kcal/mol (T_c ?4·5°) for 3a and 12·7 kcal/mol (T_c 1·0°) for 12a. The rather large rotational barrier is attributed to the compressed structure of each system. The benzene ring distortion of the cyclophanes is deduced from the bathochromic shift of the B-band and the diamagnetic shift of the benzene proton signals in the PMR.     

Synthesis of Quinolone Analogues： 7-[2-Aminomethylaziridin-l-yl]- quinolones

New quinolone derivatives of 7-[2-aminomethylaziridin-1-yl]quinolone-3-carboxylic acids were synthesized. The structures of these compounds were characterized by 1H NMR and HRESI-MS.     

The synthesis and biological activity of new 7-[2-(cyanomethyl)piperazinyl]- and 7-[3-(cyanomethyl)piperazinyl]quinolone antibacterials

Some novel 7-[2- or 3-(cyanomethyl)piperazinyl]quinolones have been prepared. Most notable, 2-cyanomethyl-piperazine 5 and 1-methyl-2-cyanomethylpiperazine 8 at the quinolone C-7 position produce products with good in vitro antibacterial activity. The key step in the synthesis of these products involves the regioselective deprotection of the benzyl group in function of the time reaction.     

Polar compounds constructed with the [Cr2O7]2- anion

Crystalline KTiOPO4 (KTP), an inorganic nonlinear optical material with a waveguide figure-of-merit that is twice that of other mixed-metal oxides, contains helical chains of TiO(4/2)O(2/2) octahedra in which a long, short Ti-O bond motif results in a net c-directed polarization. The alternating long and short Ti-O bonds that occur along these chains are the major contributors to the large nonlinear optic and electrooptic coefficients. Analogous chains have been constructed using dichromate [Cr2O7]2- anions and [M(py)4]2+ (M = Cu, Zn) cations; these new transition metal oxides crystallize in the same space group as KTP. Crystal data for Cu(py)4Cr2O7: orthorhombic, space group Pna2(1) (No. 33), with a = 15.941(7) A, b = 16.324(3) A, c = 8.857(2) A, and Z = 4; for Zn(py)4Cr2O7, orthorhombic, space group Pna2(1) (No. 33), with a = 16.503(1) A, b = 16.005(1) A, c = 8.8130(5) A, and Z = 4; for Cd(py)4Cr2O7, monoclinic, space group C2/c (No. 15), with a = 14.8034(9) A, b = 11.1847(7) A, c = 15.788(1) A, beta = 110.023(1) degrees, and Z = 4.     

[7+2]- and [11+2]-cycloaddition reactions of diazo-azoles with isocyanates to azolo[5,1-d] [1,2,3,5] tetrazine-4-ones

Diazo-azoles react as 1,7- or 1,11-dipoles with isocyanates to form the hitherto unknown pyrazolo[5,1-d] [1,2,3,5]tetrazine-4-ones, [1,2,3,5]tetrazino[5,4-b]indazole-4-ones and [1,2,3]triazolo[5,1-d][1,2,3,5]tetrazine-4-ones in a [7+2]- or [11+2]-cycloaddition reaction.