Spectrofluorimetric determination of thiols by use of N[P-(2-benzoxazolyl)phenyl]maleimide

The weak fluorescence of N-[P-(2-benzoxazolyl)phenyl]maleimide (BOPM) can be greatly enhanced by thiol-containing compounds. A sensitive and simple spectrofluorimetric method based on the use of BOPM has been developed for the determination of thiols such as cysteine (Cys) and reduced glutathione (GSH). Calibration plots were linear in the concentration range from 0 to 1.6 x 10(-7) mol L(-1) for Cys and 0 to 1.7 x 10(-7) mol L(-1) for GSH. The detection limits (3a) were 2.36 x 10(-10) mol L(-1) for Cys and 1.49 x 10(-10) mol L(-1) for GSH. Many other amino acids (present at 100-fold greater concentrations) did not interfere with the determination. The proposed method has been used for the determination of Cys in protein hydrolysate and cystine electrolyte or GSH in serum, with recoveries of 95.4-103.7%.     

High-performance liquid chromatography/chemiluminescence determination of biological thiols with N-[4-(6-dimethylamino-2-benzofuranyl)phenyl]maleimide

The peroxyoxalate chemiluminescence detection of biological thiols combined with high-performance liquid chromatography (HPLC) is described. SH groups of the thiol compounds including glutathione (GSH), cysteine, N-acetylcysteine, cysteamine, and D-penicillamine were labelled with N-[4-(6-dimethylamino-2-benzofuranyl)phenyl]maleimide (DBPM), a specific fluorogenic reagent for SH group. The labelling reaction was carried out at 60 degrees C for 30 min and at pH 8.5 and a sample of the resulting reaction mixture was subjected to HPLC. Five kinds of labelled thiols were separated within 12 min on ODS-80 column (150 x 4.6 mm ID; 5 microns) and detected in the ranges from 500 fmol to 2 pmol/100 microL (cysteamine and N-acetylcysteine), to 3 pmol/100 microL (cysteine) and to 5 pmol/100 microL (GSH and D-penicillamine). The lower detection limits were from 7 fmol (cysteamine) to 113 fmol (GSH) per 100 microL (S/N = 2). The method was applied to the determination of thiols in a rat liver. The amounts of glutathione and cysteine were 1.23 +/- 0.15 mumol/g (n = 5) and 0.15 +/- 0.04 mumol/g (n = 5), respectively.     

A new fluorogenic thiol-selective reagent: N-{p-[2-(6-dimethylamino)benzofuranyl]phenyl}maleimide

N-{p-[2-(6-Dimethylamino)benzofuranyl]phenyl}maleimide (DBPM), has been synthesized and found to give fluorescent products when reacted with certain thiols. The reaction is very sensitive, and concentrations as low as 10(-9)M can be detected.     

Syntheses and thermostabilities of N-[4-(N′-substituted aminocarbonyl)phenyl]maleimide polymers

Three types of novel N-[4-(N′-substituted aminocarbonyl)phenyl] maleimide (RPhMI: N-substituent (R) = phenyl, cyclohexyl, and cyclododecyl) were synthesized and homopolymerized under several conditions. In the copolymerizations of RPhMI (M₁) with styrene (ST; M₂) or methyl methacrylate (MMA; M₂), monomer reactivity ratios and Alfrey-Price Q, e values were determined. All homopolymers decomposed without softening and melting points. The initial degradation temperatures (T_d) of poly(RPhMI)s were over 320°C. The glass transition temperatures (T_g) of RPhMI copolymers were much higher than those of N-phenylmaleimide (PhMI)–ST, PhMI–MMA, N-cyclohexylmaleimide (CHMI)–ST, and CHMI–MMA copolymers. Thermal stability of the terpolymers of RPhMI with ST and acrylonitrile (AN) was higher than that of ST–AN copolymers, i.e., AS resin. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. A Polym. Chem. 36: 2001–2012, 1998     

High-performance liquid chromatography-fluorometry for the determination of thiols in biological samples using N-[4-(6-dimethylamino-2-benzofuranyl) phenyl]-maleimide

The selective determination of thiols in biological samples was investigated by high-performance liquid chromatography using N-[4-(6-dimethylamino-2-benzofuranyl)phenyl] maleimide, which was found to give fluorescent products when treated with certain thiols. Six kinds of thiol (reduced glutathione, cysteine, N-acetylcysteine, cysteamine, homocysteine and coenzyme A) could be separated simultaneously within ca. 12 min and determined at final level of sensitivity. The method was successfully applied to the determination of thiols in rat tissues and plasma and in human normal serum.     

1，4-双{2-[4-[2-苯并恶唑)苯基]乙烯基}苯及衍生物的合成

通过Wittig-Horner反应，以对苯二甲醛和2—(4-氯甲基苯基)苯并恶唑为主要 原料，合成了八个新型1，4-双{2-[4-(2—苯并恶唑)苯基]乙烯基}苯及衍生物．通 过IR，^1H NMR,UV-vis和元素分析等方法确认了它们的化学结构，分析数据表明各 标题化合物分子结构中的C=C双键均为反式结构特．     

N-[4-(三氟甲氧基)苯基]氨基甲酸苯酯的合成

以三氟甲氧基苯为起始原料,经硝化、加氢还原和酰化反应合成了N-[4-(三氟甲氧基)苯基]氨基甲酸苯酯,总收率84.6%,纯度98.9%,其结构经¹H NMR和MS（ESI）确证。     

N-[4-(N''''-取代酰胺基)苯基]马来酰亚胺的合成与表征

N-取代马来酰亚胺(RMI)是一类重要的新型树脂改性单体，由于其具有刚性五元环的结构，能显著提高聚合物的玻璃化温度和热分解温度，改善材料的工艺性和力学性能。但文献对于在N-取代基团中引入杂环结构的单体合成报道很少。本文报道了由顺丁烯二酸酐、8-氨基喹啉、对甲苯胺为主要原料合成N-[4-(N’-8-喹林基)苯甲酰胺基]马来酰亚胺(QPM)和N-[4-(N’-4-甲基苯基)苯甲酰胺基]马来酰亚胺(TPM)的方法，     

Photometric determination of N-(p-nitrophenyl)maleimide

A procedure has been developed for the photometric determination of N-(p-nitrophenyl)maleimide based on the formation of a salt of the acinitro form of N-(p-nitrophenyl)maleic acid monoamide, which is formed on the hydrolysis of maleimide in concentrated acetic acid. Maleimide is dissolved in concentrated acetic acid, and the obtained solution is neutralized with an alkali. A bright yellow color of the reaction product appears.     

Functionalized monomers based on N-(4-hydroxy phenyl)maleimide

N-(4-Hydroxy phenyl)maleimide (HPMI) is functionalized with acryloyl, methacryloyl, allyl, propargyl and cyanate groups and the structures of the materials are characterized by FTIR, ¹H NMR and ¹³C NMR. Thermal curing behaviours of the monomers and thermal stabilities of the polymers are studied using thermal analysis. Introduction of polymerizable groups shifts the curing exotherm to low temperatures, and the curing behaviour is dictated by the polymerizable substituent present in the aromatic ring. Polymer from acryloyl-functionalized monomer shows the highest thermal stability (402 °C), whereas the highest char value (49 % at 700 °C) is noted for the polymer obtained from propargyl-functionalized monomer. Polymers derived from functionalization of HPMI with acryloyl and methacryloyl showed better thermal stabilities. Thermosets formed by the thermal polymerization of HPMI functionalized with propargyl and cyanate groups showed higher char values at 700 °C in nitrogen atmosphere.     

新型N-[2-(取代苯并噻唑-2-氨基甲酰基)苯基]取代氟基苯甲酰胺的合成及其抗癌活性

2,4-二氟苯甲酸或2-氟苯甲酸与二氯亚砜经酰氯化反应,再与邻氨基苯甲酸反应后在醋酸酐中闭环,最后与取代苯并噻唑胺反应合成了9个新型的N-[2-(取代苯并噻唑-2-氨基甲酰基)苯基]取代氟基苯甲酰胺(6a～6i),其结构经1H NMR,13C NMR,IR和元素分析表征。采用MTT法对6a～6i进行抑制PC3癌细胞体外活性测试,结果表明6a～6i具有不同程度的抑制PC3癌细胞活性,其中10μmol.L-16b对PC3的抑制率为69.9%。     

N-[1-(取代苯基)乙基]-2-羟基苯甲酰肼的合成、表征及抑菌活性

依据邻羟基二苯醚及芳香肼类化合物的抗菌特性, 以邻羟苯基为分子核心, 酰肼键为桥基, 设计合成了7种未见报道的N-(取代苯基)乙基-2-羟基苯甲酰肼类化合物. 以水杨酸甲酯为原料, 经肼解反应后与取代苯乙酮缩合, 再与硼氢化钠反应制得目标化合物, 化合物结构经IR, ¹H NMR和元素分析等证实. 抗菌活性测试结果表明, 该类化合物对不同菌株的抑菌活性具有明显的选择性和特异性. 当质量浓度为1×10^-4 g/mL时, 化合物3b和3e对大肠杆菌和白色念珠菌的抑菌率高达100%, 有极强的抑菌活性; 所有化合物对金黄色葡萄球菌的抑菌率均大于70%, 有一定的抑菌活性. 构效关系分析结果表明, 苯基中引入Cl或Br等卤原子能显著增强化合物的抑菌活性, 而引入-NO₂及-CH₃基团则会降低其抑菌活性.     

N-[4-(dicyanomethylazo)phenyl]-2-saccharin-2-ylacetamide in the synthesis of pyridazine and pyrimidine derivatives

N-[4-(Dicyanomethylazo)phenyl]-2-saccharin-2-ylacetamide ( 2 ) proved to be a convenient precursor for the synthesis of a variety of pyridazine and pyrimidine derivatives 4a,b,6 , and 7 . Also a series of substituted pyrimidines 10–16 were prepared from the reaction of N-[4-(2-amino-1-cyano-2-substitutedvinylazo)phenyl]-2-(saccharin-2-yl)acetamide 9a,b with different reagents via initial addition to either the cyano or amino group, followed by cyclization. Some of the synthesized heterocycles were screened for their biological activity. © 2003 Wiley Periodicals, Inc. Heteroatom Chem 15:2–8, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10194