The Effect of 7 H -Dibenzo[ c,g ]carbazole and Benzo[ a ]pyrene Mixture on DNA Adduct Formation in Strain A/J Mouse Model: Preliminary Report

Complex mixtures consist of homocyclic and heterocyclic polycyclic aromatic compounds (PACs) represented by benzo[ a ]pyrene (B a P) and 7 H -dibenzo[ c,g ]carbazole (DBC), respectively. To exert their biological effects, PACs are metabolized into reactive intermediates, which can form DNA adducts. In this preliminary report, male A/J mice were given a single intraperitoneal injection. Groups of three animals were treated with DBC (2 or 10 mg/kg) or B a P (10 or 100 mg/kg). Mixtures of DBC:B a P were given at doses of 2:10, 2:100, 10:10, or 10:100 mg/kg. DNA adduct levels in lungs collected three days posttreatment were determined by the 32 P-postlabeling method. The results indicate that, in the lungs, exposure to mixtures containing more B a P than DBC resulted in the absence of adduct 3 (DBC) and significantly higher total adduct levels. This suggests that B a P is being preferentially metabolized, resulting in less DBC adduction.     

Cross-linked polymers based on 2,3,5,6-tetra-substituted pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (DPP): Synthesis, optical and electronic properties

A series of 2,3,5,6-tetra-substituted pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione (DPP) derivatives carrying thienyl-, 3,4-ethylenedioxy-thienyl- (EDOT-) and 3,4-ethylenedithiathienyl- (EDTT-) substituent groups have been synthesized and electrochemically polymerized. The polymers were investigated using UV/vis absorption spectroscopy and cyclic voltammetry. It was found that the growth of the polymers proceeded as random coupling of the thiophene groups in the 2-,3-,5-, and 6-positions of the DPP chromophore. In the cross-linked polymers, conjugated sequences were only built through coupling of thiophene groups in 3,6-positions, and separated by non-conjugated sequences through coupling with thiophene units in other positions of the DPP core.     

Comparison of N-Heterocyclic Aromatics Dibenzo[c,g]Carbazole and Dibenz[a,j]Acridine : Metabolism,DNA Binding and Mutation

N-Heterocyclic aromatics, such as carbazole and acridine derivatives, are environmental carcinogenic pollutants. Examples of these compounds are 7H-dibenzo[c,g]carbazole (DBC) and dibenz[a,j]acridine (DBA). The ionization potential (IP) for DBC is lower than for DBA. DBC is metabolized in lung and liver by way of phenols or directly through radical cations. DBC-induced liver and lung tumors have mutations in the 61^st codon of ras. DBA is metabolized in skin by way of a diol-epoxide of DBA. DBA-induced skin tumors have mutations in 12^th, 13^th and 61^st codons of ras. In summary, the metabolic activation of DBC proceeds through different adduction pattern pathways than does DBA and leads to different ras mutational spectra.     

8-硫-1,6-二氮双环[4.3.0]壬烷-7,9-二酮的合成及单晶结构

以二硫化碳、甲醇、氢氧化钾为起始原料,经3步反应生成5-甲氧基-1,3,4-噻二唑-2(3H)-酮,再与1,4-二溴丁烷进行取代,然后脱甲基,最后发生亲核取代反应得到8-硫-1,6-二氮双环[4.3.0]壬烷-7,9-二酮。通过熔点、1HNMR、13CNMR、元素分析及X射线衍射分析等方法对产物的结构进行了表征,目标化合物属于三斜晶系,P1空间群,晶胞参数a=0.784 00(16)nm,b=1.046 4(2)nm,c=1.051 4(2)nm,α=63.84(3)°,β=79.62(3)°,γ=89.42(3)°,V=0.759 2(3)nm3,Z=4,wR(F2)=0.125,μ=0.37 mm-1。     

一种新型吡咯并吡咯二酮衍生物的设计与合成

以2,2'-联二噻吩为原料,通过溴化、选择性还原、氨基化环化、甲酰基化、加成-消除反应及缩合反应等成功合成了一种新型的吡咯并吡咯二酮衍生物(Ⅰ),并通过核磁共振波谱、傅里叶变换红外光谱、质谱和元素分析对其结构进行了表征。该化合物具有良好的溶解性能,其溶液呈现鲜艳的紫红色,在可见光区530～700 nm有强吸收,可望成为低能隙聚合物太阳能电池材料的重要结构单元,从而获得转化率高的光伏器件。