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1.
A series of S-(2-haloethyl)-L-cysteine derivatives, which are analogs of the proposed glutathione half-mustard metabolites of dihaloethanes, were synthesized and studied with respect to their hydrolysis and alkylation rates in aqueous solution. The trend of relative hydrolysis rates, Br greater than Cl much greater than F, paralleled their respective leaving group abilities; however, a dramatic rate increase was seen at pH 8 versus pH's 6 or 4. Hydrolysis of S-(2-chloroethyl)-L-cysteine analogs, where the ionizable groups were blocked (carboxyl esterified and/or N-acetylated), revealed that the amine moiety was responsible for the increased hydrolysis of mustard gas (beta, beta'-dichlorodiethyl sulfide) gave similar results with S-(2-chloroethyl)-L-cysteine, a finding which is consistent with the reaction intermediate being a highly charged species. The alkylation rates with 4-(p-nitrobenzyl)-pyridine were not affected by blocking the ionizable groups. A mechanism of internal cyclization is proposed to explain the accelerated alkaline hydrolysis rates noted with S-(2-haloethyl)-L-cysteines but not with the N-acetylated analogs (mercapturic acids). This scheme proposes the formation of 3-(thiomorpholine)-carboxylic acid as an alternative pathway to the generally accepted hydrolysis reaction. This compound and not S-(2-hydroxyethyl)-L-cysteine was the identified product following pH 10 hydrolysis. Increased hydrolysis half-time of amine-blocked cysteine analogs versus parent cysteine analogs may exist with S-(2-haloethyl)-glutathione derivatives which may explain the substantial nucleic acid alkylation seen with S-(2-haloethyl) derivatives of glutathione.  相似文献   

2.
A series of related S-(2-haloethyl)-L-cysteine analogs were synthesized and their interaction with DNA was studied with plasmid pBR322. Both S-(2-chloroethyl)-L-cysteine (CEC) and S-(2-bromoethyl)-L-cysteine (BrEC) rapidly induced relaxation of the supercoiled plasmid as determined by agarose gel electrophoresis and electron microscopy, whereas S-(2-fluoroethyl)-L-cysteine did not interact with DNA. The relaxation was most probably due to strand scission at alkylated labile sites in the DNA. When 35S-labeled CEC or BrEC was used as the substrate, covalent binding of 35S to DNA was obtained; CEF displayed a somewhat higher binding than BrEC. No binding of 35S was obtained with (2-hydroxyethyl)-L-[35S]cysteine, [35S]cysteine, or [35S]cystine, substrates which did not induce relaxation of the DNA. Esterification of the carboxyl group resulted in a somewhat lower rate of DNA strand scission, whereas N-acetylation prevented the cysteine analogs from inducing DNA strand breaks. S-(2-Chloroethyl)-glutathione (GSH) did not interact with DNA as determined by lack of effect on the superhelicity of DNA, a finding which is in agreement with the hypothesis that the primary amine groups of CEC or BrEC may participate in the formation of reactive intermediates which can interact with DNA. S-(2-Hydroxyethyl)-GSH and S-(2-hydroxyethyl)-L-cysteine were unable to induce DNA strand breaks. Neutral denaturation of supercoiled pBR322 treated with the analogs revealed that compounds which were able to induce DNA strand breaks also interfered with denaturation of double-stranded circular DNA. No such interference was observed when double-stranded linear DNA (obtained by BamH1 restriction digestion) was treated with the analogs prior to denaturation. These data indicate that a marked difference exists between S-(2-chloroethyl)-L-cysteine and S-(2-chloroethyl)-glutathione in their reaction with supercoiled plasmid DNA. Either a major difference exists in the reactivity of the corresponding episulfonium ions of these conjugates or a separate mechanism of alkylation based on a free alpha-amino of the cysteine conjugate is participating in DNA strand breakage and possible crosslinking. In vivo toxic effects of these S-(2-chloroethyl) conjugates are predicted to be distinctly different.  相似文献   

3.
S-(1,2,3,4,4-Pentachloro-1,3-butadienyl)- -cysteine (PCBC) has been identified as the penultimate compound responsible for hexachlorobutadiene-induced nephrotoxicity. The primary goal of these studies was to determine the mechanism of PCBC-induced toxicity in rabbit renal proximal tubules by examining the early changes in tubular physiology. PCBC (20–500 μ ) induced a specific sequence of toxic events. Following 15 min of exposure, 200 μ PCBC increased basal (25%) and ouabain-insensitive (78%) respiration. This was followed by a decrease in basal (46%), nystatin-stimulated (54%), and ouabain-insensitive (21%) respiration and a decrease in glutathione content (79%). Finally, there was a decrease in cell viability as measured by a decrease in LDH retention at 60 min. Direct probing of mitochondrial function revealed that the initial increase in respiration resulted from the uncoupling of oxidative phosphorylation, while the late changes in respiration appeared to result from gross mitochondrial damage characterized by inhibited state 3 respiration, inhibited cytochrome c-cytochrome oxidase, and inhibited electron transport. Studies utilizing tubules with decreased glutathione content revealed that glutathione plays little if any role in the early events of PCBC-induced toxicity. These results suggest that PCBC-induced mitochondrial dysfunction may initiate the renal proximal tubule injury.  相似文献   

4.
S-(2-18F-氟代乙基)-L-蛋氨酸的合成及其放射药理活性   总被引:1,自引:0,他引:1  
目的研制肿瘤氨基酸代谢显像剂S-(2-18F-氟代乙基)-L-蛋氨酸(18FEMET),评价其区分炎症和肿瘤的价值。方法采用亲核取代反应,由两步法合成18FEMET。测定正常小鼠、肿瘤及炎症小鼠体内FEMET生物分布,对模型小鼠进行18FEMET PET显像,并与2-18F-2-脱氧-D-葡萄糖(FDG)和O-(2-18F-氟代乙基)-L-酪氨酸(FET)比较。结果18FEMET手工合成时间约为70 min,未校正总放化产率为15%~25%,放化纯度大于95%。正常小鼠中胰腺、肾脏、结肠、肝和心脏等脏器摄取18FEMET较高,且放射性滞留时间较长,血液和脑摄取18FEMET较低。肿瘤细胞可高度摄取18FEMET,FDG和FET,炎症组织也可高度摄取FDG,但几乎不摄取18FEMET和FET。结论18FEMET制备简便,能够区分肿瘤和炎症,可望成为一种有前景的特异性肿瘤氨基酸代谢PET显像剂。  相似文献   

5.
为了寻找高效、低毒的抗病毒剂,本文通过用腺嘌呤及嘧啶碱基与3-氯-2-甲基丙烯缩合合成6个DHPA类似物的中间体5a,5b,6~8a和8b。应用OsO4催化,在N-甲基吗琳-N-氧化物氧化下对烯键进行邻位双羟化,合成了5个DHPA类似物1~4a,b。对化合物5a,5b,6~8a,8b的1HNMR数据进行了初步总结。对4个DHPA类似物测定了它们对S-腺苷-L-高半胱氨酸水解酶(SAH)的抑制活性,其中化合物1的IC50为1.1mmol·L-1,其余化合物均无抑制活性。  相似文献   

6.
The purpose of this study was to investigate the protective effect of S-2-(3-aminopropylamino)ethylphosphorothioic acid (WR-2721) on whole-body irradiation-induced inhibition of intestinal transport function. The jejunal transport of fluid and sugars was studied in male Swiss-Webster mice before and 3 days after whole-body irradiation (1000 rads). The rates of glucose and water transport were decreased by 86 and 70%, respectively, in irradiated animals. However, the rate of transport of 3-O-methyl- -glucose (3MG) was not affected. In mice receiving WR-2721 (500 mg/kg, ip) 15 to 30 min prior to whole-body irradiation, net water flux was unaffected and the rate of -glucose transport was decreased only 8%. WR-2721 administered alone (500 mg/kg, ip) had no effect on either -glucose transport or net water flux across the jejunal mucosa. The results suggest that WR-2721 protects against irradiation-induced inhibition of some intestinal transport functions.  相似文献   

7.
目的 制备(1R,2S)-2-(3,4-二氟苯基)环丙胺扁桃酸盐(TCGM3)单晶,并对其空间结构进行解析。方法 通过优化溶剂、温度等结晶工艺参数,制备TCGM3单晶,采用单晶X射线衍射技术对其进行空间结构解析。结果 外形完整的TCGM3单晶可通过甲醇体系室温蒸发4 d得到。单晶X射线衍射结果表明TCGM3该晶胞属于正交晶系,P212121空间群,结构偏离因子R=0.04,分子式为C17H17F2NO3,相对分子质量为321.32 g/mol,立体构型与预测构型一致。结论 通过单晶培养及对其进行单晶X射线衍射分析和结构解析,确证了TCGM3的空间结构。  相似文献   

8.
目的 基于信号转导和转录活化因子3(STAT3)信号通路探讨三氟甲基化二氢喹喔啉酮类化合物S-3-(三氟甲基)-6,7-双[4-(三氟甲基)苯基]-3,4-二氢喹啉-2(1H)-酮(2o)对人结直肠癌细胞生长的抑制作用。方法 采用 MTT法检测三氟甲基化二氢喹喔啉酮类化合物 2b、2e、2f、2g、2k、2l、2m、2o、2q(20 μmo·L-1)作 用 48 h 对 人 结 直 肠 癌 细 胞DLD-1 存活率的影响,检测化合物2o(0.5、1.0、2.0、5.0、7.5、10.0、12.5、15.0、17.5 μmo·L-1)作用48 h对人结直肠癌细胞HCT116、RKO和DLD-1存活率的影响;克隆形成实验检测化合物2o(2.5、5.0、10.0 μmo·L-1)对RKO、DLD-1、HCT116细胞增殖的影响;流式细胞术和 Hoechst染色检测化合物 2o 对细胞凋亡的影响;细胞划痕实验检测化合物 2o 对 DLD-1 和RKO 细胞迁移率的影响;Western blotting 法检测化合物 2o 对 RKO 细胞 p-STAT3、STAT3、骨髓白血病细胞分化蛋白(MCL)-1、生存素(Survivin)、B淋巴细胞瘤-2(Bcl-2)、Bcl-2相关X蛋白(Bax)蛋白表达水平的影响,检测化合物2o对白细胞介素-6(IL-6)刺激下p-STAT3、STAT3蛋白表达水平的影响。结果 化合物2o对DLD-1细胞的杀伤能力较其他化 合 物 强 ; 化 合 物 2o 对 HCT116、 RKO 和 DLD-1 细 胞 的 半 数 抑 制 浓 度 (IC50) 分 别 为 (3.573±0.172)、(8.056±0.458)、(6.226±0.458)μmo·L-1。与对照组比较,化合物2o明显降低了HCT116、RKO和DLD-1细胞的集落形成能力;显著降低DLD-1和RKO细胞迁移率(P<0.01、0.001);明显增加RKO、DLD-1细胞凋亡率;明显增加HCT116和RKO细胞核亮染比例;明显降低p-STAT3、MCL-1、Survivin、Bcl-2蛋白表达,明显升高Bax蛋白表达,对STAT3蛋白表达无明显影响。与对照组比较,IL-6刺激的模型组p-STAT3蛋白表达明显升高,STAT3蛋白表达无明显变化;与模型组比较,随着化合物2o浓度的升高,p-STAT3蛋白表达明显降低,STAT3蛋白表达无明显变化。结论 化合物2o可能通过下调STAT3信号通路发挥抗人结直肠癌作用。  相似文献   

9.
A series of novel 3-(2-haloethyl)aryltriazenes, many of which exhibit marked antileukemic activity in animal test neoplasms, react readily with DNA under physiological conditions. With regard to a single strand scission (SSS), in contrast to the related 2-haloethynitrosoureas which exhibit both Type I and Type II SSS (single strand scission) of DNA, the triazenes appear to react via Type II SSS of DNA by base alkylation followed by depurination or depyrimidination and subsequent hydrolysis of the apurinic site. The latter reaction was confirmed using apurinic site-specific endonuclease VI. A 3-(2-chloroethyl)aryltriazene readily degraded poly A by phosphate alkylation at a rate much faster than given by comparable nitrosoureas. Overall, the triazenes showed a preference for reaction at the more acidic phosphate sites in the DNA owing to their unique acid-promoted decomposition. This may, in part, account for the lack of detection of DNA interstrand cross-links and indicates a fundamentally different mechanism of action of the 3-(2-haloethyl)triazenes from the 2-haloethylnitrosoureas.  相似文献   

10.
Among N-(halophenyl)succinimides, N-(3,5-dichlorophenyl)succinimide (NDPS) is a potent nephrotoxicant as well as an agricultural fungicide. Although two chloride groups on the phenyl ring are essential to induce optimal nephrotoxicity, the role of halogen groups in NDPS nephrotoxicity is not clear. In this study, N-(3-bromophenyl)-2-hydroxysuccinimide (NBPHS) was prepared as a monohalophenyl derivative of N-(3,5-dichlorophenyl)-2-hydroxysuccinimide (NDHS), an oxidative and nephrotoxicant metabolite of NDPS. The nephrotoxic potential of NBPHS was evaluated in vivo and in vitro to determine the role of halogen groups in N-(halophenyl)succinimide nephrotoxicity. Male Fischer 344 rats (four/group) were administered a single intraperitoneal (i.p.) injection of NBPHS (0.1, 0.4 or 0.8 mmol/kg) or vehicle (25% dimethyl sulfoxide in sesame oil) and renal function monitored for 48 h. Administration of NBPHS (0.8 mmol/kg) induced nephrotoxicity, while very mild changes or no changes in renal function were observed following administration of 0.4 mmol/kg or 0.1 mmol/kg of NBPHS, respectively. Nephrotoxicity induced by NBPHS (0.8 mmol/kg) was characterized by diuresis, transiently increased proteinuria, glucosuria and hematuria, elevated kidney weight, and reduced tetraethylammonium (TEA) uptake by renal cortical slices, and was not as marked as nephrotoxicity induced by NDHS (0.1 mmol/kg) or NDPS (0.4 mmol/kg). In the in vitro studies, the effects of NBPHS on organic ion accumulation, pyruvate-stimulated gluconeogenesis, and lactatc dehydrogenase (LDH) release were measured using renal cortical slices. NBPHS decreased p-aminohippurate (PAH) and TEA accumulation at NBPHS bath concentrations of 0.05 mM and 0.5 mM or greater, respectively. Renal gluconeogenesis was inhibited by NBPHS at 1 mM bath concentration, while LDH leakage was not increased at NBPHS bath concentrations up to 1 mM. The results demonstrate that NBPHS is a mild nephrotoxicant in vivo and in vitro, but does not have cytotoxic effects to renal tissues at the concentrations tested. From these results, it appears that halogen groups are essential to the nephrotoxic potential of N-(halophenyl)-2-hydroxysuccinimides or N-(halophenyl)succinimides and play an important role in the mechanism of NDPS nephrotoxicity following NDHS formation.  相似文献   

11.
A new class of 5-(1-cyanamido-2-haloethyl)-2'-deoxyuridines (4-6) and arabinouridines (7, 8) were synthesized by the regiospecific addition of halogenocyanamides (X-NHCN) to the 5-vinyl substituent of the respective 5-vinyl-2'-deoxyuridine (2) and 2'-arabinouridine (3). Reaction of 2 with sodium azide, ceric ammonium nitrate, and acetonitrile-methanol or water afforded the 5-(1-hydroxy-2-azidoethyl)-(10) and 5-(1-methoxy-2-azidoethyl)-2'-deoxyuridines (11). In vitro antiviral activities against HSV-1-TK(+) (KOS and E-377), HSV-1-TK(-), HSV-2, VZV, HCMV, and DHBV were determined. Of the newly synthesized compounds, 5-(1-cyanamido-2-iodoethyl)-2'-deoxyuridine (6) exhibited the most potent anti-HSV-1 activity, which was equipotent to acyclovir and superior to 5-ethyl-2'-deoxyuridine (EDU). In addition, it was significantly inhibitory for thymidine kinase deficient strain of HSV-1 (EC(50) = 2.3-15.3 microM). The 5-(1-cyanamido-2-haloethyl)-2'-deoxyuridines (4-6) all were approximately equipotent against HSV-2 and were approximately 1.5- and 15-fold less inhibitory for HSV-2 than EDU and acyclovir, respectively. Compounds 4-6 were all inactive against HCMV but exhibited appreciable antiviral activity against VZV. Their anti-VZV activity was similar or higher to that of EDU and approximately 5-12-fold lower than that of acyclovir. The 5-(1-cyanamido-2-haloethyl)-(7,8) analogues of arabinouridine were moderately inhibitory for VZV and HSV-1 (strain KOS), whereas compounds 10 and 11 were inactive against herpes viruses. Compounds 5 and 6 also demonstrated modest anti-hepatitis B virus activity against DHBV (EC(50) = 19.9-23.6 microM). Interestingly, the related 5-(1-azido-2-bromoethyl)-2'-deoxyuridine (1n) analogue proved to be markedly inhibitory to DHBV replication (EC(50) = 2.6-6.6 microM). All compounds investigated exhibited low host cell toxicity to several stationary and proliferating host cell lines as well as mitogen-stimulated proliferating human T lymphocytes.  相似文献   

12.
TNF-α converting enzyme (TACE) is a validated therapeutic target for the development of oral tumor necrosis factor-α (TNF-α) inhibitors. Here we report the pre-clinical results and characterization of a selective and potent TACE inhibitor, (2R, 3S)-2-( [4-(2-butynyloxy)phenyl]sulfonyl amino)-N,3-dihydroxybutanamide (TMI-2), in various in vitro and in vivo assays. TMI-2 is a potent TACE inhibitor in an enzymatic FRET assay (IC50=2 nM). It is more than 250-fold selective over MMP-1, -7, -9, -14, and ADAM-10 in vitro. In cell-based assays and human whole blood, TMI-2 inhibits lipopolysaccharide (LPS)-induced TNF secretion with IC50s<1 uM. Importantly, TMI-2 inhibits the spontaneous release of TNF-α in human synovium tissue explants of rheumatoid arthritis patients with an IC50 of 0.8 μM. In vivo, TMI-2 potently inhibits LPS-induced TNF-α production in mice (ED50=3 mg/kg). In the adjuvant-induced arthritis (AIA) model in rats, treatment with TMI-2 at 30 mg/kg and 100 mg/kg p.o. b.i.d. was highly effective in reducing joint arthritis scores. In a semi-therapeutic collagen-induced arthritis (CIA) model in mice, TMI-2 is highly effective in reducing disease severity scores after oral treatment at 100 mg/kg twice per day. In summary, TMI-2 is a potent and selective TACE inhibitor that inhibits TNF-α production and reduces the arthritis scores in pre-clinical models. TMI-2 represents a novel class of TACE inhibitors that may be effective and beneficial in the treatment of rheumatoid arthritis as well as other TNF-mediated inflammatory autoimmune diseases.  相似文献   

13.
报道了29个新的1-(1-取代苯基)-2-(1H-1,2,4-三唑或苯并三唑基)-O-(取代苄基)乙酮肟醚类化合物的合成与体外抗菌试验。结果表明,大多数化合物对大部分真菌有抑菌活性,化合物T1,T4,T6,T11,T12,B1,B3,B4和B6对部分真菌抑菌活性优于或相当于奥昔康唑。  相似文献   

14.
We present the discovery of a novel category of 5-substituted acyclic pyrimidine nucleosides as potent antiviral agents. A series of 1-[(2-hydroxyethoxy)methyl] (5-7), 1-[(2-hydroxy-1-(hydroxymethyl)ethoxy)methyl] (8-10), and 1-[4-hydroxy-3-(hydroxymethyl)-1-butyl] (11-13) derivatives of 5-(1-azido-2-haloethyl)uracil were synthesized and evaluated for their biological activity in cell culture. 1-[4-Hydroxy-3-(hydroxymethyl)-1-butyl]-5-(1-azido-2-chloroethyl)uracil (12) was the most effective antiviral agent in the in vitro assays against DHBV (EC(50) = 0.31-1.55 microM) and HCMV (EC(50) = 3.1 microM). None of the compounds investigated showed any detectable toxicity to several stationary and proliferating host cells.  相似文献   

15.
The reactivity of simple epoxides with 4-(p-nitrobenzyl)-pyridine was compared with their mutagenicity in Salmonella typhimurium TA 100 and Escherichia coli WP 2 uvrA. The order of reactivity correlated well with mutagenicity, trichloropropylene oxide being most potent followed by epichlorohydrin, styrene oxide, glycidol and propylene oxide. The results suggest that 4-(p-nitrobenzyl)-pyridine alkylation is a simple and reliable primary assay in the evaluation of mutagenic properties.  相似文献   

16.
目的建立毛细管电泳法测定(S)-2-(6-羟基-2,3-二氢苯并呋喃-3-基)乙酸甲酯中R异构体的方法。方法采用毛细管电泳法。以磺酸-β-环糊精(S-β-CD)为选择剂;25 mmol/L硼酸盐缓冲液(pH 8.9,含S-β-CD 1.8%)为运行缓冲液;运行电压为25 kV;柱温为15℃;检测波长:214 nm;3.4 kPa压力进样10 s。结果 (S)-2-(6-羟基-2,3-二氢苯并呋喃-3-基)乙酸甲酯与R异构体的分离度为2.9。R异构体在2~30μg/m L与峰面积线性关系良好(r=0.999 5),平均回收率为96.6%,RSD值为4.9%(n=6)。结论建立的毛细管电泳法操作简便,结果准确可靠,可用于(S)-2-(6-羟基-2,3-二氢苯并呋喃-3-基)乙酸甲酯中R异构体的控制。  相似文献   

17.
d,l-15(R)-15-Methyl-PGF methyl ester 11-trimethylsilyl ether(II)wasprepared from selective monosilylation of d,l-15(R)-15-methyl-PGFmethyl ester(I) withtrimethylsilyldiethylamine in acetone. Oxidation of(II ) with Collin's reagent gave d,l-15(R)-15-methyl-PGE2 methyl ester 11-trimethylsilyl ether(III)which,without purification,was converted to d,l-15(R)-15-methyl-PGE2 methyl ester(IV)under mild acidic conditions.  相似文献   

18.
目的寻找新的高效抗革兰氏阳性菌的喹诺酮类药物。方法设计合成了dl-7-(4,4-二甲基-3-氨甲基-吡咯烷-1-基)-1-环丙基-6-氟-8-甲氧基-1,4-二氢-4-氧代喹啉-3-羧酸及其类似物,测定其体外活性。结果共合成10个目标化合物,经1H NMR,MS确证其结构。目标化合物具有良好的抗革兰氏阳性菌的活性,尤其是化合物22不仅对4株革兰氏阳性耐药菌(两株MRSA,两株MRSE)的活性表现突出,MIC值为0.015~0.5 mg·L-1,其活性是加替沙星(MIC值为0.125~16 mg·L-1)的4~128倍,而且,对铜绿假单孢菌03-5的MIC值为0.008 mg·L-1,其活性是加替沙星(MIC值为0.03 mg·L-1)的4倍。结论化合物22值得进一步深入评价。  相似文献   

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