The inhibitory effect of vitamin E on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced DNA injury and the fixation of the DNA injury in mouse lungs

In order to estimate the effect of vitamin E on DNA injury and K-ras point mutation at an early stage of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK)-induced lung tumorigenesis in mice, the present study was carried out. Presupplement with vitamin E about 15 times more than control for a week significantly inhibited NNK-induced O⁶-methylguanine formation in the lungs of mice at 4 and 168 h after the injection. At 30 days after the NNK injection, the activation of K-ras oncogene with a 12th codon GC→AT transition was detected in 56% of lung samples tested by mutant-allele-specific amplification. Vitamin E supplement reduced the frequency of the mutation to 30%. These results suggest that vitamin E suppresses NNK-induced DNA injury and subsequent fixation of the injury during the initiation and post-initiation phases of the lung tumorigenesis in mice. Received: 26 January 1998 / Accepted: 20 April 1998     

Metabolism of a glucuronide conjugate of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in rats

 Besides 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), [4-(methylnitrosamino)-1-(3-pyridyl)but-1-yl]-β-O-d-glucosiduronic acid (NNAL-Glu) is another important metabolite of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) which has been detected in the urine of tobacco users and non-smokers heavily exposed to sidestream cigarette smoke. In order to evaluate the toxicological significance of NNAL-Glu formation and excretion, the metabolism of [5-³H]-NNAL-Glu was studied in rats. Five male F344 rats were administered 3.7 mg/kg [5-³H]-NNAL-Glu by i.v. injection and the metabolites in urine analysed by HPLC. More than 90% of the radioactivity was excreted in urine within the first 24 h. Unchanged NNAL-Glu accounted for 81.2±3.1% of the total radioactivity; the remaining part of the dose appears to be deconjugated resulting in the urinary excretion of NNAL (3.6±1.7%) and its α-hydroxylation (11.5±2.2%) and N-oxidation (3.6±1.6%) products. The presence of α-hydroxylation products of NNAL-Glu in urine suggests that this NNK metabolite may be activated in vivo to carcinogenic intermediates. Received: 25 April 1994 / Accepted: 29 June 1994     

Enhancements of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) metabolism and carcinogenic risk via NNK/arsenic interaction

Epidemiological studies indicated an enhancement of cigarette smoke-induced carcinogenicity, including hepatocellular carcinoma, by arsenic. We believe that arsenic will enhance the expression of hepatic CYP2A enzyme and NNK metabolism (a cigarette smoke component), thus its metabolites, and carcinogenic DNA adducts. Male ICR mice were exposed to NNK (0.5 mg/mouse) and sodium arsenite (0, 10, or 20 mg/kg) daily via gavaging for 10 days and their urine was collected at day 10 for NNK metabolite analysis. Liver samples were also obtained for CYP2A enzyme and DNA adducts evaluations. Both the cyp2a4/5 mRNA levels and the CYP2A enzyme activity were significantly elevated in arsenic-treated mice liver. Furthermore, urinary NNK metabolites in NNK/arsenic co-treated mice also increased compared to those treated with NNK alone. Concomitantly, DNA adducts (N(7)-methylguanine and O(6)-methylguanine) were significantly elevated in the livers of mice co-treated with NNK and arsenic. Our findings provide clear evidence that arsenic increased NNK metabolism by up-regulation of CYP2A expression and activity leading to an increased NNK metabolism and DNA adducts (N(7)-methylguanine and O(6)-methylguanine). These findings suggest that in the presence of arsenic, NNK could induce greater DNA adducts formation in hepatic tissues resulting in higher carcinogenic potential.     

Mass spectrometric analysis of 4-hydroxy-1-(3-pyridyl)-1-butanone-releasing DNA adducts in human lung

An improved analytical method was developed for the analysis of 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB)-releasing DNA adducts in lung samples of patients undergoing surgery for lung cancer. HPB-releasing adducts can be formed by metabolic activation of the tobacco-specific nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and N'-nitrosonornicotine, and have been reported to play an important role in tobacco carcinogenesis. [2,2,3,3-D(4)]HPB (D(4)-HPB) was used as an internal standard, and HPB released by acid hydrolysis of DNA was determined by gas chromatography/mass spectrometry in the negative ion chemical ionisation mode. The method is sensitive with a limit of detection of 5.9 fmol HPB and a limit of quantification of 15.2 fmol HBP/mg DNA. The recovery of HPB was 82+/-17% and the background response was 10.1+/-1.8 fmol HPB/sample. The concentration of HPB-releasing lung DNA adducts was significantly higher (p<0.0001) in 21 self-reported smokers compared to in 11 self-reported nonsmokers (404+/-258 fmol versus 59+/-56 fmol HPB/mg DNA, respectively). HPB-releasing hemoglobin adduct concentrations were only marginally higher in a subset of 12 smokers compared to in 7 nonsmokers (63+/-53 fmol versus 42+/-34 fmol HPB/g hemoglobin; p=0.36). No correlation was found between HPB-releasing adducts in DNA and hemoglobin (p=0.074).     

Recent Studies on Mechanisms of Bioactivation and Detoxification of 4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanone (NNK), A Tobacco-Specific Lung Carcinogen

Abstract

This article reviews recent advances in the biochemistry and molecular biology of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a tobacco-specific pulmonary carcinogen believed to be involved in the induction of lung cancer in smokers. Several aspects of NNK bioactivation are addressed, including identification of its metabolites in laboratory animals and humans, cytochrome P450 enzyme involvement in its metabolic activation, DNA and protein adduct formation, biological significance of the major DNA adducts formed, and mutations in oncogenes from tumors induced by NNK. Collectively, the presently available data provide a reasonably clear picture of NNK bioactivation in rodents, although there are still important gaps in our mechanistic understanding of NNK-induced tumorigenesis. The studies in rodents and primates have facilitated development of methods to assess NNK bioactivation in humans, which will be applicable to studies of lung cancer susceptibility and prevention.     

Nicotine and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone induce cyclooxygenase-2 activity in human gastric cancer cells: Involvement of nicotinic acetylcholine receptor (nAChR) and beta-adrenergic receptor signaling pathways

Induction of cyclooxygenase-2 (COX-2) associates with cigarette smoke exposure in many malignancies. Nicotine and its derivative, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), are the two important components in cigarette smoke that contributes to cancer development. However, the molecular mechanism(s) by which nicotine or NNK promotes gastric carcinogenesis remains largely unknown. We found that nicotine and NNK significantly enhanced cell proliferation in AGS cells that expressed both alpha7 nicotinic acetylcholine receptor (α7 nAChR) and β-adrenergic receptors. Treatment of cells with α-bungarotoxin (α-BTX, α7nAChR antagonist) or propranolol (β-adrenergic receptor antagonist) blocked NNK-induced COX-2/PGE₂ and cell proliferation, while nicotine-mediated cell growth and COX-2/PGE₂ induction can only be suppressed by propranolol, but not α-BTX. Moreover, in contrast to the dependence of growth promoting effect of nicotine on Erk activation, inhibitor of p38 mitogen-activated protein kinase (MAPK) repressed NNK-induced COX-2 upregulation and resulted in suppression of cell growth. In addition, nicotine and NNK mediated COX-2 induction via different receptors to modulate several G1/S transition regulatory proteins and promote gastric cancer cell growth. Selective COX-2 inhibitor (SC-236) caused G1 arrest and abrogated nicotine/NNK-induced cell proliferation. Aberrant expression of cyclin D1 and other G1 regulatory proteins are reversed by blockade of COX-2. These results pointed to the importance of adrenergic and nicotinic receptors in gastric tumor growth through MAPK/COX-2 activation, which may perhaps provide a chemoprevention strategy for cigarette smoke-related gastric carcinogenesis.     

6-［4-(4′-吡啶)氨基苯］-4，5-二氢-3(2H)哒嗪酮对大鼠胸主动脉环收缩功能的影响

目的 研究新型钙增敏强心剂6-［4-(4′-吡啶)氨基苯］-4，5-二氢-3(2H)哒嗪酮(MCI-154)的扩血管作用机制。方法 采用生物张力换能器及生理记录仪测定大鼠离体胸主动脉环和蜕膜胸主动脉环的收缩张力。结果 MCI-154可浓度依赖性抑制1 nmol·L^-1~10 μmol·L^-1去甲肾上腺素（pD₂′为4.21±0.23）和80 mmol·L^-1 KCl（IC₅₀为7 μmol·L^-1）引起的血管环收缩，提示其可通过抑制血管平滑肌细胞膜上受体操纵性和电压依赖性钙通道而减少胞外钙内流。在无Ca²⁺ K-H液中，MCI-154预处理可浓度依赖性降低3 μmol·L^-1苯肾上腺素（IC₅₀为5 μmol·L^-1）及20 mmol·L^-1 咖啡因（IC₅₀为16 μmol·L^-1）引起的血管环收缩张力，提示其可抑制血管平滑肌细胞胞内钙释放。在1 μmol·L^-1 Ca²⁺溶液中，MCI-154可显著降低蜕膜血管环收缩张力（IC₅₀为10 μmol·L^-1)，提示其可降低血管平滑肌对Ca²⁺的敏感性。结论 MCI-154可通过抑制血管平滑肌胞外钙内流、胞内钙释放和降低其对Ca²⁺敏感性来降低血管平滑肌收缩张力，体外具有扩血管效应。     

6-[4-(4′-吡啶)氨基苯]-4,5-二氢-3(2H)哒嗪酮对大鼠胸主动脉环收缩功能的影响

目的研究新型钙增敏强心剂6-[4-(4′-吡啶)氨基苯]-4,5-二氢-3(2H)哒嗪酮(MCI-154)的扩血管作用机制。方法采用生物张力换能器及生理记录仪测定大鼠离体胸主动脉环和蜕膜胸主动脉环的收缩张力。结果MCI-154可浓度依赖性抑制1nmol.L-1~10μmol.L-1去甲肾上腺素(pD2′为4.21±0.23)和80mmol.L-1KCl(IC50为7μmol.L-1)引起的血管环收缩,提示其可通过抑制血管平滑肌细胞膜上受体操纵性和电压依赖性钙通道而减少胞外钙内流。在无Ca2+K-H液中,MCI-154预处理可浓度依赖性降低3μmol.L-1苯肾上腺素(IC50为5μmol.L-1)及20mmol.L-1咖啡因(IC50为16μmol.L-1)引起的血管环收缩张力,提示其可抑制血管平滑肌细胞胞内钙释放。在1μmol.L-1Ca2+溶液中,MCI-154可显著降低蜕膜血管环收缩张力(IC50为10μmol.L-1),提示其可降低血管平滑肌对Ca2+的敏感性。结论MCI-154可通过抑制血管平滑肌胞外钙内流、胞内钙释放和降低其对Ca2+敏感性来降低血管平滑肌收缩张力,体外具有扩血管效应。     

Overexpression of SLURP-1 and -2 alleviates the tumorigenic action of tobacco-derived nitrosamine on immortalized oral epithelial cells

Recent research has demonstrated that mucocutaneous epithelial cells express functional nicotinic acetylcholine receptors (nAChRs) and that tobacco-derived carcinogenic nitrosamines, such as 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and SLURP (secreted mammalian Ly-6/urokinase plasminogen activator receptor-related protein)-1 and -2 can act as non-canonical ligands of these receptors. It was found that recombinant SLURP-1 and -2 can lessen tumorigenic activity of nitrosamines. The immortalized esophageal keratinocytes (Het-1A cells) exhibit low SLURP-1 and -2 mRNA levels that decrease further after treatment with NNK. Based on these observations, we hypothesized that overexpression of full length SLURP proteins may protect Het-1A cells from malignant transformation by NNK. The Het-1A cells transfected with either SLURP-1 or -2 vector produced the highest amounts of respective proteins between 24 and 48 h, at which point they were exposed to 1 microM NNK for 24 h and their tumorigenic activities were subsequently evaluated by plating in soft agar and injecting subcutaneously to Nu/Nu mice. Transfection with either SLURP-1 or -2 cDNA in both cases significantly (p<0.05) diminished the number of colonies produced by NNK exposed cells. SLURP-1 was more efficient than SLURP-2 in abolishing the tumorigenic effect in nude mice. Thus, the anti-tumorigenic activities of SLURP-1 and -2 were demonstrated both in vitro and in vivo. The obtained results suggest that SLURP-like proteins may become useful for developing novel anti-cancer therapies.     

1-(4-羟基苯基)-2-[1-甲基-3-(4-羟基苯基)丙氨基]乙酮盐酸盐对离体蛙心的影响

目的　研究 1- (4 -羟基苯基 ) - 2 - [1-甲基 - 3- (4 -羟基苯基 )丙氨基 ]乙酮盐酸盐对 β -受体的作用。 方法　用斯氏法制备青蛙离体心脏标本 ,用BL - 4 10生物机能实验仪记录心脏收缩活动。结果　β -受体激动剂异丙肾上腺素对离体蛙心有非常明显的兴奋作用 ,10ng·ml-1浓度时可增加离体蛙心脏收缩张力 199.2 9%± 6 9.6 9% (n =8) ;1- (4 -羟基苯基 ) -2 - [1-甲基 - 3- (4 -羟基苯基 )丙氨基 ]乙酮盐酸盐饱和上清药液 2 0 %～ 10 0 % ,对离体蛙心脏亦有明显兴奋作用 ,可分别增加离体蛙心脏收缩张力 81.4 3%± 34.4 4 %、6 0 .5 3%± 2 0 .18%、74 .5 3%± 32 .75 %、74 .34%± 39.6 9%、6 0 .91%± 2 7.73% (n =8) ,但未见明显的剂量效应关系。结论　 1- (4 -羟基苯基 ) - 2 - [1-甲基 - 3- (4 -羟基苯基 )丙氨基 ]乙酮盐酸盐对 β -受体具有激动作用。     

维生素B1催化合成1-(3-甲氧基-4-丙氧基-5-硝基苯基)-4-(3,4,5-三甲氧基苯基)-1,4-二酮

研究以NaCN和维生素B1为催化剂合成MK-287的关键中间体1-(3-甲氧基-4-丙氧基-5-硝基苯基)-4-(3，4，5-三甲氧基苯基)-1，4-二酮（1）的催化效果。结果表明：维生素B1较文献报道的催化剂ETB具有反应时间短、成本低廉的优点，可代替ETB合成目的化合物。     

LC-MS/MS法研究1-[1-(6-甲氧基-2-萘基)乙基]-2-(4-硝基苄基)-6,7-二甲氧基-1,2,3,4-四氢异喹啉氢溴酸盐在大鼠体内的代谢产物

采用液相色谱-串联质谱法对大鼠灌胃1-［1-(6-甲氧基-2-萘基)乙基］-2-(4-硝基苄基)-6,7-二甲氧基-1,2,3,4-四氢异喹啉氢溴酸盐(编号P91024)后粪便、尿液、胆汁和血浆中的主要代谢产物进行研究。通过比较给药样品和空白样品的全扫描总离子流色谱和选择离子扫描色谱图差别寻找I相代谢产物；根据其一级和二级质谱图，确定I相代谢产物的分子结构。完全提取I相代谢产物后的样品溶液，再用葡糖醛酸酶酶解，得II相结合物的苷元部分，采用与I相代谢产物鉴定同样方法寻找和鉴定II相代谢产物苷元的结构，进而确证II相代谢产物的分子结构。从大鼠粪便中鉴定出P91024的2个I相代谢物，从胆汁中鉴定出1个I相和5个II相代谢产物，从尿液中鉴定出1个I相和3个II相代谢产物，从血浆中鉴定出4个I相和1个II相代谢产物；并分别分析推测出它们的结构。P91024在大鼠体内被代谢转化为多种产物，利用LC-MS/MS可以快速寻找和鉴定。     

4-(4-苯基哌嗪-1-基)-3-O-甲基-D-肌醇的制备及镇咳活性

右旋肌醇甲醚经缩酮制化得3-O-甲基-1，2：5，6-二-O-异亚丙基-D-肌醇，经甲磺酰化、水解、与4-苯基哌嗪缩合制得左羟丙哌嗪类似物4-（4-苯基哌嗪-1-基）-3-O-甲基-D-肌醇，总收率38％。镇咳药效实验表明，目标物对致咳小鼠的镇咳作用明显，但不及左羟丙哌嗪。     

1-(3-(9H-Carbazol-9-yl)-1-propyl)-4-(2-methoxyphenyl)-4-piperidinol,a novel subtype selective inhibitor of the mouse type II GABA-transporter

The selectivity of new derivatives of the γ-aminobutyric acid (GABA)-uptake inhibitor, tiagabine was characterized at the four cloned mouse GABA transporters (mGAT1 through mGAT4) by measuring [³H]-GABA uptake into stably transfected baby hamster kidney cells. While tiagabine is a highly selective inhibitor of mGAT1 (K_i=0.11±0.02 μM), these derivatives exhibited low potencies at mGAT1 but differential activities at mGAT2, mGAT3 and mGAT4. In particular, 1-(3-(9H-carbazol-9-yl)-1-propyl)-4-(2-methoxyphenyl)-4-piperidinol (NNC 05-2090) was a potent inhibitor of mGAT2 (K_i=1.4±0.3 μM) showing at least 10 fold selectivity over mGAT1, mGAT3 and mGAT4. NNC 05-2090 is the first subtype selective inhibitor of mGAT2 and may represent a novel useful tool for investigating the physiological roles of GAT2 in the brain and periphery.     

Synthesis and antileukemic activity of new 3-(1-phenyl-3-methylpyrazol-5-yl)-2-styrylquinazolin-4(3H)-ones

3-(1-Phenyl-3-methylpyrazol-5-yl)-2-styrylquinazolin-4(3H)-ones 14a-q and 15a-q were synthesized by refluxing in acetic acid the corresponding 2-methylquinazolinones 12 and 13 with the opportune benzoic aldehyde for 12 h. The synthesized styrylquinazolinones 14a-q and 15a-q were tested in vitro for their antileukemic activity against L1210 (murine leukemia), K562 (human chronic myelogenous leukemia) and HL60 (human leukemia) cell lines showing in some cases good activity.     

1-(5-硝基吲哚-2-羰基)-4-[3-(1-甲基乙胺基)-2-吡啶基]哌嗪的制备

地拉韦定(delavirdine)是由美国Pharmacia&Upjohn公司研制的非核苷HIV-1逆转录酶抑制剂(NNRTIs),临床与其它抗HIV药联合使用,用于治疗获得性免疫缺陷综合征[1].1-(5-硝基吲哚-2-羰基)-4-[3-(1-甲基乙胺基)-2-吡啶基]哌嗪(1)是其重要中间体.文献[2-4]以5-硝基吲哚-2-羧酸(2)和1-[3-(1-甲基乙胺基)-2-吡啶基]哌嗪(3)为原料,在1-(3-二甲胺基丙基)-3-乙基碳二亚胺(EDC)作用下缩合制得.EDC价昂,后处理用氯仿作提取溶剂,且需通过柱色谱纯化,不适于规模化生产.     

The pyridyloxobutyl DNA adduct,O6-[4-oxo-4-(3-pyridyl)butyl]guanine,is detected in tissues from 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-treated A/J mice

The tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), is a potent pulmonary carcinogen. This unsymmetric nitrosamine can be metabolically activated to lung DNA methylating and pyridyloxobutylating intermediates. The methyl DNA adducts are well characterized. The pyridyloxobutyl adducts are unstable under DNA hydrolysis conditions and decompose to release 4-hydroxy-1-(3-pyridyl)-1-butanone (HPB). One of the HPB-releasing adducts,O6-[4-oxo-4-(3-pyridyl)butyl]guanine (O6-pobG), has been detected in DNA reacted in vitro with the model pyridyloxobutylating agent, 4-(acetoxymethylnitrosamino)-1-(3-pyridyl)-1-butanone (NNKOAc). To determine whether this adduct was formed in vivo, A/J mice were treated with 10 mumol of [5-3H]NNK and sacrificed 24 h postinjection. The mutagenic O6-pobG was detected in liver but not lung DNA from these animals. Since 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL) is a major metabolite of NNK, it is also possible that these animals are activating NNAL to a pyridylhydroxybutylating agent. Therefore, we also measured the levels of O6-[4-hydroxy-4-(3-pyridyl)butyl]guanine (O6-phbG) in these DNA samples. While radioactivity did coelute with synthetic standard for this potential NNAL adduct in one lung DNA sample, significant levels of O6-phbG were not detected in any other lung or liver DNA samples. The pyridyloxobutyl adduct, O6-pobG, was also observed in lung and liver DNA from mice treated with 4.2 mumol of [5-3H]NNKOAc in the presence but not absence of 2.5 mumol of O6-benzylguanine, a known depletor of the repair protein O6-alkylguanine-DNA alkyltransferase (AGT). These data indicate that this adduct is formed in vivo but is repaired in part by AGT. Cell-free extracts from A/J mouse lung and liver were used to determine the relative rate of O6-alkylguanine repair. O6-mG and O6-pobG were removed from DNA to the same extent in a competitive assay, suggesting that low levels of O6-pobG in lungs of NNK-treated mice did not result from preferential repair of O6-pobG by AGT. It is more likely that initial levels of O6-pobG are much lower than initial levels of O6-mG in lung DNA from NNK-treated A/J mice. These data are consistent with previous studies, which indicate that DNA methylation is the critical pathway for NNK-induced lung carcinogenesis in A/J mice.     

Synthesis and Antimicrobial Activity of Some New 2-(3-(4-Aryl)-1-phenyl-1H-pyrazol-4-yl) Chroman-4-ones

Seven new 2-(3-(4-aryl)-1-phenyl-1H-pyrazol-4-yl) chroman-4-ones (4a-4g) have been synthesized by cyclization of 2-hydroxychalcone analogues of pyrazole 3a-3g using conc. HCl in acetic acid. The structures of the compounds 4a-4g were established by the combined use of (1)HNMR, IR and mass spectra. All the seven compounds were tested in vitro for their antibacterial activity against two Gram positive bacteria namely Staphylococcus aureus and Bacillus subtilis and two Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The compounds 4b, 4c, 4e, 4f, 4g have displayed good antibacterial activity when compared with commercially available antibiotic, ciprofloxacin. These compounds also were screened for their antifungal activity against two ear pathogenic fungi, namely Aspergillus Niger and A. flavus. The compounds 4a, 4c, 4d, 4g exhibited good antifungal activity when compared with commercially available antifungal, fluconazole.     

7-氨基-3-(1-吡啶甲基)头孢烯酸(7-APCA)卤化物的合成路线

7-氨基-3-(1-吡啶甲基)头孢烯酸(7-APCA)卤化物是头孢他啶合成的重要中间体,笔者在查阅了大量的文献资料的基础上,综述了7-氨基-3-(1-吡啶甲基)头孢烯酸(7-APCA)卤化物合成方法的优点、缺点,同时阐述了笔者试验结果,以7-ACA为原料制备7-APCA卤化物的合成路线。