Hatai Mayuko, Horiyama Shizuyo, Yoshikawa Noriko, Kinoshita Eriko, Kagota Satomi, Shinozuka Kazumasa, Nakamura Kazuki
Department of Pharmacology, School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University.
Mukogawa Women's University, Institute for Bioscience.
Chem Pharm Bull (Tokyo). 2019;67(9):1000-1005. doi: 10.1248/cpb.c19-00345.
α,β-Unsaturated carbonyl compounds readily form adducts with SH or NH residues, which are nucleophilic agents, by Michael addition. Glutathione (GSH) is a tripeptide that contains an SH residue and functions as an antioxidant. We demonstrated previously that acrolein (ACR), crotonaldehyde (CA), and methyl vinyl ketone (MVK) are present in nicotine- and tar-removed cigarette smoke extract (CSE) and reacted with GSH in B16-BL6 mouse melanoma cells to form GSH-ACR, GSH-CA, and GSH-MVK adducts, suggesting a possible mechanism for CSE-induced cytotoxicity. In this study, we searched for novel α,β-unsaturated carbonyl compounds other than ACR, CA, and MVK. We selected candidate compounds in CSE based on accurate mass values generated using LC/MS analysis of products formed between CSE and GSH, and identified these using GC/MS analysis and library screening. As a result, we isolated trans-2-methyl-2-butenal, 2-methyl-2-cyclopenten-1-one, 3-methyl-2-cyclopenten-1-one, and furfural, which were poorly reactive with GSH and only very weakly inhibited growth of Colon-26 mouse carcinoma cells and BALB/3T3 clone A31 mouse normal cells. We also isolated 2-cyclopenten-1-one, trans-2-pentenal, 3-methyl-2-butenal and ethyl vinyl ketone, which were highly reactive with GSH and significantly inhibited the growth of both cell lines. Our data suggest that the reactivity of compounds in CSE with GSH may be positively correlated with the effect on inhibiting cell growth. Notably, trans-2-pentenal showed marked inhibition of carcinoma cells growth, whereas this compound exhibited little inhibitory effect on normal cells. trans-2-Pentenal may be a potent candidate or seed for antitumor agents.
α,β-不饱和羰基化合物可通过迈克尔加成反应与作为亲核试剂的SH或NH残基轻松形成加合物。谷胱甘肽（GSH）是一种含有SH残基的三肽，具有抗氧化功能。我们之前证明，在去除尼古丁和焦油的香烟烟雾提取物（CSE）中存在丙烯醛（ACR）、巴豆醛（CA）和甲基乙烯基酮（MVK），它们在B16-BL6小鼠黑色素瘤细胞中与GSH反应形成GSH-ACR、GSH-CA和GSH-MVK加合物，这提示了CSE诱导细胞毒性的一种可能机制。在本研究中，我们寻找了除ACR、CA和MVK之外的新型α,β-不饱和羰基化合物。我们根据使用CSE与GSH反应生成的产物进行LC/MS分析所产生的精确质量值，在CSE中选择候选化合物，并通过GC/MS分析和库筛选对其进行鉴定。结果，我们分离出反式-2-甲基-2-丁烯醛、2-甲基-2-环戊烯-1-酮、3-甲基-2-环戊烯-1-酮和糠醛，它们与GSH的反应性较差，对Colon-26小鼠癌细胞和BALB/3T3克隆A31小鼠正常细胞的生长仅有非常微弱的抑制作用。我们还分离出2-环戊烯-1-酮、反式-2-戊烯醛、3-甲基-2-丁烯醛和乙基乙烯基酮，它们与GSH的反应性很高，并显著抑制这两种细胞系的生长。我们的数据表明，CSE中的化合物与GSH的反应性可能与抑制细胞生长的作用呈正相关。值得注意的是，反式-2-戊烯醛对癌细胞生长有显著抑制作用，而该化合物对正常细胞的抑制作用很小。反式-2-戊烯醛可能是一种有效的抗肿瘤药物候选物或种子。
