CAJ | 학술논문

根据活性基团的协同催化原理，设计合成了有机小分子核酸切割剂1-(N-胍乙基)-4-(N-羟乙基)哌嗪盐酸盐(4)，并通过核磁共振和液相色谱-质谱联用技术对其结构进行了表征.利用琼糖凝胶电泳研究了pH值对其切割pUC 19 DNA 效率的影响，通过自由基猝灭实验研究其切割DNA的反应类型.运用密度泛函理论，利用 Gaussian 软件进行了理论计算，研究其裂解DNA的反应方式.研究结果表明，在pH=7.2时化合物4的裂解效率最高，且能通过非氧化还原反应以磷酯转移的方式裂解DNA的磷酸二酯键.
근거활성기단적협동최화원리，설계합성료유궤소분자핵산절할제1-(N-고을기)-4-(N-간을기)고진염산염(4)，병통과핵자공진화액상색보-질보련용기술대기결구진행료표정.이용경당응효전영연구료pH치대기절할pUC 19 DNA 효솔적영향，통과자유기졸멸실험연구기절할DNA적반응류형.운용밀도범함이론，이용 Gaussian 연건진행료이론계산，연구기렬해DNA적반응방식.연구결과표명，재pH=7.2시화합물4적렬해효솔최고，차능통과비양화환원반응이린지전이적방식렬해DNA적린산이지건.
The artificial nucleic acid cleaving agents have attracted extensive attention due to their potential applications in molecular biological technology and drug development. Metal-free cleaving reagents have been considered safer for their hydrolytic pathway of cleaving the P-O bond of phosphodiester in nucleic acids and have shown clinical potential. It is known that guanidinium is the arginine residue and the key functionality at the active site in staphylococcal nuclease( SNase) for DNA hydrolysis. Some small organic molecules as guani-dinium derivatives have been used to cleave phosphodiester for DNA hydrolysis. We report here, according to active groups synergetic catalysis principle, the design and synthsis of a novel phosphodiester receptor 1-( N-guanidinoethyl)-4-( N-hydroxyethyl)-piperazidine hydrochloride ( 4 ) and the preliminary studies of its DNA cleavage activity. In the compound, the guanidinium group serves to recognize, bind, and electrophili-cally activate the anionic phosphodiester through hydrogen bonding and electrostatic interaction. The hydroxyl group works as a nucleophilic group in the transphosphorylation reaction, which is expected to be highly effi-cient because of the proximity effect. A “couple hardness with softness” piperazidine is designed to connect these two groups. Compound 4 was synthesized via a three-step reaction( nucleophilic substitution, hydrazinol-ysis and guanylation) . Its structure was confirmed by 1 H NMR, 13 C NMR and LC-MS. The influence of pH on the cleaving of pUC 19 DNA was studied by sugar gel electrophoresis. The mechanism of cleaving DNA by the compound was proved through the free radicals quenches experiments. The way of DNA cleavage was dis-cussed through density functional theory and theoretical investigation by Gaussian. The results indicate that with pH value of 7.2 is the optimal pH for DNA cleavage in the presence of compound 4 , the phosphodiester bond of DNA would be cleaved by compound 4 via a transphosphorylation pathway through oxidation-reduction reaction. Thus, this compound may be useful as artificial nucleic acid cleaving agent and the study may be usefully applied to achieve a more effective DNA cleavage for optimizing the structure and the distance of func-tional group to synergistic catalytic cleavage of the phosphodiester bond. In conclusion, design and synthesis of a novel phosphodiester receptor compound 4 containing guanidinoethyl and hydroxyethyl side arms was achieved successfully. We propose to introduce more such compounds as cleaving agents of nucleic acids to be widely investigated and found to be quite efficient.