脱克拉定糖阿奇霉素衍生物的设计、合成和活性研究

发布时间：2018-04-15 11:22

  本文选题：大环内酯 + 抗菌活性　； 参考：《山东大学》2016年博士论文

【摘要】：大环内酯是治疗细菌感染的重要药物,活性主要来自化合物的大环。阿奇霉素和克拉霉素为第二代大环内酯,它们比第一代大环内酯红霉素的药代动力学性质更好,稳定性更强。然而,细菌耐药性的出现促使研究出对耐药菌活性更好的新型大环内酯类药物成为一项亟待完成的任务。在核糖体的50S亚基上,从肽酰转移酶的中心到肽释放通道有三个可能结合位置。大环内酯通过和50S亚基结合以及堵塞肽通道出口,阻止蛋白质合成。据报道红霉素的2'位羟基能够与23SrRNA上结构域V的A2058结合(这是第一个结合位点)。第二个位点是酮内酯的11,12位氨基甲酸酯侧链与A752结合,能保证酮内酯类对耐药性菌种的优良活性。第三个结合位点是CP-544372的4"-O-芳烷基基团能和50S亚基的A位和P位的核苷酸发生作用。最近几年,耐药性愈加恶化,新的大环内酯抗生素研发的需求十分迫切。耐药性主要是erm编码的核糖体甲基化和mefA编码的外排泵耐药。由erm表达的甲基化酶让A2058甲基化,造成了主要的大环内酯耐药。由mef基因表达的外排泵会把药物泵到胞外造成中等水平的耐药。因此,迫切需要研发出能够克服肺炎链球菌耐药性的大环内酯抗生素,科学家也希望新的结构能够保持优良的药代动力学性质同时对酸稳定。综上所述,我们以肽酰转移酶中心区域(peptidyl transferase center, PTC)的核苷酸为靶点,设计了3-O-芳烷基氨基甲酸酯一脱克拉定糖阿奇霉素11,12环碳酸酯A。我们希望3-0-芳烷基氨基甲酸酯侧链能够与PTC区域的核苷酸G2505,C2610和U2586等通过氢键、π键堆积和静电作用结合。在此基础上,我们以肽酰转移酶中心区域和结构域II的A752为靶点,设计3-O-芳烷基氨基甲酸酯-11-O-芳烷基氨基甲酸酯阿奇霉素B,同时进行了活性测定。它的11位侧链可以与A752作用,产生核糖体亲和力。同时,我们设计了以erm介导的甲基化的核糖体为靶点的2'-O-芳烷基氨基甲酸酯-11,12-环碳酸酯脱糖阿奇霉素C-E。C-E是我们合成的3个系列的未见文献报道的全新的化合物,2'-O-侧链可以与A2058(在耐辐射球菌中是A2041)和其周围核苷酸通过疏水键、氢键和π键作用结合。我们合成了71个新型氮杂内酯类,它们的结构已通过几种谱进行了确证。之后,我们采用肉汤稀释法进行目标化合物的体外活性测定,以最小抑菌浓度(MIC, minimum inhibitory concentrations)表示。抗菌活性总结如下：1.对阴性菌活性：化合物C6、D1和D2对大肠杆菌活性最强,MIC值是32μg/mL,与对照药克拉霉素相当(32μg/mL)。活性最好化合物对铜绿假单胞菌的MIC值是4μg/mL,比对照药显著提高。2.对敏感菌活性：化合物B7对敏感性金黄色葡萄球菌、敏感性化脓球菌活性最强,MIC值分别为1和0.03μg/mL。令人鼓舞的是,化合物B8(0.5μg/mL)对枯草芽孢杆菌活性比对照药阿奇霉素提高了两倍(1 μg/mL)。3.对耐药菌活性：对表皮葡萄球菌活性最好的为B8 (0.125 μg/mL),比对照的阿奇霉素(0.25μg/mL)和克拉霉素(0.25μg/mL)提高了两倍。化合物A3、B7、C15、C16和D8对耐药金葡菌的MIC是32μ8/mL,与对照药物克拉霉素相等(32μg/mL)。化合物A1对红霉素耐药的化脓球菌有强的活性,MIC是8 μg/mL,活性比对照药物提高了32倍(256μg/mL)。E3对耐药化脓菌的MIC为16 μg/mL,活性比对照药强16倍。化合物2, A3, A8, A15, B4, B6, B8, C13, D8, E2, E4, E8和E9也表现出了对耐药性化脓球菌中等水平的活性(32μg/mL)。多数化合物对erm耐药链球菌有比对照提高许多的活性。活性最佳的B8对ermB链球菌的活性比对照(256 μg/m L)提高256倍,它的MIC值是1μg/mL。化合物B6、B7、A7、A8对mefA耐药菌的MIC分别为0.5μg/mL,0.25 μg/mL,1 μg/mL,1μg//mL,比对照药物阿奇霉素显著提高(4μg/mL)。化合物A3 (1 μg/mL), B8 (1 μg/mL), B2 (2 μg/mL), B7 (2 μg/mL), C15 (2 μg/mL),表现出了优异的抗mefA+ermB型耐药肺炎链球菌活性,抗菌活性分别比阿奇霉素(256 μg/mL)提高了256倍,256倍,128倍,128倍,128倍。对71个化合物的MIC分析而得出的构效关系：1.B8对枯草芽孢杆菌(0.5 μg/mL).表皮(0.125 μg/mL).erm型耐药的肺炎链球菌(1μg/mL)和ermB+mefA链球菌(1μg/mL)的活性都为最佳,可能是B8的11位侧链和A752作用,而且3-O-芳烷基氨基甲酸酯基团与PTC区域的核苷酸结合位点结合。这能提高化合物对敏感和耐药菌活性,尤其是对erm和erm+mef链球菌。结合方式包括氢键、静电力和π键堆积等。2.对于敏感的金葡菌、芽孢杆菌、表皮葡萄球菌、erm+mef链球菌和耐药的化脓菌,3-O-正己基D8的活性比3-O-正戊基D7更好。具有3-O-正己基的B8也表现出对这4种细菌强的活性。所以C-3位侧链末端的正己基基团对抗菌活性的提高是有利的。我们推测3-O-正己基氨基甲酸酯侧链具有适宜的长度和空间构象,所以能够到达PTC区域并与核苷酸发生作用。3.经过体外抗菌活性测试发现,化合物C3,C6-C7,C11-C13,D7-D8, E2-E4, E7-E9对ermB型耐药性肺炎链球菌的活性是16-64 μg/mL,是对照药物(MIC为256 μg/mL)的4-16倍。我们猜测被测化合物的2’OH可能通过氢键和范德华力与甲基化的A2058(A2041)或其附近核苷酸结合。总而言之,我合成71个3-0-脱克拉定糖阿奇霉素并测了活性。在此基础上,本文中进行了构效关系分析和总结。
[Abstract]:Macrolides are the important drugs for treatment of bacterial infections, mainly due to the activity of macrocyclic compounds. Azithromycin and clarithromycin for second generation macrolides, they better pharmacokinetic properties first generation macrolide erythromycin is more stable. However, the emergence of resistant bacteria to research on drug resistant bacteria and better activity of the new high macrolides has become an urgent task. In the ribosomal 50S subunit of the enzyme, transfer from the center to the peptidyl peptide release channel has three possible binding sites of macrolides. Through 50S subunit binding and blocking peptide exit, prevent protein synthesis. According to reports of erythromycin 2'can 23SrRNA and hydroxyl A2058 binding domain of V (this is the first binding site). Second sites are 11,12 carbamate side chains and A752 ketolide combination, can guarantee the ketolides on Excellent activity of antibiotic resistant bacteria. The third binding sites are CP-544372 4 -O- aralkyl group and 50S subunits A and P nucleotides occurred. In recent years, drug resistance worse, new macrolide antibiotic research is urgently needed. Drug resistance is mainly ERM encoding ribosomal methylation and mefA encoding efflux pump resistance methylase. By the expression of ERM for A2058 methylation, resulting in macrolide resistance mainly by MEF gene. The expression of the efflux pump to pump drugs to the extracellular resistance caused by the medium level. Therefore, an urgent need to develop to overcome macrolide antibiotics for pneumonia antimicrobial resistance of Streptococcus, scientists also hope that the new structure can maintain excellent pharmacokinetic properties of acid stable. In summary, our region to the peptidyl transferase center (peptidyl transferase, center, PTC) nuclear glucoside Acid as the target, the design of 3-O- aryl alkyl carbamate a descladinosylation azithromycin 11,12 cyclocarbonate A. we want 3-0- aralkyl carbamic acid ester side chain with nucleotide G2505 PTC region, C2610 and U2586 by hydrogen bonding, with pi bond stacking and electrostatic interaction. On this basis, we transferase the central area and the II domain to the peptidyl A752 as the target, the design of 3-O- aryl alkyl carbamate -11-O- aryl alkyl carbamate and azithromycin B activity. The 11 side chain which can interact with A752 ribosome affinity. At the same time, we design the methylation mediated by ERM ribosome targeting 2'-O- aryl alkyl carbamate -11,12- cyclocarbonate desugarization azithromycin C-E.C-E is the new 3 series compounds we synthesized has not been reported in the literature, 2'-O- and A2058 in the side chain (radiation resistant ball Bacteria is A2041) and its surrounding nucleotides through hydrophobic binding, hydrogen bonds and pi bond. We synthesized 71 novel azalides, their structure has been through several spectra were confirmed. Then, we use the in vitro activity of target compounds by broth dilution method, the minimum inhibitory concentration (MIC, minimum inhibitory concentrations). The antibacterial activity are summarized as follows: 1. of negative bacteria activity: compounds C6, D1 and D2 of Escherichia coli was the strongest, MIC value is 32 g/mL, and the control drug is clarithromycin (32 g/mL). The best activity of compounds of Pseudomonas aeruginosa MIC value is 4 g/mL, compared with the control improve.2. on sensitive bacteria activity: compound B7 on the sensitivity of Staphylococcus aureus, sensitivity pyococcus activity, MIC values were 1 and 0.03 g/mL. encouragingly, compound B8 (0.5 g/ mL) of Bacillus subtilis rod 鑿屾椿鎬ф瘮瀵圭収鑽�闃垮�囬湁绱犳彁楂樹簡涓ゅ，

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