Discovery of MC-02,331, a New Cephalosporin Exhibiting Potent Activity Against Methicillin-resistant Staphylococcus aureus.
作者:SCOTT J. HECKER、IN-SEOP CHO、TOMASZ W. GLINKA、ZHIJIA J. ZHANG、MARY E. PRICE、VING J. LEE、BURTON G. CHRISTENSEN、AMY BOGGS、SUZANNE CHAMBERLAND、FRANÇOIS MALOUIN、THOMAS R. PARR、THAMIL ANNAMALAI、JOHANNE BLAIS、EMMETT L. BOND、LAURA CASE、CHRISTINE CHAN、JAC CRASE、RIA FRITH、DAVID GRIFFITH、LAURIE HARFORD、NANCY LIU、MARIA LUDWIKOW、KRISTINA MATHIAS、DAVID REA、ROBERT WILLIAMS
DOI:10.7164/antibiotics.51.722
日期:——
A systematic approach toward building activity against methicillin-resistant staphylococci into the cephalosporin class of β-lactam antibiotics is described. Initial work focused on finding the optimal linkage between the cephem nucleus and a biphenyl pharmacophore, which established that a thio linkage afforded potent activity in vitro. Efforts to optimize this activity by altering substitution on the pharmacophore afforded iodophenylthio analog MC-02, 002, which although highly potent against MRSA, was also highly bound to serum proteins. Further work to decrease serum protein binding showed that replacement of the iodo substituent by the positively-charged isothiouronium group afforded potent activity and reduced serum binding, but insufficient aqueous solubility. Solubility was enhanced by incorporation of a second positively-charged group into the 7-acyl substituent. Such derivatives (MC-02, 171 and MC-02, 306) lacked sufficient stability to staphylococcal β-lactamase enzymes. The second positive charge was incorporated into the cephem 3-substituent in order to utilize the β-lactamase-stable aminothiazolyl-(oximino)acetyl class of 7-substituents. These efforts culminated with the discovery of bis(isothiouroniummethyl)phenylthio analog MC-02, 331, whose profile is acceptable with respect to potency against MRSA, serum binding, aqueous solubility, and β-lactamase stability.
描述了一种将耐甲氧西林葡萄球菌的活性构建到头孢菌素类 β-内酰胺抗生素中的系统方法。最初的工作重点是寻找头孢烯核和联苯药效团之间的最佳连接,这证实了硫键在体外具有有效的活性。通过改变药效基团上的取代来优化这种活性,得到了碘苯硫基类似物 MC-02, 002,它虽然对 MRSA 非常有效,但也与血清蛋白高度结合。减少血清蛋白结合的进一步研究表明,用带正电荷的异硫脲基团取代碘取代基可提供有效的活性并减少血清结合,但水溶性不足。通过将第二个带正电荷的基团并入 7-酰基取代基中,溶解度得到增强。此类衍生物(MC-02、171 和 MC-02、306)对葡萄球菌 β-内酰胺酶缺乏足够的稳定性。将第二个正电荷并入头孢烯 3-取代基中,以便利用 β-内酰胺酶稳定的氨基噻唑基-(肟基)乙酰基类 7-取代基。这些努力最终发现了双(异硫脲甲基)苯硫基类似物 MC-02, 331,其在抗 MRSA 效力、血清结合、水溶性和 β-内酰胺酶稳定性方面的表现是可接受的。