Development of Des-Fatty Acyl-Polymyxin B Decapeptide Analogs with Pseudomonas aeruginosa-Specific Antimicrobial Activity
作者:Naoko Katsuma、Yuki Sato、Kazuhiro Ohki、Keiko Okimura、Kuniharu Ohnishi、Naoki Sakura
DOI:10.1248/cpb.57.332
日期:——
Twelve N-terminal analogs of des-fatty acyl-polymyxin B (Des-FA-[X1]-PMB, X=various amino acids or peptides) were synthesized and examined for their antimicrobial activity against Escherichia coli (E. coli), Salmonella Typhimurium (S. Typhimurium) and Pseudomonas aeruginosa (P. aeruginosa). It was found that Des-FA-[Dap1]-, Des-FA-[Ser1]-, Des-FA-[Dab-Dab-Dab1]- and Des-FA-[Arg-Arg-Arg1]-PMB had potent activity only against P. aeruginosa, with MIC values of 0.5—1 nmol/ml. Analogs in which X was Lys, Arg, Leu or Ala did not have increased antimicrobial activity against the three bacterial species tested compared with the lead compounds Des-FA-[Dab1]-PMB and polymyxin B (PMB). Des-FA-[Trp1]-PMB and Des-FA-[Phe1]-PMB had reduced activity against P. aeruginosa. The results indicate that compact hydrophilic amino acids (C3) or basic tripeptides at the N-terminal provide specificity for bactericidal activity towards P. aeruginosa. For LPS-binding activity, Des-FA-[Dab-Dab-Dab1]-PMB and Des-FA-[Arg-Arg-Arg1]-PMB showed activity comparable to PMB, while Des-FA-[Ala-Ala-Ala1]-PMB showed very low activity. Reduced acute toxicity of Des-FA-[Dap1]-PMB and Des-FA-[Trp1]-PMB was demonstrated by a mouse tail intravenous administration test, with LD50 values of 23.5 and 19.0 μmol/kg, respectively, in contrast to PMB (LD50, 4.8 μmol/kg).
合成了 12 个去脂肪酰基多粘菌素 B(Des-FA-[X1]-PMB,X=各种氨基酸或肽)的 N 端类似物,并考察了它们对大肠杆菌(E. coli)、鼠伤寒沙门氏菌(S. Typhimurium)和铜绿假单胞菌(P. aeruginosa)的抗菌活性。研究发现,Des-FA-[Dap1]-、Des-FA-[Ser1]-、Des-FA-[Dab-Dab-Dab1]-和 Des-FA-[Arg-Arg-Arg1]-PMB仅对铜绿假单胞菌具有强效活性,其 MIC 值为 0.5-1 nmol/ml。与先导化合物 Des-FA-[Dab1]-PMB 和多粘菌素 B (PMB) 相比,X 为 Lys、Arg、Leu 或 Ala 的类似物对三种受试细菌的抗菌活性并没有提高。Des-FA-[Trp1]-PMB 和 Des-FA-[Phe1]-PMB 对铜绿假单胞菌的活性降低。结果表明,N-末端的紧密亲水氨基酸(C3)或碱性三肽为铜绿假单胞菌的杀菌活性提供了特异性。在 LPS 结合活性方面,Des-FA-[Dab-Dab-Dab1]-PMB 和 Des-FA-[Arg-Arg-Arg1]-PMB 的活性与 PMB 相当,而 Des-FA-[Ala-Ala-Ala1]-PMB 的活性则非常低。小鼠尾部静脉注射试验表明,Des-FA-[Dap1]-PMB 和 Des-FA-[Trp1]-PMB 的急性毒性较低,半数致死剂量分别为 23.5 和 19.0 μmol/kg,而 PMB 的半数致死剂量为 4.8 μmol/kg。