ABSTRACT
8-Nitro-benzothiazinones (BTZs), such as BTZ043 and PBTZ169, inhibit decaprenylphosphoryl-β-
d
-ribose 2′-oxidase (DprE1) and display nanomolar bactericidal activity against
Mycobacterium tuberculosis
in vitro
. Structure-activity relationship (SAR) studies revealed the 8-nitro group of the BTZ scaffold to be crucial for the mechanism of action, which involves formation of a semimercaptal bond with Cys387 in the active site of DprE1. To date, substitution of the 8-nitro group has led to extensive loss of antimycobacterial activity. Here, we report the synthesis and characterization of the pyrrole-benzothiazinones PyrBTZ01 and PyrBTZ02, non-nitro-benzothiazinones that retain significant antimycobacterial activity, with MICs of 0.16 μg/ml against
M. tuberculosis
. These compounds inhibit DprE1 with 50% inhibitory concentration (IC
50
) values of <8 μM and present favorable
in vitro
absorption-distribution-metabolism-excretion/toxicity (ADME/T) and
in vivo
pharmacokinetic profiles. The most promising compound, PyrBTZ01, did not show efficacy in a mouse model of acute tuberculosis, suggesting that BTZ-mediated killing through DprE1 inhibition requires a combination of both covalent bond formation and compound potency.
摘要
8-硝基苯并噻嗪酮(BTZs),如 BTZ043 和 PBTZ169,可抑制十烯丙基磷酰基-β-巯基-巯基乙醇(decaprenylphosphoryl-β-d-巯基乙醇)。
d
-核糖 2′-氧化酶(DprE1),对结核分枝杆菌具有纳摩尔级的杀菌活性。
结核分枝杆菌
体外
.结构-活性关系(SAR)研究显示,BTZ 支架的 8-硝基对其作用机制至关重要,该机制涉及与 DprE1 活性位点的 Cys387 形成半巯基键。迄今为止,8-硝基取代已导致抗霉菌活性的广泛丧失。在此,我们报告了吡咯-苯并噻嗪酮 PyrBTZ01 和 PyrBTZ02 的合成和表征,这两种非硝基苯并噻嗪酮保留了显著的抗霉菌活性。
结核杆菌
.这些化合物对 DprE1 的抑制浓度为 50%(IC
50
这些化合物对 DprE1 的抑制作用为 50%的抑制浓度(IC 50
体外
吸收-分布-代谢-排泄/毒性(ADME/T)和
体内
药代动力学特征。最有前途的化合物 PyrBTZ01 在急性结核病小鼠模型中未显示出疗效,这表明通过 DprE1 抑制 BTZ 介导的杀灭作用需要共价键形成和化合物效力的共同作用。