ABSTRACT
The emergence of resistance against current antibiotics calls for the development of new compounds to treat infectious diseases. Synthetic pantothenamides are pantothenate analogs that possess broad-spectrum antibacterial activity
in vitro
in minimal media. Pantothenamides were shown to be substrates of the bacterial coenzyme A (CoA) biosynthetic pathway, causing cellular CoA depletion and interference with fatty acid synthesis. In spite of their potential use and selectivity for bacterial metabolic routes, these compounds have never made it to the clinic. In the present study, we show that pantothenamides are not active as antibiotics in the presence of serum, and we found that they were hydrolyzed by ubiquitous pantetheinases of the vanin family. To address this further, we synthesized a series of pantetheinase inhibitors based on a pantothenate scaffold that inhibited serum pantetheinase activity in the nanomolar range. Mass spectrometric analysis showed that addition of these pantetheinase inhibitors prevented hydrolysis of pantothenamides by serum. We found that combinations of these novel pantetheinase inhibitors and prototypic pantothenamides like N5-Pan and N7-Pan exerted antimicrobial activity
in vitro
, particularly against Gram-positive bacteria (
Staphylococcus aureus
,
Staphylococcus epidermidis
,
Streptococcus pneumoniae
, and
Streptococcus pyogenes
) even in the presence of serum. These results indicate that pantothenamides, when protected against degradation by host pantetheinases, are potentially useful antimicrobial agents.
摘要
随着现有抗生素耐药性的出现,需要开发新的化合物来治疗传染性疾病。合成
泛酸酰胺是
泛酸盐类似物,具有广谱抗菌活性
体外
在最小
培养基中具有广谱抗菌活性。研究表明,泛酰
苯胺是细菌
辅酶 A(CoA)
生物合成途径的底物,可导致细胞 CoA 枯竭并干扰
脂肪酸合成。尽管这些化合物在细菌代谢途径中具有潜在的用途和选择性,但却从未应用于临床。在本研究中,我们发现泛
硫氨酸在血清存在的情况下并不具有抗生素活性,而且它们会被无处不在的
香兰素家族泛
硫氨酸酶
水解。为了进一步解决这个问题,我们合成了一系列基于
泛酸盐支架的泛酪素酶
抑制剂,它们能在纳摩尔范围内抑制血清泛酪素酶的活性。质谱分析表明,加入这些泛
硫氨酸酶
抑制剂可防止血清
水解
泛酸。我们发现,这些新型
泛影葡胺酶
抑制剂与 N5-Pan 和 N7-Pan 等原型
泛影葡胺的组合具有抗菌活性
在体外
尤其是对革兰氏阳性菌(
金黄色葡萄球菌、葡萄球菌
金黄色葡萄球菌
,
表皮葡萄球菌
,
肺炎链球菌
和
化脓性链球菌
),即使在有血清存在的情况下也是如此。这些结果表明,泛
硫酰胺在受到宿主泛
硫酶降解保护的情况下,有可能成为有用的抗菌剂。