Identification of 2-aminothiazole-4-carboxylate derivatives active against Mycobacterium tuberculosis H37Rv and the beta-ketoacyl-ACP synthase mtFabH.
BACKGROUND
Tuberculosis (TB) is a disease which kills two million people every year and infects approximately over one-third of the world's population. The difficulty in managing tuberculosis is the prolonged treatment duration, the emergence of drug resistance and co-infection with HIV/AIDS. Tuberculosis control requires new drugs that act at novel drug targets to help combat resistant forms of Mycobacterium tuberculosis and reduce treatment duration.


RESULTS
Our approach was to modify the naturally occurring and synthetically challenging antibiotic thiolactomycin (TLM) to the more tractable 2-aminothiazole-4-carboxylate scaffold to generate compounds that mimic TLM's novel mode of action. We report here the identification of a series of compounds possessing excellent activity against M. tuberculosis H(37)R(v) and, dissociatively, against the beta-ketoacyl synthase enzyme mtFabH which is targeted by TLM. Specifically, methyl 2-amino-5-benzylthiazole-4-carboxylate was found to inhibit M. tuberculosis H(37)R(v) with an MIC of 0.06 microg/ml (240 nM), but showed no activity against mtFabH, whereas methyl 2-(2-bromoacetamido)-5-(3-chlorophenyl)thiazole-4-carboxylate inhibited mtFabH with an IC(50) of 0.95+/-0.05 microg/ml (2.43+/-0.13 microM) but was not active against the whole cell organism.


CONCLUSIONS
These findings clearly identify the 2-aminothiazole-4-carboxylate scaffold as a promising new template towards the discovery of a new class of anti-tubercular agents.
Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow, United Kingdom.
Qosay
Q
Al-Balas
Nahoum G
NG
Anthony
Bilal
B
Al-Jaidi
Amani
A
Alnimr
Grainne
G
Abbott
Alistair K
AK
Brown
Rebecca C
RC
Taylor
Gurdyal S
GS
Besra
Timothy D
TD
McHugh
Stephen H
SH
Gillespie
Blair F
BF
Johnston
Simon P
SP
Mackay
Geoffrey D
GD
Coxon
D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase / Q000037:antagonists & inhibitors*; D000995:Antitubercular Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000201:enzymology; D013844:Thiazoles / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*
D000995:Antitubercular Agents; D013844:Thiazoles; D015099:3-Oxoacyl-(Acyl-Carrier-Protein) Synthase