Design, synthesis and structure-activity relationship studies of novel indazole analogues as DNA gyrase inhibitors with Gram-positive antibacterial activity

In this study, we report the design, synthesis and structure-activity relationships of novel indazole derivatives as DNA gyrase inhibitors with Gram-positive antibacterial activity. Our results show that selected compounds from this series exhibit potent antibacterial activity against Gram-positive bacteria including multi-drug resistant strains that is methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE).     

Potent DNA gyrase inhibitors; novel 5-vinylpyrazole analogues with Gram-positive antibacterial activity

In this study, we designed and synthesized novel 5-vinylpyrazole analogues by decreasing the lipophilicity of the parent compounds 1a,b; 3-[(3-methoxycarbonyl)cyclohexylaminomethyl]indazoles while keeping the van der Waals interaction with the lipophilic area of DNA gyrase B. The selected compound 8bb exhibited good antibacterial activity against staphylococci and enterococci, including multi-drug resistant strains.     

Theoretical basis for reducing time-lines to the determination of positive Mycobacterium tuberculosis cultures using thymidylate kinase (TMK) assays

Background  

In vitro culture of pathogens on growth media forms a "pillar" for both infectious disease diagnosis and drug sensitivity profiling. Conventional cultures of Mycobacterium tuberculosis (M.tb) on Lowenstein Jensen (LJ) medium, however, take over two months to yield observable growth, thereby delaying diagnosis and appropriate intervention. Since DNA duplication during interphase precedes microbial division, "para-DNA synthesis assays" could be used to predict impending microbial growth. Mycobacterial thymidylate kinase (TMKmyc) is a phosphotransferase critical for the synthesis of the thymidine triphosphate precursor necessary for M.tb DNA synthesis. Assays based on high-affinity detection of secretory TMKmyc levels in culture using specific antibodies are considered. The aim of this study was to define algorithms for predicting positive TB cultures using antibody-based assays of TMKmyc levels in vitro.     

Synthesis and SAR of aminopyrimidines as novel c-Jun N-terminal kinase (JNK) inhibitors

The development of a series of novel aminopyrimidines as inhibitors of c-Jun N-terminal kinases is described. The synthesis, in vitro inhibitory values for JNK1, JNK2 and CDK2, and the in vitro inhibitory value for a c-Jun cellular assay are discussed.     

Pyridopyrimidine analogues as novel adenosine kinase inhibitors

A novel series of pyridopyrimidine analogues 9 was identified as potent adenosine kinase inhibitors based on the SAR and computational studies. Substitution of the C7 position of the pyridopyrimidino core with C2' substituted pyridino moiety increased the in vivo potency and enhanced oral bioavailability of these adenosine kinase inhibitors.     

Thymidine and thymidine-5'-O-monophosphate analogues as inhibitors of Mycobacterium tuberculosis thymidylate kinase

The affinity of a series of 2', 3'- and 5-modified thymidine analogues for Mycobacterium tuberculosis thymidine monophosphate kinase (TMPKmt) was evaluated. The affinities of several non-phosphorylated analogues are in the same order of magnitude as those of their phosphorylated congeners. In view of drug delivery problems associated with phosphorylated compounds, these 'free' nucleosides seem more promising leads in the search of TMPKmt inhibitors as novel anti-tuberculosis agents.     

Benzothiazoles as Rho-associated kinase (ROCK-II) inhibitors

A series of benzothiazole derivatives as ROCK inhibitors have been discovered. Compounds with good biochemical and cellular potency, and sufficient kinase selectivity have been identified.     

Synthesis and SAR of piperazine amides as novel c-jun N-terminal kinase (JNK) inhibitors

A novel series of c-jun N-terminal kinase (JNK) inhibitors were designed and developed from a high-throughput-screening hit. Through the optimization of the piperazine amide 1, several potent compounds were discovered. The X-ray crystal structure of 4g showed a unique binding mode different from other well known JNK3 inhibitors.     

Synthesis and SAR of novel isoxazoles as potent c-jun N-terminal kinase (JNK) inhibitors

The design and synthesis of isoxazole 3 is described, a potent JNK inhibitor with two fold selectivity over p38. Optimization of this scaffold led to compounds 27 and 28 which showed greatly improved selectivity over p38 by maintaining the JNK3 potency of compound 3. Extensive SAR studies will be described as well as preliminary in vivo data of the two lead compounds.     

Discovery and SAR of novel Naphthyridines as potent inhibitors of spleen tyrosine kinase (SYK)

The discovery of novel 5,7-disubstituted[1,6]naphthyridines as potent inhibitors of Spleen Tyrosine Kinase (SYK) is discussed. The SAR reveals the necessity for a 7-aryl group with preference towards para substitution and that this in combination with 5-aminoalkylamino substituents further improved the potency of the compounds. The initial SAR as well as a survey of the other positions is discussed in detail.     

Discovery of novel FMS kinase inhibitors as anti-inflammatory agents

The optimization of the arylamide lead 2 resulted in identification of a highly potent series of 2,4-disubstituted arylamides. Compound 8 (FMS kinase IC(50)=0.0008 microM) served as a proof-of-concept candidate in a collagen-induced model of arthritis in mice.     

Exploring 9-benzyl purines as inhibitors of glutamate racemase (MurI) in Gram-positive bacteria

An early SAR study of a screening hit series has generated a series of 9-benzyl purines as inhibitors of bacterial glutamate racemase (MurI) with micromolar enzyme potency and improved physical properties. X-ray co-crystal EI structures were obtained.     

Synthesis and evaluation of thymidine-5'-O-monophosphate analogues as inhibitors of Mycobacterium tuberculosis thymidylate kinase

A number of 2'- and 3'-modified thymidine 5'-O-monophosphate analogues were synthesized as potential leads for new anti-mycobacterial drugs. Evaluation of their affinity for Mycobacterium tuberculosis thymidine monophosphate kinase showed that a 2'-halogeno substituent and a 3'-azido function are the most favorable leads for further development of potent inhibitors of this enzyme.     

3,5-Disubstituted quinolines as novel c-Jun N-terminal kinase inhibitors

The structure-based design and synthesis of a novel series of c-Jun N-terminal kinase (JNK) inhibitors with selectivity against p38 is reported. The unique structure of 3,5-disubstituted quinolines (2) was developed from the previously reported 4-(2,7-phenanthrolin-9-yl)phenol (1). The X-ray crystal structure of 16a in JNK3 reveals an unexpected binding mode for this new scaffold with protein.     

Synthesis and SAR of novel quinazolines as potent and brain-penetrant c-jun N-terminal kinase (JNK) inhibitors

Quinazoline 3 was discovered as a novel c-jun N-terminal kinase (JNK) inhibitor with good brain penetration and pharmacokinetic (PK) properties. A number of analogs which were potent both in the biochemical and cellular assays were discovered. Quinazoline 13a was found to be a potent JNK3 inhibitor (IC₅₀ = 40 nM), with >500-fold selectivity over p38, and had good PK and brain penetration properties. With these properties, 13a is considered a potential candidate for in vivo evaluation.     

Synthesis and SAR of 4-substituted-2-aminopyrimidines as novel c-Jun N-terminal kinase (JNK) inhibitors

The development of a series of novel 4-substituted-2-aminopyrimidines as inhibitors of c-Jun N-terminal kinases is described. The synthesis, in vitro inhibitory values for JNK1, and the in vitro inhibitory value for a c-Jun cellular assay are discussed. Optimization of microsomal clearance led to the identification of 9c, whose kinase selectivity is reported.     

Design,synthesis, and biological evaluation of novel aminopyrimidinylisoindolines as AXL kinase inhibitors

A novel series of aminopyrimidinylisoindoline derivatives 1a-w having an aminopyrimidine scaffold as a hinge region binding motif were designed and synthesized. Among them, six compounds showed potent inhibitory activities against AXL kinase with IC₅₀ values of submicromolar range. Especially, compound 1u possessing (4-acetylpiperazin-1-yl)phenyl moiety exhibited extremely excellent efficacy (IC₅₀?=?<0.00050?μM). Their in vitro antiproliferative activities were tested over five cancer cell lines. Most compounds showed good antiproliferative activities against HeLa cell line. The kinase panel profiling of 50 different kinases and the selected inhibitory activities for the representative compound 1u were carried out. The compound 1u exhibited excellent inhibitory activities (IC₅₀?=?<0.00050, 0.025, and 0.050?μM for AXL, MER, and TYRO3, respectively) against TAM family, together with potent antiproliferative activity against MV4-11 cell line (GI₅₀?=?0.10?μM) related to acute myeloid leukemia (AML).     

Discovery of 4-azaindoles as novel inhibitors of c-Met kinase

A series of 4-azaindole inhibitors of c-Met kinase is described. The postulated binding mode was confirmed by an X-ray crystal structure and series optimisation was performed on the basis of this structure. Future directions for series development are discussed.     

Design,synthesis and structure-activity relationship evaluation of novel LpxC inhibitors as Gram-negative antibacterial agents

LpxC inhibitors are new-type antibacterial agents developed in the last twenty years, mainly against Gram-negative bacteria infections. To develop novel LpxC inhibitors with good antibacterial activities and biological metabolism, we summarized the basic skeleton of reported LpxC inhibitors, designed and synthesized several series of compounds and tested their antibacterial activities against Escherichial coli and Pseudomonas aeruginosa in vitro. Structure-activity relationships have been discussed in this article. The metabolism stability of YDL-2, YDL-5, YDL-8, YDL-14, YDL-20–YDL-23 have been evaluated in liver microsomes, which indicated that the 2-amino isopropyl group may be a preferred structure than the 2-hydroxy ethyl group in the design of LpxC inhibitors.