Thiazole Analogue Research Articles

Structural Requirements for Ga3+ Coordination in Synthetic Analogues of the Siderophore Piscibactin Deduced by Chemical Synthesis and Density Functional Theory Calculations.

Stereoselective total synthesis of several analogues of piscibactin (Pcb), the siderophore produced by different pathogenic Gram-negative bacteria, was performed. The acid-sensitive α-methylthiazoline moiety was replaced by a more stable thiazole ring, differing in the configuration of the OH group at the C-13 position. The ability of these Pcb analogues to form complexes with Ga3+ as a mimic of Fe3+ showed that the configuration of the hydroxyl group at C-13 as 13S is crucial for the chelation of Ga3+ to preserve the metal coordination, while the presence of a thiazole ring instead of the α-methylthiazoline moiety does not affect such coordination. A complete 1H and 13C NMR chemical shift assignment of the diastereoisomer mixtures around C9/C10 was done for diagnostic stereochemical disposition. Additionally, density functional theory calculations were performed not only for confirming the stereochemistry of the Ga3+ complex among the six possible diastereoisomers but also for deducing the ability of these to form octahedral coordination spheres with gallium. Finally, the lack of antimicrobial activity of Pcb and Pcb thiazole analogue Ga3+ complexes against Vibrio anguillarum agrees with one of the roles of siderophores in protecting pathogens from metal ion toxicity. The efficient metal coordination shown by this scaffold suggests its possible use as a starting point for the design of new chelating agents or vectors for the development of new antibacterials that exploit the "Trojan horse" strategy using the microbial iron uptake mechanisms. The results obtained will be of great help in the development of biotechnological applications for these types of compounds.

A Thiazole Analogue Exhibits an Anti-Proliferative Effect in Different Human Carcinoma Cell Lines and Its Mechanism Based on Molecular Modeling

Purpose: Aim of this study is to assess the anti-proliferative effect of the thiazole analogue (5-acetyl-4-methyl-2-(3-pyridyl) thiazole) with different human carcinoma cell lines and to postulate its possible mechanism of action using molecular modeling. Methods: Three different human carcinoma cell lines were used namely hepatocyte carcinoma (HEPG2), breast adenocarcinoma (MCF7) and colon cancer (HCT116). Molecular docking simulations for tested thiazole analogue and its virtual analogues against the cytochrome P-450 2A6 enzyme and mutated SOD were performed. Results: Cell lines cytotoxicity revealed that the tested thiazole analogue exerts a significant anti-proliferative activity in all the used human carcinoma cell lines with a pronounced anti-proliferative effect in liver carcinoma cell line HEPG2 (IC50 = 23.8 μg/ml) whereas the anti-proliferative effect in colon carcinoma and breast cancer cell lines was poor with IC50 = 50 μg/ml and IC50 > 50 μg/ml respectively. The postulated mechanism of action revealed the high affinity to inhibit SOD and CYP2A6 enzymes in the liver. Conclusion: The thiazole analogue (5-acetyl-4-methyl-2-(3-pyridyl)thiazole) is a potential liver specific anticancer agent capable of interfering with both apoptotic signaling pathway and the free radical processing in liver which leads to more studies on liver cancer from different perspective rather than the apoptotic signaling pathway.

Inside Cover: Naturally Inspired Peptide Leads: Alanine Scanning Reveals an Actin‐Targeting Thiazole Analogue of Bisebromoamide (ChemBioChem 17/2016)

Inside Cover: Naturally Inspired Peptide Leads: Alanine Scanning Reveals an Actin‐Targeting Thiazole Analogue of Bisebromoamide (ChemBioChem 17/2016)

Naturally Inspired Peptide Leads: Alanine Scanning Reveals an Actin-Targeting Thiazole Analogue of Bisebromoamide.

Systematic alanine scanning of the linear peptide bisebromoamide (BBA), isolated from a marine cyanobacterium, was enabled by solid‐phase peptide synthesis of thiazole analogues. The analogues have comparable cytotoxicity (nanomolar) to that of BBA, and cellular morphology assays indicated that they target the actin cytoskeleton. Pathway inhibition in human colon tumour (HCT116) cells was explored by reverse phase protein array (RPPA) analysis, which showed a dose‐dependent response in IRS‐1 expression. Alanine scanning reveals a structural dependence to the cytotoxicity, actin targeting and pathway inhibition, and allows a new readily synthesised lead to be proposed.

Secondary Metabolites from the Deep-Sea Derived Fungus Acaromyces ingoldii FS121

Activity-guided isolation of the fermentation broth of the deep-sea derived fungus Acaromyces ingoldii FS121, which was obtained from the China South Sea, yielded a new naphtha-[2,3-b]pyrandione analogue, acaromycin A (1) and a new thiazole analogue, acaromyester A (2), as well as the known compound (+)-cryptosporin (3). Their structures, including absolute configurations, were determined by extensive spectroscopic analysis and electronic circular dichroism (ECD) spectra. Compounds 1–3 were evaluated for in vitro growth inhibitory activities against four tumor cell lines (MCF-7, NCI-H460, SF-268 and HepG-2), wherein compounds 1 and 3 exhibited considerable growth inhibitory effects, with IC50 values less than 10 µM.

Structure-Based Design of Selective Janus Kinase 2 Imidazo[4,5-d]pyrrolo[2,3-b]pyridine Inhibitors.

Early hit to lead work on a pyrrolopyridine chemotype provided access to compounds with biochemical and cellular potency against Janus kinase 2 (JAK2). Structure-based drug design along the extended hinge region of JAK2 led to the identification of an important H-bond interaction with the side chain of Tyr 931, which improved JAK family selectivity. The 4,5-dimethyl thiazole analogue 18 demonstrated high levels of JAK family selectivity and was identified as a promising lead for the program.

Total Synthesis of a Noricumazole A Library and Evaluation of HCV Inhibition

The total synthesis of 16 new ion channel inhibitors derived from noricumazole A, a secondary metabolite from the myxobacterium Sorangium cellulosum, is reported. Particular focus of library design is put on stereochemical permutations in the central region (C9 and C11), the oxazole moiety and the side chain at C4 of the isochromanone moiety. Noricumazole A and all new noricumazole derivatives were tested in an assay system with inhibitory effect on the hepatitis C virus (HCV) life cycle. Most of them are moderate to strong HCV inhibitors (350 nM-6 nM) but also exert pronounced cytotoxicity. In contrast, the thiazole analogue of noricumazole A is a strong HCV inhibitor with only moderate cytotoxic property. It may become a lead structure with a good therapeutic index (CC(50)/IC(50)) of greater than 10.

Resistance Analysis and Characterization of a Thiazole Analogue, BP008, as a Potent Hepatitis C Virus NS5A Inhibitor

Hepatitis C virus (HCV) is a global health problem, affecting approximately 3% of the world's population. The standard treatment for HCV infection is often poorly tolerated and ineffective. Therefore, the development of novel or more effective treatment strategies to treat chronic HCV infection is urgently needed. In this report, BP008, a potent small-molecule inhibitor of HCV replication, was developed from a class of compounds with thiazol core structures by means of utilizing a cell-based HCV replicon system. The compound reduced the reporter expression of the HCV1b replicon with a 50% effective concentration (EC(50)) and selective index value of 4.1 ± 0.7 nM and >12,195, respectively. Sequencing analyses of several individual clones derived from BP008-resistant RNAs purified from cells harboring HCV1b replicon revealed that amino acid substitutions mainly within the N-terminal region (domain I) of NS5A were associated with decreased inhibitor susceptibility. Q24L, P58S, and Y93H are the key substitutions for resistance selection; F149L and V153M play the compensatory role in the replication and drug resistance processes. Moreover, BP008 displayed synergistic effects with alpha interferon (IFN-α), NS3 protease inhibitor, and NS5B polymerase inhibitor, as well as good oral bioavailability in SD rats and favorable exposure in rat liver. In summary, our results pointed to an effective small-molecule inhibitor, BP008, that potentially targets HCV NS5A. BP008 can be considered a part of a more effective therapeutic strategy for HCV in the future.

Structure−Function Relationships within Keppler-Type Antitumor Ruthenium(III) Complexes: the Case of 2-Aminothiazolium[trans-tetrachlorobis(2-aminothiazole)ruthenate(III)

Keppler-type ruthenium(III) complexes exhibit promising antitumor properties. We report here a study of 2-aminothiazolium[trans-tetrachlorobis(2-aminothiazole)ruthenate(III)], both in the solid state and in solution. The crystal structure has been solved and found to exhibit classical features. Important solvatochromic effects were revealed. Notably, we observed that introduction of an amino group in position 2 greatly accelerates chloride hydrolysis compared to the thiazole analogue; this latter finding may be of interest for a fine-tuning of the reactivity of these novel metallodrugs.

Thiourea Inhibitors of Herpes Viruses. Part 1. Bis‐(aryl)thiourea Inhibitors of CMV.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Thiourea inhibitors of herpes viruses. Part 1: bis-(aryl)thiourea inhibitors of CMV.

Bis-(aryl)thioureas were found to be potent and selective inhibitors of cytomegalovirus (CMV) in cultured HFF cells. Of these, the thiazole analogue 38 was investigated as a potential development candidate.

The effect of a vitamin B1 thiazole analogue on ion channels formed by alpha-latrotoxin and sea anemone toxin in bilayer lipid membranes.

The effect of a vitamin B1 thiazole analogue on ion channels formed by alpha-latrotoxin and sea anemone toxin in bilayer lipid membranes.

Asymmetric synthesis of (1 R,2 S,3 R)-2-acetyl-4-(1,2,3,4-tetrahydroxybutyl)thiazole

Two different methods for preparing the thiazole analogue 3 of the biologically active compound (1 R,2 S,3 R)-2-acetyl-4(5)-(1,2,3,4- tetrahydroxybutyl)imidazole 1 are reported.

Asymmetric synthesis of (1R, 2S, 3R)-2-acetyl-5-(1,2,3,4-tetrahydroxybutyl)thiazole

A method for preparing the thiazole analogue 2 of the biologically active compound (1R, 2S, 3R)-2-acetyl-4(5)-(1,2,3,4-tetrahydroxybutyl)imidazole 1 is reported.

LOCAL USE OF SULFATHIAZOLE POWDER FOR ACUTE PHARYNGEAL INFECTIONS

A study of acute pharyngeal infections treated by the topical application of sulfathiazole powder in the otolaryngologic dispensary of St. Luke's Hospital is presented here. Sulfathiazole (2-[paraaminobenzenesulfonamido]-thiazole) is the thiazole analogue of sulfapyridine (2-[paraaminobenzenesulfonamido]-pyridine) and was first reported on by Fosbinder and Walker 1 and by Lott and Bergeim. 2 These authors described the methods of preparation and their experiments with these drugs against streptococcic and pneumococcic infections in mice. The original work on the physical and chemical characteristics of sulfathiazole and its salt was done at that time, and tests for the estimation of the drug in the body were described. Van Dyke and his co-workers 3 showed the rapid metabolism of this drug in the body. Sulfathiazole was proved to be more rapidly absorbed than other sulfanilamide derivatives, the concentration in the blood reaching its highest level in one to three hours after ingestion of the drug. Moreover, it disappeared and

SULFATHIAZOLE FOR TREATMENT OF STAPHYLOCOCCIC MENINGITIS

Sulfathiazole (2-[paraaminobenzenesulfonamido]-thiazole), the newest of the sulfanilamide group of drugs, is ready to take its place in the armamentarium of chemotherapy. Sulfathiazole therapy has progressed so rapidly since the release of the drug that the literature associated with it is poorly organized. Our interest in the drug was stimulated by what impressed us as an almost unbelievable therapeutic result in what we had feared was an incurable condition. The report of this case follows. We feel that a preliminary review of the literature concerning sulfathiazole is worth while at this time. Sulfathiazole is the thiazole analogue of sulfapyridine (2-[paraaminobenzenesulfonamido]-pyridine) and was first reported by Forsbinder and Walter¹and by Lott and Bergeim.²These authors described the methods of preparation and their experiments with these drugs against streptococcic and pneumococcic infections in mice. The original work on the physical and chemical characteristics of sulfathiazole and its salt was done at that