Current Development of Thiazole-Containing Compounds as Potential Antibacterials against Methicillin-Resistant Staphylococcus aureus

The emergence of multi-drug-resistant bacteria is threatening to human health and life around the world. In particular, methicillin-resistant Staphylococcus aureus (MRSA) causes fatal injuries to human beings and serious economic losses to animal husbandry due to its easy transmission and difficult treatment. Currently, the development of novel, highly effective, and low-toxicity antimicrobials is important to combat MRSA infections. Thiazole-containing compounds with good biological activity are widely used in clinical practice, and appropriate structural modifications make it possible to develop new antimicrobials. Here, we review thiazole-containing compounds and their antibacterial effects against MRSA reported in the past two decades and discuss their structure-activity relationships as well as the corresponding antimicrobial mechanisms. Some thiazole-containing compounds exhibit potent antibacterial efficacy in vitro and in vivo after appropriate structural modifications and could be used as antibacterial candidates. This Review provides insights into the development of thiazole-containing compounds as antimicrobials to combat MRSA infections.

Design, synthesis and biological evaluation of pyrazolo[3,4-d]pyridazinone derivatives as covalent FGFR inhibitors

Fibroblast growth factor receptors (FGFRs) have emerged as promising targets for anticancer therapy. In this study, we synthesized and evaluated the biological activity of 66 pyrazolo[3,4-d]pyridazinone derivatives. Kinase inhibition, cell proliferation, and whole blood stability assays were used to evaluate their activity on FGFR, allowing us to explore structure−activity relationships and thus to gain understanding of the structural requirements to modulate covalent inhibitors’ selectivity and reactivity. Among them, compound 10h exhibited potent enzymatic activity against FGFR and remarkably inhibited proliferation of various cancer cells associated with FGFR dysregulation, and suppressed FGFR signaling pathway in cancer cells by the immunoblot analysis. Moreover, 10h displayed highly potent antitumor efficacy (TGI = 91.6%, at a dose of 50 mg/kg) in the FGFR1-amplified NCI-H1581 xenograft model.

Synthetic Cathinone Analogues Structurally Related to the Central Stimulant Methylphenidate as Dopamine Reuptake Inhibitors

Synthetic cathinones are, primarily, stimulant drugs of abuse that act at monoamine transporters (e.g., the dopamine transporter or DAT) as releasing agents or as reuptake inhibitors. In the past few years, the emergence of >150 new synthetic cathinones has attracted considerable attention from medical and law enforcement communities. threo-Methylphenidate (tMP), used clinically for the treatment of ADHD and narcolepsy, is also a DAT reuptake inhibitor. tMP is somewhat structurally similar to abused cathinone stimulants, and the structure-activity relationships (SAR) of tMP have been well-defined. Hence, available tMP literature might assist in understanding the SAR of synthetic cathinones, about which less is known. In the present study, we synthesized and examined eight 2-benzoylpiperidine analogues (4, 6-12) to determine if tMP SAR might be applicable to cathinone SAR. The benzoylpiperidine analogues were evaluated in a competition assay using live-cell imaging against APP⁺ in HEK293 cells stably expressing hDAT and in cells coexpressing DAT and voltage-gated Ca²⁺ channels. All compounds were found to be DAT reuptake inhibitors, and a significant correlation was obtained between the potency of the benzoylpiperidines and tMP binding data (r = 0.91), suggesting that the SAR of tMP analogues might be directly applicable to certain synthetic cathinones as DAT reuptake inhibitors.