52057-91-7Relevant articles and documents
N-thiadiazole-4-hydroxy-2-quinolone-3-carboxamides bearing heteroaromatic rings as novel antibacterial agents: Design, synthesis, biological evaluation and target identification
Xue, Wenjie,Li, Xueyao,Ma, Guixing,Zhang, Hongmin,Chen, Ya,Kirchmair, Johannes,Xia, Jie,Wu, Song
, (2020/02/04)
Due to the occurrence of antibiotic resistance, bacterial infectious diseases have become a serious threat to public health. To overcome antibiotic resistance, novel antibiotics are urgently needed. N-thiadiazole-4-hydroxy-2-quinolone-3-carboxamides are a potential new class of antibacterial agents, as one of its derivatives was identified as an antibacterial agent against S. aureus. However, no potency-directed structural optimization has been performed. In this study, we designed and synthesized 37 derivatives, and evaluated their antibacterial activity against S. aureus ATCC29213, which led to the identification of ten potent antibacterial agents with minimum inhibitory concentration (MIC) values below 1 μg/mL. Next, we performed bacterial growth inhibition assays against a panel of drug-resistant clinical isolates, including methicillin-resistant S. aureus, and cytotoxicity assays with HepG2 and HUVEC cells. One of the tested compounds named 1-ethyl-4-hydroxy-2-oxo-N-(5-(thiazol-2-yl)-1,3,4-thiadiazol-2-yl)-1,2-dihydroquinoline-3-carboxamide (g37) showed 2 to 128-times improvement compared with vancomycin in term of antibacterial potency against the tested strains (MICs: 0.25–1 μg/mL vs. 1–64 μg/mL) and an optimal selective toxicity (HepG2/MRSA, 110.6 to 221.2; HUVEC/MRSA, 77.6–155.2). Further, comprehensive evaluation indicated that g37 did not induce resistance development of MRSA over 20 passages, and it has been confirmed as a bactericidal, metabolically stable, orally active antibacterial agent. More importantly, we have identified the S. aureus DNA gyrase B as its potential target and proposed a potential binding mode by molecular docking. Taken together, the present work reports the most potent derivative of this chemical series (g37) and uncovers its potential target, which lays a solid foundation for further lead optimization facilitated by the structure-based drug design technique.
Preparation of 2-amino-5-alkyl -1, 3, 4-thiadiazole
-
Paragraph 0024-0026; 0052-0055, (2017/04/19)
The invention discloses a method for preparing 2-amino-5-alkyl-1,3,4-thiadiazole. The method comprises the following steps of adding A mol of thiosemicarbazide, B mol of carboxylic acid, C mol of phosphorus oxychloride and D mol of silica gel in a dry reaction container, grinding at a room temperature until the raw materials are completely reacted, and standing to obtain a crude product, wherein A: B: C = 1: (1 to 1.2): (1 to 1.2), and A: D = 1: (5 to 10); then adding alkaline solution in the crude product until the pH value of the obtained mixed solution is 8-8.2, then carrying out suction filtration on the mixed solution, dissolving the filter cake by a solvent and then further carrying out suction filtration, removing silica gel, then carrying out reduced pressure concentration on the finally-obtained filtrate, and removing the solvent to obtain 2-amino-5-alkyl-1,3,4-thiadiazole. The method disclosed by the invention is a solid-phase reaction, silica gel is used as a carrier, the operation process is simple, the reaction time is short, the reaction conditions are moderate, the equipment requirements are low, and the yield of the target product is up to more than 91%.
Preparation method and application of long carbon chain thiadiazole
-
Paragraph 0033; 0036; 0037, (2017/02/23)
The present invention belongs to the field of organic corrosion inhibitor. A preparation method of long carbon chain thiadiazole is as follows: (1) grinding carboxylic acid, thiosemicarbazide and a solid super acidic catalyst in a ball mill; (2) adding the ground mixture into a reaction flask, at heating with 500W microwave power auxiliary irradiation for 5-10 min, extracting the reaction mixture by using an organic solvent, recovering the solid super acid, concentrating to obtain a solid, conducting base precipitation, filtration and purification on the to solid obtain 2-amino-5-alkyl-1,3,4-thiadiazole. The solid super acidic catalyst has excellent catalytic activity, can avoid environmental pollution caused by concentrated sulfuric acid catalysis, and can be reused; by grinding, the starting materials are completely encased in the solid super acid, and react completely under microwave conditions; and the method has the advantages of short reaction time, high yield and easiness to operation control. The thiadiazole compound has corrosion inhibition effect on copper in an acidic medium, and maintains the inhibition effect of more than 90% under strong acid conditions.
Synthesis, characterization and biological evaluation of some novel fluoroquinolones
Pandit, Neelanjana,Shah, Kamal,Agrawal, Neetu,Upmanyu, Neeraj,Shrivastava, Sushant K.,Mishra, Pradeep
, p. 843 - 851 (2016/04/20)
Different derivatives of fluoroquinolones were synthesized by combining it with different thiadiazoles. The synthesized compounds were characterized by infrared spectroscopy, proton nuclear magnetic resonance and mass spectral data. The compounds were screened for their antibacterial and antifungal activity. Ciprofloxacin derivatives with thiadiazoles 7c showed good antibacterial as well as antifungal activities, whereas 13c and 13e showed antibacterial and antifungal activity respectively. Sparfloxacin derivative 8c showed both antibacterial and antifungal activity. Sparfloxacin derivatives 14b and 14e showed antibacterial and antifungal activity respectively.
