Synthetic Methods and Pharmacological Potentials of Triazolothiadiazines: A Review.

This review article examines the synthetic pathways for triazolothiadiazine derivatives, such as triazolo[3,4-b]thiadiazines, triazolo[5,1-b]thiadiazines, and triazolo[4,3-c]thiadiazines, originating from triazole derivatives, thiadiazine derivatives, or thiocarbohydrazide. The triazolothiadiazine derivatives exhibit several biological actions, including antibacterial, anticancer, antiviral, antiproliferative, analgesic, anti-inflammatory, and antioxidant properties. The review article aims to assist researchers in creating new biologically active compounds for designing target-oriented triazolothiadiazine-based medicines to treat multifunctional disorders.

Design, synthesis and docking studies of novel thiazole derivatives incorporating pyridine moiety and assessment as antimicrobial agents.

A novel series of substituted 4,6-dimethyl-2-oxo-1-(thiazol-2-ylamino)-1,2-dihydropyridine-3-carbonitrile derivatives 6, 9, 13, 15, and 17 was synthesized in a good to excellent yield from the reaction of 1-(3-cyano-4,6-dimethyl-2-oxopyridin-1(2H)-yl)thiourea with 2-oxo-N'-arylpropanehydrazonoyl chloride, chloroacetone, α-bromoketones, ethyl chloroacetate, and 2,3-dichloroquinoxaline, respectively. The potential DNA gyrase inhibitory activity was examined using in silico molecular docking simulation. The novel thiazoles exhibit dock score values between - 6.4 and - 9.2 kcal/mol and they were screened for their antimicrobial activities. Compound 13a shown good antibacterial activities with MIC ranged from 93.7-46.9 µg/mL, in addition, it shown good antifungal activities with MIC ranged from 7.8 and 5.8 µg/mL.

Design, Synthesis, and Antimicrobial Evaluation of Novel Pyrazoles and Pyrazolyl 1,3,4-Thiadiazine Derivatives.

A novel series of pyrazolyl 1,3,4-thiadiazines 5a⁻c, 8a⁻c, 12, 15a⁻c, 17a⁻c, and 20 was prepared from the reaction of pyrazole-1-carbothiohydrazide 1a,b with 2-oxo-N'-arylpropanehydrazonoyl chloride, 2-chloro-2-(2-arylhydrazono)acetate, and 3-bromoacetylcoumarin. Moreover, the regioselective reaction of 5-pyrazolone-1-carbothiohydrazide 1a with 4-substituted diazonium salts and 4-(dimethylamino)benzaldehyde gave the corresponding hydrazones 21a⁻c and 22. The newly prepared compounds were characterized by spectroscopy and elemental analysis. Many new synthesized compounds showed considerable antimicrobial activity against tested microorganisms. Hydrazones 21a⁻c and 22 showed remarkable antibacterial and antifungal activities. 4-(2-(p-tolyl)hydrazineylidene)-pyrazole-1-carbothiohydrazide 21a displayed the highest antibacterial and antifungal activities with minimum inhibitory concentration (MIC) values lower than standard drugs chloramphenicol and clotrimazole, in the range of 62.5⁻125 and 2.9⁻7.8 µg/mL, respectively.

New Potential Antimalarial Agents: Design, Synthesis and Biological Evaluation of Some Novel Quinoline Derivatives as Antimalarial Agents.

A novel series of dihydropyrimidines (DHPMs) 4a-j; 2-oxopyran-3-carboxylate 7a,b; 1-amino-1,2-dihydropyridine-3-carboxylate 8; and 1,3,4-oxadiazole derivatives 12 with quinolinyl residues have been synthesized in fairly good yields. The structure of the newly synthesized compounds was elucidated on the basis of analytical and spectral analyses. In vitro antimalarial evaluation of the synthesized quinoline derivatives against Plasmodium falciparum revealed them to possess moderate to high antimalarial activities, with IC50 values ranging from 0.014-5.87 µg/mL. Compounds 4b,g,i and 12 showed excellent antimalarial activity against to Plasmodium falciparum compared with the antimalarial agent chloroquine (CQ).