In an attempt to find a new and a safer drug for tuberculosis, we have synthesized a series of fluoronitrobenzothiazolopyrazolines for antitubercular activity. The series comprises three subclasses: fluorobenzothiazolopyrazolines (11a–f), fluoronitrobenzothiazolopyrazoline, nitro group at 5th position (12a–f) and 4th position (13a–f). All compounds were screened for their in‐vitro antitubercular activity against Mycobacterium tuberculosis H37Rv strain by using Middlebrook 7H‐9 broth. An introduction of NO2 group at 5th position of benzothiazole ring (12a–f) increased the antitubercular activity whereas introduction of NO2 group at 4th position (13a–f) was found to decrease the activity remarkably. Two compounds from each series showing good antitubercular activity were tested for cytotoxicity on THP‐1 cell lines and they showed low cytotoxicity.

A series of novel 5,6-unsubstituted thieno-[2,3-d]-pyrimidines has been synthesized and tested for growth inhibition of Mycobacterium tuberculosis H37Rv. Of twelve compounds synthesized eleven have shown antimycobacterial activity that differs in potency. Compounds 7b, 7c, 7d, 7e, 7f, and 7g exhibited good antimycobacterial activity. MIC values of the compounds tested were comparable with pyrazinamide. Six compounds which have shown good antimycobacterial activity were also subjected for cytotoxicity studies and were found to possess poor cytotoxicity. The study indicates the definite need for focusing attention on thienopyrimidines for further lead optimization.

A new series of 4-((5-fluoro-6-(substituted)-1H-benzo[d]imidazol-2-ylthio)methyl)-benzoic acids 4a-o and 2-(5-fluoro-6-(substituted)-1H-benzo[d]imidazol-2-ylthio)-2-methylpropanoic acids 8a-e were synthesized, and their inhibitory potencies against soluble epoxide hydrolase (sEH) and 5-lipoxygenase (5-LOX) were investigated. These molecules were designed based on the combination of 5-LOX and sEH pharmacophores, resulting in hybrid analogs with potent sEH and 5-LOX inhibitory activity. Compound 4g showed remarkable activity with IC values of less than 1 μM (0.9 μM) against 5-LOX, while compound 4k displayed promising activity against sEH with IC ≤ 1 μM (0.7 μM). These compounds were evaluated for their in vivo potential using the carrageenan-induced rat paw edema assay. Based on the obtained results, the structure-activity relationship was established and a correlation between the activities was observed. Compounds 4f, 4g, 4k, 4n, and 8e showed potent anti-inflammatory activity and significant inhibition of edema (64.13, 67.39, 66.30, 65.21, and 58.69%, respectively) at a dose of 100 mg/kg, comparable to the standard drug ibuprofen (70.65%) at 3 h.

Thienopyrimidines as Novel Inhibitors of Mycobacterium tuberculosis: Synthesis and in vitro Studies. -The compounds (X) are tested for growth inhibition of Mycobacterium tuberculosis H37Rv. The compounds (Xb)-(Xg) exhibit good antimycobacterial activity. They are also subject for cytotoxicity studies and possess poor cytotoxicity. -(RASHMI*, P.; NARGUND, L. V. G.; HAZRA, K.; CHANDRA, J. N. N. S.; Arch. Pharm. (Weinheim, Ger.) 344 (2011) 7, 459-465, http://dx.

Benzothiazole is a molecule that has a wide range of pharmacological activities. The addition of a fluorine atom into the structure of benzothiazole enhances the various activities of the drug as the alteration of hydrogen or oxygen atom from a carbon bond by a fluorine atom improves desirable pharmacological properties such as greater biological half-life, higher ability to bind with the targeted receptor, and also enhances the lipophilic character of the drug. The special property that makes fluorine a very important molecule in the drug discovery includes a very small radius of the fluorine atom, a higher attacking power towards electrons, and a very low polarizability of the fluorine atom. Literature reveals that strong electron-attacking groups like fluorine in the structure of benzothiazole can exhibit anticancer activity of the drug, benzothiazole with Sulphonamide or with beta-lactam ring enhances the anti-inflammatory and antioxidant activity. Benzothiazole with oxadiazole shows potent anthelmintic activity [1-5].