Search

Background: Coumarin and benzophenone possess a vast sphere of biological activities, whereas thiazoles display various pharmacological properties. Hence, present study focused on the incorporation of coumarin and thiazole core to the benzophenone skeleton to enhance the bioactivity, anticipating their interesting biological properties. Objective: The objective of the current work is the synthesis and biological evaluation of a novel series of coumarin fused thiazole derivatives. Methods: A novel series of coumarin conjugated thiazolyl acetamide hybrid derivatives were synthesized by a multistep reaction sequence and were characterized by the FT-IR, LCMS, and NMR spectral techniques. The newly synthesized compounds were screened for anti-cancer activity by in silico and in vitro methods. The cytotoxicity of the synthesized unique compounds was executed for two different cancer cell lines, MCF-7 (Breast cancer) and KB (Oral cancer), in comparison with standard paclitaxel by MTT assay. Results: The compound 7f is a potent motif with an acceptable range of IC50 values, for anti-cancer activity, i.e., 63.54μg/ml and 55.67μg/ml, against the MCF-7 and KB cell lines, respectively. Molecule docking model revealed that this compound formed three conventional hydrogen bonds with the active sites of the amino acids, MET 769, ARG 817, and LYS 721. Conclusion: Compound 7f with two methyl groups on the phenoxy ring and one 4-position methoxy group on the benzoyl ring, showed a significant cytotoxic effect. An advantageous level of low toxicity against normal cell line (L292) by MTT assay was determined.

Benzothiazole (1, 3-benzothiazole) is one of the heterocyclic compounds, which is a weak base having varied biological activities. The unique methine center present in the thiazole ring makes benzothiazole as the most important heterocyclic compound. It is a common and integral structure of many natural and synthetic bioactive molecules. Benzothiazole derivatives show a variety of activities, with less toxic effects and their derivatives showed enhanced activities, which has proven Benzothiazole scaffold as one of the important moieties in medicinal chemistry. Benzothiazole ring containing compounds possess various pharmacological activities such as anti-viral, anti-microbial, antiallergic, anti-diabetic, anti-tumor, anti-inflammatory, anthelmitic and anti-cancer, which makes benzothiazole a rapidly developing and interesting compound in the medicinal chemistry. This review briefly explains the importance, common methods of synthesis of the benzothiazole scaffold and also explains the popular benzothiazole molecules which have applications in various fields of chemistry. A review has been carried out based on various pharmacological activities containing benzothiazole moieties and rationalize the activities based on the structural variations. Literature on benzothiazole derivatives reveals that substitution on the C-2 carbon atom and C-6 are the reasons for a variety of biological activities.

Background: Compounds containing CN3 groups are named as guanidine derivatives, which have a rich history in biological and bio-inspired activity. Many guanidine moieties are reported for the antimicrobial activity. Present study aims to the enhancement of bio-activity of the guanidine subunits by conjugating with benzothiazole. Methods: A new series of benzothiazole guanidines have been synthesized from the reaction of thiourea derivatives of 6-substituted benzothiazoles with different substituted anilines in presence of HgCl2. The synthesized compounds were characterized through FT-IR, mass and 1H NMR spectral techniques. The synthesized compounds were screened for the Antimicrobial activity by disc diffusion method and antioxidant activity was assigned by DPPH and ABTS assay. Results: The products were screened for antimicrobial activity. They were found to exhibit moderate to potent activity against the tested microorganisms and have shown minimum inhibition concentration of 1.56 µg/mL for Candida albicans, 0.78 µg/mL for Aspergillus niger, 25 µg/mL for S. aureus and 12.5 µg/mL for E. coli. The derivatives were also tested for antioxidant DPPH and ABTS assays and they were found to have significant activities compared to the standards. Conclusion: In the present work, a new series of benzothiazole guanidinyl derivatives were synthesized in good yields by employing HgCl2 reagent. Synthesized compounds were screened for antimicrobial and antioxidant activities and compounds containing p-methoxy, o-hydroxy showed better antioxidant activities and antimicrobial activities.

The title compound C26H23N3O3S was synthesized by Steglich esterification of 4-[(6-ethoxy benzothiazol-2-yl) diazenyl] phenol with Indan-2-ylacetic acid. The synthesized compound was recrystallized by slow evaporation of the saturated solution of ethanol and single crystal was selected for X-ray Diffraction study and was characterized by UV–Vis, FT-IR, 1H NMR spectroscopic techniques. A triclinic unit cell of C26H23N3O3S was diffracted for X-ray beam of wavelength 0.71075Å generated from Mo-Kα, data were solved by SHELXL-97 and molecular and packing diagram were determined by MERCURY, from which R value obtained was 0.0613.

The present study validates the synthesis of two new series of benzothiazole conjugated pyrazole analogs by the coupling of benzothiazole hydrazine with 4-formyl pyrazole derivatives, which was set up by Vilsmeier-Haack reaction. The synthetic approach was initiated by coupling different acetophenones and phenyl hydrazine to synthesize the Schiff's bases, which further undergo cyclization with Vilsmeier-Haack reagent followed by the imine formation. A singlet at 7.1 ppm in 1H NMR indicated the protons of azo methane linkage (Schiff's base formation). Synthesized compounds were characterized by FT-IR, LC-MS, 1H NMR and 13C NMR spectroscopic techniques. The peak at 1593 cm−1(>C=N-) indicated the formation of the azo methane linkage in the synthesized compounds. In 1H NMR spectroscopy, a singlet peak at 8.89 ppm indicated the pyrazole proton, which confirmed the presence of 5-membered pyrazole ring.The recently synthesized compounds were screened for the anticancer and anti-tubercular (anti-TB) activities. MIC values of the compounds for in-vitroanti-TB activity were 1.6 μg/ml and MIC value of the compounds for in-vitroanti-cancer activities were 67.65 µg/ml and 70.31 µg/ml, against HELA and KB cell lines respectively. Most active compounds were found to be less toxic, which was determined by MTT assay method with normal cell line (L292). Biological screening of the synthesized series of compounds reveals that, Compound 5bwas the potent molecule.

Diabetes and tuberculosis are the chronic diseasea, highly affected mankind. Globally 422 million adults suffer from diabetes and two million deaths occur due to tuberculosis. A library of the mercaptooxadiazole analogs were synthesized by cyclization of benzohydrazide, followed by the nucleophillic alkylation/arylation. Characterization was done by FT-IR, LCMS and NMR spectral techniques. The newly synthesized compounds were screened for the antibacterial, antioxidant, anti-diabetic and anti-tubercular (anti-TB) activities. Some of the compounds show superior in-vitroanti-TB activity with 1.6 μg/ml as MIC value and a better anti-diabetic activity with 62% inhibitory potency. The level of toxicity of active compounds was determined with normal cell line (L292) by MTT assay and was found to be non-toxic over the MIC values. Experimental data hypothesized that compound 5eis the most prominent non-toxic drug candidature with lengthened activity against bacterial, fungal, tubercular and diabetic activities.