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Background: In recent years, 2-aminobenzothiazoles were reported as antibacterial, antihelmintic, antitumor, antimalarial, antiviral, analgesic and anti-inflammatory agents. Objectives: The study aimed to explore new potential 2-aminobenzothiazoles as antibacterial and anthelmintic agents. Methods: A favorable two-step method was used for the synthesis of new 2-aminobenzothiazole derivatives (4a-4j) by Schiff base. All synthesized compounds were tested for antibacterial activity using an in vitro cup-plate method and antihelmintic activity using in vitro earthworm paralysis and death method. Pharmacokinetics in silico studies were performed to predict the drug performance in the body using the Molinspiration kit. The molecular docking was performed to check the catalytic binding site between the dihydrofolate reductase and synthesized compounds (4a-4j). Results: The compound 4d emerged as the most effective vermifuge and vermicide among all tested compounds. The compounds 4c, 4f, 4g, 4i and 4j were examined as highly potent against gram-positive bacteria. The compounds 4b, 4h, and 4i showed maximum inhibition against gram-negative bacteria. In molecular docking, the compounds 4c and 4j showed a good binding orientation in the catalytic binding pocket of the DHFR receptor (PDB ID: 4LAE). These synthesized compounds could have evolved to shape orally active compounds shown in pharmacokinetics in silico studies. Conclusions: The research outcomes showed that explored 2-aminobenzothiazoles have good anti-bacterial and anthelmintic activity.

A series of pyrazolo[4,3-c]cinnoline derivatives was synthesized, characterized and evaluated for anti-inflammatory and antibacterial activity. Test compounds that exhibited good anti-inflammatory activity were further screened for their ulcerogenic and lipid peroxidation activity. Compounds 4d and 4l showed promising anti-inflammatory activity with reduced ulcerogenic and lipid peroxidation activity when compared to naproxen. Docking results of these two compounds with COX-2 (PDB ID: 1CX2) also exhibited a strong binding profile. Among the test derivatives, compound 4i displayed significant antibacterial property against gram-negative (Escherichia coli and Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus) bacteria. However, compound 4b emerged as the best dual anti-inflammatory–antibacterial agent in the present study.

In the present study, a new series of compounds (3 to 22) containing pyrazole moiety clubbed with 1,2-diazanaphthalene ring, structurally related to celecoxib and naproxen was synthesized. The compounds were evaluated for anti-inflammatory activity using carrageenan induced rat paw edema bioassay. Compounds showing marked anti-inflammatory activity were further tested for their analgesic, ulcerogenic and lipid peroxidation effect using naproxen as reference drug. The results showed that compounds 6, 13 and 14 exhibited good anti-inflammatory and analgesic activity with minimum gastric irritation. Compounds 13 and 14 emerged as potent anti-inflammatory (with percentage inhibition of 79.23 and 76) and analgesic agent (with percentage protection of 68.72 and 67.68) in the present study. Key words: Cinnoline, pyrazole, anti-inflammatory activity, analgesic activity, lipid peroxidation.

Nꞌ-{[2-(piperidin-1-yl)quinolin-3-yl]methylene}pyridine-4-carbohydrazide 2 has been synthesized through condensation of 2-(piperidin-1-yl)quinoline-3-carbaldehyde 1 with isonicotinic acid hydrazide (INH) in absolute ethanol. The structure of the title compound 2 was established on the basis of IR, 1H-NMR, 13C-NMR and mass spectral data.

1-(8-Chloro-3-methyl-1H-pyrazolo[4,3-c]cinnolin-1-yl)-2-(2-chlorophenyl)ethanone 2 has been synthesized through condensation of 3-acetyl-6-chloro-1H-cinnolin-4-one 1 with 2-(2-chlorophenyl)acetohydrazide in polar aprotic solvent containing catalytic amount of conc. HCl. The structure of the title compound 2 was established on the basis of IR, 1H-NMR, 13C-NMR and mass spectral data.