Azolo[d]pyridazinones in medicinal chemistry.

Azolo[d]pyridazinone is a privileged structure and versatile pharmacophore whose derivatives are associated with diverse biological activities, in particular antidiabetic, antiasthmatic, anticancer, analgesic, anti-inflammatory, antithrombotic, antidepressant and antimicrobial activities. The importance of this scaffold against some targets like PDE, COX and DPP-4 has been reviewed in detail previously. In the present review, we have summarized comprehensive information on azolo[d]pyridazinone derivatives investigated by many researchers for their diverse pharmacological activities, structure-activity relationship and molecular modeling studies since 2000. The review may lead scientists in the research fields of organic synthesis, medicinal chemistry and pharmacology to the strategic design and development of azolo[d]pyridazinone-based drug candidates in the future.

Synthesis and antimycobacterial activities of some new thiazolylhydrazone derivatives.

This Letter reports the synthesis and evaluation of some thiazolylhydrazone derivatives for their in vitro antimycobacterial activities against Mycobacterium tuberculosis H37Rv. The cytotoxic activities of all compounds were also evaluated. The compounds exhibited promising antimycobacterial activity with MICs of 1.03-72.46 µM and weak cytotoxicity (8.9-36.8% at 50 µg/mL). Among them, 1-(4-(1H-1,2,4-triazol-1-yl)benzylidene)-2-(4-(4-nitrophenyl)thiazol-2-yl)hydrazine 10 was found to be the most active compound (MIC of 1.03 µM) with a good safety profile (16.4% at 50 µg/mL). Molecular modeling studies were done to have an idea for the mechanism of the action of the target compounds. According the docking results it can be claimed that these compounds may bind most likely to TMPK than InhA or CYP121.

1-(4-Methoxyphenyl)-5-(3,4,5-trimethoxyphenyl)-1H-1,2,4-triazole-3-carboxamides: synthesis, molecular modeling, evaluation of their anti-inflammatory activity and ulcerogenicity.

A series of novel 1-(4-methoxyphenyl)-5-(3,4,5-trimethoxyphenyl)-1H-1,2,4-triazole-3-carboxamides were synthesized and confirmed with different spectroscopic techniques. The prepared compounds exhibited remarkable anti-inflammatory activity that represents 38%-100% of indomethacin activity and 44%-115% of celecoxib activity after 3 h. The anilides 5a-l and hydrazide 6 exhibit low incidence of gastric ulceration compared to indomethacin which was confirmed with histopathological investigation. In vitro COX-1/COX-2 inhibition studies showed compounds 4b (COX-1 IC50 = 45.9 µM; COX-2 IC50 = 68.2 µM) and 6 (COX-1 IC50 = 39.8 µM; COX-2 IC50 = 46.3 µM) are the most potent COX inhibitors in the tested compounds. The binding mode for some of the tested compounds to the enzymes was predicted using docking studies.

Synthesis, molecular modeling and evaluation of novel N'-2-(4-benzylpiperidin-/piperazin-1-yl)acylhydrazone derivatives as dual inhibitors for cholinesterases and Aß aggregation.

To develop new drugs for treatment of Alzheimer's disease, a group of N'-2-(4-Benzylpiperidin-/piperazin-1-yl)acylhydrazones was designed, synthesized and tested for their ability to inhibit acetylcholinesterase, butyrylcholinesterase and aggregation of amyloid beta peptides (1-40, 1-42 and 1-40_1-42). The enzyme inhibition assay results indicated that compounds moderately inhibit both acetylcholinesterase and butyrylcholinesterase. ß-Amyloid aggregation results showed that all compounds exhibited remarkable Aß fibril aggregation inhibition activity with a nearly similar potential as the reference compound rifampicin, which makes them promising anti-Alzheimer drug candidates. Docking experiments were carried out with the aim to understand the interactions of the most active compounds with the active site of the cholinesterase enzymes.

Synthesis and evaluation of human monoamine oxidase inhibitory activities of some 3,5-diaryl-N-substituted-4,5-dihydro-1H-pyrazole-1-carbothioamide derivatives.

Sixteen 3-aryl-5-(4-fluorophenyl)-N-substituted-4,5-dihydro-1H-pyrazole-1-carbothioamide derivatives were synthesized and their structure were identified by UV, IR, (1) H NMR, mass spectra, and microanalyses. The compounds were evaluated in vitro for their human monoamine oxidase (hMAO) inhibitory activities and their MAO-A and -B selectivity. All the compounds were found to potently inhibit MAO-A isoforms. 5-(4-Fluorophenyl)-3-(4-methoxyphenyl)-N-methyl-4,5-dihydro-1H-pyrazole-1-carbothioamide (1.0 × 10(-3) µM) was found to inhibit hMAO-A most selectively and potently. The binding mode of 5-(4-fluorophenyl)-3-(4-methoxyphenyl)-N-methyl-4,5-dihydro-1H-pyrazole-1-carbothioamide to hMAO-A was also predicted using docking studies.