Synthesis and evaluation of 2-amino-5-sulfanyl-1,3,4-thiadiazoles as antidepressant, anxiolytic, and anticonvulsant agents

1,3,4-Thiadiazole and 1,2,4-triazole-5-thione derivatives bearing 2-pentyl-5-phenyl-2,4-dihydro-3H-1,2,4-triazole-3-one ring: Synthesis, molecular docking, urease inhibition, and crystal structure

Two series of 1,3,4-thiadiazole (40a-o) and 1,2,4-triazole-5-thione (41a-l) derivatives bearing a 2-pentyl-5-phenyl-1,2,4-triazole-3-one ring were synthesized and then studied for their urease inhibitory activities using thiourea as a standard drug. Among the two groups, the first group (40a-o) did not show good activity while the second group (41a-l) showed excellent activity. Compound 41j (1091.24 ± 14.02 µM) of the second series of compounds showed lower activity than thiourea, while the remaining 11 compounds (41a-i, k, and l) showed better activity than thiourea (183.92 ± 13.14 µM). Among the 11 compounds, 41b (15.96 ± 2.28 µM) having the 3-F group on the phenyl ring showed the highest inhibitory activity. Urease kinetic studies of 41b, which is the most active compound, determined it to have an un-competitive inhibition potential. Moreover, in silico analysis against urease from jack bean with 27 new heterocyclic compounds and the reference molecule was carried out to see the necessary interactions responsible for urease activity. The docking calculations of all compounds supported stronger binding to the receptor than the reference molecule, with high inhibition constants. In addition, compound 40m was characterized by single-crystal X-ray diffraction analysis. X-ray analysis reveals that the structures of the compound 40m crystallize in the monoclinic P21/c space group with the cell parameters: a = 10.2155(9) Å, b = 22.1709(18) Å, c = 21.4858(17) Å, β = 99.677(8)°, V = 4797.0(7) ų . X-ray diffraction analyses were also performed to gain insights into the role of weak intermolecular interactions and C-H…X (halogen) interactions in compound 40m that influence the crystal packing.

1,3,4-Thiadiazole Scaffold: As Anti-Epileptic Agents

A wide range of biological activities is exhibited by 1,3,4-thiadiazole moiety such as antidiabetic, anticancer, anti-inflammatory, anticonvulsant, antiviral, antihypertensive, and antimicrobial. To date, drugs such as butazolamide, and acetazolamide. Several modifications have been done in the 1,3,4-thiadiazole moiety which showed good potency as anticonvulsant agents which are highly effective and have less toxicity. After in-depth literature survey in this review, we have compiled various derivatives of 1,3,4-thiadiazole scaffold as anticonvulsant agents.

Synthetic and therapeutic perspectives of nitrogen containing heterocycles as anti-convulsants

Epilepsy is one of the commonly prevailing neurological disorders. According to the reports, it is evident that about 80% of the epileptic cases have been observed in developing countries. Although there are many drugs with significant potency available in the market; still there is an issue of selectivity and toxicity. Therefore, continuous attempts have been made by the researchers to develop newer therapeutic agents against epilepsy. Many synthetic strategies have been available in the literature to synthesize various classes of anticonvulsants with promising activity. In the presented review, authors have summarized some newer synthetic routes being used for the synthesis of nitrogen-containing anticonvulsants taking a cue from the reported established anticonvulsant drugs viz. vigabatrin, sodium valproate, oxcarbazepine, felbamate, retigabine, and gabapentin. Various derivatives with the substitution for better anticonvulsant profile have been described in the figures for easy comparative study. The structure-activity relationship (SAR) of compounds with maximum potency has also been discussed. This article may serve as a boost for the researchers to modify the pre-existing synthetic routes as well as to improve potency and yield of the compounds.

Synthesis of Some Novel Thiadiazole Derivative Compounds and Screening Their Antidepressant-Like Activities

Novel thiadiazole derivatives were synthesized through the reaction of acetylated 2-aminothiadiazole and piperazine derivatives. The chemical structures of the compounds were clarified by Infrared Spectroscopy (IR), ¹H Nuclear Magnetic Resonance Spectroscopy (¹H-NMR), ¹³C Nuclear Magnetic Resonance Spectroscopy (¹³C-NMR) and Electronspray Ionisation Mass Spectroscopy (ESI-MS) spectroscopic methods. Antidepressant-like activities were evaluated by the tail-suspension (TST) and modified forced swimming (MFST) methods. Besides, possible influence of the test compounds on motor activities of the animals were examined by activity cage tests. In the TST, administration of the compounds 2c, 2d, 2e, 2f, 2g and 2h significantly decreased the immobility time of mice regarding the control values. Further, in the MFST, the same compounds reduced the total number of immobility behaviors while increasing swimming performance. However, no change was observed in the total number of climbing behaviors. These data suggested that compounds 2c, 2d, 2e, 2f, 2g and 2h possess notable antidepressant-like activities. Reference drug fluoxetine (10 mg/kg) was also exhibited its antidepressant activity, as expected. No significant difference was seen between the locomotor activity values of the test groups signifying that observed antidepressant-like activities are specific. Theoretical calculation of absorption, distribution, metabolism, excretion (ADME) properties for the obtained compounds were performed and obtained data supported the antidepressant-like potential of these novel thiadiazole derivatives.

Synthesis and Evaluation of New 1,3,4-Thiadiazole Derivatives as Antinociceptive Agents

In the current work, new 1,3,4-thiadiazole derivatives were synthesized and investigated for their antinociceptive effects on nociceptive pathways of nervous system. The effects of these compounds against mechanical, thermal and chemical stimuli were evaluated by tail-clip, hot-plate and acetic acid-induced writhing tests, respectively. In addition, activity cage was performed to assess the locomotor activity of animals. The obtained data indicated that compounds 3b, 3c, 3d, 3e, 3g and 3h increased the reaction times of mice both in the hot-plate and tail-clip tests, indicating the centrally mediated antinociceptive activity of these compounds. Additionally, the number of writhing behavior was significantly decreased by the administration of compounds 3a, 3c, 3e and 3f, which pointed out the peripherally mediated antinociceptive activity induced by these four compounds. According to the activity cage tests, compounds 3a, 3c and 3f significantly decreased both horizontal and vertical locomotor activity of mice. Antinociceptive behavior of these three compounds may be non-specific and caused by possible sedative effect or motor impairments.

2,2'-[(1,3,4-Thia-diazole-2,5-di-yl)bis-(sulfanedi-yl)]diaceto-nitrile

In the title compound, C₆H₄N₄S₃, the 1,3,4-thia­diazole ring is essentially planar, with an r.m.s. deviation of 0.001 Å. The two N—C—S—C torsion angles in the mol­ecule are −23.41 (15) and 0.62 (14)°. One aceto­nitrile group is above the plane of the 1,3,4-thia­diazole ring and the other is below it, indicating syn and anti orientations. In the crystal, C—H⋯N hydrogen bonds link the molecules into ribbons along [010].

Synthesis, biological evaluation, and molecular docking studies of cinnamic acyl 1,3,4-thiadiazole amide derivatives as novel antitubulin agents

A series of cinnamic acyl 1,3,4-thiadiazole amide derivatives (6a-10e) have been designed and synthesized, and their biological activities were also evaluated as potential antiproliferation and tubulin polymerization inhibitors. Among all the compounds, 10e showed the most potent activity in vitro, which inhibited the growth of MCF-7 and A549 cell lines with IC(50) values of 0.28 and 0.52μg/mL, respectively. Compound 10e also exhibited significant tubulin polymerization inhibitory activity (IC(50)=1.16μg/mL). Docking simulation was performed to insert compound 10e into the crystal structure of tubulin at colchicine binding site to determine the probable binding model. Based on the preliminary results, compound 10e with potent inhibitory activity in tumor growth may be a potential anticancer agent.