Synthesis and antiviral activity of new acrylamide derivatives containing 1,2,3-thiadiazole as inhibitors of hepatitis B virus replication

Sodium Carbonate-Promoted Formation of 5-Amino-1,2,4-thiadiazoles and 5-Amino-1,2,4-selenadiazoles with Elemental Sulfur and Selenium

Sodium carbonate-promoted facile synthesis of 5-amino-1,2,4-thiadiazoles and 5-amino-1,2,4-selenadiazoles with elemental sulfur and selenium, respectively, was developed. This method was carried out with O2 in the air as the green oxidant, and it has several advantages, including low cost, low toxicity, and stable sulfur and selenium sources, good to excellent yields with water as the sole byproduct, simple operation, and a broad substrate scope. Preliminary mechanistic studies indicate that the formation of the 1,2,4-thiadiazole ring and the 1,2,4-selenadiazole ring undergoes different processes.

Chromone Containing Hybrid Analogs: Synthesis and Applications in Medicinal Chemistry

The use of privileged scaffolds has proven beneficial for generating novel bioactive scaffolds in drug discovery program. Chromone is one such privileged scaffold that has been exploited for designing pharmacologically active analogs. The molecular hybridization technique combines the pharmacophoric features of two or more bioactive compounds to avail a better pharmacological activity in the resultant hybrid analogs. The current review summarizes the rationale and techniques involved in developing hybrid analogs of chromone, which show potential in fields of obesity, diabetes, cancer, Alzheimer's disease and microbial infections. Here the molecular hybrids of chromone with various pharmacologically active analogs or fragments (donepezil, tacrine, pyrimidines, azoles, furanchalcones, hydrazones, quinolines, etc.) are discussed with their structure-activity relationship against above-mentioned diseases. Detailed methodologies for the synthesis of corresponding hybrid analogs have also been described, with suitable synthetic schemes. The current review will shed light on various strategies utilized for the design of hybrid analogs in the field of drug discovery. The importance of hybrid analogs in various disease conditions is also illustrated.

Steroid-triazole conjugates: A brief overview of synthesis and their application as anticancer agents

Steroids are biomolecules that play pivotal roles in various physiological and drug discovery processes. Abundant research has been fuelled towards steroid-heterocycles conjugates over the last few decades as potential therapeutic agents against various diseases especially as anticancer agents. In this context various steroid-triazole conjugates have been synthesized and studied for their anticancer potential against various cancer cell lines. A thorough search of the literatures revealed that a concise review pertaining the present topic is not compiled. Therefore, in thus review we summarize the synthesis, anticancer activity against various cancer cell lines and structure activity relationship (SAR) of various steroid-triazole conjugates. This review can lay down the path towards the development of various steroid-heterocycles conjugates with lesser side effects and profound efficacy.

Chemistry and Therapeutic Aspect of Triazole: Insight into the Structure-activity Relationship

The triazole ring is a highly significant heterocycle that occurs naturally in many commodities and is a common feature in pharmaceuticals. Recently, heterocyclic compounds and their derivatives have been getting a lot of attention in medicinal chemistry because they have a lot of pharmacological and biological potential. For example, a lot of drugs have nitrogen-containing heterocyclic moieties. The triazole ring is often used as a bio-isostere of the oxadiazole nucleus. The oxygen atom in the oxadiazole nucleus is replaced by nitrogen in the triazole analogue. This article explores the pharmacological properties of the triazole moiety, including but not limited to antibacterial, analgesic, anticonvulsant, anthelmintic, anti-inflammatory, antitubercular, antimalarial, antioxidant, antiviral, and other properties. Additionally, we discuss the diverse multi- target pharmacological activities exhibited by triazole-based compounds. Based on a literature review, it is evident that triazole-based chemicals hold significant potential for various applications.

Novel isoxazoline-linked 1,3,4-thiadiazole hybrids as anticancer agents: Design, synthesis, biological evaluation, molecular docking, and molecular dynamics simulation

In the current study, natural (R)-carvone was utilized as a starting material for the efficient synthesis of two series of isoxazoline derivatives bearing the 1,3,4-thiadiazole moiety. The new compounds were obtained in good yields and were characterized by ¹ H and ¹³ C NMR and HRMS analysis. The newly synthesized monoterpenic isoxazoline 1,3,4-thiadiazole and their thiosemicarbazone intermediate derivatives were evaluated for their anticancer activity in four cancer cell lines (HT-1080, A-549, MCF-7, and MDA-MB-231). Most of the synthesized compounds exhibited moderate to high anticancer effects. Compound 13c showed the highest anticancer activity with IC₅₀ values ranging from 19.33 ± 1.81 to 34.81 ± 3.03 µM. Further investigation revealed that compounds 12e and 13c could inhibit the cell growth of HT-1080 and MCF-7 cells by inducing apoptosis through caspase-3/7 activation. The apoptotic effect was accompanied by an S phase and G2/M cell cycle arrest for 13c and 12e, respectively. Compounds 12e and 13c were assessed in silico using molecular docking and molecular dynamics. We found that compound 13c is moderately active against the caspase-3 protein, which triggers apoptosis via intrinsic and extrinsic routes, making compound 13c a promising candidate to activate the proapoptotic protein (caspase-3).

Quantification of a New Antifungal Drug Based on 1,3,4-Thiadiazole by HPLC-ESI/MS: Method Development, Validation and Pharmacokinetic Application

The high sensitive HPLC-ESI/MS method for quantitative determination of a new antifungal drug - 2-[(1Z)-1-(3,5-diphenyl-1,3,4-thiadiazol-2(3Н)-ylidene)methyl]-3,5-diphenyl-1,3,4-thiadiazol-3-ium chloride (TDZ) - was developed and fully validated. TDZ was separated from plasma and urine samples by acetonitrile deproteinization and extraction without time-consuming sample preparation. The reversed-phase high-performance liquid chromatography on Kromasil 100-3.5 C8 column of TDZ in isocratic elution mode using 0.03% trifluoroacetic acid : acetonitrile (65:35, v/v) at a flow rate of 0.2 mL min^-1 was performed. Determination of TDZ was carried out by a positive electrospray ionization in a selected ion monitoring mode for [M⁺]=489 m/z. The method of absolute calibration was used for quantification of TDZ in two concentrations ranges: 100-2500 pg mL^-1 and 2500-30 000 pg mL^-1. The established method showed a good linearity (R=0.999 for both ranges), the limits of determination and quantification were 50 and 100 pg mL^-1, respectively. The Intra- and Inter-day precision values were measured by t-Distribution and Fisher's Exact Test and were in accordance with the regulatory guidance. Low matrix effects and good recovery were found for TDZ. The present method was successfully applied to determine the pharmacokinetic parameters of TDZ by means of intravenous and oral administrations to rats at 5.0 mg kg^-1 and 10.0 mg kg^-1, respectively.

Triazole analogues as potential pharmacological agents: a brief review

Background

A large number of studies have recently reported that, because of their significant biological and pharmacological properties, heterocyclic compounds and their derivatives have attracted a strong interest in medicinal chemistry. The triazole nucleus is one of the most important heterocycles which has a feature of natural products as well as medicinal agents. Heterocyclic nitrogen is abundantly present in most medicinal compounds. The derivatization of triazole ring is based on the phenomenon of bio-isosteres in which substituted the oxygen atom of oxadiazole nucleus with nitrogen triazole analogue.

Main text

This review focuses on recent synthetic procedure of triazole moiety, which comprises of various pharmacological activities such as antimicrobial, anticonvulsant, anti-inflammatory, analgesic, antitubercular, anthelmintic, antioxidant, antimalarial, antiviral, etc..

Conclusion

This review highlights the current status of triazole compounds as different multi-target pharmacological activities. From the literature survey, triazole is the most widely used compound in different potential activities.

I2/DMSO-Catalyzed Transformation of N-tosylhydrazones to 1,2,3-thiadiazoles

An iodine/DMSO catalyzed selective cyclization of N-tosylhydrazones with sulfur without adding external oxidant was developed for the synthesis of 4-aryl-1,2,3-thiadiazoles. In this reaction, oxidation of HI by using DMSO as dual oxidant and solvent is the key, which allowed the regeneration of I₂, ensuring thus the success of the synthesis. This protocol features by simple operation, high step-economy (one-pot fashion), broad substrate scope as well as scale-up ability.

Perylenequinonoid-Catalyzed [4 + 1] and [4 + 2] Annulations of Azoalkenes: Photocatalytic Access to 1,2,3-Thiadiazole/1,4,5,6-Tetrahydropyridazine Derivatives

Nitrogen-containing heterocycles are especially considered "privileged" structural scaffolds for the development of new drugs. However, traditional methods of organic synthesis are mainly based on thermal cycloaddition reaction; thus, the exploration of new strategies for the rapid assembly of N-heterocycles under mild conditions is highly desirable. Here, we developed a new method that visible light along with 1 mol % cercosporin, which is one of the perylenequinonoid pigments with excellent properties of photosensitization and can be easily produced by a new isolated endophytic fungus Cercospora sp. JNU001 strain with high yield through microbial fermentation, catalyzes the synthesis of 1,2,3-thiadiazoles and 1,4,5,6-tetrahydropyridazines by a photocatalytic process with good regioselectivity and broad functional-group compatibility under mild conditions. Thus, a bridge between microbial fermentation and organic photocatalysis for the construction of nitrogen-containing heterocycles was set up in a sustainable, environmentally friendly manner.

Synthesis of Novel 2,5-Disubstituted-1,3,4-thiadiazoles Clubbed 1,2,4-Triazole, 1,3,4-Thiadiazole, 1,3,4-Oxadiazole and/or Schiff Base as Potential Antimicrobial and Antiproliferative Agents

In the present study, a new series of 2,5-disubstituted-1,3,4-thiadiazole tethered 1,2,4-triazole, 1,3,4-thiadiazole, 1,3,4-oxadiazole and Schiff base derivatives were synthesized and characterized by IR, ¹H-NMR, ¹³C-NMR, MS and elemental analyses. All compounds were screened for their antibacterial, antifungal and antiproliferative activity. Some of the synthesized derivatives have displayed promising biological activity.

Synthesis and antiviral activity of some new bis-1,3-thiazole derivatives

Treatment of 3-phenyl-1,3-thiazolidin-4-one derivative 1 with phenylisothiocyanate in DMF, in the presence of potassium hydroxide, at room temperature gave the non-isolable potassium salt 2. The in-situ reaction of 2 with differently substituted N-aryl hydrazonoyl chlorides 3, 7a-d and 14a-d afforded the corresponding 2-(pyrazolyl)thiazolylimino-5-(thiadiazolylidene)thiazolidin-4-one derivatives 6, 10a-d and 17a-d, respectively. Reaction of 2 with further α-haloketones yielded the 4-(pyrazolyl)thiazolylimino-bis-thiazolidine derivatives 22, 25 and 26. Single crystal X-ray analysis was used in structure elucidation of the products. The in-vitro antiviral screening against four viruses (Poliovirus, Influenza A (H1N1) virus, Hepatitis B virus and Hepatitis C virus) for the obtained compounds was examined. Structure activity relationship (SAR) was also studied. The goal of the work was achieved in discovering a very active compound 10a as anti HCV agent (EC50 0.56 μM).

Synthesis of novel triazoles, tetrazine, thiadiazoles and their biological activities

An expedient synthesis of novel triazoles, tetrazine and thiadiazoles, using conveniently accessible and commercially available starting materials has been achieved. The synthesized compounds were characterized by spectroscopic and elemental analyses, and screened for their antibacterial activities against four different strains, namely E. coli, P. aeruginosa, S. aureus and B. megaterium. In particular, the compounds 5, 24 and 26h exhibited excellent antibacterial activities compared to the reference antibiotic. To get further insight about their behavior, these compounds were tested for their antioxidant activities via SOD-like activity, DPPH free radical scavenging activity, ABST and NO, which showed promising results. Furthermore, these compounds effectively promoted the cleavage of genomic DNA as well, in the absence of any external additives.

Non-nucleoside anti-HBV agents: advances in structural optimization and mechanism of action investigations

In this review, we focus on the recent advances in discovery, structural modifications and biological activities studies of several distinct classes of synthetic non-nucleoside small molecular compounds with new mechanisms.

A review of non-nucleoside anti-hepatitis B virus agents

Hepatitis B Virus is the most common cause of chronic liver disease worldwide. Currently approved agents of chronic HBV infection treatment include interferon and nucleoside analogues. However, the side effects of interferon and the viral resistance of nucleoside analogues make the current treatment far from satisfactory. Therefore, new drugs with novel structures and mechanisms are needed. Recently, a number of non-nucleoside HBV inhibitors have been obtained from natural sources or prepared by synthesis/semi-synthesis. Some of them exhibited potent anti-HBV activity with novel mechanisms. These compounds provide useful information for the medicinal chemist to develop novel non-nucleoside compounds as anti-HBV agents.

Microwave assisted synthesis, antifungal activity and DFT theoretical study of some novel 1,2,4-triazole derivatives containing the 1,2,3-thiadiazole moiety

In order to investigate the biological activity of 1,2,4-triazole compounds, seventeen novel 1,2,4-triazole derivatives containing 1,2,3-thiadiazole moieties were synthesized by multi-step reactions under microwave assisted conditions. The structures were characterized by 1H-NMR, 13C-NMR, MS and elemental analyses. The target compounds were evaluated for their in vivo fungicidal activities against Corynespora cassiicola, Pseudomonas syringae pv. Lachrymans, and Pseudoperonospora cubensis, and the results indicated that some of the title compounds displayed good fungicidal activities. Theoretical calculations on the title compounds were carried out at the B3LYP/6-31G (d,p). level. The full geometry optimization was carried out using the 6-31G(d,p) basis set, and the frontier orbital energy, atomic net charges were discussed, and the structure-activity relationships were also studied.

Synthesis, Crystal Structure, and Fungicidal Activity of 5-(4-cyclopropyl-5-((3-fluorobenzyl)thio)-4H-1,2,4-triazol-3-yl)-4-methyl-1,2,3-thiadiazole

A new 1,2,3-thiadiazole compound was synthesized and characterized. The crystal structure of the title compound (C15H14FN5S2, Mr = 347.43) has been determined by single-crystal X-ray diffraction. The crystal is of triclinic, space group P-1 witha=7.0490(14),b=9.0212(18),c=12.799(3) Å,α= 89.97(3)°,β= 82.27(3)°,γ= 73.17(3)°,V= 771.3(3)  Å3, Z = 2, F(000) = 360, Dc = 1.496 g/cm3,μ= 0.036 mm−1, the finalR1= 0.0358, andwR2= 0.0986 for 2204 observed reflections withI>2σ(I). A total of 5697 reflections were collected, of which 2719 were independent (Rint=0.0028). The herbicidal activity of title compound was determined; the results showed that the title compound displayed excellent fungicidal activity.

Ionic liquid as soluble support for synthesis of 1,2,3-thiadiazoles and 1,2,3-selenadiazoles

A convenient synthesis of 1,2,3-thiadiazoles and 1,2,3-selenadiazoles was achieved using an ionic liquid as a novel soluble support. Ionic liquid-supported sulfonyl hydrazine was synthesized and reacted with a number of ketones to afford the corresponding ionic liquid-supported hydrazones that were converted to 1,2,3-thiadiazoles in the presence of thionyl chloride. The reaction of ionic liquid-supported hydrazones with selenium dioxide in acetonitrile afforded 1,2,3-selenadiazoles. The advantages of this methodology were the ease of workup, simple reaction conditions, and high purity.