Benzothiazole incorporated thiazolidin-4-ones and azetidin-2-ones derivatives: Synthesis and in vitro antimicrobial evaluation

Green design and synthesis of some novel thiazolidinone appended benzothiazole-triazole hybrids as antimicrobial agents

The global increase in bacterial resistance poses a significant threat, jeopardizing the effectiveness of antibiotics. Therefore, the development of new and efficient antimicrobial agents is pre-dominant. Taking this into consideration, in the present study, we designed and reported the facile synthesis of two novel series benzothiazole-triazole and thiazolidinone-appended benzothiazole-triazole hybrids using a molecular hybridization approach in a one-pot process. The synthesized compounds were tested for microbial growth inhibition against bacterial and fungal strains. Among all the synthetics, compounds derived from methoxyphenyl and heteroaromatic ring substitutions exhibited promising inhibitory activity. The current investigation has emphasized that benzothiazole-triazole hybrids incorporating thiazolidinone can be a promising and potent category of molecules with potential biological activities. This sustainable and eco-friendly protocol involves the metal-free, catalyst-free synthesis of bioactive scaffolds, which merges broad tolerance for functional groups with a short reaction time, resulting in good to excellent yields.

Design, Synthesis and Biological Activities of (Thio)Urea Benzothiazole Derivatives

(Thio)ureas ((T)Us) and benzothiazoles (BTs) each have demonstrated to have a great variety of biological activities. When these groups come together, the 2-(thio)ureabenzothizoles [(T)UBTs] are formed, improving the physicochemical as well as the biological properties, making these compounds very interesting in medicinal chemistry. Frentizole, bentaluron and methabenzthiazuron are examples of UBTs used for treatment of rheumatoid arthritis and as wood preservatives and herbicides in winter corn crops, respectively. With this antecedent, we recently reported a bibliographic review about the synthesis of this class of compounds, from the reaction of substituted 2-aminobenzothiazoles (ABTs) with iso(thio)cyanates, (thio)phosgenes, (thio)carbamoyl chlorides, 1,1'-(thio)carbonyldiimidazoles, and carbon disulfide. Herein, we prepared a bibliographic review about those features of design, chemical synthesis, and biological activities relating to (T)UBTs as potential therapeutic agents. This review is about synthetic methodologies generated from 1968 to the present day, highlighting the focus to transform (T)UBTs to compounds containing a range substituents, as illustrated with 37 schemes and 11 figures and concluded with 148 references. In this topic, the scientists dedicated to medicinal chemistry and pharmaceutical industry will find useful information for the design and synthesis of this interesting group of compounds with the aim of repurposing these compounds.

The application of hydrazones and hydrazide-hydrazones in the synthesis of bioactive azetidin-2-one derivatives: A mini review

The hydrazones and hydrazide-hydrazones beside possessing crucial bioactivity can serve as useful intermediates in the synthesis of heterocyclic systems like 1,3-benzothiazin-4-one, 1,3-thiazolidin-4-one, azetidin-2-one and 1,3,4-oxadiazole derivatives. The azetidin-2-one derivatives show mainly antibacterial, antitubercular and antifungal activity as well as anti-inflammatory, antioxidant, anticonvulsant and antidepressant activity and activity against Parkinson's disease. This review is focused on the literature reports which consider the synthesis and biological properties of azetidin-2-one derivatives.

Review on the Developments of Benzothiazole-containing Antimicrobial Agents

The infectious diseases caused by bacterial resistance to antibiotics constitute an increasing threat to human health on a global scale. An increasing number of infections, including tuberculosis, pneumonia, salmonellosis and gonorrhea, are becoming progressively challenging to cure owing to the ineffectiveness of current clinically used antibiotics and presents a serious health threat worldwide in medical community. The major concern of this global health threat is the ability of microorganisms to develop one or several mechanisms of resistance to antibiotics, making them inefficient to therapeutic treatment. The quest for discovering novel scaffold with antimicrobial property is particularly in great need to face future challenges in hospital and healthcare settings. Hence, the development of benzothiazoles is of considerable interest to medicinal chemists. Benzothiazole, being part of an important class of heterocyclic scaffold retains a wide spectrum of various attractive pharmacological activities. Antibiotic resistance represents an increasing burden comprising medical cost, hospital stay and mortality. Several derivatives containing a benzothiazole scaffold, reported in the literature, were found to display remarkable potencies towards diverse Grampositive and Gram-negative bacterial pathogens. The principal focus concerns the antibacterial potential of benzothiazole-based derivatives as antimicrobial agents interacting with targets in bacterial pathogens. In this review, we also disclose the significance of the benzothiazole moiety in the discovery of new antibacterial compounds, the potential of benzothiazole-based derivatives in the case of resistant bacterial strains, optimization of their antibacterial activity, and their future perspectives. The structure-activity relationship study and the mode of action of the title derivatives are highlighted too.

Microwave Irradiated Synthesis of Pyrimidine Containing, Thiazolidin-4-ones: Antimicrobial, Anti-tuberculosis, Antimalarial, and Anti-protozoa evaluation

Aim:

This study aims to synthesize thiazolidine-4-one compounds with a pyrimidine nucleus and evaluate against different species of bacteria, fungi, protozoa, and the malaria parasite.

Background:

Microwave irradiation was the best method for synthesizing the thiazolidin-4-one ring system. It took only 15 minutes for synthesizing thiazolidin-4-one while the conventional method required 12 hours. The rapid reaction was the main concern of this research.

Objective:

Pyrimidine and Thiazolidin-4-one nucleus have broad-spectrum biological activity and when it is introduced with other hetero atoms containing moiety, many types of biological activities have been found; antimicrobial, anti-tuberculosis, anti-protozoa, antimalarial are the main activities. The activity of these compounds inspired us to do extra research on Thiazolidin-4-one fused pyrimidines with different functional groups. The aim of this is to synthesize a combination of these two ring systems in less time by using a microwave irradiation method and to evaluate new compounds for different bioactivity.

Method:

2-(4-Chlorophenyl)-3-(4-(substituted phenyl)-6-(substituted aryl) pyrimidin-2-yl) thiazolidin-4-ones (6A-J) were synthesized by microwave irradiation to save energy and time. The structure of all newly synthesized motifs was characterized by spectral analysis (1H NMR, 13C NMR, IR, spectroscopy) and screened for antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Streptococcus pyogenes, antifungal activity against Candida albicans, Aspergillus niger, Aspergillus clavatus, anti-tuberculosis activity against M. tuberculosis H37RV, antimalarial activity against Plasmodium falciparum and anti-protozoa activity against L. mexicana and T. cruzi.

Result:

Because of microwave irradiation synthesis, time period is very less for preparing the new compound. Biological response given by compounds 6B, 6C, 6D, 6E, 6G, 6H, and 6J was found excellent.

Conclusion:

Good yield with purity of the newly synthesized thiazolidine-4-one compounds obtained in less time by using microwave irradiation. The biological response of some of the compounds of this series was found excellent

Saturated Five-Membered Thiazolidines and Their Derivatives: From Synthesis to Biological Applications

In past decades, interdisciplinary research has been of great interest for scholars. Thiazolidine motifs behave as a bridge between organic synthesis and medicinal chemistry and compel researchers to explore new drug candidates. Thiazolidine motifs are very intriguing heterocyclic five-membered moieties present in diverse natural and bioactive compounds having sulfur at the first position and nitrogen at the third position. The presence of sulfur enhances their pharmacological properties, and, therefore, they are used as vehicles in the synthesis of valuable organic combinations. They show varied biological properties viz. anticancer, anticonvulsant, antimicrobial, anti-inflammatory, neuroprotective, antioxidant activity and so on. This diversity in the biological response makes it a highly prized moiety. Based on literature studies, various synthetic approaches like multicomponent reaction, click reaction, nano-catalysis and green chemistry have been employed to improve their selectivity, purity, product yield and pharmacokinetic activity. In this review article, we have summarized systematic approaches for the synthesis of thiazolidine and its derivatives, along with their pharmacological activity, including advantages of green synthesis, atom economy, cleaner reaction profile and catalyst recovery which will help scientists to probe and stimulate the study of these scaffolds.

Novel benzothiazole hydrazine carboxamide hybrid scaffolds as potential in vitro GABA AT enzyme inhibitors: Synthesis, molecular docking and antiepileptic evaluation

In the present study, a series of newer benzothiazole derivatives containing thiazolidin-4-one (5a-g) and azetidin-2-one (6a-g), were synthesized by the cyclization of benzothiazolyl arylidene hydrazine carboxamide derivatives with thioglycolic acid and chloroacetyl chloride, respectively. Results of in vivo anticonvulsant screening revealed that compounds having 2,4-dicholoro (5c and 6c) and 4-nitro substituent (5g) at the phenyl ring have promising anticonvulsant activities without any neurotoxicity. Selected compounds were also evaluated for their in vitro GABA AT inhibition. The results indicated that compound 5c (IC₅₀ 15.26 μM) exhibited excellent activity as compared to the standard drug vigabatrin (IC₅₀ 39.72 μM) suggesting the potential of these benzothiazole analogues as new anticonvulsant agents.

Biological Aspects of Emerging Benzothiazoles: A Short Review

In recent years heterocyclic compounds analogues and derivatives have attracted wide attention due to their useful biological and pharmacological properties. Benzothiazole is among the usually occurring heterocyclic nuclei in many marine as well as natural plant products. Benzothiazole is a privileged bicyclic ring system with multiple applications. It is known to exhibit a wide range of biological properties including anticancer, antimicrobial, and antidiabetic, anticonvulsant, anti-inflammatory, antiviral, antitubercular activities. A large number of therapeutic agents are synthesized with the help of benzothiazole nucleus. During recent years there have been some interesting developments in the biological activities of benzothiazole derivatives. These compounds have special significance in the field of medicinal chemistry due to their remarkable pharmacological potentialities. This review is mainly an attempt to present the research work reported in the recent scientific literature on different biological activities of benzothiazole compounds.