Activity of benzothiazoles and chemical derivatives on Plasmodium falciparum

Antimalarial activities of benzothiazole analogs: A systematic review

BACKGROUND

Benzothiazole derivatives have been reported to possess a wide range of biological activities, including antimalarial activity. This systematic review aims to summarize and evaluate the antimalarial activities of benzothiazole analogs.

METHODS

We conducted an electronic search using nine databases in October 2017 and subsequently updated in September 2022. We included all original in vitro and in vivo studies that documented the antimalarial activities of compounds containing benzothiazole analogs with no restriction. The risk of bias of each included study was assessed by ToxRTool.

RESULTS

Twenty-eight articles were included in our study, which are in vitro, in vivo, or both. Of these, 232 substances were identified to have potent antiplasmodial activity against various strains of the malaria parasite. Benzothiazole analogs show different antimalarial mechanisms, including inhibition of Plasmodium falciparum enzymes in in vitro studies and inhibition of blood parasites in in vivo studies.

CONCLUSIONS

Benzothiazole derivatives are promising substances for treating malaria. The structure-activity relationship studies suggest that the substitution pattern of the benzothiazole scaffold plays a crucial role in determining the antimalarial activity of the analog.

A Review on Synthetic Thiazole Derivatives as an Antimalarial Agent

BACKGROUND

Thiazole is a widely studied core structure in heterocyclic chemistry and has proven to be a valuable scaffold in medicinal chemistry. The presence of thiazole in both naturally occurring and synthetic pharmacologically active compounds demonstrates the adaptability of these derivatives.

METHODS

The current study attempted to review and compile the contributions of numerous researchers over the last 20 years to the medicinal importance of these scaffolds, with a primary focus on antimalarial activity. The review is based on an extensive search of PubMed, Google Scholar, Elsevier, and other renowned journal sites for a thorough literature survey involving various research and review articles.

RESULTS

A comprehensive review of the antimalarial activity of the thiazole scaffold revealed potential therapeutic targets in Plasmodium species. Furthermore, the correlation of structure-activity-relationship (SAR) studies from various articles suggests that the thiazole ring has therapeutic potential.

CONCLUSION

This article intends to point researchers in the right direction for developing potential thiazole-based compounds as antimalarial agents in the future.

Exploration of the Antimicrobial Effects of Benzothiazolylthiazolidin-4-One and In Silico Mechanistic Investigation

BACKGROUND

Infectious diseases still affect large populations causing significant morbidity and mortality. Bacterial and fungal infections for centuries were the main factors of death and disability of millions of humans. Despite the progress in the control of infectious diseases, the appearance of resistance of microbes to existing drugs creates the need for the development of new effective antimicrobial agents. In an attempt to improve the antibacterial activity of previously synthesized compounds modifications to their structures were performed.

METHODS

Nineteen thiazolidinone derivatives with 6-Cl, 4-OMe, 6-CN, 6-adamantan, 4-Me, 6-adamantan substituents at benzothiazole ring were synthesized and evaluated against panel of four bacterial strains S. aureus, L. monocytogenes, E. coli and S. typhimirium and three resistant strains MRSA, E. coli and P. aeruginosa in order to improve activity of previously evaluated 6-OCF3-benzothiazole-based thiazolidinones. The evaluation of minimum inhibitory and minimum bactericidal concentration was determined by microdilution method. As reference compounds ampicillin and streptomycin were used.

RESULTS

All compounds showed antibacterial activity with MIC in range of 0.12-0.75 mg/mL and MBC at 0.25->1.00 mg/mL The most active compound among all tested appeared to be compound 18, with MIC at 0.10 mg/mL and MBC at 0.12 mg/mL against P. aeruginosa. as well as against resistant strain P. aeruginosa with MIC at 0.06 mg/mL and MBC at 0.12 mg/mL almost equipotent with streptomycin and better than ampicillin. Docking studies predicted that the inhibition of LD-carboxypeptidase is probably the possible mechanism of antibacterial activity of tested compounds.

CONCLUSION

The best improvement of antibacterial activity after modifications was achieved by replacement of 6-OCF3 substituent in benzothiazole moiety by 6-Cl against S. aureus, MRSA and resistant strain of E. coli by 2.5 folds, while against L. monocytogenes and S. typhimirium from 4 to 5 folds.

Advancement in Pharmacological Activities of Benzothiazole and its Derivatives: An Up to Date Review

Benzothiazole is a heterocyclic aromatic and bicyclic compound in which, benzene ring is attached with thiazole ring. This nucleus is established in marine as well as terrestrial natural compounds. The benzothiazole skeleton is established in a broad variety of bioactive heterocycles and natural products. The benzothiazole nucleus is considered as the principle moiety in several biologically active compounds. Over the decade, chemists are paying more attention towards the revision of the biological and therapeutic activities such as antimicrobial, analgesic, antiinflammatory, antitubercular, antiviral and antioxidant of benzothiazole containing compounds. The molecular structures of a number of potent drugs including Frentizole, Pramipexole, Thioflavin T and Riluzole etc., are based on benzothiazole skeleton. The present work is the compilation and presentation of all available information in a systematic manner with an aim to present the findings in a way, which may be beneficial for future research.

An epigrammatic status of the 'azole'-based antimalarial drugs

The development of multidrug resistance in the malarial parasite has sabotaged majority of the eradication efforts by restraining the inhibition profile of first line as well as second line antimalarial drugs, thus necessitating the development of novel pharmaceutics constructed on appropriate scaffolds with superior potency against the drug-resistant and drug-susceptible Plasmodium parasite. Over the past decades, the infectious malarial parasite has developed resistance against most of the contemporary therapeutics, thus necessitating the rational development of novel approaches principally focused on MDR malaria. This review presents an epigrammatic collation of the epidemiology and the contemporary antimalarial therapeutics based on the 'azole' motif.

Facile Synthesis of a Series of Non-Symmetric Thioethers Including a Benzothiazole Moiety and Their Use as Efficient In Vitro anti-Trypanosoma cruzi Agents

A series of 2-benzylsulfanyl benzothiazole (BTA) derivatives were synthesized and fully characterized and in vitro tested against two strains of T. cruzi (NINOA and INC-5), exhibiting good activities at low concentrations.

2-Mercapto Benzothiazole Derivatives: As Potential Leads for the Diabetic Management

BACKGROUND

Results of our previous studies on antiglycation activity, and the noncytotoxicity of 2-mercapto benzothiazoles, encouraged us to further widen our investigation towards the identification of leads against diabetes mellitus.

METHODS

33 derivatives of 2-mercapto benzothiazoles 1-33 were evaluated for in vitro α- glucosidase inhibitory activity. Mode of inhibition was deduced by kinetic studies. To predict the interactions of 2-mercapto benzothiazole derivatives 1-33 with the binding pocket of α-glucosidase enzyme, molecular docking studies were performed on the selected inhibitors.

RESULTS

Compounds 2-4, 6-7, 9-26, 28 and 30 showed many folds potent α-glucosidase inhibitory activity in the range of IC50 = 31.21-208.63 μM, as compared to the standard drug acarbose (IC50 = 875.75 ± 2.08 μM). It was important to note that except derivative 28, all other derivatives were also found previously to have antiglycating potential in the range of IC50 = 187.12-707.21 μM.

CONCLUSION

A number of compounds were identified as dual nature as antiglycating agent and α- glucosidase inhibitors. These compounds may serve as potential lead candidates for the management of diabetes mellitus.

Interactions with polynucleotides and antitumor activity of amidino and imidazolinyl substituted 2-phenylbenzothiazole mesylates

Based on previously reported antiproliferative activity screening, four most promising disubstituted 2-phenylbenzothiazole hydrochlorides were chosen for detailed study. Water solubility, as well as liphophilicity/hydrophilicity balance of organic core were modified by conversion to mesylate salts. For purpose of structure/activity studies their structures were determined by X-ray structure analysis. Detailed analysis of interactions of new compounds with double stranded (ds-) DNA/RNA by UV/Vis and CD titrations, thermal melting and viscometry experiments revealed that most of studied compounds intercalate into ds-RNA but bind into minor groove of AT-DNA, and agglomerate along GC-DNA. Furthermore, compounds also interact with ss-RNA, but only amino-imidazolinyl 2-phenylbenzothiazole, 4b displayed well defined orientation and dominant binding mode (by induced CD signals) with poly A and poly G. Besides, in vitro investigations revealed moderate to high antiproliferative activity of benzothiazoles against seven human cancer cell lines, while in some cases (HTC 116, SW620, MIA PaCa-2) high correlation between the type of the amidino group and cytotoxic activity was observed.

Synthesis, anti-breast cancer activity, and molecular modeling of some benzothiazole and benzoxazole derivatives

A new series of benzothiazoles and benzoxazoles was synthesized using 4-benzothiazol-2-yl-phenylamine and 4-benzoxazol-2-yl-phenylamine as starting materials. All the prepared compounds were evaluated for their antitumor activities against human breast cancer cell lines, MCF-7 and MDA-231, using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cell viability analysis. Almost all the tested compounds revealed potent antitumor activity, especially the N-methyl piperazinyl substituted derivatives 6f and 6c, which displayed the most potent inhibitory activity with IC50 values ranging from 8 to 17 nM. Docking the synthesized compounds into the epidermal growth factor receptor (EGFR), which is highly expressed in breast cancer, was employed to explore the possible interactions of these compounds with the EGFR. The activity of the reported compounds supports its clinical promise as a component of therapeutic strategies for cancer, for which high concentrations of chemotherapeutic agents are always a major limitation.

5-Chloro-2-phenyl-1,3-benzothiazole

In the structure of the title compound, C₁₃H₈ClNS, the dihedral angle between the benzothia­zole ring system and the phenyl ring is 7.11 (8)°. In the crystal, mol­ecules are arranged parallel to the c axis.

Synthesis and antimicrobial activity of new 4-thiazolidinone derivatives containing 2-amino-6-methoxybenzothiazole

A novel series of Schiff bases 5a-j and 4-thiazolidinones 6a-j have been prepared from the building blocks 2-chloro pyridine-3-carboxylic acid [1] and 2-amino-6-methoxy-benzothiazole [2]. All of the synthesized compounds have been confirmed by elemental analyses, IR, (1)H NMR and (13)C NMR spectral data. These newly synthesized compounds were screened for their antimicrobial activity. Variable and modest activity was observed against the investigated strains of bacteria and fungi, however, compound 6h revealed significant antibacterial activity against Escherichia coli. Compounds 1, 2, 3, 5c, 5g and 5h, on the other hand, revealed potent antifungal activity against Candida albicans compared to the reference drug greseofulvin.

Synthesis and biological evaluation of new heterocyclic quinolinones as anti-parasite and anti-HIV drug candidates

We have synthesized quinolinones with potential antiparasitic and anti-HIV activities by an original two-step method involving microwave irradiation and have evaluated their activities against Plasmodium falciparum, Leishmania donovani, Trichomonas vaginalis, and HIV. None of the tested compounds had been previously described using this method of synthesis. One of the compounds had interesting antiparasitic and anti-HIV activity, which could be improved by substitution with different radicals.

Synthesis and NMR spectral assignments of novel nitrogen and sulfur heterocyclic compounds

Synthesis and NMR spectral studies of multidentate N and S heterocycles, 1,3,5-tris(N-methylbenzimidazolyl)benzene, 1,3,5-tris(benzimidazolyl)benzene,1,3,5-tris(benzothiazolyl) benzene, 2,2'-bipyridine 3,3'-bis(benzothiazolyl)benzene and 1,2,4,5-tetrakis(benzothiazolyl) benzene have been carried out. 2D (1)H-(1)H PFG-COSY as well as (1)H-(13)C single and multiple bond correlated (2D GRASP-HSQC and GRASP-HMBC) experiments have been employed to characterize the compounds. 1D NOE experiments have been useful in understanding the structure of 1,3,5-tris(N-methylenzimidazolyl)benzene.

Synthesis and antiplasmodial activity of new 4-aryl-2-trichloromethylquinazolines

A series of original 4-aryl-substituted 2-trichloromethylquinazoline derivatives was synthesized using a microwave-assisted Suzuki-Miyaura cross-coupling approach. Antiplasmodial activity was evaluated on both chloroquino-resistant and -sensitive Plasmodium falciparum strains, and the selectivity indexes for THP1 and HepG2 human cells were also calculated, revealing their antiplasmodial potential.

(1)H and (13)C chemical shifts for 2-aryl and 2-N-arylamino benzothiazole derivatives

The (1)H and (13)C NMR resonances for forty-three 2-aryl and 2-N-arylamino benzothiazole derivatives were completely assigned using a concerted application of one- and two-dimensional experiments (DEPT, gs-COSY, gs-HMQC and gs-HMBC).