Background: Thiazole is a good pharmacophore nucleus due to its various pharmaceutical applications. Its derivatives have a wide range of biological activities such as antioxidant, analgesic, and antimicrobial including antibacterial, antifungal, antimalarial, anticancer, antiallergic, antihypertensive, anti-inflammatory, and antipsychotic. Indeed, the thiazole scaffold is contained in more than 18 FDA-approved drugs as well as in numerous experimental drugs. Objective: To summarize recent literature on the biological activities of thiazole ring-containing compounds Methods: A literature survey regarding the topics from the year 2015 up to now was carried out. Older publications were not included, since they were previously analyzed in available peer reviews. Results: Nearly 124 research articles were found, critically analyzed, and arranged regarding the synthesis and biological activities of thiazoles derivatives in the last 5 years.

Background: Diabetes Mellitus (DM), is a metabolic disorder characterized by high blood glucose levels. The main types of diabetes mellitus are Diabetes mellitus type I, Diabetes mellitus type II, gestational diabetes and Diabetes of other etiology. Diabetes type II, the Non Insulin Dependent Type (NIDDM) is the most common type, characterized by the impairment in activation of the intracellular mechanism leading to the insertion and usage of glucose after interaction of insulin with its receptor, known as insulin resistance. Although, a number of drugs have been developed for the treatment of diabetes type II, their ability to reduce blood glucose levels is limited, while several side effects are also observed. Furthermore, none of the market drugs targets the enhancement of the action of the intracellular part of insulin receptor or recuperation of the glucose transport mechanism in GLUT4 dependent cells. The Protein Tyrosine Phosphatase (PTP1b) is the main enzyme involved in insulin receptor desensitization and has become a drug target for the treatment of Diabetes type II. Several PTP1b inhibitors have already been found, interacting with the binding site of the enzyme, surrounding the catalytic amino acid Cys215 and the neighboring area or with the allosteric site of the enzyme, placed at a distance of 20 Å from the active site, around Phe280. However, the research continues for finding more potent inhibitors with increased cell permeability and specificity. Objective: The aim of this review is to show the attempts made in developing of Protein Tyrosine Phosphatase (PTP1b) inhibitors with high potency, selectivity and bioavailability and to sum up the indications for favorable structural characteristics of effective PTP1b inhibitors. Methods: The methods used include a literature survey and the use of Protein Structure Databanks such as PuBMed Structure and RCSB and the tools they provide. Conclusion: The research for finding PTP1b inhibitors started with the design of molecules mimicking the Tyrosine substrate of the enzyme. The study revealed that an aromatic ring connected to a polar group, which preferably enables hydrogen bond formation, is the minimum requirement for small inhibitors binding to the active site surrounding Cys215. Molecules bearing two hydrogen bond donor/acceptor (Hb d/a) groups at a distance of 8.5-11.5 Å may form more stable complexes, interacting simultaneously with a secondary area A2. Longer molecules with two Hb d/a groups at a distance of 17 Å or 19 Å may enable additional interactions with secondary sites (B and C) that confer stability as well as specificity. An aromatic ring linked to polar or Hb d/a moieties is also required for allosteric inhibitors. A lower distance between Hb d/a moieties, around 7.5 Å may favor allosteric interaction. Permanent inhibition of the enzyme by oxidation of the catalytic Cys215 has also been referred. Moreover, covalent modification of Cys121, placed near but not inside the catalytic pocket has been associated with permanent inhibition of the enzyme.

Background: Bacterial infections are a growing problem worldwide causing morbidity and mortality mainly in developing countries. Moreover, the increased number of microorganisms, developing multiple resistances to known drugs, due to abuse of antibiotics, is another serious problem. This problem becomes more serious for immunocompromised patients and those who are often disposed to opportunistic fungal infections.Objective: The objective of this manuscript is to give an overview of new findings in the field of antimicrobial agents among five-membered heterocyclic compounds. These heterocyclic compounds especially five-membered attracted the interest of the scientific community not only for their occurrence in nature but also due to their wide range of biological activities.Method: To reach our goal, a literature survey that covers the last decade was performed.Results: As a result, recent data on the biological activity of thiazole, thiazolidinone, benzothiazole and thiadiazole derivatives are mentioned.Conclusion: It should be mentioned that despite the progress in the development of new antimicrobial agents, there is still room for new findings. Thus, research still continues.

The coronavirus disease, COVID-19, caused by the novel coronavirus SARS-CoV-2, which first emerged in Wuhan, China and was made known to the World in December 2019 turned into a pandemic causing more than 126,124 deaths worldwide up to April 16th, 2020. It has 79.5% sequence identity with SARS-CoV-1 and the same strategy for host cell invasion through the ACE-2 surface protein. Since the development of novel drugs is a long-lasting process, researchers look for effective substances among drugs already approved or developed for other purposes. The 3D structure of the SARS-CoV-2 main protease was compared with the 3D structures of seven proteases, which are drug targets, and docking analysis to the SARS-CoV-2 protease structure of thirty four approved and on-trial protease inhibitors was performed. Increased 3D structural similarity between the SARS-CoV-2 main protease, the HCV protease and α-thrombin was found. According to docking analysis the most promising results were found for HCV protease, DPP-4, α-thrombin and coagulation Factor Xa known inhibitors, with several of them exhibiting estimated free binding energy lower than −8.00 kcal/mol and better prediction results than reference compounds. Since some of the compounds are well-tolerated drugs, the promising in silico results may warrant further evaluation for viral anticipation. DPP-4 inhibitors with anti-viral action may be more useful for infected patients with diabetes, while anti-coagulant treatment is proposed in severe SARS-CoV-2 induced pneumonia.

Background: Thiazole and benzothiazole derivatives, as well as thiazolidinones are very important scaffolds in medicinal chemistry. Literature has revealed that they possess a wide spectrum of biological activities including antimicrobial activity. Objective: The goal of this paper is the designing of new benzothiazole based thiazolidinones and the evaluation of their biological activities. Methods: The designed compounds were synthesized using classical organic synthesis methods. The antimicrobial activity was evaluated using the method of microdilution. Results: The twelve newly synthesized compounds showed antimicrobial properties. All compounds appeared to be more active than ampicillin in most studied strains and in some cases, more active than streptomycin. Antifungal activity, in most cases was also better than the reference drugs ketoconazole and bifonazole. The prediction of cytotoxicity revealed that the synthesized compounds were not toxic (LD50 350-1000 mg/kg of body weight). Docking studies on the antibacterial activity confirmed the biological results. Conclusion: The twelve new compounds were synthesized and studied for their antimicrobial activity. The compounds appeared to be promising antimicrobial agents and could be the lead compounds for new, more potent drugs. According to the docking prediction, the compounds could be MurB inhibitors.