Synthesis and antimicrobial activity of rhodanine derivatives

Exploring 2-Tetradecanoylimino-3-aryl-4-methyl-1,3-thiazolines Derivatives as Alkaline Phosphatase Inhibitors: Biochemical Evaluation and Computational Analysis

The current study focused on the laboratory approach in conjunction with computational methods for the synthesis and bioactivity assessment of unique 2-tetradecanoylimino-3-aryl-4-methyl-1,3-thiazolines (2a-2k). Processes included cyclizing 1-aroyl-3-arylthioureas with propan-2-one in the presence of trimethylamine and bromine. By using spectroscopic techniques and elemental analyses, structures were elucidated. To assess the electronic properties, density functional theory (DFT) calculations were made, while binding interactions of synthesized derivatives were studied by the molecular docking tool. Promising results were found during the evaluation of bioactivity of synthesized compounds against alkaline phosphatase. The drug likeliness score, an indicator used for any chemical entity posing as a drug, was within acceptable limits. The data suggested that most of the derivatives were potent inhibitors of alkaline phosphatase, which in turn may act as lead molecules to synthesize derivatives having desired pharmacological profiles for the treatment of specific diseases associated with abnormal levels of ALPs.

Drug screening of rhodanine derivatives for antibacterial activity

Introduction: Bacteriological infections are a major risk to human health. These include all hospital and public-acquired infections. In drug discovery, rhodanines are privileged heterocyclic frameworks. Their derivatives possess strong anti-bacterial activity and some of them have shown potent activity against multidrug-resistant pathogens, both under in vitro and in vivo conditions. To treat multi-drug resistant pathogens, the development of novel potent drugs, with superior anti-bacterial efficacy, is paramount. One avenue which shows promise is the design and development of novel rhodanines.Areas covered: This review summarizes the status on rhodanine-based derivatives and their anti-bacterial activity, based on published research over the past six years. Furthermore, to facilitate the design of novel derivatives with improved functions, their structure-activity relationships are assessed with reference to their efficacy as anti-bacterial agents and their toxicity.Expert opinion: The pharmacological activity of molecules bearing a rhodanine scaffold needs to be very critically assessed in spite of considerable information available from various biological evaluations. Although, some data on structure-activity relationship frameworks is available, information is not adequate to optimize the efficacy of rhodanine derivatives for different applications.

Asymmetric synthesis of highly functionalized spirothiazolidinone tetrahydroquinolines via a squaramide-catalyzed cascade reaction

A bifunctional squaramide-catalyzed asymmetric cascade aza-Michael/Michael addition reaction for the synthesis of chiral spirothiazolidinone tetrahydroquinolines with three contiguous stereocenters has been developed. This cascade reaction proceeded well under mild conditions, and afforded the desired products in high to excellent yields (up to >99% yield) with excellent diastereoselectivities (>25 : 1 dr) and high enantioselectivities (up to 96% ee). More importantly, both the amplification and the derivation experiments do not affect the stereoselectivity.

Simultaneous Improvement of Antimicrobial, Antifouling, and Transport Properties of Forward Osmosis Membranes with Immobilized Highly-Compatible Polyrhodanine Nanoparticles

This work shows that incorporating highly compatible polyrhodanine nanoparticles (PRh-NPs) into a polyamide (PA) active layer allows for fabricating forward osmosis (FO) thin-film composite (TFC)-PRh membranes that have simultaneously improved antimicrobial, antifouling, and transport properties. To the best of our knowledge, this is the first reported study of its kind to this date. The presence of the PRh-NPs on the surface of the TFC-PRh membranes active layers is evaluated using FT-IR spectroscopy, SEM, and XPS. The microscopic interactions and their impact on the compatibility of the PRh-NPs with the PA chains were studied using molecular dynamics simulations. When tested in forward osmosis, the TFC-PRh-0.01 membrane (with 0.01 wt % PRh) shows significantly improved permeability and selectivity because of the small size and the high compatibility of the PRh-NPs with PA chains. For example, the TFC-PRh-0.01 membrane exhibits a FO water flux of 41 l/(m²·h), higher than a water flux of 34 l/(m²·h) for the pristine TFC membrane, when 1.5 molar NaCl was used as draw solution in the active-layer feed-solution mode. Moreover, the reverse solute flux of the TFC-PRh-0.01 membrane decreases to about 115 mmol/(m²·h) representing a 52% improvement in the reverse solute flux of this membrane in comparison to the pristine TFC membrane. The surfaces of the TFC-PRh membranes were found to be smoother and more hydrophilic than those of the pristine TFC membrane, providing improved antifouling properties confirmed by a flux decline of about 38% for the TFC-PRh-0.01 membranes against a flux decline of about 50% for the pristine TFC membrane when evaluated with a sodium alginate solution. The antimicrobial traits of the TFC-PRh-0.01 membrane evaluated using colony-forming units and fluorescence imaging indicate that the PRh-NPs hinder cell deposition on the TFC-PRh-0.01 membrane surface effectively, limiting biofilm formation.

Quinoline-based antimalarial hybrid compounds

Quinoline-containing compounds, such as quinine and chloroquine, have a long-standing history as potent antimalarial agents. However, the increasing resistance of the Plasmodium parasite against these drugs and the lack of licensed malaria vaccines have forced chemists to develop synthetic strategies toward novel biologically active molecules. A strategy that has attracted considerable attention in current medicinal chemistry is based on the conjugation of two biologically active molecules into one hybrid compound. Since quinolines are considered to be privileged antimalarial building blocks, the synthesis of quinoline-containing antimalarial hybrids has been elaborated extensively in recent years. This review provides a literature overview of antimalarial hybrid molecules containing a quinoline core, covering publications between 2009 and 2014.

New class of methyl tetrazole based hybrid of (Z)-5-benzylidene-2-(piperazin-1-yl)thiazol-4(%H)-one as potent antitubercular agents

In search of potential therapeutics for tuberculosis, we describe here the synthesis and in vitro antitubercular activity of a novel series of thiazolone piperazine tetrazole derivatives. Among all the synthesized derivatives, four compounds (10, 14, 20 and 33) exhibited more potent activity (MIC=3.08, 3.01, 2.62 and 2.51 μM) than ethambutol (MIC=9.78 μM) and pyrazinamide (MIC=101.53 μM) against Mycobacterium tuberculosis. Furthermore, they displayed no toxicity against Vero cells (C1008) and mouse bone marrow derived macrophages (MBMDMϕ). These investigated analogues have emerged as possible lead molecule to enlarge the scope of the study.

Recent pharmacological developments on rhodanines and 2,4-thiazolidinediones

Thiazolidines are five-member heterocyclic having sulfur, nitrogen, and oxygen atoms in their ring structure and exhibiting potent as well as wide range of pharmacological activities. In this minireview, recent updates on synthesis and pharmacological evaluations of molecules based on 2,4-thiazolidine and rhodanine are discussed.

Synthesis and biological evaluation of new glutamic acid-based inhibitors of MurD ligase

Mur ligases catalyze the biosynthesis of the UDP-MurNAc-pentapeptide precursor of peptidoglycan, an essential polymer of bacterial cell-wall. They constitute attractive targets for the development of novel antibacterial agents. Here we report on the synthesis of a series of 2,4-diaminoquinazolines, quinazoline-2,4(1H,3H)-diones, 5-benzylidenerhodanines and 5-benzylidenethiazolidine-2,4-diones and their inhibitory activities against MurD from Escherichia coli. Compounds (R)-27 and (S)-27 showed inhibitory activity against MurD with IC(50) values of 174 and 206 microM, respectively, which makes them promising starting points for optimization.

Synthesis and evaluation of some new fluorinated hydroquinazoline derivatives as antifungal agents

The key intermediate octahydroquinazoline (1) was obtained in one pot synthesis by a modification of the Biginelli reaction. Compound 1 was allowed to react with phenacyl bromide and bromomalononitrile to furnish thiazolo[2,3-b]quinazoline 3 and 12, respectively. Interaction of compound 12 with formamide, formic acid and phenyl isothiocyanate yielded the corresponding pyrimidino[4',5':4.5]thiazolo[2,3-b] quinazolines 13, 14 and 17, respectively. The structure of the synthesized compounds were elucidated by elemental analyses and spectroscopic analyses. Some of the prepared compounds were tested for their antifungal activity in comparison with tioconazole as a reference fungicide.