Synthesis and Anticancer Activity of Indolin-2-one Derivatives Bearing the 4-Thiazolidinone Moiety

Anticancer Potential of the S-Heterocyclic Ring Containing Drugs and its Bioactivation to Reactive Metabolites

Sulfur-containing heterocyclic derivatives have been disclosed for binding with a wide range of cancer-specific protein targets. Various interesting derivatives of sulfur-containing heterocyclics such as benzothiazole, thiazole, thiophene, thiazolidinedione, benzothiophene, and phenothiazine, etc have been shown to inhibit diverse signaling pathways implicated in cancer. Significant progress has also been made in molecular targeted therapy against specific enzymes such as kinase receptors due to potential binding interactions inside the ATP pocket. Sulfur-containing heterocyclic ring metal complexes i. e., benzothiazole, thiazole, thiophene, benzothiophene and phenothiazines are among the most promising active anticancer compounds. However, sulfur heteroaromatic rings, particularly thiophene, are of high structural alert due to their metabolism to reactive metabolites. The mere presence of a structural alert itself does not determine compound toxicity therefore, this review focuses on some specific findings that shed light on factors influencing the toxicity. In the current review, synthetic strategies of introducing the sulfur core ring in the synthesized derivatives are discussed with their structure-activity relationships to enhance our understanding of toxicity mechanisms and develop safer therapeutic options. The sulfur-containing marketed anticancer drugs included in this review direct the synthesis of novel compounds and will help in the development of potent, safer sulfur-based anticancer drugs in near future.

Recent advances in synthetic strategies and SAR of thiazolidin-4-one containing molecules in cancer therapeutics

Cancer is one of the life-threatening diseases accountable for millions of demises globally. The inadequate effectiveness of the existing chemotherapy and its harmful effects has resulted in the necessity of developing innovative anticancer agents. Thiazolidin-4-one scaffold is among the most important chemical skeletons that illustrate anticancer activity. Thiazolidin-4-one derivatives have been the subject of extensive research and current scientific literature reveals that these compounds have shown significant anticancer activities. This manuscript is an earnest attempt to review novel thiazolidin-4-one derivatives demonstrating considerable potential as anticancer agents along with a brief discussion of medicinal chemistry-related aspects of these compounds and structural activity relationship studies in order to develop possible multi-target enzyme inhibitors. Most recently, various synthetic strategies have been developed by researchers to get various thiazolidin-4-one derivatives. In this review, the authors highlight the various synthetic, green, and nanomaterial-based synthesis routes of thiazolidin-4-ones as well as their role in anticancer activity by inhibition of various enzymes and cell lines. The detailed description of the existing modern standards in the field presented in this article may be interesting and beneficial to the scientists for further exploration of these heterocyclic compounds as possible anticancer agents.

2-(4-Oxo-1,3-thiazolidin-2-ylidene)acetamid as promising scaffold for designing new antifungal compounds

1,3-Thiazolidin-4-one derivatives with a exocyclic C=C double bond in position 2 of the hetero ring have a wide spectrum of biological activity, but their fungicidal activity has not been studied as much as it should be. This paper presents a simple and convenient approach for obtaining potential antifungal agents based on 2-(4-oxo-1,3-thiazolidin-2-ylidene)acetamides. The first examples of evaluating the fungicidal activity of 8 obtained compounds on 8 strains of phytopathogenic fungi are presented. A highly active compound 4e with EC50 of 0.85 and 2.29 µg/mL against A. solani and P. lingam, respectively, was found to be promising for further study.

Rhodanine-3-acetamide derivatives as aldose and aldehyde reductase inhibitors to treat diabetic complications: synthesis, biological evaluation, molecular docking and simulation studies

In diabetes, increased accumulation of sorbitol has been associated with diabetic complications through polyol pathway. Aldose reductase (AR) is one of the key factors involved in reduction of glucose to sorbitol, thereby its inhibition is important for the management of diabetic complications. In the present study, a series of seven 4-oxo-2-thioxo-1,3-thiazolidin-3-yl acetamide derivatives 3(a–g) were synthesized by the reaction of 5-(4-hydroxy-3-methoxybenzylidene)-4-oxo-2-thioxo-1,3-thiazolidin-3-yl acetic acid (2a) and 5-(4-methoxybenzylidene)-4-oxo-2-thioxo-1,3-thiazolidin-3-yl acetic acid (2b) with different amines. The synthesized compounds 3(a–g) were investigated for their in vitro aldehyde reductase (ALR1) and aldose reductase (ALR2) enzyme inhibitory potential. Compound 3c, 3d, 3e, and 3f showed ALR1 inhibition at lower micromolar concentration whereas all the compounds were more active than the standard inhibitor valproic acid. Most of the compounds were active against ALR2 but compound 3a and 3f showed higher inhibition than the standard drug sulindac. Overall, the most potent compound against aldose reductase was 3f with an inhibitory concentration of 0.12 ± 0.01 µM. In vitro results showed that vanillin derivatives exhibited better activity against both aldehyde reductase and aldose reductase. The molecular docking studies were carried out to investigate the binding affinities of synthesized derivatives with both ALR1 and ALR2. The binding site analysis of potent compounds revealed similar interactions as were found by cognate ligands within the active sites of enzymes.

Structure-activity relationship studies of indolin-2-one derivatives as vascular endothelial growth factor receptor inhibitors and anticancer agents

Angiogenesis is a requirement for the growth of cancer cells. The family of vascular endothelial growth factor receptors (VEGFRs) is the main target in metastasis. Indolin-2-one is proved to be an essential scaffold of antiangiogenic drugs. Sunitinib is the first oral indolin-2-one derivative marketed as a VEGFR inhibitor in the treatment of renal cell carcinoma and gastrointestinal stromal tumors. Therefore, novel compounds possessing the scaffold of sunitinib were designed and synthesized by different researchers to improve the anticancer activity, bioavailability, and solubility, and to decrease the toxicity of sunitinib. In this comprehensive review, the structure-activity relationship of different indolin-2-one analogs as VEGFR inhibitors is discussed. It has been observed that the indolin-2-one core is necessary for the inhibition of VEGFRs. It was determined that substitutions at C-3 of the oxindole ring play an important role in their antiangiogenic and anticancer activities.

Design, synthesis, and biological evaluation of imidazopyridine-linked thiazolidinone as potential anticancer agents

In this study, two series of imidazopyridine-linked thiazolidinone rings (5a-h and 6a-h) constituting 16 new compounds were synthesized and tested for their antiproliferative activity against a panel of three human cancer cell lines, that is, MCF-7 (human breast cancer), A549 (human lung cancer), and DU145 (human prostate cancer). Three compounds, 5h, 6f, and 6h, exhibited remarkable results against all three cell lines, but compound 6h was found to be the most active one against the breast cancer cell line. Among all the synthesized compounds, 6h displayed the highest antioxidant results. Furthermore, the potent compounds 5h, 6f, and 6h showed no signs of toxicity at doses ranging from 50 to 500 mg/kg of animal body weight. The biochemical parameters (SGOT and SGPT) of compound 6h nearly matched the control in hepatotoxicity studies. The molecular docking and MM-GBSADG binding studies are in agreement with the in vitro anticancer and antioxidant activity results. The most promising compound 6h was found to have the highest docking score and binding energy, and its absorption, distribution, metabolism, and excretion (ADME) parameters are in the acceptable range. Thus, it can be concluded that 6h, an imidazopyridine derivative endowed with a thiazolidinone ring system, has the potential to be developed as an anticancer agent.

Design, synthesis, biological evaluation, and molecular modeling studies of rhodanine derivatives as pancreatic lipase inhibitors

A series of rhodanine-3-acetic acid derivatives were synthesized via Knoevenagel condensation of rhodanine-3-acetic acid with various substituted aromatic aldehydes. The synthesized derivatives were screened in vitro for understanding the inhibitory potential towards pancreatic lipase (PL), a key enzyme responsible for the digestion of dietary fats. Derivative 8f exhibited a potential inhibitory activity towards PL (IC₅₀ = 5.16 µM), comparable to that of the standard drug, orlistat (0.99 µM). An increase in the density of the aromatic ring resulted in potential PL inhibition. The enzyme kinetics of 8f exhibited a reversible competitive-type inhibition, similar to that of orlistat. Derivative 8f exhibited a MolDock score of -125.19 kcal/mol in docking studies, and the results were in accordance with their PL inhibitory potential. Furthermore, the reactive carbonyl group of 8f existed at a distance adjacent to Ser152 (≈3 Å) similar to that of orlistat. Molecular dynamics simulation (10 ns) of the 8f-PL complex revealed a stable binding conformation of 8f in the active site of PL (maximum root mean square displacement of ≈2.25 Å). The present study identified novel rhodanine-3-acetic acid derivatives with promising PL inhibitory potential, and further lead optimization might result in potent PL inhibitors.

New hydrazide-hydrazones and 1,3-thiazolidin-4-ones with 3-hydroxy-2-naphthoic moiety: Synthesis, in vitro and in vivo studies

In this research we synthesized, identified and evaluated new hydrazide-hydrazones (1-3) and 1,3-thiazolidin-4-one derivatives (4-6) for in vitro and in vivo activity. New hydrazide-hydrazones (1-3) were obtained by the condensation reaction of 3-hydroxy-2-naphthoic acid hydrazide with appropriate aldehydes. Synthesized hydrazide-hydrazones (1-3) were subjected to cyclization reaction with mercaptoacetic acid which afforded with new 1,3-thiazolidin-4-one derivatives (4-6). Among 1,3-thiazolidin-4-one derivatives tested (4-6), compound 6 exhibited highest and most selective cytotoxicity towards human renal adenocarcinoma cells (769-P) and it did not affect the growth of normal cells (H9c2, GMK). Whereas its hydrazide-hydrazone (compound 3) showed significant antiproliferative activity against both tested human cancer cell lines: renal adenocarcinoma (769-P) and hepatocellular carcinoma (HepG2), however with less selectivity. The in vivo studies focused on the antinociceptive activity of newly synthesized 1,3-thiazolidin-4-one derivatives (4-6). The preliminary screening of novel compounds showed that 1,3-thiazolidin-4-one derivatives (4-6) are safe and not toxic against CNS of mice. Among tested derivatives one compound (6) displayed significant analgesic activity.

Indolin-2-one compounds targeting thioredoxin reductase as potential anticancer drug leads

Several compounds bearing the indolinone chemical scaffold are known to possess anticancer properties. For example, the tyrosine kinase inhibitor sunitinib is an arylideneindolin-2-one compound. The chemical versatility associated with structural modifications of indolinone compounds underlies the potential to discover additional derivatives possessing anticancer properties. Previously synthesized 3-(2-oxoethylidene)indolin-2-one compounds, also known as supercinnamaldehyde (SCA) compounds in reference to the parent compound 1 [1-methyl-3(2-oxopropylidene)indolin-2-one], bear a nitrogen-linked α,β-unsaturated carbonyl (Michael acceptor) moiety. Here we found that analogs bearing N-substituents, in particular compound 4 and 5 carrying an N-butyl and N-benzyl substituent, respectively, were strongly cytotoxic towards human HCT 116 colorectal and MCF-7 breast carcinoma cells. These compounds also displayed strong thioredoxin reductase (TrxR) inhibitory activity that was likely attributed to the electrophilicity of the Michael acceptor moiety. Their selectivity towards cellular TrxR inhibition over related antioxidant enzymes glutathione reductase (GR), thioredoxin (Trx) and glutathione peroxidase (GPx) was mediated through targeting of the selenocysteine (Sec) residue in the highly accessible C-terminal active site of TrxR. TrxR inhibition mediated by indolin-2-one compounds led to cellular Trx oxidation, increased oxidative stress and activation of apoptosis signal-regulating kinase 1 (ASK1). These events also led to activation of p38 and JNK mitogen-activated protein kinase (MAPK) signaling pathways, and cell death with apoptotic features of PARP cleavage and caspase 3 activation. In conclusion, these results suggest that indolin-2-one-based compounds specifically targeting TrxR may serve as novel drug leads for anticancer therapy.

5-Ene-4-thiazolidinones - An efficient tool in medicinal chemistry

The presented review is an attempt to summarize a huge volume of data on 5-ene-4-thiazolidinones being a widely studied class of small molecules used in modern organic and medicinal chemistry. The manuscript covers approaches to the synthesis of 5-ene-4-thiazolidinone derivatives: modification of the C5 position of the basic core; synthesis of the target compounds in the one-pot or multistage reactions or transformation of other related heterocycles. The most prominent pharmacological profiles of 5-ene derivatives of different 4-thiazolidinone subtypes belonging to hit-, lead-compounds, drug-candidates and drugs as well as the most studied targets have been discussed. Currently target compounds (especially 5-en-rhodanines) are assigned as frequent hitters or pan-assay interference compounds (PAINS) within high-throughput screening campaigns. Nevertheless, the crucial impact of the presence/nature of C5 substituent (namely 5-ene) on the pharmacological effects of 5-ene-4-thiazolidinones was confirmed by the numerous listed findings from the original articles. The main directions for active 5-ene-4-thiazolidinones optimization have been shown: i) complication of the fragment in the C5 position; ii) introduction of the substituents in the N3 position (especially fragments with carboxylic group or its derivatives); iii) annealing in complex heterocyclic systems; iv) combination with other pharmacologically attractive fragments within hybrid pharmacophore approach. Moreover, the utilization of 5-ene-4-thiazolidinones in the synthesis of complex compounds with potent pharmacological application is described. The chemical transformations cover mainly the reactions which involve the exocyclic double bond in C5 position of the main core and correspond to the abovementioned direction of the 5-ene-4-thiazolidinone modification.

2-(Thienothiazolylimino)-1,3-thiazolidin-4-ones inhibit cell division cycle 25 A phosphatase

Cell division cycle dual phosphatases (CDC25) are essential enzymes that regulate cell progression in cell cycle. Three isoforms exist as CDC25A, B and C. Over-expression of each CDC25 enzyme is found in cancers of diverse origins. Thiazolidinone derivatives have been reported to display anti-proliferative activities, bactericidal activities and to reduce inflammation process. New 2-(thienothiazolylimino)-1,3-thiazolidin-4-ones were synthesized and evaluated as inhibitors of CDC25 phosphatase. Among the molecules tested, compound 6 inhibited CDC25A with an IC50 estimated at 6.2±1.0μM. The binding of thiazolidinone derivative 6 onto CDC25A protein was reversible. In cellulo, compound 6 treatment led to MCF7 and MDA-MB-231 cell growth arrest. To our knowledge, it is the first time that such 4-thiazolidinone derivatives are characterized as CDC25 potential inhibitor.

Design, synthesis and biological evaluation of novel bromophenol derivatives incorporating indolin-2-one moiety as potential anticancer agents

A series of bromophenol derivatives containing indolin-2-one moiety were designed and evaluated that for their anticancer activities against A549, Bel7402, HepG2, HeLa and HCT116 cancer cell lines using MTT assay in vitro. Among them, seven compounds (4g–4i, 5h, 6d, 7a, 7b) showed potent activity against the tested five human cancer cell lines. Wound-healing assay demonstrated that compound 4g can be used as a potent compound for inactivating invasion and metastasis by inhibiting the migration of cancer cells. The structure–activity relationships (SARs) of bromophenol derivatives had been discussed, which were useful for exploring and developing bromophenol derivatives as novel anticancer drugs.

Facile synthesis of benzonitrile/nicotinonitrile based s-triazines as new potential antimycobacterial agents

A common strategy to synthesize 4/6-(4-(4-methylpiperazin-1-yl)-6-(4-(4-oxo-2-phenylthiazolidin-3-yl)phenyl)-1,3,5-triazin-2-yloxy)benzonitriles/nicotinonitriles was developed by applying an efficient palladium-catalyzed C-C Suzuki coupling. Moreover, the synthesized compounds were also tested for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Rv using BACTEC MGIT and Lowenstein-Jensen MIC methods. Several compounds displayed profound antimycobacterial activity in combination with low toxicity towards mammalian cells. The best results were observed amongst the nicotinonitrile substituted s-triazine analogs and it could be a potential starting point to develop new lead compounds in the fight against M. tuberculosis H37Rv. The newly synthesized compounds were characterized by IR, (1)H NMR, (13)C NMR, MS and elemental analysis.

Rational approaches, design strategies, structure activity relationship and mechanistic insights for anticancer hybrids

A Hybrid drug which comprises the incorporation of two drug pharmacophores in one single molecule are basically designed to interact with multiple targets or to amplify its effect through action on another bio target as one single molecule or to counterbalance the known side effects associated with the other hybrid part(.) The present review article offers a detailed account of the design strategies employed for the synthesis of anticancer agents via molecular hybridization techniques. Over the years, the researchers have employed this technique to discover some promising chemical architectures displaying significant anticancer profiles. Molecular hybridization as a tool has been particularly utilized for targeting tubulin protein as exemplified through the number of research papers. The microtubule inhibitors such as taxol, colchicine, chalcones, combretasatin, phenstatins and vinca alkaloids have been utilized as one of the functionality of the hybrids and promising results have been obtained in most of the cases with some of the tubulin based hybrids exhibiting anticancer activity at nanomolar level. Linkage with steroids as biological carrier vector for anticancer drugs and the inclusion of pyrrolo [2,1-c] [1,4]benzodiazepines (PBDs), a family of DNA interactive antitumor antibiotics derived from Streptomyces species in hybrid structure based drug design has also emerged as a potential strategy. Various heteroaryl based hybrids in particular isatin and coumarins have also been designed and reported to posses' remarkable inhibitory potential. Apart from presenting the design strategies, the article also highlights the structure activity relationship along with mechanistic insights revealed during the biological evaluation of the hybrids.

A novel pH probe based on a rhodamine–rhodamine platform

A novel pH probe based on rhodamine–rhodanine platform.

Design, synthesis and anticancer activity of 4-morpholinothieno[3,2-d]pyrimidine derivatives bearing arylmethylene hydrazine moiety

Three series of 4-morpholinothieno[3,2-d]pyrimidine derivatives containing arylmethylene hydrazine moiety (11a-f, 13a-k and 15a-h) were synthesized and their chemical structures as well as the relative stereochemistry were confirmed. The synthesized compounds were evaluated for their cytotoxicity against three cancer cell lines (H460, HT-29, MDA-MB-231). Most of them exhibited moderate to significant cytotoxicity and high-selectivity against one or more cell lines, especially compounds 11c, 13b, 15f and 15g possessing dramatically increased cytotoxicity as compared with the positive controls, which were further evaluated for six other cancer cell lines and one normal cell line. The most promising compound 11c, bearing 3,4-methylenedioxy phenyl group, showed remarkable cytotoxicity against H460, HT-29 and MDA-MB-231 cell lines with IC(50)values of 0.003 µM, 0.42 µM and 0.74 µM, which was 1.6- to 290-fold more potent than GDC-0941.