Synthesis and Biological Evaluation of Imidazo[2,1-b][1,3,4]thiadiazole-Linked Oxindoles as Potent Tubulin Polymerization Inhibitors

Regioselective synthesis and in vitro cytotoxicity evaluation of 3-thiooxindole derivatives: Tubulin polymerization inhibition and apoptosis inducing studies

Herein, regiospecific nucleophilic ring-opening of spiroaziridine oxindoles has been established to afford 3-substituted-thiooxindole derivatives as anticancer agents. Among the new series, compounds 7d and 9c exhibited promising cytotoxic activity toward HCT-116 cells with IC₅₀ values of 6.73 ± 0.36 and 6.64 ± 0.95 µM, respectively. Further, AO/EB, DCFDA, and DAPI staining studies were executed to establish the underlying apoptosis mechanism which displayed significant nuclear and morphological alterations. JC-1 staining and annexin V binding assay inferred the loss of mitochondrial membrane potential in HCT-116 cancer cells. Cell cycle analysis showed the treatment of 9c against HCT-116 cells, arrested the cell cycle in G2-M phase. In addition, tubulin binding assay revealed that compound 9c exhibited tubulin polymerase inhibition with IC₅₀ value of 9.73 ± 0.18 μM. This inhibition of tubulin polymerase was further supported by binding interactions of 9c with tubulin through docking studies on PDB ID: 3E22.

Thiadiazole derivatives as anticancer agents

In spite of substantial progress made toward understanding cancer pathogenesis, this disease remains one of the leading causes of mortality. Thus, there is an urgent need to develop novel, more effective anticancer therapeutics. Thiadiazole ring is a versatile scaffold widely studied in medicinal chemistry. Mesoionic character of this ring allows thiadiazole-containing compounds to cross cellular membrane and interact strongly with biological targets. Consequently, these compounds exert a broad spectrum of biological activities. This review presents the current state of knowledge on thiadiazole derivatives that demonstrate in vitro and/or in vivo efficacy across the cancer models with an emphasis on targets of action. The influence of the substituent on the compounds' activity is depicted. Furthermore, the results from clinical trials assessing thiadiazole-containing drugs in cancer patients are summarized.

Synthesis of new arylisoxazole-oxindole conjugates as potent antiproliferative agents

A new series of arylisoxazole-oxindole derivatives (6a-r) were synthesized and evaluated for their antiproliferative activity against human cancer cell lines including non-small cell lung (A549), cervical (HeLa), breast (MCF-7), and prostate (DU-145) cancer cell lines. The synthesized compounds (6a-r) demonstrated excellent to moderate cytotoxicity with IC₅₀ values ranging from 0.82 to 3.69 μm. Some new compounds (6m-r) exhibited profound cytotoxicity better or similar to positive control. More particularly, the compound 6q possesses donating substituent like methoxy group presented at 5-position on D ring exhibited remarkable antiproliferative activity against A-549 (lung cancer) with an IC₅₀ value 0.82 μm. Further studies to determine the mechanistic aspects of these conjugates are under progress.

Indole molecules as inhibitors of tubulin polymerization: potential new anticancer agents, an update (2013–2015)

Discovery of new indole-based tubulin polymerization inhibitors will continue to dominate the synthetic efforts of many medicinal chemists working in the field. The indole ring system is an essential part of several tubulin inhibitors identified in the recent years. The present review article will update the synthesis, anticancer and tubulin inhibition activities of several important new indole classes such as 2-phenylindoles (28, 29 & 30), oxindoles (35 & 38), indole-3-acrylamides (44), indolines (46), aroylindoles (49), carbozoles (75, 76 & 82), azacarbolines (87) and annulated indoles (100–105).

Aryl-imidazothiadiazole analogues as microtubule disrupting agents

Disruption of tubulin polymerization and the docked pose of 5k in the colchicine binding site of tubulin.

Imidazothiazole and related heterocyclic systems. Synthesis, chemical and biological properties

Fused heterobicyclic systems have gained much importance in the field of medicinal chemistry because of their broad spectrum of physiological activities. Among the heterocyclic rings containing bridgehead nitrogen atom, imidazothiazoles derivatives are especially attractive because of their different biological activities. Since many imidazothiazoles derivatives are effective for treating several diseases, is interesting to analyze the behavior of some isosteric related heterocycles, such as pirrolothiazoles, imidazothiadiazoles and imidazotriazoles. In this context, this review summarizes the current knowledge about the syntheses and biological behavior of these families of heterocycles. Traditional synthetic methodologies as well as alternative synthetic procedures are described. Among these last methodologies, the use of multicomponent reaction, novel and efficient coupling reagents, and environmental friendly strategies, like microwave assistance and solvent-free condition in ionic liquids are also summarized. This review includes the biological assessments, docking research and studies of mechanism of action performed in order to obtain the compounds leading to the development of new drugs.

Synthesis of imidazothiadiazole–benzimidazole conjugates as mitochondrial apoptosis inducers

A series of imidazothiadiazole–benzimidazole conjugates (3a–z) were synthesized and evaluated for their cytotoxic activity against a set of four selected human cancer cell lines. Compounds3band3yexhibited significant antiproliferative activity against the ME-180 (cervical) cell line.