Novel Synthetic Indazoles Abrogate Angiogenesis in Erlich Ascites Tumor Bearing Mice.

BACKGROUND: Indazoles are known for their anti-cancer properties. OBJECTIVE: The current investigation was on the synthesis and evaluation of novel indazole derivatives for their anticancer properties. METHODS: A series of novel indazoles were synthesized and characterized by IR, NMR and LCMS. We performed cytotoxic studies for all synthesized compounds on different cell lines such as HeLa, MCF-7 and EAC using MTT assay. The lead compound was tested further for its anti-tumor and anti-angiogenic effect on EAT tumor model. RESULTS: Amongst the series of compounds synthesized, compound KA8 showed potent antiproliferative effect against Hela, MCF-7 and EAC cell lines with IC50 values 10.4 to 11.5 and 13.5 µM respectively. In addition, our compound KA8 significantly decreased the cell viability, body weight, ascites volume and it also showed superior survival ability of mice compared to control groups. Furthermore, it suppressed the formation of neovasculature in the peritoneum of EAT-bearing mice. CONCLUSION: The findings reveal that the lead compound KA8 possesses potent anti-tumor and anti-angiogenic properties thereby promising it to be developed as a novel anticancer agent with further mechanistic studies.

Regioselective Synthesis of 2,5-Disubstituted-1,3,4-thiadiazoles and 1,3,4-Oxadiazoles via Alkyl 2-(Methylthio)-2-thioxoacetates and Alkyl 2-Amino-2-thioxoacetates.

An acid-catalyzed regioselective cyclization reaction of 2,5-disubstituted-1,3,4-thiadiazoles and 1,3,4-oxadiazoles has been developed. The synthetic precursors alkyl 2-(methylthio)-2-thioxoacetates/alkyl 2-amino-2-thioxoacetates react efficiently with acyl hydrazides, which transformed into a series of dehydrative and desulfurative products with employment of p-TSA and AcOH through a regioselective cyclization process. The alkyl 2-amino-2-thioxoacetate pathway generates excellent yield among the mentioned procedures. The reported methods are operationally simplistic and highly efficient with metal-free conditions and demonstrate significant functional group compatibility. Regioselective cyclized products were confirmed by single-crystal X-ray diffraction studies.

A panoramic view on synthetic applications of α-oxothioamides: a highly regioselective synthesis of 2-acyl-4-(het)arylthiazoles and thioethers.

Highly regioselective synthesis of 2-acyl-4-(het)arylthiazoles and thioethers by the reaction between α-oxothioamides and α-bromoketones in the absence of base in DMF and in the presence of triethylamine in acetonitrile, respectively, has been reported. This thiazole synthesis is an important extended work of the Hantzsch thiazole synthesis, which overcomes the drawbacks of earlier reported methods. The probable mechanisms for the formation of thiazoles and thioethers are also presented.

The regioselective synthesis of 2,5- and 4,5-disubstituted thiazoles via the cyclization of 2-oxo-2-(amino)ethanedithioates with isocyanides.

The regioselective synthesis of 2-(methylthio)-N-aryl/alkylthiazole-5-carboxamides and ethyl-5-(aryl/alkyl carbamoyl)thiazole-4-carboxylates was carried out via the base-induced cyclization of methyl-2-oxo-2-(amino)ethanedithioates with TosMIC and ethyl isocyanoacetate, respectively, with high yields. The regioisomeric products were confirmed based on X-ray diffraction studies. An advantage of the present method is the wide-ranging isocyanide reactivity compared to earlier protocols, while the catalyst-free nature and rapid reaction times are noteworthy features.

Base Induced Condensation of Malononitrile with Erlenmeyer Azlactones: An Unexpected Synthesis of Multi-Substituted Δ2 -Pyrrolines and Their Cytotoxicity.

An efficient, metal free approach to synthesize multi-substituted Δ2 -pyrroline derivatives by mild base catalyzed cyclocondensation of malononitrile with Erlenmeyer azlactones via 1,2 addition was developed. The modularity of this reaction was used to assemble a range of poly-substituted pyrrolines. Further, synthesized products were screened for cytotoxic properties on different cancer cell lines such as A549 (Human lung adenocarcinoma cells), HeLa (Human cervical adenocarcinoma cells), Jurkat (Human chronic myeloid leukemia cells) and K562 (Human leukemic T cell Lymphoblast cells). Among the synthesized library of compounds, 6f and 6q displayed potent cytotoxic activity.

The reaction of arylmethyl isocyanides and arylmethylamines with xanthate esters: a facile and unexpected synthesis of carbamothioates.

An unexpected formation of carbamothioates by a sodium hydride-mediated reaction of arylmethyl isocyanides with xanthate esters in DMF is reported. The products thus obtained were compared with the carbamothioates obtained by the sodium hydride-mediated condensation of the corresponding benzylamines and xanthate esters in DMF. To account for these unexpected reactions, a mechanism is proposed in which the key steps are supported by quantum chemical calculations.

Synthesis, Cytotoxic and Heparanase Inhibition Studies of 5-oxo-1-arylpyrrolidine-3- carboxamides of Hydrazides and 4-amino-5-aryl-4H-1,2,4-triazole-3-thiol.

Design of chemically novel, biologically potent small heterocyclic molecules with anticancer activities, which targets the enzyme heparanase has gained prominent clinical interest. We have synthesized a novel class of carboxamide derivatives by coupling various substituted aromatic acid hydrazides and triazoleamine with pyrrolidine carboxylic acid by using coupling agents. The synthesized compounds are characterized by spectroscopic techniques such as FT-IR, HRMS and NMR. These compounds are investigated for cytotoxicity on different cancer cell lines and heparanase inhibitory activity. Most of them showed moderate heparanase inhibitory activity and good cytotoxicity.

Anti-Cancer Activity of 2,4-Disubstituted Thiophene Derivatives: Dual Inhibitors of Lipoxygenase and Cyclooxygenase.

2,4-Disubstituted thiophene derivatives were synthesized and assessed for antiinflammatory and anti-cancer activities by targeting two important enzymes of the arachidonic acid metabolism. Both lipoxygenase and cyclooxygenase enzymes play vital role in chronic inflammation and carcinogenesis. Previous studies have proved that COX-2 and 5-LOX are highly activated in various types of cancers; hence inhibition of these clinically important enzymes constitutes the essential criterion for the suppression of tumor progression and metastasis. Among the tested derivatives, 2d and 2g compounds emerged as potent inhibitors of lipoxygenase and cyclooxygenase enzymes. The potent inhibitor of cyclooxygenase was further tested for in vitro cytotoxicity on cervical cancer (HeLa) cells and in vivo tumor model studies using EAT bearing mice where 2-(3,4,5- trimethoxyphenyl)-4-(N-methylindol-3-yl) thiophene (2g) showed eloquent activity. Further, in silico modeling results confirmed the active catalytic ligand binding pockets, which is evident from higher atomic contact energy values of 2d and 2g than compared to standard drug. Thus, 2g may find better application in management of inflammation and in proapoptotic therapeutic engineering.

A new ibuprofen derivative inhibits platelet aggregation and ROS mediated platelet apoptosis.

Thrombocytopenia is a serious issue connected with the pathogenesis of several human diseases including chronic inflammation, arthritis, Alzheimer's disease, cardiovascular diseases (CVDs) and other oxidative stress-associated pathologies. The indiscriminate use of antibiotics and other biological drugs are reported to result in thrombocytopenia, which is often neglected during the treatment regime. In addition, augmented oxidative stress induced by drugs and pathological conditions has also been shown to induce thrombocytopenia, which seems to be the most obvious consequence of elevated rate of platelet apoptosis. Thus, blocking oxidative stress-induced platelet apoptosis would be of prime importance in order to negotiate thrombocytopenia and associated human pathologies. The current study presents the synthesis and platelet protective nature of novel ibuprofen derivatives. The potent anti-oxidant ibuprofen derivative 4f was selected for the study and the platelet protective efficacy and platelet aggregation inhibitory property has been demonstrated. The compound 4f dose dependently mitigates the oxidative stress-induced platelet apoptosis in both platelet rich plasma and washed platelets. The platelet protective nature of compound 4f was determined by assessing various apoptotic markers such as ROS generation, cytosolic Ca2+ levels, PS externalization, cytochrome C translocation, Caspase activation, mitochondrial membrane depolarization, cytotoxicity, LDH leakage and tyrosine phosphorylation of cytosolic proteins. Furthermore, compound 4f dose dependently ameliorated agonist induced platelet aggregation. Therefore, compound 4f can be estimated as a potential candidate in the treatment regime of pathological disorders associated with platelet activation and apoptosis. In addition, compound 4f can be used as an auxiliary therapeutic agent in pathologies associated with thrombocytopenia.