Explorations of novel pyridine-pyrimidine hybrid phosphonate derivatives as aurora kinase inhibitors.

For developing novel therapeutic agents with good anticancer activities, a series of novel pyridine-pyrimidine hybrid phosphonate derivatives4(a-q) were synthesized by the Kabachnik-Fields method using CAN as catalyst. The compound 4o exhibited the most potent anticancer activity with an IC50 value of 13.62 µM, 17.49 µM, 5.81 µM, 1.59 µM and 2.11 µM against selected cancer cell lines A549, Hep-G2, HeLa, MCF-7, and HL-60, respectively. Compound 4o displayed seven times more selectivity towards Hep-G2 cancer cell lines compared to the human normal hepatocyte cell line LO2 (IC50 value 95.33 µM). Structure-Activity Relationship (SAR) studies were conducted on the variation in the aromatic ring (five-membered heterocyclic ring, six-membered heterocyclic ring) and the variation of substituents on the phenyl ring (electron donating groups, electron withdrawing groups). Furthermore, the mechanism of anticancer activity was clarified by further explorations in bioactivity by using in vitro aurora kinase inhibitory activity and molecular docking studies. The results showed that the compound 4o at IC50concentrationdemonstrated distinctive morphological changes such as cell detachment, cell wall deformation, cell shrinkage and reduced number of viable cells in cancer cell lines. Compound 4o induced early apoptosis and late apoptosis of 27.7% and 6.1% respectively.

Synthesis and evaluation of novel sulfonamide analogues of 6/7-aminoflavones as anticancer agents via topoisomerase II inhibition.

A series of new sulfonamide analogues of 6/7-aminoflavones were synthesized by using molecular hybridization approach. These new sulfonamide analogues were screened for antiproliferative activity against human hepatocellular carcinoma (HepG-2), human lung cancer cell line (A-549), human colorectal adenocarcinoma (Caco-2) cancer cell lines. Compounds 5p, 5q, 5t, 5v, 5w and 5x exhibited good anticancer activity against selected cancer cell lines. These compounds were further evaluated to predict their ability to inhibit topoisomerase-II enzyme. Compound 5x has shown potent antiproliferative activity (IC50 value 0.98 µM) as compared to standard drug Adriamycin (IC50 = 0.94 µM) indicating that these compounds exhibits anticancer activity via inhibition of topoisomerase-II enzyme. Docking results also have supported above observations by indicating that compounds are held in the active pocket by combination of various hydrogen and hydrophobic interactions with Top II-DNA-etoposide enzyme.

Synthesis and antimicrobial evaluation of novel ethyl 2-(2-(4-substituted)acetamido)-4-subtituted-thiazole-5-carboxylate derivatives.

A series of novel molecules containing thiazole ring structure were designed and synthesized. The structures of the synthesized compounds were elucidated and confirmed by (1)H NMR, (13)C NMR, Mass spectrum and the purity was checked through HPLC analysis. Among these synthesized compounds, 3a-3i and 6a-6c were tested for their antimicrobial activity (minimum inhibitory concentration) against a series of strains of Bacillus subtilis, Staphylococcus aureus and Escherichia coli for antibacterial activity and against the strains of Candida albicans, Aspergillus flavus and Aspergillus niger for antifungal activity respectively. The results of the antimicrobial screening data revealed that most of the tested compounds showed moderate to good microbial inhibitions.

One pot three components microwave assisted and conventional synthesis of new 3-(4-chloro-2-hydroxyphenyl)-2-(substituted) thiazolidin-4-one as antimicrobial agents.

A one-pot, three-component, microwave assisted and conventional synthesis of new 3-(4-chloro-2-hydroxyphenyl)-2-(substituted) thiazolidin-4-one (4a-n) was carried out by using N,N-dimethylformamide as a solvent with high product yield. Among these synthesized compounds (4f, 4g, 4l and 4m) were found to be a broad spectrum molecule active against all bacterial and fungus strains tested, except fungus Aspergillus niger. Amongst the compounds (4g, 4l and 4m) were found to be more potent than respective standard drugs used in the experiment against Candida albicans, Staphylococcus aureus and Aspergillus flavus, respectively. All synthesized compounds were also tested for their cytotoxic activity against HeLa and MCF-7 cell lines by the sulforhodamine B (SRB) assay. This study shows that all compounds were non-cytotoxic in nature, and confirmed their antimicrobial specificity apart from any general cytotoxicity.

A novel amalgamation of 1,2,3-triazoles, piperidines and thieno pyridine rings and evaluation of their antifungal activity.

It is the first report of the novel amalgamation of 1,2,3-triazoles, piperidines, thieno pyridine rings and evaluation of their antifungal activity. The synthesized compounds showed interesting moderate to good antifungal activity, wherein they were able to discriminate between the two species Aspergillus flavus and Aspergillus niger of the same genus. In addition, the main highlight of this series is the sensitivity of the fungal strain Cryptococcus neoformans to the compounds having p-chlorobenzoyl (9h), methane sulfonyl (9i) and p-methylbenzene sulfonyl (9j) attached to the piperazine nitrogen.

Green synthesis of tetrahydropyrimidine analogues and evaluation of their antimicrobial activity.

It is the first report of 1,3,4,5-tetrasubstituted 1,2,3,6-tetrahydropyrimidines derivatives, catalyzed by ZrOCl2. The mild reaction conditions, excellent yields in shorter reaction time and evasion of cumbersome workup procedures make this process economically lucrative for industrial application. The novelty and highlight of the present method is the promising antibacterial and antifungal activity shown by compounds (4a, 4b, 4e, 4f, 4h and 4l) compared to standard.