Narahari Deshapande

Synthesis, characterization and optoelectronic investigations of bithiophene substituted 1,3,4-oxadiazole derivatives as green fluorescent materials

A series of novel unsymmetrical bithiophene substituted oxadiazole derivatives 2(a–e) were designed and synthesised by employing palladium catalysed Suzuki cross coupling reaction. These bipolar molecules consist of bithiophene as an electron donor unit (D) and electron transporting oxadiazole as acceptor unit (A). The structural integrity of all the new compounds was confirmed by 1H NMR, 13C NMR and GC-MS analysis. The photophysical and electrochemical properties have been studied in detail using UV-Vis absorption, fluorescence spectroscopy and CV measurements. All compounds emit intense green fluorescence with good quantum yields. Density functional theory computations have been carried out to understand the structure–property relationship, the computed values are found to be in good agreement with the experimental results. The results demonstrated that the novel bithiophene containing oxadiazole derivatives could play an important role in organic optoelectronics.

A practical one-pot synthesis of coumarins in aqueous sodium bicarbonate via intramolecular Wittig reaction at room temperature

An efficient, simple and relatively inexpensive method for the synthesis of coumarins in aqueous sodium bicarbonate at ambient temperature has been developed. It features an intramolecular Wittig reaction of substituted 2-formylphenyl 2-bromoacetate in saturated aqueous sodium bicarbonate. Its advantages include benign reaction conditions, easy work-up and good overall yield with short reaction time. Various substituted coumarins have been synthesized by utilizing this methodology.

Synthesis of novel N-9 substituted 6-(4-(4-propoxyphenyl)piperazin-1-yl)-9H-purine derivatives as inducers of apoptosis in MCF-7 breast cancer cells

A series of N-9 substituted 6-(4-(4-propoxyphenyl)piperazin-1-yl)-9H-purine derivatives (PP05–PP21) were prepared and evaluated for their anticancer activity against a panel of human cancer cell lines. Evaluation of results revealed that some of the synthesized compounds exhibited promising anticancer activity against the examined cancer cell lines. The structure–activity relationship (SAR) studies in the present work revealed that simple N-9 alkyl substituted 6-(4-(4-propoxyphenyl)piperazin-1-yl)-9H-purines are potent anticancer agents. Among all the compounds, PP17 (9-sec-butyl-6-(4-(4-propoxyphenyl)piperazin-1-yl)-9H-purine) showed good inhibitory activity against MCF-7 cells. Cell cycle analysis of the compound suggested that induces G2/M phase arrest. Biochemical experiments showed that PP17 significantly induced MCF-7 cell apoptosis. Therefore, compound PP17 with a potent in vitro anticancer activity can serve as a promising lead compound for further study.

Synthesis and antimicrobial activity of novel sulfides and sulfones of methylene-bridged benzisoxazolylimidazo[2,1-b][1,3,4]thiadiazoles

GRAPHICAL ABSTRACT Abstract Novel classes of 3-(6-Aryl-5-phenylsulfanylimidazo[2,1-b][1,3,4]thiadiazol-2-yl-methyl)-benzo[d]isoxazoles (2a–f) and 3-(5-Benzenesulfonyl-6-arylimidazo[2,1-b][1,3,4] thiadiazol-2-yl-methyl)-benzo[d]isoxazoles (3a–f) have been synthesized. The sulfide derivatives (2a–f) were obtained by the nucleophilic substitution of bromo derivatives (1a–f) with thiophenols, and sulfone derivatives (3a–f) were obtained by the oxidation of 2a–f. All the newly synthesized compounds were characterized by elemental analysis, infrared, nuclear magnetic resonance, and mass spectroscopic data. Furthermore, these novel sulfide and sulfone derivatives were screened for their antibacterial and antifungal activities against various microorganisms.

Exploring the potential of newly synthesized 4-methyl-6-morpholino-pyrimidine derivatives as antiproliferative agents

In view of exploring the potential of pyrimidine derivatives as anticancer agents, a series of 4-methyl-6-morpholinopyrimidine derivatives was synthesised and characterised by NMR (1H & 13C), SC-XRD and mass spectral analysis. The in vitro anticancer activity of these compounds was investigated using different human cancer cell lines, namely HeLa (cervix), NCI-H460 (lung), MCF-7 (breast), HepG2 (liver) and IMR-32 (brain). Compounds 4c and 5h exhibited potent anticancer activity in a dose-dependent manner as compared to other derivatives, with IC50 values of 5.88 ± 1.22 and 6.11 ± 2.12 μM on HeLa and NCI-H460, cells respectively. The inhibitory effect of 4c and 5h on cancer cell proliferation was shown to be a consequence of reactive oxygen species (ROS) generation and subsequent induction of cellular apoptosis, as evidenced by an increase in hypodiploid (subG1) population, early apoptotic cell population, caspase-3/7 activity, loss of mitochondrial membrane potential and degradation of nuclear DNA. Furthermore, molecular docking studies revealed that 4c and 5h compounds bind to the ATP binding pocket of the mammalian target of rapamycin (mTOR). Based on our results, we conclude that 4-methyl-6-morpholinopyrimidine derivatives prevent cancer cell proliferation by inducing apoptosis and thus have potential to be further explored for anticancer properties.

Synthesis and in vitro anticancer activity of 6-chloro-7-methyl-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one derivatives: molecular docking and interaction with bovine serum albumin

ABSTRACT A novel series of 6-chloro-7-methyl-5H-[1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one derivatives were synthesized. Structure of the newly synthesized compounds was established by their analytical and spectroscopic data. The title compounds were evaluated for their anticancer activity against human breast cancer (T-47D) and lung cancer (NCI-H226) cell lines. Effects of compounds on the cell morphology of these cell lines were studied. Among the series of compounds tested, 6-chloro-7-methyl-2-(4-((2-(piperidin-1-yl)ethylamino)methyl) phenyl)-[1,3,4]thiadiazolo[3,2-a]pyrimidin-5-one [MTDP4(9)] exhibited good anticancer activity against both cell lines. Further, the binding interaction of [MTDP4(9)] with bovine serum albumin has been investigated by UV, fluorescence and molecular docking studies.