Research Publications (Applied Sciences)
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Item Synthesis and characterization of 2′,3′-epoxy propyl-N-methyl-2-oxopyrrolidinium salicylate ionic liquid and study of its interaction with water or methanol(Royal Society of Chemistry, 2016) Vasanthakumar, Arumugam; Bahadur, Indra; Redhi, Gan G.; Gengan, Robert MoonsamyImportant physico-chemical properties of ionic liquids (ILs) can be manipulated by adjusting the nature of the cation or anion. These properties are exploited in applications such as organic synthesis, catalysis and electrochemical processes to mention a few. In this work, the novel pyrrolidone ionic liquid N-(2′,3′-epoxypropyl)-N-methyl-2-oxopyrrolidinium salicylate [EPMpyr]+[SAL]− was synthesized using two steps and characterized. The temperature dependent density and speed of sound for ionic liquid, methanol, water, and their corresponding binary mixtures of {IL (1) + methanol or water (2)} were measured over the entire range of mole fractions at temperatures from T = (293.15 to 313.15) K in steps of 5 K, under atmospheric pressure. The calculated thermodynamic properties such as excess molar volume VEm, isentropic compressibility ks, intermolecular free length Lf, and deviation in isentropic compressibility Δks, were derived from the investigated density and speed of sound data. The resulting experimental data for excess molar volumes VEm, intermolecular free length Lf, and deviation in isentropic compressibility Δks, were well fitted to the Redlich–Kister polynomial equation. The effect of temperature and concentration on thermophysical properties was also provided.Item Moringa oleifera gold nanoparticles modulate oncogenes, tumor suppressor genes, and Caspase-9 splice variants in A549 cells(Wiley Online Library, 2016) Tiloke, Charlette; Phulukdaree, Alisa; Anand, Krishnan; Gengan, Robert MoonsamyGold nanoparticles (AuNP's) facilitate cancer cell recognition and can be manufactured by green synthesis using nutrient rich medicinal plants such as Moringa oleifera (MO). Targeting dysregulated oncogenes and tumor suppressor genes is crucial for cancer therapeutics. We investigated the antiproliferative effects of AuNP synthesized from MO aqueous leaf extracts (MLAuNP) in A549 lung and SNO oesophageal cancer cells. A one‐pot green synthesis technique was used to synthesise MLAuNP. A549, SNO cancer cells and normal peripheral blood mononuclear cells (PBMCs) were exposed to MLAuNP and CAuNP to evaluate cytotoxicity (MTT assay); apoptosis was measured by phosphatidylserine (PS) externalization, mitochondrial depolarization (ΔΨm) (flow cytometry), caspase‐3/7, −9 activity, and ATP levels (luminometry). The mRNA expression of c‐myc, p53, Skp2, Fbw7α, and caspase‐9 splice variants was determined using qPCR, while relative protein expression of c‐myc, p53, SRp30a, Bax, Bcl‐2, Smac/DIABLO, Hsp70, and PARP‐1 were determined by Western blotting. MLAuNP and CAuNP were not cytotoxic to PBMCs, whilst its pro‐apoptotic properties were confirmed in A549 and SNO cells. MLAuNP significantly increased caspase activity in SNO cells while MLAuNP significantly increased PS externalization, ΔΨm, caspase‐9, caspase‐3/7 activities, and decreased ATP levels in A549 cells. Also, p53 mRNA and protein levels, SRp30a (P = 0.428), Bax, Smac/DIABLO and PARP‐1 24 kDa fragment levels were significantly increased. Conversely, MLAuNP significantly decreased Bcl‐2, Hsp70, Skp2, Fbw7α, c‐myc mRNA, and protein levels and activated alternate splicing with caspase‐9a splice variant being significantly increased. MLAuNP possesses antiproliferative properties and induced apoptosis in A549 cells by activating alternate splicing of caspase‐9. J. Cell. Biochem. 117: 2302–2314, 2016.Item 4-Dihydroxy-3-(indol-2-)-yl-quinoline via substantial methodology-fisher indole synthesis(Heterocyclic Letters, 2016) Pitchai, P.; Nepolraj, A.; Sathiyaseelan, M.; Gengan, Robert MoonsamyFisher indole methodology, a simple application was used to generate indole as a substitution on the quinoline ring. Conventional heating and microwave irradiation was compared. The ease of work up procedure, reduced time and moreover the high yield is exceptional however microwave irradiation presented more advantages.Item Vilsmeier-Haack reaction : a manifest protocol to synthesise bisquinoline(NISCAIR-CSIR, India, 2016-04) Makhanya, Talent Raymond; Pitchai, P.; Gengan, Robert Moonsamy; Mohan, P.S.Synthesis of bisquinolines from methyl anthranilate and ethyl acetoacetate is described. This synthesis has been accomplished in three steps. Vilsmeier-Haack reaction is used as a key tool to assemble bisquinoline. Microwave heating during each step of the reaction gives high yield of products in short reaction times.Item Utility of Michael type addition on the synthesis of pyrimidines and antibacterial studies of 4,6-diaryl-3,4-dihydropyrimidin-2(1H)-ylidene) cyanamides(JOCPR, 2015) Babu, K.; Pitchai, P.; Gengan, Robert MoonsamySynthesis, characterization and antibacterial studies of newer 4,6-diaryl-3,4-dihydropyrimidin-2(1H)-ylidene) cyanamide derivatives are reported. The structures of all the synthesized compounds were elucidated by the value of spectral data; introduced against selective microorganism using disc diffusion method displayed comparatively good proposition.Item Green synthesis of gold nanoparticles using marine algae and evaluation of their catalytic activity(SpringerOpen, 2016) Ramakrishna, M.; Babu, Dandamudi Rajesh; Gengan, Robert Moonsamy; Chandra, S.; Rao, G. NageswaraThe hazardous effects of current nanoparticle synthesis methods have steered researchers to focus on developing newer eco-friendly methods for synthesizing nanoparticles using non-toxic chemicals. Owing to the diverse applications of nanoparticles in various fields such as catalysis, medicine, diagnostics, and sensors, several novel green approaches have been explored for synthesiz-ing nanoparticles using different natural sources such as plants, algae, bacteria, and fungi. Hence, in the present work, a green method for the synthesis of gold nanoparti-cles (AuNPs) under ambient conditions using aqueous extracts of marine brown algae is reported and the syn-thesized AuNPs were evaluated for their catalytic effi-ciency. The aqueous extracts of algae comprise reducing as well as capping agents required for the formation of AuNPs. The Fourier transform infrared spectra of the extracts revealed the presence of compounds having hydroxyl groups that are largely responsible for the reduction of auric chloride to AuNPs at room temperature. Results from high-resolution transmission electron micro-scopy and dynamic light scattering studies suggested that most of the biosynthesized AuNPs are nearly spherical in shape with an average size in the range of 27–35 nm. High negative values of zeta potential measurement confirmed the stability of AuNPs. Moreover, the reduction kinetics of AuNPs studied by UV–visible spectrophotometry showed that they have good catalytic efficiency in the degradation of dyes as well as reduction of nitro compounds in the presence of sodium borohydride as reducing agent. This simple process for the biosynthesis of gold nanoparticles is rapid, cost-effective and eco-friendly. The formation of AuNPs was observed with the change of pale yellow gold solution to ruby red color of gold nanoparticles and con-firmed by surface plasmon spectra using UV–visible spectroscopy. Nanoparticles synthesized through such environmentally benign routes can be used for synthesizing many other metal nanoparticles as well as for a wide range of biomedical applications, for commercial production on a large scale and also can be used as efficient catalysts for different organic reactions.Item Efficient catalytic activity of ionic liquid-supported NiFe2O4 magnetic nanoparticle doped Titanium Dioxide nano-composite(IJCEA, 2016-12) Vasanthakumar, Arumugam; Redhi, Gan G.; Gengan, Robert MoonsamyIn this work the author disclose an effective and environment-friendly approach to the preparation of an ionic liquid supported, magnetic nanoparticle doped titanium oxide nanocomposite. The novel ionic liquid N-(2′, 3′-epoxypropyl)-N-methyl-2- pyrrolidonium salicylate was first synthesized and characterized by 1H-NMR, 13C-NMR, elemental Analysis and FTIR. It was subsequently used for the preparation of a composite material by traditional protocols. This ionic liquid is able to connect the NiFe2O4 magnetic nanoparticles with titanium dioxide via strong ionic liquid interactions. The composite was characterized by FT-IR, Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDS) analysis, Transmission Electron Microscopy (TEM), High-Resolution Transmission Electron Microscopy (TEM) and Diffraction studies (DF). The catalytic activities of these composites were assessed by the reduction of nitro aniline with the aid of UV spectroscopy. Furthermore, the composite material was easily recovered and re-used with negligible loss of its catalytical activity.Item A novel alkaloid, four alkaloid precursors and a coumarin from Feronia limonia(NISCAIR-CSIR, India, 2012-12) Pitchai, P.; Ulagi, R.; Mohan, P. S.; Gengan, Robert MoonsamyA new quinoline alkaloid has been isolated from the flowers of Feronia limonia along with four alkaloid precursors, one coumarin, a known steroid stigmasterol and p-coumaric acid. The structures of compounds have been elucidated on the basis of spectroscopic data and comparison with the literature.Item A one pot microwave assisted synthesis of 3-acyl-2,4-dihydroxyquinoline followed by synthesis of 7-methyldibenzo[c,f][2,7]naphthyridin-6(5H)-ones via three routes(NISCAIR, 2013) Pitchai, P.; Uvarani, C.; Gengan, Robert Moonsamy; Mohan, P. S.An easy one pot microwave assisted synthesis of 3-acyl-2,4-dihydroxyquinoline from simple precursors followed by convenient synthesis of novel and potential HIV integrase inhibitors 7-methyldibenzo[c,f][2,7]naphthyridin-6(5H)-ones has been achieved through three different routes. Mild reaction conditions and good yields are obtained by applying microwave and photochemical techniques.Item Derivatives of coumarins, cinnamic acid and tyramine from leaves of Limonia crenulata(Pharmascope, 2013) Pitchai, P.; Ulagi, R.; Mohan, P. S.; Gengan, Robert MoonsamyThe present research was designed to isolate the Coumarins, Cinnamic acid and Tyramine from Leaves of Limonia crenulata . N - benzoyl tyramine and 2,4 - dihydroxy - 3 - methoxy cinnamic acid were isolated for the first time from the leaves of Limonia crenulata. Known compounds stigmasterol, daphnetin - 8 - methyl eth er and umbelliferone were also recovered by chromatographic separation techniques. Five compounds were isolated from the acetone extract of Limonia Crenulata and their structures were confirmed from spectral evidence and comparison with literature values. The compounds included derivatives of coumarins, cinnamic acid and tyramine.