Faculty Publications
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Item Identification and characterization of novel indole based small molecules as anticancer agents through SIRT1 inhibition(2013) Panathur, N.; Udayakumar, U.; Koushik, P.V.; Alvala, M.; Yogeeswari, P.; Sriram, D.; Kumar, V.In our pursuit to develop new potential anticancer leads, we designed a combination of structural units of indole and substituted triazole; and a library of 1-{1-methyl-2-[4-phenyl-5-(propan-2-ylsulfanyl)-4H-1,2,4-triazol-3- yl]-1H-indol-3-yl}methanamine derivatives was synthesized and characterized. Cytotoxic evaluations of these molecules over a panel of three human cancer cell lines were carried out. Few molecules exhibited potent growth inhibitory action against the treated cancer cell lines at lower micro molar concentration. An in vitro assay investigation of these active compounds using recombinant human SIRT1 enzyme showed that one of the compounds (IT-14) inhibited the deacetylation activity of the enzyme. The in vivo study of IT-14 exemplified its promising action by reducing the prostate weight to the body weight ratio in prostate hyperplasia animal models. A remarkable decrease in the disruption of histoarchitecture of the prostate tissues isolated from IT-14 treated animal compared to that of the positive control was observed. The molecular interactions with SIRT1 enzyme were also supported by molecular docking simulations. Hence this compound can act as a lead molecule to treat prostatic hyperplasia. © 2013 Elsevier Masson SAS. All rights reserved.Item New D-?-A type indole based chromogens for DSSC: Design, synthesis and performance studies(Elsevier Ltd, 2015) Babu, D.D.; Gachumale, S.R.; Anandan, S.; Vasudeva Adhikari, A.V.Three new Donor-?-Acceptor type dyes D1-3 carrying 3-(1-hexyl-1H-indol-3-yl)-2-(thiophen-2-yl)acrylonitrile as backbone with three different acceptor units were designed and synthesized as promising sensitizers for solar cell application. The new dyes were characterized using various spectral and elemental analyses. Their optical and electrochemical properties were investigated using spectrophotometry and cyclic voltammetry respectively, while their photovoltaic performance was evaluated by a device fabrication study. The devices were subjected to electrochemical impedance spectroscopy to gain an insight into the interfacial charge transfer and recombination process while in use. Further, density functional theory study was carried out to investigate their Frontier Molecular Orbital energy states. The study reveals that the dye carrying 4-aminobenzoic acid as an acceptor showed the highest photovoltaic efficiency among the three dyes. This can be attributed to the longer electron lifetime and lower recombination rates. Additionally, a Single crystal X-ray diffraction study confirmed the structure of a key intermediate. © 2014 Elsevier Ltd. All rights reserved.Item Molecular Engineering and Theoretical Investigation of Novel Metal-Free Organic Chromophores for Dye-Sensitized Solar Cells(Elsevier Ltd, 2015) Babu, D.D.; Cheema, H.; Elsherbiny, D.; El-Shafei, A.; Vasudeva Adhikari, A.V.In this work we report design and synthesis of three new metal free D-D-A-?-A type dyes (E1-3) with different acceptor/anchoring groups, as effective sensitizers for nanocrystalline titanium dioxide based dye sensitized solar cells. All the three dyes carry electron donating methoxy group as an auxiliary and indole as a principal donor, cyanovinylene as an auxiliary acceptor and thiophene as a ?-spacer. Whereas, cyanoacetic acid, rhodanine-3-acetic acid and 4-aminobenzoic acid perform as acceptor/anchoring moieties, respectively in the dyes E1-3. Though the dye containing 4-aminobenzoic acid unit (E3) exhibits comparatively lower ?max, it shows the highest power conversion efficiency arising from the higher electron life time and good light-harvesting capability. The DFT studies reveal a better charge separation between the HOMO and LUMO levels of E3, further substantiating the experimental results. Among the three dyes, E3 shows the best photovoltaic performance with short-circuit current density (Jsc) of 9.35 mA cm-2, open-circuit voltage (Voc) of 620 mV and fill factor (FF) of 0.71, corresponding to an overall conversion efficiency of 4.12% under standard global AM 1.5G. © 2015 Elsevier Ltd. All rights reserved.Item Molecular engineering and theoretical investigation of metal-free organic Chromophores for dye-sensitized solar cells(American Scientific Publishers, 2016) Babu, D.D.; Vasudeva Adhikari, A.V.A new donor-?-bridge-acceptor (D- ? -A) based sensitizer comprising of indole moiety in the donor segment, thiophene as ? spacer and 2-phenylacetic acid as an acceptor unit was designed and synthesized. It was characterized using FTIR, NMR, MS and elemental analyses. Its photophysical and electrochemcial properties were studied by UV-vis spectrometry and cyclic voltammetry, respectively. DFT simulations were also carried out using TURBOMOLE software package. © 2016 American Scientific Publishers All rights reserved.Item Highly efficient panchromatic dye-sensitized solar cells: Synergistic interaction of ruthenium sensitizer with novel co-sensitizers carrying different acceptor units(Elsevier Ltd, 2016) Babu, D.D.; Elsherbiny, D.; Cheema, H.; El-Shafei, A.; Vasudeva Adhikari, A.V.Herein, we report the molecular design, synthesis and photovoltaic performance studies of three new organic co-sensitizers, N1-3 carrying indole and thiophene units linked to different acceptors/anchoring groups, as co-adsorbents for dye sensitized solar cells. We present the role of anchoring/acceptor units on co-sensitization properties N1-3. Their photo-physical and electrochemical results along with molecular geometry, obtained from Density Functional Theory are utilized to rationalize the influence of co-sensitizer structures on photovoltaic properties for DSSCs. We have shown that, the co-sensitization effect is profoundly dependent upon the anchoring/acceptor unit in the co-adsorbents. Among them, N3 containing 4-aminobenzoic acid shows promising co-sensitization results and exhibits an enhanced efficiency of 9.26%, when co-sensitized with a ruthenium dye, HD-14. Further, the study highlights the importance of molecular matching between the sensitizer and co-sensitizer in enhancing the efficiency. Furthermore, vertical electronic excitations are calculated using time dependent density functional theory studies. © 2016 Elsevier Ltd. All rights reserved.Item Synthesis and photovoltaic performance of a novel asymmetric dual-channel co-sensitizer for dye-sensitized solar cell beyond 10% efficiency(Elsevier Ltd, 2017) Babu, D.D.; Su, R.; Naik, P.; El-Shafei, A.; Vasudeva Adhikari, A.V.In this paper, we report the design and synthesis of a new bi-anchoring indole based co-sensitizer DBA-8 with A-?-D-A (acceptor-? bridge-donor-acceptor) architecture, carrying indole moiety as a donor and barbituric acid as acceptor/anchoring groups. Its photo-physical and electrochemical properties along with molecular geometries, calculated from Density Functional Theory (DFT) are employed to comprehend the effect of co-sensitizer structure on photovoltaic characteristics of DSSCs. The abovementioned organic dye (DBA-8) was employed as a co-sensitizer along with well-known ruthenium based sensitizer NCSU-10 in order to broaden the spectral responses of the co-sensitized DSSC. In the present work, for the first time we are demonstrating the profound role of a dual-anchoring co-sensitizer that can play in ameliorating the overall performance of a solar cell. The photovoltaic studies indicated that, the co-sensitizer DBA-8 succeeded in increasing the light harvesting ability in the device significantly. Notably, the device co-sensitized using 0.2 mM DBA-8 along with ruthenium based chromophore NCSU-10, showed a maximum efficiency of 10.68% (Jsc = 25.14 mAcm?2, Voc = 0.695 V, ff = 61.2%). Further, the good agreement between the theoretically and experimentally obtained ?max data vindicate that, the energy functional and basis set employed in this study can be successfully utilized for predicting the absorption spectra of new photosensitizers, with great precision before synthesis. Furthermore, all these findings showcase the vast potential of bi-anchoring molecules in improving the overall performance of the dye-sensitized solar cells. © 2017 Elsevier LtdItem Facile synthesis of indole-pyrimidine hybrids and evaluation of their anticancer and antimicrobial activity(Elsevier B.V., 2017) Gokhale, N.; Udayakumar, U.; Kumsi, M.The paper describes the facile synthesis of new N-cyclopropyl-1-methyl-1H-indole-2-carboxamide derivatives bearing substituted 2-amino pyrimidine moiety at position-3 of the indole ring. All the intermediate and title compounds were characterized adeptly by 1H NMR, 13C NMR, ESI–MS and elemental analyses. These compounds were evaluated for their in vitro anticancer activity against HeLa, HepG2 and MCF-7 cells. Three among 22 molecules, showed more than 70% growth inhibition against all three tested cancer cells. The nature of the substituent group on the pyrimidine ring (R2) affected significantly the anti-proliferative activity of the molecules. The anti-microbial evaluation of the title molecules revealed the significance of fluoro/chloro groups (R2) in enhancing their inhibition activity. Eight molecules which contain fluoro/chloro groups showed potent anti-microbial activity. In addition, the active molecules displayed negligible toxicity to benign Vero cells. © 2015 King Saud University