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Divyashri G.,Academy of Scientific and Innovative Research AcSIR New Delhi | Divyashri G.,Indian Central Food Technological Research Institute | Krishna G.,Indian Central Food Technological Research Institute | Muralidhara,Indian Central Food Technological Research Institute | Prapulla S.G.,Indian Central Food Technological Research Institute
Journal of Medical Microbiology | Year: 2015

Accumulating evidence suggests that probiotic bacteria play a vital role in modulating various aspects integral to the health and well-being of humans. In the present study, probiotic attributes and the antioxidant, anti-inflammatory and neuromodulatory potential of Enterococcus faecium CFR 3003 were investigated by employing suitable model systems. E. faecium exhibited robust resistance to gastrointestinal stress conditions as it could withstand acid stress at pH 1.5, 2 and 3. The bacterium also survived at a bile salt concentration of 0.45 %, and better tolerance was observed towards pepsin and trypsin. E. faecium produced lactic acid as a major metabolic product, followed by butyric acid. Lyophilized cell-free supernatant (LCS) of E. faecium exhibited significant antioxidant capacity evaluated against 1,1-diphenyl-2-picryl-hydrazyl, ascorbate autooxidation, oxygen radical absorbance and reducing power. Interestingly, E. faecium, Lactobacillus rhamnosus GG MTCC 1408 and LCS showed a significant anti-inflammatory effect by negatively modulating TNF-α production and upregulating IL-10 levels in LPS-stimulated macrophage cell lines. In an in vivo mice model, the propensity of probiotic supplements to modulate endogenous oxidative markers and redox status in brain regions was assessed. Young mice provided with oral supplements (daily for 28 days) of E. faecium and L. rhamnosus exhibited diminished oxidative markers in the brain and enhanced activities of antioxidant enzymes with a concomitant increase in γ-aminobutyric acid and dopamine levels. Collectively, our findings clearly suggest the propensity of these bacteria to protect against tissue damage mediated through free radicals and inflammatory cytokines. Although the underlying molecular mechanisms need further studies, it is tempting to speculate that probiotics confer a neuroprotective advantage in vivo against oxidative damage-mediated neurodegenerative conditions. © 2015 The Authors. Source

Naeem K.C.,Indian National Institute for Interdisciplinary Science and Technology | Naeem K.C.,Academy of Scientific and Innovative Research AcSIR New Delhi | Subhakumari A.,Indian National Institute for Interdisciplinary Science and Technology | Varughese S.,Indian National Institute for Interdisciplinary Science and Technology | And 2 more authors.
Journal of Materials Chemistry C | Year: 2015

Two donor-π-acceptor type fluorophores consisting of anthracene as the donor and benzoxazole (ABO) or benzothiazole (ABT) as the acceptor are synthesised. Both fluorophores exhibit excellent solid state luminescence, and respond to external stimuli such as mechanical force (mechanochromism) and protons (acidochromism). Though the differences between the two molecules are marginal, their stimuli responsive behaviours are contrasting. ABO shows stable mechanochromism but the protonation induced colour change is unstable. On the other hand, ABT shows stable acidochromism but luminescence changes induced by mechanical stress are reverted back quickly. A detailed study reveals that the variance in the heteroatoms in benzoxazole/benzothiazole moieties (oxygen and sulphur, respectively) significantly affects both the intra- and intermolecular electronic interactions of the molecules resulting in such observations. In the case of ABO, the benzoxazole moieties interact through weak edge-to-edge π-stacking, whereas in ABT, the ring overlap is more significant making the π-stacking a stronger face-to-face type, which helps in the restoration of the molecular ordering in ABT, which is energetically more viable. Regarding the acidochromic properties, the presence of more electronegative oxygen (compared to sulphur) in ABO draws electrons efficiently towards it making the nitrogen less basic and the complex formed between ABO and TFA less stable. On the other hand, electron density on the nitrogen in ABT might be higher compared to ABO due to the presence of less electronegative sulphur leading to the formation of a stable complex between ABT and TFA. © The Royal Society of Chemistry. Source

Bejoymohandas K.S.,Indian National Institute for Interdisciplinary Science and Technology | Bejoymohandas K.S.,Academy of Scientific and Innovative Research AcSIR New Delhi | Kumar A.,University of Burgundy | Varughese S.,Indian National Institute for Interdisciplinary Science and Technology | And 4 more authors.
Journal of Materials Chemistry C | Year: 2015

Herein, we have synthesized a series of 2′,6′-difluoro-2,3′-bipyridine cyclometalating ligands by substituting electron-withdrawing (-CHO, -CF3, and -CN) and electron-donating (-OMe and -NMe2) groups at the 4′ position of the pyridyl moiety and utilized them for the construction of five new iridium(iii) complexes (Ir1-Ir5) in the presence of picolinate as an ancillary ligand. The photophysical properties of the developed iridium(iii) compounds were investigated with a view to understand the substituent effects. The strong electron-withdrawing (-CN) group containing the iridium(iii) compound (Ir3) exhibits highly efficient genuine green phosphorescence (λmax = 508 nm) at room temperature in solution and in thin film, with an excellent quantum efficiency (ΦPL) of 0.90 and 0.98, respectively. On the other hand, the -CF3 group substituted iridium(iii) compound (Ir2) displays a sky-blue emission (λmax = 468 nm) with a promising quantum efficiency (ΦPL = 0.88 and 0.84 in solution and in thin film, respectively). The -CHO substituted iridium(iii) complex (Ir1) showed greenish-yellow emission (λmax = 542 nm). Most importantly, the strong electron-donating -NMe2 substituted iridium(iii) complex (Ir5) gives a structureless and a broad emission profile in the wavelength region 450 to 700 nm (λmax = 520 nm) with a poor quantum efficiency. An intense blue phosphorescence with impressive quantum efficiency, especially in thin-film noted in the case of the -OMe substituted iridium(iii) complex (Ir4). Comprehensive density functional theory (DFT) and time-dependent DFT (TD-DFT) approaches have been performed on the ground and excited states of the synthesized iridium(iii) complexes, in order to obtain information about the absorption and emission processes and to gain deeper insights into the photophysical properties. The combinations of a smaller ΔES1-T1 and higher contribution of 3MLCT in the emission process result in the higher quantum yields and lifetime values for complexes Ir1-Ir3. Multi-layered Phosphorescent Organic Light Emitting Diodes (PhOLEDs) were designed using the phosphorescent dopants Ir2, Ir3 and Ir4 and their elecroluminescence properties were evaluated. Compound Ir4 at a doping level of 5 wt% shows the best performance with an external quantum efficiency of 4.7%, in the nonoptimized device, and a power efficiency of 5.8 lm W-1, together with a true-blue chromacity CIEx,y = 0.15, 0.17 recorded at the maximum brightness of 33 180 cd m-2. This journal is © The Royal Society of Chemistry. Source

Parkash J.,CSIR - Central Electrochemical Research Institute | Parkash J.,Academy of Scientific and Innovative Research AcSIR New Delhi | Kashyap S.,CSIR - Central Electrochemical Research Institute | Kirti S.,CSIR - Central Electrochemical Research Institute | And 4 more authors.
Plant Gene | Year: 2015

Medicinal importance of Picrorhiza (Picrorhiza kurrooa Royle ex Benth - an herb of western Himalayan region) and its endangered status in Red Data Book presses an urgent need for intensive R&D interventions towards ensuring its availability for the medicinal use, its sustainability and improvement. The present study was conducted on cathepsin B cysteine protease in Picrorhiza. Cathepsin B cysteine protease has been reported to function in diverse processes such as senescence, abscission, programmed cell death, fruit ripening and in response to pathogen and pest attacks. A full-length cDNA-Pk-cbcp encoding cathepsin B-like cysteine protease was cloned from Picrorhiza. The full length Pk-cbcp cDNA consisted of 1369 bp with an open reading frame of 1080 bp, 80 bp 5′ untranslated region and 209 bp 3′ untranslated region. The deduced Pk-cbcp protein contained 359 amino acids with a molecular weight of 39.981 kDa and an isoelectric point of 5.75. Secondary structure analysis revealed that Pk-cbcp had 28.97% α-helices, 14.48% β-turns, 19.50% extended strands and 37.05% random coils. Semi-quantitative PCR analysis revealed 157% higher expression of Pk-cbcp during senescence compared to that of pre-senescence. Further, application of phytohormones abscisic acid, jasmonic acid and cytokinin influenced the temporal expression status of Pk-cbcp. Abscisic acid and jasmonic acid increased the expression level whereas cytokinin reduced the expression. The findings suggest the role of Pk-cbcp in leaf senescence in Picrorhiza which may be differentially mediated through phytohormones. © 2015 The Authors. Source

Kandhadi J.,Indian Institute of Chemical Technology | Yeduru V.,Indian Institute of Chemical Technology | Yeduru V.,Academy of Scientific and Innovative Research AcSIR New Delhi | Bangal P.R.,Indian Institute of Chemical Technology | And 3 more authors.
Physical Chemistry Chemical Physics | Year: 2015

Two different donor-acceptor systems based on corrole-ferrocene and corrole-anthraquinone having the 'Olefin Bridge' at the β-pyrrole position have been designed and synthesized. Both the dyads corrole-ferrocene (Cor-Fc) and corrole-anthraquinone (Cor-AQ) are characterized by elemental analysis, ESI-MS, 1H NMR, UV-Visible, fluorescence spectroscopies (steady-state, femtosecond time-resolved), femtosecond transient absorption spectroscopy (fs-TA) and electrochemical methods. 1H-NMR shows that two doublets at 6.50 and 7.25(δ) ppm belong to vinylic protons, which are characteristic of the formation of dyads. UV-Visible absorption spectra showed that dyads are merely superpositions of their respective constituent monomers and dominated by corrole S1 ← S0 (Q-band) and S2 ← S0 (Soret band) transitions with a systematic red-shift of both Soret and Q-bands along with the broadening of the bands. A prominent splitting of the Soret band for both the dyads is observed due to bulky substitutions at the peripheral position, which deviate from the planarity of the corrole macrocycle. Both the dyads exhibit significant fluorescence emission quenching (95-97%) of corrole emission compared to the free-base corrole monomer. Emission quenching is attributed to the excited-state intramolecular photoinduced electron transfer (PET) from corrole to anthraquinone in the Cor-AQ dyad, whereas in the Cor-Fc dyad it is reversed. The electron-transfer rates (kET) for Cor-AQ and Cor-Fc were found to be 3.33 × 1011 and 2.78 × 1010 s-1, respectively. Despite their very different driving forces, charge separation (CS) and charge recombination (CR) are found to be in identical timescales. This journal is © the Owner Societies. Source

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