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101.
S. Ganesh P. Velavendan N. K. Pandey U. Kamachi Mudali R. Natarajan 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(3):2091-2094
A fiber optic aided spectrophotometric technique has been developed for determination of ruthenium in nitric acid medium. The developed method is simple, accurate and applicable to aqueous streams of nuclear reprocessing. The system obeys Lambert–Beer’s law at 468 nm in the concentration range of 30–360 μg/mL of ruthenium. The molar absorption coefficient, detection limit and Sandell’s sensitivity are 68.477 L Mol?1 cm?1, 31 μg/mL and 0.0124 μg/cm2 respectively. Relative standard deviation was less than 2 % and correlation coefficient was 0.9998. The results obtained by the developed procedure are in good agreement with those obtained by the standard ICP-OES method. Fission products like zirconium and strontium are not interfering. Uranium is interfering and needs prior separation by solvent extraction method. The developed method is adaptable for remote operation and on-line monitoring. 相似文献
102.
Shaila Lalkuwar Bajoria Virendra Kisan Rathod N. K. Pandey U. Kamachi Mudali R. Natarajan 《Journal of Radioanalytical and Nuclear Chemistry》2013,295(1):271-276
Extraction power of solvent depends upon the physical properties of the system. Tri-n-butyl phosphate (TBP) in dodecane is a versatile solvent used in the nuclear fuel reprocessing like PUREX process. The study of physical properties like density, viscosity, interfacial tension and solubility for TBP–nitric acid–dodecane system will be helpful in carrying out different extraction studies during PUREX process. Thus, physical properties like density, viscosity, interfacial tension and solubility have been measured for TBP–nitric acid–dodecane system using pycnometer, viscometer, pendant drop method and high performance liquid chromatography respectively. It has been observed that density and viscosity increases but interfacial tension and solubility decreases with the concentration of TBP in dodecane–nitric acid system. Physical properties of 30 % TBP–nitric acid–dodecane system have also been studied in detail. All these studies will also be useful in stripping out dissolved TBP from the nuclear waste. 相似文献
103.
104.
Nguyen Huy Thuan Ramesh Prasad Pandey Ta Thi Thu Thuy Je Won Park Jae Kyung Sohng 《Applied biochemistry and biotechnology》2013,171(8):1956-1967
Myricetin is an important flavonol whose medically important properties include activities as an antioxidant, anticarcinogen, and antimutagen. The solubility, stability, and other biological properties of the compounds can be enhanced by conjugating aglycon with sugar moieties. The type of sugar moiety also plays a significant role in the biological and physical properties of the natural product glycosides. Reconstructed Escherichia coli containing thymidine diphosphate-α-l-rhamnose sugar gene cassette and Arabidopsis-derived glycosyltransferase were used for rhamnosylation of myricetin. Myricetin (100 μM) was exogenously supplemented to induced cultures of engineered E. coli. The formation of target product—myricetin-3-O-α-l-rhamnoside—was confirmed by chromatographic and NMR analyses. The yield of product was improved by using various mutants and methylated cyclodextrin as a molecular carrier for myricetin in combination with E. coli M3G3. The maximal yield of product is 55.6 μM (3.31-fold higher than the control E. coli MG3) and shows 55.6 % bioconversion of substrate under optimized conditions. 相似文献
105.
Sonika Pandey Avinash Mishra Manish Kumar Patel Bhavanath Jha 《Applied biochemistry and biotechnology》2013,171(1):1-9
Cumin is an annual herbaceous medicinally important plant having diverse applications. An efficient and reproducible method of Agrobacterium-mediated genetic transformation was herein established for the first time. A direct regeneration method without callus induction was optimised using embryos as explant material in Gamborg’s B5 medium supplemented with 0.5-μM 6-benzyladenine and 2.0-μM α-naphthalene acetic acid. About 1,020 embryos (a mean of 255 embryos per batch) were used for the optimisation of transformation conditions. These conditions were an Agrobacterium cell suspension of 0.6 OD600, a co-cultivation time of 72 h, 300-μM acetosyringone and wounding of explants using a razor blade. Pre-cultured elongated embryos were treated using optimised conditions. About 720 embryos (a mean of 180 embryos per batch) were used for transformation and 95 % embryos showed transient β-glucuronidase expression after co-cultivation. Putative transformed embryos were cultured on B5 medium for shoot proliferation and 21 regenerated plants were obtained after selection and allowed to root. T0 plantlets showed β-glucuronidase expression and gene integration was confirmed via PCR amplification of 0.96 and 1.28 kb fragments of the hygromycin-phosphotransferase II and β-glucuronidase genes, respectively. In this study, a transformation efficiency of 1.5 % was demonstrated and a total of 11 transgenic plants were obtained at the hardening stage, however, only four plants acclimatised during hardening. Gene copy number was analysed by Southern blot analysis of hardened plants and single-copy gene integration was observed. This is the first successful attempt of Agrobacterium-mediated genetic transformation of cumin. 相似文献
106.
Theodoros Aggelopoulos Argyro Bekatorou Ashok Pandey Maria Kanellaki Athanasios A. Koutinas 《Applied biochemistry and biotechnology》2013,170(8):1885-1895
The exploitation of various agro-industrial wastes for microbial cell mass production of Kluyveromyces marxianus, kefir, and Saccharomyces cerevisiae is reported in the present investigation. Specifically, the promotional effect of whole orange pulp on cell growth in mixtures consisting of cheese whey, molasses, and potato pulp in submerged fermentation processes was examined. A 2- to 3-fold increase of cell mass was observed in the presence of orange pulp. Likewise, the promotional effect of brewer’s spent grains on cell growth in solid state fermentation of mixtures of whey, molasses, potato pulp, malt spent rootlets, and orange pulp was examined. The cell mass was increased by 3-fold for K. marxianus and 2-fold for S. cerevisiae in the presence of these substrates, proving their suitability for single-cell protein production without the need for extra nutrients. Cell growth kinetics were also studied by measurements of cell counts at various time intervals at different concentrations of added orange pulp. The protein content of the fermented substrates was increased substantially, indicating potential use of mixed agro-industrial wastes of negligible cost, as protein-enriched livestock feed, achieving at the same time creation of added value and waste minimization. 相似文献
107.
Ankit S. Macwan Nidhi Srivastava Saleem Javed Ashwani Kumar 《Applied biochemistry and biotechnology》2013,169(4):1397-1404
Enzyme “hexachlorocyclohexane (HCH) dehydrochlorinase LinA” mediates first step of aerobic microbial degradation of a chlorinated insecticide γ-HCH. The archetypal LinA-type1 consists of 156 amino acids that include a directly repeated hexapeptide motif GIHFAP at positions 141–146 and 148–153. Analysis of a series of LinA mutants, containing none, one, two, or three units of this repeated motif revealed that two units, as present in wild-type LinA, are required for its optimal activity and stability. Moreover, the presence of a bend in its secondary structure due to a proline residue that precedes the distal repeated unit contributes to enhanced LinA activity. 相似文献
108.
Dr. Manivannan Ethirajan Dr. Ping Chen Dr. Tymish Y. Ohulchanskyy Dr. Lalit N. Goswami Dr. Anurag Gupta Dr. Avinash Srivatsan Dr. Mahabeer P. Dobhal Joseph R. Missert Prof. Paras N. Prasad Prof. Karl M. Kadish Prof. Ravindra K. Pandey 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(21):6670-6684
We report herein a simple and efficient approach to the synthesis of a variety of meso‐substituted purpurinimides. The reaction of meso ‐ substituted purpurinimide with N‐bromosuccinimide regioselectively introduced a bromo functionality at the 20‐position, which on further reaction with a variety of boronic acids under Suzuki reaction conditions yielded the corresponding meso‐substituted analogues. Interestingly, the free base and the metalated analogues showed remarkable differences in photosensitizing efficacy (PDT) and tumor‐imaging ability. For example, the free‐base conjugate showed significant in vitro PDT efficacy, but limited tumor avidity in mice bearing tumors, whereas the corresponding NiII derivative did not produce any cell kill, but showed excellent tumor‐imaging ability at a dose of 0.3 μmol kg?1 at 24, 48, and 72 h post‐injection. The limited PDT efficacy of the NiII analogue could be due to its inability to produce singlet oxygen, a key cytotoxic agent required for cell kill in PDT. Based on electrochemical and spectroelectrochemical data in DMSO, the first one‐electron oxidation (0.52 V vs. SCE) and the first one‐electron reduction (?0.57–0.67 V vs. SCE) of both the free base and the corresponding NiII conjugates are centered on the cyanine dye, whereas the second one‐electron reduction (?0.81 V vs. SCE) of the two conjugates is assigned to the purpurinimide part of the molecule. Reduction of the cyanine dye unit is facile and occurs prior to reduction of the purpurinimide group, which suggests that the cyanine dye unit as an oxidant could be the driving force for quenching of the excited triplet state of the molecules. An interaction between the cyanine dye and the purpurinimide group is clearly observed in the free‐base conjugate, which compares with a negligible interaction between the two functional groups in the NiII conjugate. As a result, the larger HOMO–LUMO gap of the free‐base conjugate and the corresponding smaller quenching constant is a reason to decrease the intramolecular quenching process and increase the production of singlet oxygen to some degree. 相似文献
109.
Dawid Kedracki Sergey K. Filippov Nidhi Gour Helmut Schlaad Corinne Nardin 《Macromolecular rapid communications》2015,36(8):768-773
Conjugation of a hydrophobic poly(2‐oxazoline) bearing tertiary amide groups along its backbone with a short single stranded nucleotide sequence results in an amphiphilic comb/graft copolymer, which organizes in fibrils upon direct dissolution in water. Supported by circular dichroism, atomic force microscopy, transmission electron microscopy, and scattering data, fibrils are formed through inter‐ and intramolecular hydrogen bonding between hydrogen accepting amide groups along the polymer backbone and hydrogen donating nucleic acid grafts leading to the formation of hollow tubes.
110.
Vijay Narayan Anoop Kumar Pandey Apoorva Dwivedi Benard Samwel Mwankemwa Avantika Maurya Ankit Kumar Sharma Vijay Singh 《印度化学会志》2022,99(8):100580
Uracil mustard belongs to the nitrogen mustard family and is primarily used in anticancer drugs. The research that follows, investigates many quantum chemical features such as the computation of global minimum energies with no negative wavenumber values using the Density Functional Theory (DFT) with Becke three functional and 6-311G (d, p)/6–311++G (d, p) basis sets. All the vibrational modes have been calibrated and justified in comparison to their experimental counterparts. Mustard's polarizability and hyperpolarizability components, Natural Bond Analysis (NBO), electronic properties, Fukui function analysis, various global parameters, Quantum Theory of Atoms In Molecule (QTAIM) analysis, ADMET analysis, and docking analysis have all been investigated using the same theory and basis sets, indicating its biochemical significance. The biological activity of the molecule is reported by using PASS software. The Full fitness score and binding affinity parameters are utilized to determine the binding strength with 6cq3 protein. The acidity of the title molecule is calculated in water solvent by polarizable continuum model (PCM) solvent effects (estimated in water). The HOMO, LUMO, and MESP plots are used to explore the nature of binding and surfaces. The Fukui functions are computed using Mulliken atomic charges for neutral atoms, cations, and anions. The Ultraviolet–visible (UV–vis) of the molecule is computed employing the TD-DFT method. 相似文献