Nath R.K.,Tripura University |
Singh Th.C.,Ddm College |
Dasgupta S.,Tripura University |
Mitra A.,MBB College |
Panda A.K.,North Bengal University
Materials Science and Engineering C | Year: 2010
Physico-chemical studies on the interaction of capsular polysaccharide (SPS) isolated from Klebsiella K18, with cationic dyes and surfactants have been reported. SPS is an integral component of gram-negative bacteria and having glucuronic acid as the potential anionic site, induced strong metachromasy (blue shift ∼ 110 nm) in the cationic dye pinacyanol chloride (PCYN). Reversal of metachromasy was observed upon addition of co-solvents which provides a qualitative measurement of stability and nature of metachromatic compound associated with PCYN-SPS interaction. Thermodynamic parameters such as association constant, changes in free energy, enthalpy and entropy of dye-polymer interaction, were evaluated which revealed the nature of interaction. Studies on fluorescence quenching of acridine orange (AO) was also performed. The interaction of SPS with cationic and cationic-non-ionic mixed surfactant systems have been studied by turbidimetry, spectrophotometry, spectrofluorometry and viscosity measurements. The studies could provide an understanding on the effects of the surfactants on binding with the polymer. The binding was found to be electrostatic in origin and also hydrophobic in nature to a certain extent. © 2010 Elsevier B.V. All rights reserved.
Chaudhuri P.S.,Tripura University |
Bhattacharjee S.,Mbb College |
Dey A.,Mbb College |
Chattopadhyay S.,Indian Institute of Chemical Technology |
Bhattacharya D.,Indian Institute of Chemical Technology
Journal of Environmental Biology | Year: 2013
A comparative analysis of earthworm communities was carried out in the rubber plantations (Hevea brasiliensis) of different age groups in West Tripura to understand the impact of such exotic and monoculture plantation in biodiversity conservation. Earthworm communities were studied on monthly basis over a period of one year (2006-2007) in the 3, 10, 14, 20 and 25 year-old plantations. Among twelve earthworm species collected from the studied sites, six species belonged to Octochaetidae [Eutyphoeus assamensis Stephenson, Eutyphoeus comillahnus Michaelsen, Lennogaster chittagongensis (Stephensen), Octochaetona beatrix Gates, Dichogaster affinis Michaelsen, Lennogaster yeicus (Stephensen)], two species each to Megascolecidae [Metaphire houlleti (Perrier), Kanchuria sp. 1] and Moniligastridae [Drawida nepalensis Michaelsen, Drawida papillifer papillifer Stephenson], one species each to Glossoscolecidae [Pontoscolex corethrurus (Muller)] and Ocnerodrilidae [Gordiodrilus elegans Beddard]. Exotic species P. corethrurus, M. houlleti and native peregrine species like D. nepalensis and D. papillifer papillifer were distributed in all the age groups of plantation, while other species showed restricted distribution. P. corethrurus contributed more than 60% biomass and 70% density of earthworm communities in rubber plantation. With aging of rubber plantations both the densities and biomasses of earthworms increased. High contents of polyphenol, flavonoid and lignin in the litters of 3 and 10 year-old-rubber plantations through their effects on food intake, probably resulted to low biomass values of earthworms in those age groups of plantation. With further increase in the age of plantations beyond 10 years, polyphenol, flavonoid and lignin contents decreased. Accordingly the biomass of earthworms increased with increase in the age of plantation. Soil moisture increased with increase in the age of plantation and there was a good positive correlation between soil moisture and earthworm biomass (p<0.01). Density, biomass and dominance of earthworms increased while species diversity, species richness and species evenness of earthworm community were decreased with increase in the age of rubber plantation. © Triveni Enterprises, Lucknow (India).
Debnath S.,MBB College |
Debnath T.,MBB College |
Majumdar S.,Tripura University |
Arunasree M.K.,University of Hyderabad |
Aparna V.,Sree Chaitanya Institute of Pharmaceutical science
Medicinal Chemistry Research | Year: 2016
The World Cancer Report 2014 shows that cancer is a leading cause of death globally, and cancer related death is likely to go up by about 70 % in the next two decades. Among several target receptors of cancer, histone deacetylases are the promising therapeutic target for many cancers. The current study deals with a primary goal of identification of novel non-hydroxamic acid histone deacetylase 8 inhibitors. In this context, six featured pharmacophoric hypotheses with hydrogen bond acceptors (A), hydrogen bond donor (D), and aromatic ring (R) were generated using 36 reported histone deacetylase 8 inhibitors. Virtual screening of database using two pharmacophore hypothesis AAAADR.161 and AAADDR.189 resulted 2000 hits each having fitness score >1.503. The pharmacophore AAADDR.189 yielded statistically significant three-dimensional quantitative structure-activity relationship model with training set (R2: 0.9756, SD: 0.0680, F: 151.6, N: 26) and test set (Q2: 0.6922, Pearson R: 0.8705, N: 10) molecules. The R2 pred value of the model was 0.6951, which confirmed the good predictive ability of the model for external data set. Hits resulted from virtual screening and known inhibitors were subjected to molecular docking study to identify the binding affinity of inhibitors with active site amino acid residues. Finally, absorption, distribution, metabolism, and excretion study were undertaken to determine the drug likeness properties of identified hits. On the basis of fitness score, predicted activities, XP Glide score, interacting amino acid residues of known inhibitors and absorption, distribution, metabolism, and excretion properties, ten structurally diverse hits are reported in this paper as potential histone deacetylase 8 inhibitors which reduce the cost of histone deacetylase 8 inhibitor discovery and enhance the process prior synthesis. © 2016 Springer Science+Business Media New York
Bhattacharjee P.R.,Mbb College
Optik | Year: 2010
This paper deals with the mirror rotation problem and the problem of rotation of refracting surface in ray optics. These two problems of rotation in ray optics have been dealt with on the basis of the generalized vectorial laws of reflection and refraction discovered by the author in 2005. In addition to the development of many interesting physical insights to the aforesaid rotation problems in ray optics, the most remarkable fact that has been discovered in the present study is that the proposition 'Velocity of light is unattainable' is not correct. Rather, it is possible to have velocity exceeding the velocity of light a result not in agreement with the special theory of relativity. © 2009 Elsevier GmbH. All rights reserved.
Pal P.,MBB College |
Bhowmik A.,Tripura University |
Roy R.,Tripura University |
Ali R.,Tripura University |
And 3 more authors.
Indian Journal of Physics | Year: 2010
Diurnal and seasonal behavior of amplitude of NWC 22.3 kHz signal transmitted from Australia (22°49′S, 114°23′E), and received at Kolkata (22°34′N, 88°24′E), India have been investigated The signal amplitude is remarkably low in October. The variations of daily maximum and daily minimum of signal amplitude have been analyzed. The signal on the present propagation path showed non-correlation with Ap index, but showed a moderate but negative correlation with 10.7 cm solar flux. © 2010 IACS.
Dinda B.,Tripura University |
Debnath S.,Mbb College |
Banik R.,Tripura University |
Sato N.,Kitasato University |
Harigaya Y.,Kitasato University
Natural Product Communications | Year: 2011
A new iridoid glucoside, 8-O-(E)-caffeoylmussaenosidic acid (1), together with ixoside (2), was isolated from the roots of Wendlandia tinctoria. The structure of the new compound was established on the basis of detailed spectroscopic (2D NMR) and chemical analysis.
Chaudhuri P.S.,MBB College |
Bhattacharjee S.,MBB College
Tropical Ecology | Year: 2011
Data on reproductive biology of eight tropical species of earthworms, viz. Pontoscolex corethrurus (Muller), Drawida assamensis Stephenson, Drawida papillifer papillifer Gates, Eutyphoeus comillahnus Michaelsen, Metaphire houlleti (Perrier), Dichogaster affinis Michaelsen, Octochaetona beatrix Gates, Lennogaster chittagongensis (Stephenson) are presen- ted. The peregrine earthworms viz. P. corethrurus, D. affinis and O. beatrix are continuous breeders with high fecundity, high hatching success and exhibit uni-parental reproduction. Native earthworm species are either semi-continuous breeders with moderate fecundity (D. p. papillifer and D. assamensis) or discrete breeders (E. comillahnus) with least fecundity. There was significantly higher cocoon production in most species during summer and monsoon. With increase in temperature, incubation period increased in E. comillahnus and O. beatrix and decreased in D. affinis, M. houlleti and D. assamensis within a temperature range of 20 - 30 °C under laboratory conditions. Incubation period of earthworm species under study showed a significant positive linear relationship (P < 0.01) with their body length. The more continuous and high rate of cocoon production, as well as, higher hatching rate in P. corethrurus, O. beatrix, D. affinis and M. houlleti with uniparental reproduction indicate their possible usefulness in vermiculture. The geophagous species such as P. corethrurus and O. beatrix might be useful for wasteland reclamation, while the phytogeophagous worms viz. D. affinis, M. houlleti can be utilized in degradation of organic wastes using soil bedding. © International Society for Tropical Ecology.
Debnath C.,MBB College |
Shil A.,Tripura University |
Hussain S.A.,Tripura University |
Bhattacharjee D.,Tripura University
Supramolecular Chemistry | Year: 2016
Present communication reports the preparation of Langmuir monolayer of water-soluble anionic dye Congo red (CR) by allowing it to adsorb from the aqueous subphase onto the preformed Langmuir monolayer of anionic stearic acid using divalent metal cations Mg2+ as mediator. Isotherm and compressibility studies of SA-Mg-CR hybrid monolayer gave valuable information about the molecular organisation in the Langmuir monolayer. Absorption spectroscopic studies revealed the formation of H-aggregates in the hybrid Langmuir–Blodgett (LB) films fabricated at lower salt concentration in the subphase. Atomic Force Microscopic image gave visual evidence of distinct nanocrystalline domains in the LB monolayer film. © 2016 Informa UK Limited, trading as Taylor & Francis Group
Sharma A.,Tripura University |
Chattopadhyay S.,Indian Institute of Science |
Adhikari K.,Mbb College |
Sinha D.,Tripura University
Chemical Physics Letters | Year: 2015
Valence universal multireference coupled cluster (VUMRCC) method suffers from numerical divergence owing to intruder states in inner valence region of molecules. Eigenvalue independent partitioning (EIP) technique in Fock space converts VUMRCC equations to a non-Hermitian eigenvalue problem . EIP makes access to the roots invaded by intruders much easier. The EIP-VUMRCC determines with significant precision the potential energy curve of the strongest bonding and inner valence 2σg MO of N2+ ion. Inclusion of full connected triple excitation CC operators is found very crucial. In ground state, perturbative T3 is considered by CCSDT1-a approximation. © 2015 Published by Elsevier B.V.
PubMed | Tripura University, Bengal Institute of Pharmaceutical science and MBB College
Type: Journal Article | Journal: Journal of advanced pharmaceutical technology & research | Year: 2015
Aldose reductase (AR) plays an important role in the development of several long-term diabetic complications. Inhibition of AR activities is a strategy for controlling complications arising from chronic diabetes. Several AR inhibitors have been reported in the literature. Flavonoid type compounds are shown to have significant AR inhibition. The objective of this study was to perform a computational work to get an idea about structural insight of flavonoid type compounds for developing as well as for searching new flavonoid based AR inhibitors. The data-set comprising 68 flavones along with their pIC50 values ranging from 0.44 to 4.59 have been collected from literature. Structure of all the flavonoids were drawn in Chembiodraw Ultra 11.0, converted into corresponding three-dimensional structure, saved as mole file and then imported to maestro project table. Imported ligands were prepared using LigPrep option of maestro 9.6 version. Three-dimensional quantitative structure-activity relationships and docking studies were performed with appropriate options of maestro 9.6 version installed in HP Z820 workstation with CentOS 6.3 (Linux). A model with partial least squares factor 5, standard deviation 0.2482, R(2) = 0.9502 and variance ratio of regression 122 has been found as the best statistical model.