A study of nerve agent model organophosphonate binding with manganese-A₂B-corrole and -A₂B₂-porphyrin systems

Kim, K.,Kim, I.,Maiti, N.,Kwon, S.J.,Bucella, D.,Egorova, O.A.,Lee, Y.S.,Kwak, J.,Churchill, D.G. Pergamon Press 2009 Polyhedron Vol.28 No.12

Herein the synthesis and binding studies of novel trans-A<SUB>2</SUB>B-corrole and trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin derivatives are presented in comparing manganese(III)-organophosphonate (OP) binding (e.g., M<SUP>n+</SUP>←O?PR(OR)<SUB>2</SUB>) capabilities. H<SUB>3</SUB>(PFP-VC) [PFP-VC=5,15-di(pentafluorophenyl)-10-(3-vinylphenyl)corrolate] was synthesized by way of literature procedures and was characterized by a variety of 2-D NMR spectroscopic techniques and single-crystal X-ray diffraction. These compounds represent the first example of 3-vinyl-phenyl-containing meso-substituted corroles or porphyrins. Mn(PFP-VC) (3) was treated separately with (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(C<SUB>3</SUB>H<SUB>6</SUB>NMe<SUB>2</SUB>), (C<SUB>4</SUB>H<SUB>9</SUB>O)<SUB>2</SUB>P?O(Me), (C<SUB>2</SUB>H<SUB>5</SUB>O)<SUB>2</SUB>P?O(CH<SUB>2</SUB>COCH<SUB>3</SUB>), (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(Me), to give 1:1 adducts, as determined by UV-Vis spectroscopy (Job Plot), giving a red shift; Ph<SUB>3</SUB>P?O, was also found to bind, but very weakly. The trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin analogue Mn(PFP-VP) (4) was also prepared by way of a literature procedure; related binding studies gave 1:1 organophosphonate-Mn(PFP-VP) adducts (Job Plot). A clean blue shift occurred for the Mn-porphyrins at higher organophosphonate loadings (K<SUB>a</SUB> values: 6.7 (0.9)-11.9 (0.4)M<SUP>-1</SUP>). DFT geometry optimizations of O?P(OMe)<SUB>2</SUB>Me binding and formal Mn-O or P-O cleavage products in the unsubstituted neutral Mn-corrolato and -porphyrinato systems with a range of metal-based spin states revealed greatest stability in formal phosphoryl oxygen binding (energies: 11-13kcal/mol) for the Mn-corrole (singlet); the Mn-porphyrin (sextet) was also quite stable.

Heteropolyacid-clay nano-composite as a novel heterogeneous catalyst for the synthesis of 2,3-dihydroquinazolinones

Bashir A. Dar,Meena Sharma,Baldev Singh,Akshya K. Sahu,Praveen Patidar,Parduman R. Sharma,Nagaraju Mupparapu,Dushyant Vyas,Sudip Maity 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.2

The present research work is intended to synthesize a series of substituted 2,3-dihydro-2-phenylquinazolin-4(1H)-ones using clay-supported heteropolyacid as a novel heterogeneous, reusable and inexpensive catalyst. This catalyst afforded excellent yields in very short reaction times that shows high selectivity without affecting other functional groups, such as carbon–carbon double bond and heterocyclic moieties. The catalyst could be recycled at least six times and reused. The synthesis involves cyclo-condensation of anthranilamide with an aldehyde at room temperature in the presence of small amount of the catalyst. No column purification is required and products can be purified by simple crystallization.

Novel lipidated sorbitol-based molecular transporters for non-viral gene delivery

Higashi, T.,Khalil, I.A.,Maiti, K.K.,Lee, W.S.,Akita, H.,Harashima, H.,Chung, S.K. Elsevier Science Publishers 2009 Journal of controlled release Vol.136 No.2

In this study, we investigated the possible use of novel lipidated sorbitol-based transporters as functional devices for the improvement of non-viral gene delivery. These transporters are composed of a sorbitol scaffold bearing 8 guanidine moieties that mimic the arginine residues of well-known cell-penetrating peptides. In addition, the transporters carry different lipid groups to aid DNA condensation and facilitate lipid vesicle-binding. We found that the transporters described in this study have the potential to function as plasmid DNA/siRNA-condensers and surface ligands for the enhancement of cellular uptake of lipid vesicles. Shorter lipid chains were found to be better for condensation, whereas longer chains were superior surface ligands. The differential activity of different cores might be explained by facilitated decondensation of cores prepared with transporters comprised of shorter lipid chains. However, we suggest that there is an optimum value of decondensation to achieve higher transfection activities. The proper use of the transporters presented in this study enabled us to prepare a highly efficient non-viral gene delivery system based on a core-shell structure, in which a condensed DNA core is encapsulated by a lipid envelope. A multifunctional envelope-type nano-device prepared with an optimal surface ligand favorably competes with commonly used transfection systems.

Absolute Entropy and Energy of Carbon Dioxide Using the Two-Phase Thermodynamic Model

Huang, Shao-Nung,Pascal, Tod A.,Goddard, William A.,Maiti, Prabal K.,Lin, Shiang-Tai American Chemical Society 2011 Journal of chemical theory and computation Vol.7 No.6

<P>The two-phase thermodynamic (2PT) model is used to determine the absolute entropy and energy of carbon dioxide over a wide range of conditions from molecular dynamics trajectories. The 2PT method determines the thermodynamic properties by applying the proper statistical mechanical partition function to the normal modes of a fluid. The vibrational density of state (DoS), obtained from the Fourier transform of the velocity autocorrelation function, converges quickly, allowing the free energy, entropy, and other thermodynamic properties to be determined from short 20-ps MD trajectories. The anharmonic effects in the vibrations are accounted for by the broadening of the normal modes into bands from sampling the velocities over the trajectory. The low frequency diffusive modes, which lead to finite DoS at zero frequency, are accounted for by considering the DoS as a superposition of gas-phase and solid-phase components (two phases). The analytical decomposition of the DoS allows for an evaluation of properties contributed by different types of molecular motions. We show that this 2PT analysis leads to accurate predictions of entropy and energy of CO<SUB>2</SUB> over a wide range of conditions (from the triple point to the critical point of both the vapor and the liquid phases along the saturation line). This allows the equation of state of CO<SUB>2</SUB> to be determined, which is limited only by the accuracy of the force field. We also validated that the 2PT entropy agrees with that determined from thermodynamic integration, but 2PT requires only a fraction of the time. A complication for CO<SUB>2</SUB> is that its equilibrium configuration is linear, which would have only two rotational modes, but during the dynamics it is never exactly linear, so that there is a third mode from rotational about the axis. In this work, we show how to treat such linear molecules in the 2PT framework.</P>

A delay dynamic model for HIV infected immune response

S.P. Bera,A. Maiti,G.P. Samanta 한국전산응용수학회 2015 Journal of applied mathematics & informatics Vol.33 No.5

Human Immune Deficiency Virus (or simply HIV) induces a persistent infection that leads to AIDS causing death in almost every infected individual. As HIV affects the immune system directly by attacking the CD4+ T cells, to exterminate the infection, the natural immune system produces virus-specific cytotoxic T lymphocytes(CTLs) that kills the infected CD4+ T cells. The reduced CD4+ T cell count produce reduced amount of cytokines to stimulate the production of CTLs to fight the invaders that weakens the body immunity succeeding to AIDS. In this paper, we introduce a mathematical model with discrete time-delay to represent this cell dynamics between CD4+ T cells and the CTLs under HIV infection. A modified functional form has been considered to describe the infection mechanism. Characteristics of the system are studied through mathematical analysis. Numerical simulations are carried out to illustrate the analytical findings.

Effect of Swietenia macrophylla seeds on normal and alloxan-induced diabetic rats

A, Maiti,S, Dewanjee,SC, Mandal Kyung Hee Oriental Medicine Research Center 2007 Oriental pharmacy and experimental medicine Vol.7 No.4

The methanol extract of the seed of Swietenia macrophylla (Meliaceae) seeds were investigated for its hypoglycaemic activity in normal and alloxan induced diabetic rats. Seed extract suspended in aqueous Tween 80 solution, the graded doses were administered to normal and experimental diabetic rats for 10 days. Fasting blood glucose levels, serum lipid profiles and changes in body weight were evaluated in normal rats while the hepatic marker enzymes and liver glycogen levels were evaluated additionally in diabetic rats. The diabetic groups treated with the seed extract were compared with standard drug glibenclamide. The findings showed the significant antidiabetic potential of the extract in ameliorating the diabetic conditions in diabetic rats. The extract also has hypoglycaemic action in normal rats. A toxicity study has been performed for the extract, which revealed that the extract is safe to use even at the doses of 3.2 mg/kg of body weight orally. The result from the present investigation indicates good correlation between the folk use and scientific investigation.

Carbon Fibers for the Repair of Abdominal Wall Defects in Rabbits

A,K,Gangwar,A,K,Sharma,Naveen Kumar,S,K,Maiti,N,Kumar,S,K,Ma 한국탄소학회 2005 Carbon Letters Vol.6 No.1

A DELAY DYNAMIC MODEL FOR HIV INFECTED IMMUNE RESPONSE

BERA, S.P.,MAITI, A.,SAMANTA, G.P. The Korean Society for Computational and Applied M 2015 Journal of applied mathematics & informatics Vol.33 No.5

Human Immune Deficiency Virus (or simply HIV) induces a persistent infection that leads to AIDS causing death in almost every infected individual. As HIV affects the immune system directly by attacking the CD4+ T cells, to exterminate the infection, the natural immune system produces virus-specific cytotoxic T lymphocytes(CTLs) that kills the infected CD4+ T cells. The reduced CD4+ T cell count produce reduced amount of cytokines to stimulate the production of CTLs to fight the invaders that weakens the body immunity succeeding to AIDS. In this paper, we introduce a mathematical model with discrete time-delay to represent this cell dynamics between CD4+ T cells and the CTLs under HIV infection. A modified functional form has been considered to describe the infection mechanism. Characteristics of the system are studied through mathematical analysis. Numerical simulations are carried out to illustrate the analytical findings.

Effect of Swietenia macrophylla seeds on normal and alloxan-induced diabetic rats

Maiti A,,Bhattacharya P,Mandal SC 경희대학교 융합한의과학연구소 2007 Oriental Pharmacy and Experimental Medicine Vol.7 No.4

The methanol extract of the seed of Swietenia macrophylla (Meliaceae) seeds were investigated for its hypoglycaemic activity in normal and alloxan induced diabetic rats. Seed extract suspended in aqueous Tween 80 solution, the graded doses were administered to normal and experimental diabetic rats for 10 days. Fasting blood glucose levels, serum lipid profiles and changes in body weight were evaluated in normal rats while the hepatic marker enzymes and liver glycogen levels were evaluated additionally in diabetic rats. The diabetic groups treated with the seed extract were compared with standard drug glibenclamide. The findings showed the significant antidiabetic potential of the extract in ameliorating the diabetic conditions in diabetic rats. The extract also has hypoglycaemic action in normal rats. A toxicity study has been performed for the extract, which revealed that the extract is safe to use even at the doses of 3.2 mg/kg of body weight orally. The result from the present investigation indicates good correlation between the folk use and scientific investigation.

Carbon Fibers for the Repair of External Abdominal Hernias in Bovines, Caprines and Canines : A Review of 18 Clinical Cases

Naveen Kumar,A.K. Sharma,A.K. Gangwar,S.K. Maiti,O.P. Gupta,N. Kumar,R.B. Mathur 한국탄소학회 2006 Carbon Letters Vol.7 No.2

During a 3-year period (2001-2004) 18 animals were surgically treated because of abdominal wall defects (hernia). Out of 18 animals 8 were bovines, 5 caprines and 5 canines. In each case the defect was bridged with carbon fibres. Carbon fibres were placed either in simple interrupted pattern or as mattress overlapping pattern. All the cases were successfully treated and no complication was observed up to six months postoperatively.