https://ir.vidyasagar.ac.in/jspui/handle/123456789/393 2026-04-26T16:05:26Z https://ir.vidyasagar.ac.in/jspui/handle/123456789/6333 Title: Multidentate ligand based Co(II/III) and Cu(II) coordination compounds: Synthesis, crystal structure and molecular property Authors: Manna, Soumen Abstract: The fundamental goal of the thesis is the synthesis of polynuclear copper(II) and cobalt(II/III) complexes by using multidentate N, O-donor Schiff base ligand and aromatic dicarboxylate as co-ligand and study of their potential application in the area of magnetism, catalysis and different biological processes. Chapter I deals with general introduction on Co(II/III) and Cu(II) coordination compounds of Schiff base ligands and their various properties (magnetic properties, catecholase activities, serum albumin interaction, CT-DNA interactions). It also describes the scope of this thesis. Chapter II comprises the synthesis of two Co formulas {[Co 2 {[Co 4 (H 2 L) 4 (H 2 O) 2 (H 2 L) 2 (H 2 O) 2 ][Co 2 (ppda)]∙2(dmf)∙3.2(H 2 (H 2 L) 2 II -Co (H 2 III mixed-valance complexes of molecular O)(m-phth)]∙8(H 2 O)} (2) [H 2 L 2- O)} (1) and = 2-[(2-hydroxy-3- methoxybenzylidene)amino]-2-(hydroxymethyl)propane-1,3-diolato, m-phth = 1,3- benzenedicarboxylate, ppda = 1,4-phenylenediacrylate, dmf = N,N-dimethylformamide] and characterized by single-crystal X-ray diffraction and magnetic studies at low temperature. The structural determination reveals that complex 1 is composed of dinuclear ion pairs, namely, a cationic [Co 2 (H 2 unit. In each of these ions, the Co L) 2 (H 2 O) 2 II ] + (1 and Co + ) and an anionic [Co 2 III (H 2 L) 2 (H 2 O)(m-phth)] centers present distorted octahedral geometries. Compound 2 is a centrosymmetric tetranuclear complex comprising two symmetry-related dinuclear Co II -Co III units bridged by the ppda anions. Alternating current/direct current (ac/dc) magnetic studies revealed that the individual Co II -Co III unit exhibits field-induced slow magnetic relaxation consistent with single-ion magnet (SIM) behavior. Ab initio NEVPT2 calculations confirm large zero-field splitting (zfs) coming from a first-order spin- orbit coupling (SOC) in both complexes (D = -62.4, -95.8, and –101.9 cm 0.216, and 0.234 for 1 + , 1 - and 2, respectively). –1 – (1 and E/D = 0.219, - ) Chapter III deals with the synthesis and structural characterization of two novel tetranuclear closed-cubane like core framework complexes [Cu 4 (2) (H 2 L 1 (L 1 ) 4 ]·3(H 2 = (E)-2-((1-hydroxybutan-2-ylimino)methyl)phenol; H 4 O) (1) and [Cu 4 L 2 (H 2 L 2 ) 4 (H 2 O) 4 = 2-((2-hydroxy-3- methoxybenzylidene)amino)-2-hydroxymethylpropane-1,3-diol). Magnetic susceptibility measurements indicate an overall weak antiferromagnetic exchange coupling in 1, while ferromagnetic exchange coupling in 2. In agreement with their closed-cubane structure, the magnetic behavior of the two complexes have been studied by employing the isotropic spin Hamiltonian of type H=J 1 (S 1 S 3 + S 1 S 4 + S 2 S 3 + S 2 S 4 ) - J 2 (S 1 S 2 + S 3 S 4 ) (J 1 magnetic exchange coupling between the four Cu(II) pairs with short Cu···Cu distances, while J 2 characterizes the magnetic exchange coupling between the remaining two intermetallic pairs with long distances). The PHI program was used to study their magnetic behavior. A good agreement between the experimental and fitted curves was found with the following parameters: g = 2.14, J 1 cm -1 and J 2 = -51.5 cm -1 for 2. = -20.3 cm -1 and J 2 = 0 cm -1 describes the for 1 and g = 2.10, J 1 Chapter IV presents the synthesis of two novel copper(II) complexes, [Cu 4 [H 2 (L) 2 (LH) 2 (H 2 O) 2 ] 2 (NO 3 ) 2 .(pydc).9H 2 O (1) and {[Cu 4 (L) 2 (LH) 2 (H 2 O) 2 (ppda)].5H 2 L = 2-[(2-hydroxy-ethylimino)-methyl]-6-methoxy-phenol, pydc = pyridine-3,5- dicarboxylate, ppda = phenylene-1,4-diacrylate]. These two complexes have been characterized by X-ray single crystal diffraction analysis and low temperature magnetic study. The structural determination reveals for complex 1 a tetranuclear species exhibiting a double-open cubane like core framework, whereas use of ppda anions results 1D coordination polymer where tetranuclear double-open cubane cores are connected by bridging ppda ligands. In both the complexes, hydrogen bonding interactions lead to 3D supramolecular structures. Low temperature magnetic study indicates antiferromagnetic coupling in both the = 101.1 O} n ] (2) complexes. A model based on an effective square tetramer of Heisenberg spins was used to determine exchange strengths of 174(2) K for 1 and 107.4(4) K for 2. Chapter V describes the synthesis and characterization of two tetranuclear Schiff base copper(II) complexes, namely [Cu 4 [Cu 4 (L) 2 (LH) 2 (H 2 O) 2 ](ClO 4 )·(tp) 0.5 ·3H 2 (L) 2 (LH) 2 O (2) (where H 2 (H 2 O) 2 ](ClO 4 ) 2 ·3H 2 O (1) and L = 2-[(2-hydroxy-ethylimino)- methyl]-6-methoxy-phenol, tp = terephthalate), by X-ray single crystal diffraction. Both complexes 1 and 2 are comprised of structurally similar tetranuclear cationic [Cu 4 (L) 2 (LH) 2 (H 2 O) 2 ] 2+ species with a double open cubane core, in which two metal centers possess a square pyramidal environment and the other two exhibit a slightly distorted octahedral coordination geometry. The interaction of complexes 1 and 2 with calf thymus DNA (CT-DNA) was investigated using electronic absorption and fluorescence studies, and the results showed that the complexes interact with CT-DNA with the related intrinsic binding constants (K ib ) of 1.8×10 6 and 1.1×10 7 L mol -1 for 1 and 2, respectively. Their interactions with bovine serum albumin (BSA) and human serum albumin (HSA) were also investigated and spectroscopic techniques showed that both complexes interact with these proteins through a ground state association process. Using 3,5-di-tertbutylcatechol (3,5- DTBC) as a model substrate, both complexes show catecholase-like activity, being able to oxidase 3,5-DTBC to 3,5-di-tertbutylquinone (3,5-DTBQ) in the presence of oxygen. 2021-12-01T00:00:00Z https://ir.vidyasagar.ac.in/jspui/handle/123456789/6278 Title: Studies on the role of Dyslipidemia and Inflammatory Responses on Cardiovascular Diseases Authors: Khan, Md. Mobidullah Abstract: Cardiovascular diseases (CVD) are the leading cause of mortality worldwide. There are several predominant factors that influence disease promotion and severity. Geographical location and demographic profile are one of the important factors for the disease outcome. Stresses, sedentary lifestyle and abnormal energy metabolism causes sustained hyperglycemia, hypertension and insulin resistance. Compelling evidence suggest that diabetes has a distinct relation with different cardiovascular disorder. Diabetes is also now epidemic worldwide. In the current study occurrence, severity and mechanism of CVD has studies in adult individuals- patients. There are different hematological and biochemical parameters like lactate dehydrogenes (LDH), (creatine phosphokinase) CPK, (creatine phosphokinase isoform mb) CPK-MB were studies in Troponin T (Ttrop-T) + ICU admitted patients. Prior the investigation all regulatory norms and ethical clearance were approved from the competent authority. In the patients Oxidative Stress markers like malondeadihyde (MDA), antioxidant components like non-protein soluble thiol (NPSH), Superoxide dismutase (SOD), catalase, were tested and measured. Human samples were also tested for the study of inflammatory markers like C-reactive protein (CRP), tumor necrosis factor alpha (TNF-α), interleukin (IL-6) etc. In other several In-vitro experiment with human blood samples and animal tissue slices other important parameters like nitric oxide (NO), nitic oxide synthase (NOS), Insulin, glucose transporter and stress induced protein dermcidin gene gel and protein expression were studied for the understanding of the mechanism of diabetes and diabetes associated CVD disorder . For the better understanding experimental rat model of high lipid and fructose fed diet (90 days iso-caloric). Rats were Investigated to evaluate some risk factors and oxidant and antioxidant status in their serum, liver and heart tissues. Present result suggest that LDH, CPK, CPK-MB, MDA, SOD, these are expressed according to the disease severity in the patients of trop-T + or trop-T markers are also associated with the age and gender of the individual. Important roles of these markers are also verified and validated in our experimental rodent model. Result from animal experiment suggests that oxidative stress and inflammatory status are the prerequisite for the diabetes and CVD. These have been suggested by the student’t test, multiple comparison ANOVA test and correlation analysis. These support the interdependence among different parameters. Several In-vitro and mouse model study suggest that stress protein dermcidin isoform-2 (DCN-2) is responsible for insulin resistance and GLUT4 and NO insensitivity which results arterial endothelial disregulation, atherosclerotic plaque formation. Role of plaque rupture, platelet aggregation has been suggested to initiate the severity of the disease. Stress induced protein dermcidin has been demonstrated with high concentration in diabetic and hyperlipidemic status. The animal experiment suggests the high lipid consumption and abnormal glucose/energy metabolism may increase the systemic oxidative stress. So present investigation may be regarded as useful background for the further studies on this area. That will be helpful for better therapeutic intervention in cardiovascular disease. 2021-01-14T00:00:00Z https://ir.vidyasagar.ac.in/jspui/handle/123456789/6268 Title: Role of probiotics as a therapeutic tool on gastrointestinal diseases in mice and study of intestinal immunomodulation Authors: Roy, Atrayee 2021-07-28T00:00:00Z https://ir.vidyasagar.ac.in/jspui/handle/123456789/6153 Title: Physicochemical studies on surfactants assemblies with special reference to the Biosurfactants Authors: Barai, Manas Abstract: Physicochemical studies on surfactant mixtures under varied composition, concentration and surfactant types have been investigated since substantial time period. Interfacial and aggregation behavior of surfactant in the form of monolayer, bilayer, micelle and gels are worthy to be carried out in view of potential applications as well as understanding their fundamental properties. Oppositely charged surfactants, through electrostatic interaction in aqueous medium, can form ion pair amphiphile (IPA). Besides the IPA, catanionic surfactant can form a variety of aggregates depending on the concentration and molar ratio of the surfactants constuting the mixture as well as other environmental conditions. Oppositely charged surfactants form a variety of aggregates that can be investigated with reference to the above perspectives. Ionic surfactants are also capable to form water insoluble species upon interaction with oppositely charged metal ions (usually bivalent or trivalent) or radicals. Metallosurfactants, prepared by mixing stoichiometric amount of anionic surfactant and metal ions, can form insoluble monolayer as well as bilayer entities, similar to the phospholipids. Hence, metallosurfactants are worthy to investigate in the form of monolayer and bilayer in combination with lipids to generate membrane mimetic systems. Interfacial and micellization behavior of N-dodecyl derivatives of amino-malonate, -aspartate and -glutamate, sodium salt (C 12 AAS)Na 2 in combination with HTAB have been investigated by surface tension, conductance, UV-vis absorption/emission spectroscopy, dynamic light scattering and viscosity studies. Critical micelle concentration (CMC) values of the surfactant mixtures were significantly lower than the predicted values, indicating strong synergistic interaction. Surface excess, limiting molecular area, surface pressure at the CMC and Gibbs free energy indicate spontaneity of micellization processes, compared to the pure components. CMC values were also determined from the sigmoidal variation in the micellar polarity (evaluated from pyrene UV-vis absorbance/emission spectra) with surfactant concentration. Aggregation number (n), determined by the static fluorescence quenching method, increased with decreasing mole fraction of the amino acid based surfactants 𝛼 ( ) because of the dominance of HTAB in micelle. Micellar size increased with decreasing 𝛼 formation of larger and complex aggregates. Micelles comprising 20 - 40 mole% (C ( ) highly viscous, in consonance with their sizes. Some of the mixed surfactant systems showed unusual viscosity (shear thickening increased viscosity with increasing temperature). Such mixed surfactant systems are considered to have potentials in gel-based drug delivery and nanoparticle synthesis. In a theoretical approach, studies on micellar structure and composition of aforementioned oppositely charged surfactants were carried out. Results suggest synergistic interaction in aqueous medium, governed by the structural parameters as well as of the mixture composition. Different parameters, viz., theoretical values of CMC and its comparison with the earlier reported values, mole fraction of surfactants at the micellar phase (X), at the interface (X bulk/interface (β R /β σ σ , leading to the 12 AAS)Na 2 were ), interaction parameters at ), ideality/non-ideality of the mixing processes and activity coefficient (f) of individual component were evaluated, using Rubingh, Rosen, Motomora and Sarmoria-Puvvada- Blankschtein (SPB) models. CMC values significantly deviated from the theoretically calculated values indicating strong synergistic interaction. With increasing 𝛼 ( ) , negative magnitude of the (β values gradually decreased, assisted by hydrophobic interactions in the mixed micelles. With increasing 𝛼 ( ) , decline in micellar mole fraction of HTAB (X higher than those compared with (C 12 AAS)Na 2 2 ) was not significant and the values were at all stiochiometries, due to the dominance of HTAB in the micelle. Micellar mole fraction values at the ideal state of (C 12 AAS)Na 2 (𝑋 indicating non ideality in mixed micellelization process. Free energy of micellization ( mG ) values were more negative than the free energy of micellization for ideal mixing ( micellization processes. With increasing 𝛼 micellization (ΔS m ( ) ideal m ) differed from X G ) indicating spontaneity of , enthalpy of micellization (ΔH m R /β ) and entropy of ) values gradually increased indicating exothermicity of micellization processes. Different physicochemical parameters of mixed micelles were correlated with the variation in the spacer length between the two carboxylate groups of (C 12 AAS)Na 2 . σ 1 ) , Another part of the dissertation includes physicochemical investigation on the gels formed by C 12 MalNa 2 , C 12 AspNa 2 and C 12 GluNa 2 in combination with HTAB at different ratio. In case of N-dodecyl amino malonate, there is only one carbon atom in between the two carboxylate groups. In case of aspartate and glutamate the number of carbon atoms, between two carboxylate moieties, are two and three respectively. The sequential increase in the number of carbon atoms, which act as speacer between the two carboxylate moieties, favor micellization due to enhanced hydrophobicity. (C mixed systems exhibited different phases, viz., gel, viscous, precipitate and clear fluid as established through ternary phase diagram. While moving from C 12 MalNa 2 to C 12 AspNa 2 to C proportion of gel and viscous phases gradually decreased. Internal structure and liquid crystalline behavior of gels were investigated by combined polarisation optical microscopy and fluorescence microscopy. Porous and flower like surface morphologies were identified by field emission scanning electron microscopy. Phase transitions along with the associated weight loss of the surfactant aggregates were found to be dependent on surfactant composition, established by thermogravimetric analysis. Thermotropic behaviour of the aggregates were investigated by differential scanning calorimetric studies. The entropy of transition from solid-to-liquid crystal-to-isotropic liquid for surfactant aggregates increased systematically with increasing proportion of (C of (C 12 AAS)Na 2 12 AAS)Na 2 12 AAS)Na 12 GluNa 2 2 -HTAB , relative . Gels comprising lower proportion (< 40 mols %) were more viscous. Gels with higher proportion of (C insignificant irritation on mouse skin, suggesting its possible application as vehicle for topical drug delivery. Surfactant mixtures also exhibited antibacterial effects on Staphylococcus aureus, a potent causative agent of skin and soft tissue infections. 12 As fourth part of the work, dicarboxylic amino acid based metallosurfactants were synthesized by stoichiometric mixing of (C insoluble metallosurfactants (C 12 AAS)Na 12 AAS) 2 2 with bivalent metal salts CaCl M 2 2 , MnCl 2 AAS)Na and CdCl coacervates formed were isolated by solvent extraction technique using chloroform. Metallosurfactants formed layered structure as observed by X-ray diffraction studies. Thermal phase transition and associated weight loss of the synthesized compounds were studied 2 resulted 2 . Water by thermogravimetric analysis. Monomolecular films of the metallosurfactants in combination with soy phosphatidylcholine (SPC) and cholesterol were investigated using Langmuir surface balance with intention to substitute naturally occurring phospholipids. With increasing mole fraction of metallosurfactants ( 𝛼 ( ) ), mean molecular area gradually increased, indicating reorganization of molecular packing at air-water interface, whereby collapse pressure did not change significantly. In case of 20 and 60 mole% (C 12 AAS) 2 M 2 , positive deviations were recorded, indicative of chain mis-match among the components of mixed monolayer. Negative deviation from the ideal values signifies associative interaction and vice versa. Spontenity of mixing of the components at air-water interface were established for all the combinations from negative Gibbs free energy changes. Dynamic surface elasticity, examined by surface rheology studies, initially increased rapidly in the surface pressure range 0 to 1.5 mN/m, after which the slope of surface elasticity vs. surface pressure profiles decreased indicating formation of relatively rigid monolayers. Brewster angle microscopic (BAM) studies suggested two dimensional phase transition (gaseous state to liquid expanded to liquid condensed state) upon compression of the monolayer at air-water interface. BAM images demonstrated homogeneous and more condensed structure of surface layer and confirmed miscibility of the components. Metallosurfactants in combination with SPC and cholesterol could form stable hybrid vesicles. Hydrodynamic diameter, zeta potential and polydispersity index values of vesicles, measured by dynamic light scattering studies, were monitored as function of time to check its stability; particles were found to be stable upto 100 days. Size, surface morphology and bilayer thickness were investigated by transmission electron microscopic studies that were comparable with the dynamic light scattering studies. Thermodynamic parameters associated with the chain melting of hybrid vesicles were investigated by differential scanning calorimetry studies. Cytotoxicity of the vesicles was assessed by MTT and cell viability studies. In vitro cytotoxicity studies revealed that hybrid vesicles could act as promising vehicles for drugs with controlled and sustained release. 2021-07-23T00:00:00Z