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Analytical Estimation of Water Contents, Specific Heat Capacity and Thermal Profiles Associated with Enzymatic Model Compound β-Cyclodextrin


Affiliations
1 School of Chemical Sciences, North Maharashtra University, Jalgaon 425 001, India
2 Department of Chemistry, Shivaji University, Kolhapur 416 004, India
 

Studies of water contents of solid β-cyclodextrin (β-CD) in crystallized and vacuum dried conditions are reported. Water contents were estimated using Karl–Fischer (KF) titration and thermo-gravimetric analysis (TGA) techniques. It was found that the water contents for crystallized and vacuum-dried samples were 6.93 and 0.86 moles of water per β-CD molecule respectively. TGA studies gave values of 6.83 and 0.52 moles of water per β-CD molecule respectively. The results agree with those reported from X-ray diffraction studies. Also, the molecular weight of the vacuum dried sample was determined using vapour pressure osmometry, which agrees well with the actual molecular weight of β-CD. The thermal profiles of α-cyclodextrin (α-CD) and β-CD are presented. The differential scanning calorimetry data was used to calculate specific heat at constant pressure (Cp) at different temperatures (338.15–468.15 K). These results are compared with similar data for α-CD and discussed in terms of motional contribution to Cp values and related conformational effects.

Keywords

Cyclodextrins, Differential Scanning Calorimetry, Specific Heat Capacity, Thermo-Gravimetric Analysis.
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  • Lehn, J. M., Toward self-organization and complex matter. Science, 2002, 295, 2400–2403.

  • Patil, K., Pawar, R. and Dagade, D., Studies of osmotic and activity coefficients in aqueous and CCl4 solutions of 18-Crown-6 at 25°C. J. Phys. Chem. A, 2002, 106, 9606–9611.

  • Dagade, D. H., Kolhapurkar, R. R., Terdale, S. S. and Patil, K. J., Thermodynamics of aqueous solutions of 18-Crown-6 at 298.15 K: enthalpy and entropy effects. J. Solution Chem., 2005, 34, 415–426.

  • Terdale, S. S., Dagade, D. H. and Patil, K. J., Thermodynamic studies of molecular interactions in aqueous α-cyclodextrin solutions: application of McMillan-Mayer and Kirkwood-Buff theories. J. Phys. Chem. B, 2006, 110, 18583–18593.

  • Terdale, S. S., Dagade, D. H. and Patil, K. J., Thermodynamic studies of drug-α-cyclodextrin interactions in water at 298.15 K: Promazine hydrochloride/chloropromazine hydrochloride + α-cyclodextrin + H2O systems. J. Phys. Chem. B, 2007, 111, 13645–13652.

  • Terdale, S. S., Dagade, D. H. and Patil, K. J., Activity and activity coefficient studies of aqueous binary and ternary solutions of 4-nitrophenol, sodium salt of 4-nitrophenol, hydroquinone and α-cyclodextrin at 298.15 K. J. Mol. Liq., 2008, 139, 61–71.

  • Shaikh, V. R., Terdale, S. S., Hundiwale, D. G. and Patil, K. J., Thermodynamic studies of drug-α-cyclodextrin interactions in water at 298.15 K: procaine hydrochloride/lidocaine hydrochloride/tetracaine hydrochloride + α-cyclodextrin + H2O systems. J. Chem. Thermodyn., 2014, 68, 161–168.

  • Shaikh, V. R., Hundiwale, D. G. and Patil, K. J., A volumetric approach: Interactions of some local anesthetical drugs with α-cyclodextrin in aqueous solutions at 298.15 K. J. Chem. Thermodyn., 2017, 107, 51–57.

  • Shaikh, V. R., Terdale, S. S., Abdul, A., Gupta, G. R., Hundiwale, D. G. and Patil, K. J., Volumetric studies of 2,2,2-cryptand in aqueous and aqueous KBr solutions at 298.15 K: an example involving solvent-induced hydrophilic and hydrophobic interactions. J. Solution Chem., 2013, 42, 2087–2103.

  • Shaikh, V. R., Terdale, S. S., Abdul, A., Gupta, G. R., Hundiwale, D. G. and Patil, K. J., Thermodynamic studies of aqueous solutions of 2,2,2-cryptand at 298.15 K: Enthalpy−entropy compensation, partial entropies, and complexation with K+ ions. J. Phys. Chem. B, 2013, 117, 16249–16259.

  • Manor, P. C. and Saenger, W., Topography of cyclodextrin inclusion complexes. III. Crystal and molecular structure of cyclohexaamylose hexahydrate, the water dimer inclusion complex. J. Am. Chem. Soc., 1974, 96, 3630–3639.

  • Linder, K. and Saenger, W., β-Cyclodextrin dodecahydrate: Crowding of water molecules within a hydrophobic cavity. Angew. Chem. Int. Ed. Engl., 1978, 17, 694–695.

  • Saenger, W., Cyclodextrin inclusion compounds in research and industry. Angew. Chem. Int. Ed. Engl., 1980, 19, 344–362.

  • Saenger, W. et al., Structures of the common cyclodextrins and their larger analogues beyond the doughnut. Chem. Rev., 1998, 98, 1787–1802.

  • Szejtli, J., Introduction and general overview of cyclodextrin chemistry. Chem. Rev., 1998, 98, 1743–1754.

  • Emmerich, W. and Trevor, M. L., Heat capacities liquids, solutions and vapours. The Royal Society of Chemistry, 2010.

  • Jolicoeur, C., Lemelin, L. L. and Lapalme, R., Heat capacity of potassium-crown ether complexes in aqueous solution. Manifestations and quantitative treatment of important relaxational heat capacity effects. J. Phys. Chem., 1979, 83, 2806–2808.

  • Briggner, L. E. and Wadsö, I., Heat capacities of maltose, maltotriose, maltotetrose and -,  -, and -cyclodextrin in the solid state and in dilute aqueous solution. J. Chem. Thermodyn., 1990, 22, 1067–1074.

  • Haines, P. J., Thermal Methods of Analysis, Principles, Applications and Problems, Springer, The Netherlands, 1995.

  • Burns, J. A. and Verrall, R. E., Thermodynamics of tetraalkyl- and bis-tetraalkylammonium bromides: II. Heat capacities of solid state from 273 to 373 K. Thermochim. Acta, 1974, 9, 277–288.

  • Dortmund Data Bank; http://www.ddbst.com/en/EED/PCP/HCP_C4577.php

  • Pelc, H. W., Hempelmann, R., Prager, M. and Zeidler, M. D. Dynamics of 18-Crown-6 ether in aqueous solution studied by quasielastic neutron scattering. Ber. Bunseiiges. Phys. Chem., 1991, 95, 2510–2516.

  • Lehn, J. M., Cryptate inclusion complexes, effects on solute-solute and solute-solvent interactions and on ionic reactivity. Pure Appl. Chem., 1980, 52, 2303–2319.


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  • Analytical Estimation of Water Contents, Specific Heat Capacity and Thermal Profiles Associated with Enzymatic Model Compound β-Cyclodextrin

Abstract Views: 227  |  PDF Views: 70

Authors

Gaurav R. Gupta
School of Chemical Sciences, North Maharashtra University, Jalgaon 425 001, India
Pankaj D. Patil
School of Chemical Sciences, North Maharashtra University, Jalgaon 425 001, India
Vasim R. Shaikh
School of Chemical Sciences, North Maharashtra University, Jalgaon 425 001, India
Rahul R. Kolhapurkar
Department of Chemistry, Shivaji University, Kolhapur 416 004, India
Dilip H. Dagade
Department of Chemistry, Shivaji University, Kolhapur 416 004, India
Kesharsingh J. Patil
School of Chemical Sciences, North Maharashtra University, Jalgaon 425 001, India

Abstract


Studies of water contents of solid β-cyclodextrin (β-CD) in crystallized and vacuum dried conditions are reported. Water contents were estimated using Karl–Fischer (KF) titration and thermo-gravimetric analysis (TGA) techniques. It was found that the water contents for crystallized and vacuum-dried samples were 6.93 and 0.86 moles of water per β-CD molecule respectively. TGA studies gave values of 6.83 and 0.52 moles of water per β-CD molecule respectively. The results agree with those reported from X-ray diffraction studies. Also, the molecular weight of the vacuum dried sample was determined using vapour pressure osmometry, which agrees well with the actual molecular weight of β-CD. The thermal profiles of α-cyclodextrin (α-CD) and β-CD are presented. The differential scanning calorimetry data was used to calculate specific heat at constant pressure (Cp) at different temperatures (338.15–468.15 K). These results are compared with similar data for α-CD and discussed in terms of motional contribution to Cp values and related conformational effects.

Keywords


Cyclodextrins, Differential Scanning Calorimetry, Specific Heat Capacity, Thermo-Gravimetric Analysis.

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DOI: https://doi.org/10.18520/cs%2Fv114%2Fi12%2F2525-2529