Enthalpies of combustion of glycylglycine and dl-alanyl-dl-alanine

Energetics of oxo- and thio-dipeptide formation via amino acid condensation: a systematic computational analysis

“…Experimental standard enthalpies (kcal mol À1 ) for the condensation reaction in the gas phase23,[40][41][42][43][44][45] and calculated values from this work…”

Revision of standard molar enthalpies of formation of glycine and l-alanine in the gaseous phase on the basis of theoretical calculations

“…d ''Best value" selection of the authors[29] is based on available 11 experimental measurements. e Weighted mean of values in references[27,31,32,34] corrected to 298.15 K.…”

“…, is based on the experimental enthalpy of formation of solid glycine, D f H m (glycine, cr, 298.15 K) = À528.1 ± 0.5 kJ Á mol À1 (''best value" selection of the authors[29] from available 11 expeirimental measurements) and enthalpy of sublimation D g cr H m (glycine, 298.15 K) = 134.4 kJ Á mol À1 . The last value was obtained using the values of D g cr H m (glycine, 432 K) = 133.7 kJ Á mol À1 (mean of values in references[27,31,32,34]), C p;m (glycine, cr, 298.15 K) = 97.8 J Á K À1 Á mol À1 (mean of values in references…”

Calculation of the standard molal thermodynamic properties of crystalline peptides

“…In order to extend the relatively sparse thermodynamic data set available in the literature for crystalline peptides (Hutchens et al, 1969a,b;Domalski, 1972;Finegold and Kumar, 1981;Roles and Wunderlich, 1991;Diaz et al, 1992;Zhang et al, 1996;Di Lorenzo et al, 1999;Drebushchak et al, 2008), the group additivity method for estimating thermodynamic properties of organic compounds (e.g., Benson and Buss, 1958;Benson, 1968;Hearing, 1988, 1993;Amend and Helgeson, 1997b;Richard and Helgeson, 1998) has been adopted. In this approach, the contribution of a group of atoms in a molecule to the thermodynamic properties of the entire compound is determined.…”

“…With the exception of poly(proline-glycine-proline), Fig. 3e, all of the C o P values refer to just one amino acid-peptide backbone combination, Diaz et al (1992). c Domalski (1972).…”