Thermodynamic (volume and compressibility) and spectral investigations of the glycine, diglycine and triglycine in aqueous α- and β-cyclodextrin solutions at T = 298.15 K

► Densities, ρ, and speeds of sound u, of (AA/peptides + oligosaccharide + water) mixtures. ► Various parameters, viz., Vϕ, Vϕ0, ΔVϕ0, Kϕ, s, Kϕ, s0, ΔKϕ, s0,and nH have been calculated. ► Group contribution of a peptide backbone unit (− CH2CONH−). ► 1H NMR measurements have also been done. ► There exist hydrophilic-ionic and hydrophilic-hydrophilic interactions.