Correlation of computed van der Waals and molecular volumes with Apparent Molar Volumes (AMV) for amino acid, carbohydrate and sulfamate tastant molecules. Relationship between Corey-Pauling-Koltun volumes (V_CPK) and computed volumes

Good linear correlations have been found between apparent molar volumes (AMV, φV) and GEPOL-generated van der Waals (V_w), molecular (V_m and accessible (V_a) volumes for 17 amino acids, 22 carbohydrates and 16 sulfamates. For a larger group of 24 sulfamates Corey-Pauling Koltun measured volumes (V_CPK) gave good linear correlations with V_w (r = 0.925) and V_m (r = 0.935). For the monosaccharides L-arabinose, D-glucose, L-lyxose, D-mannose and D-xylose the computer volumes and areas are slightly greater for the β- than for the α-anomers. However, for some methylated sugars the reverse occurs. The use of 'effective' Bondi, rather than Pauling, van der Waals radii has little effect on the computed volumes and areas for the sulfamates. The effect, on the computed volumes and areas, of using a number of different sets of van der Waals radii has been examined for sucrose, glycine and cyclamate. The effect of increasing the probe (sphere) radius from 1.4 Å to 2.0 Å has been examined and it is found that the van der Waals and molecular volumes and the corresponding areas remain virtually unchanged, but the accessible volumes increase by ca. 31% and the accessible areas by ca. 22%. The GEPOL program generally gives van der Waals volumes in good agreement with those available in the literature.