This study reports experimental data and modeling results for the partitioning of a single solute (from two pairs of structurally similar biomolecules (N-acetyl-D-glucosamine and N-acetyl-D-mannosamine) and (D- as well as L-phenylalanine)) to coexisting liquid phases of the high-pressure three-phase (vapor-liquid-liquid) equilibrium (VLLE) of the ternary system (ethene + water + 2-propanol) at 293 and 333 K and at pressures up to 17 MPa. The experiments were performed with an analytical view cell at low solute concentrations (below 1.5 and 3.0 g dm(-3) for the aminosugars and the phenylalanines, respectively). At such solute concentrations, the VLL-phase equilibrium of the system (ethene + water + 2-propanol) is only slightly disturbed by the low-volatile fourth compound, and the results for the partition coefficient of the solute are at nearly infinite dilution. The new experimental results are correlated using the modification of Melhem et al. for the (cubic) Peng-Robinson equation of state with two different mixing rules and estimated pure-component properties of the solutes. (c) 2007 Elsevier B.V. All rights reserved.