The influence of newly synthesized N-alkanoyl-N-methyllactitolamines (decanoyl [C(10)MELA], lauoroyl [C(12)MELA] and miristoyl [C(14)MELA]) on the thermotropic phase transition of phosphatidylcholine bilayer was compared with common sugar-based surfactants N-dodecyl-beta-D-glucopyramoside [C12G1] and decanoyl-N-methyl glucamide [MEGA-10]. The results indicate that C(n)MELA are very active at the membrane surface and disturb the phospholipid bilayer structure less than commercially used MEGA-10 and C12G1. (c) 2006 Elsevier B.V. All rights reserved.