A series of soft cationic surfactants, containing a saccharide-derived moiety in their hydrophilic grouping-2-(alkyldimethylammonio) ethylgluconamide bromides, denoted as C(n)GAB, n = 10,12,14 and 16 - were analyzed with respect to their influence on the thermotropic phase behavior of phosphatidylcholine (DPPC)/cholesterol bilayers. The compounds were found to be uniformly distributed in the studied lipid bilayer. As usual, the longer the chain of C(n)GAB, the stronger was the effect on T-m and Delta H-m, except C(16)GAB. Having the longest chain, C(16)GAB reduces T-m to the smallest extent and does not affect Delta H-m until the molar ratio of surfactant/DPPC is 0.15. The interactions with model cells in vitro were determined by cytotoxicity evaluation with respect to two cell lines - mouse fibroblast cell line L929 and human lung cancer cell line A549. The toxicity of C(n)GABs is much lower than a classical DTAB. (C) 2014 Elsevier B.V. All rights reserved.