A novel method for measuring membrane-water partition coefficients of hydrophobic organic chemicals: comparison with 1-octanol-water partitioning.
A novel method of measuring membrane-water partitioning characteristics of very hydrophobic organic chemicals is described. Partition coefficients are reported for a series of halogenated aromatic hydrocarbons of varying molar volume between water and L-a-phosphatidylcholine dimyristoyl (DMPC) membrane vesicles and two solvents, n-hexane and 1-octanol. The results indicate that n-hexane and 1-octanol are satisfactory surrogates for DMPC membranes for chemicals with 1-octanol-water partition coefficients (log KOW) less than 5.5 or molar volumes less than 230 cm3/mol. Chemicals with higher log KOW or molar volume values display marked differences in membrane-water, 1-octanol-water, and n-hexane-water partitioning. Implications for lipid- and organism-water partitioning of hydrophobic chemicals are discussed.
Gobas
F A
FA
Department of Chemical Engineering and Applied Chemistry, University of Toronto, Ontario, Canada.
Lahittete
J M
JM
Garofalo
G
G
Shiu
W Y
WY
Mackay
D
D
D020003:1-Octanol; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002849:Chromatography, Gas; D004134:Dimyristoylphosphatidylcholine; D008567:Membranes, Artificial; D000442:Octanols; D012995:Solubility; D014867:Water
D008567:Membranes, Artificial; D000442:Octanols; D014867:Water; D020003:1-Octanol; D004134:Dimyristoylphosphatidylcholine