Octanol/water partition coefficients for environmentally important organic compounds

Abstract

Partition coefficients PO,w ((i)) describing the distribution of a solute i onto coexisting phases of 1-octanol and water are needed in a large variety of applications. They can be measured directly by HPLC as long as log PO,w ((i))≧ 3.5. For more hydrophobic substances, several experimental procedures have been proposed in the literature. The reliability of those methods is questionable. Therefore, in the present work, PO,w ((i)) is determined experimentally by three HPLC methods using reversed-phase HPLC [1]. Results from different procedures are compared critically. The method of Braumann [2] proved to be superior over the OECD-guidelines [3]. It was therefore applied to determine octanol/water partition coefficients for 23 substances at 25 °C. For eight of those substances (4-methylindole; 9-(hydroxymethyl)anthracene; N-ethylcarbazol; ethylcyclohexane; trans-2-octene; l,l-dimethyl-(ethy])cyclohexane; heptylbenzene; 4-dodecyl-l,3-benzenediol) no experimentally determined number for PO,w ((i)) has been published before.

Salinity impacts on water solubility and n‐octanol/water partition coefficients of selected pesticides and oil constituents

“…The log K OW values of dibenzothiophene have been reported as 4.17 and 4.44 using the shake flask method [17,18] and 4.36 (25 8C) by a dialysis tubing/ultrasonic agitation method, which is a modified slow-stirring technique [19]. The mean measured log K OW value AE standard error of dibenzothiophene was 4.5 AE 0.05 in distilled water at 25 8C using the shake flask method and is consistent with the literature along with the measured value using the slow-stirring method.…”

Carotenoids Play a Positive Role in the Degradation of Heterocycles by Sphingobium yanoikuyae

“…Increases in the polar zeaxanthin production by strain XLDN2-5 might decrease the membrane fluidity during the biodegradation; enhance the diffusion barrier of the membrane to balance the generation and quenching of ROS; thus ultimately protect this bacterium from oxidative damage, resulting in an improved strain XLDN2-5 survival rate and more efficient biodegradation. Additionally, CA and BT have log P o-w values of about 3, and DBT has a log P o-w value of about 4 [51] , [52] . Interaction of the molecules with the cell membrane might affect the membrane fluidity by disruption of lipid packing [53] , [54] , [55] .…”

Hexanol biosynthesis from syngas by Clostridium carboxidivorans P7 – product toxicity, temperature dependence and in situ extraction

“…Although the effect of acids during fermentation is well understood, and toxicity data are available for both ethanol and butanol, there are no data concerning the potential toxicity of hexanol toward C. carboxidivorans P7 (Fernandez-Naveira et al, 2017). The IC 50 of hexanol (LogP octanol/water 2.03) is expected to be even lower than the values reported for butanol (LogP octanol/water 0.88) and ethanol (LogP octanol/water -0.31) (Ritter et al, 1995), given that the toxicity of short-to-medium chain length alcohols increases as the chain gets longer due to the corresponding nonpolar characteristics of the carbon chain, as reported for Escherichia coli (Wilbanks and Trinh, 2017). Growth of the model acetogen C. ljungdahlii has already been tested in the presence of hexanol, with 10 mM hexanol (1 g/L) causing slight growth impairment and !50 mM (5 g/L) causing complete growth inhibition (Lauer et al, 2018).…”