title: Partition coefficients of quinones and hydroquinones and their relation to biochemical reactivity.
abstract: Some major effects of ring substituents on the partition coefficients of quinone headgroups are described. Attention is drawn to the large differences in partition coefficients in cyclohexane/water of the two major freely diffusing redox forms, the quinone, Q, and the hydroquinone, QH2. Methoxy substituents cause a marked increase of the cyclohexane/water partition coefficient of the hydroquinone, but this effect is absent in the quinone and is also not seen in measurements in octanol/water. The relation between partition coefficients and biochemical specificity of quinone binding sites is explored.
authors.affiliation: Glynn Research Institute, Bodmin, Cornwall, UK.
authors.forename: P R
authors.initials: PR
authors.lastname: Rich
authors.forename: R
authors.initials: R
authors.lastname: Harper
mesh_terms: D016227:Benzoquinones; D003510:Cyclohexanes; D006873:Hydroquinones; D000442:Octanols; D011809:Quinones; D012995:Solubility; D013329:Structure-Activity Relationship; D014867:Water
chemical_list: D016227:Benzoquinones; D003510:Cyclohexanes; D006873:Hydroquinones; D000442:Octanols; D011809:Quinones; D014867:Water; C004532:quinone