title: Chemoimmunotherapy of cancer. 3. Analytical measurement of chemical half-lives of monofunctional alkylators.
abstract: The objective of this study is the measurement of the rates of hydrolysis of a series of chloroethyl sulfide derivatives, under stimulated physiological conditions. Interferences encountered with the conventional spectrophotometric method prompted the use of a rapid-response, chloride selective electrode. This probe was readily capable of monitoring the hydrolytic rate, which is identical with the rate of chloride ion formation. Since the desired subsecond half-lives were not achieved by any of the compounds, factors influencing the rates were investigated. The results suggest that the rate-controlling cyclization step may be inhibited, due to coordination of undissociated protonic functional groups on the aromatic portions of the structures with the lone-pair electrons on sulfur.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D004563:Electrochemistry; D006207:Half-Life; D006868:Hydrolysis; D007700:Kinetics; D009588:Nitrogen Mustard Compounds / Q000378:metabolism*; D013816:Thermodynamics
chemical_list: D009588:Nitrogen Mustard Compounds