A Convenient Single Step Preparation of Dopamine-4-O-Sulfate

Metabolism and excretion of a new 5-lipoxygenase inhibitor in rats, guinea-pigs, beagles and rhesus monkeys

1. The 5-lipoxygenase inhibitor (I), a substituted benzothiazole is metabolized mainly by glucuronide and/or sulphate conjugation in rat, guinea-pig, beagle and rhesus monkey. Glucuronidation is the major pathway, and sulphation is more extensive in rat and beagle than in guinea-pig and rhesus monkey. 2. After a single oral dosing of 14C-I (10 mg/kg), more than 96% of the dose was excreted in 7 days in all four species, however there is species difference in urinary excretion, which was 2.8 +/- 0.3% in rat, 46.9 +/- 1.6% in guinea-pig, 2.6% in beagle and 68.2% in rhesus monkey. 3. After a single i.v. dose of 14C-I to bile duct-cannulated rats and guinea pigs, bile was a major route of elimination, and in rats the ratio of glucuronide to sulphate in excreta increased from 0.71 +/- 0.01 to 0.93 +/- 0.05 as the dose was increased from 0.2 to 20 mg/kg.

Preparation of dopamine 3-O-sulphate and dopamine 4-O-sulphate as reference substances and high-performance liquid chromatographic trace determination

Simple syntheses of the biologically important but hitherto difficult to obtain dopamine sulpho conjugates dopamine 3-O-sulphate (I) and dopamine 4-O-sulphate (II), as analytical reference substances, starting from dopamine hydrochloride are described. A method for the determination of I and II with reversed-phase high-performance liquid chromatographic separation and coulometric detection in human urine together with calibration and current-voltage curves are presented. Detection limits of approximately 100 pg of I or II and unequivocal substance identifications even in very complex substrates such as human urine are reported.