Chemospecific deuteration of prostaglandin silyl ethers.

Complete chemical selectivity (i.e., chemospecificity) has been achieved in the homogeneous deuteration of C5-C6 and endocyclic C10-C11 prostaglandin double bonds without arrangement or partial reduction of C13-C14- or C8-C12 double bonds. The homogeneous deuteration reaction utilizes protection of the C13-C14 double bond as the C15O-silyl ether and protection of the carboxyl group as the methyl ester prior to reduction under molecular deuterium with tris(triphenylphosphine)chlorohodium (I) (Wilkinson's catalyst) in 60:40 acetone:benzene at 25 degrees C. The reaction has been used to prepare six specifically deuterated prostaglandin: 5,6-dideuterio-PGE1 alpha 5,6-dideuterio-PGE1, 5,6-dideuterio-PGB1, 3,3,4,4,5,6-hexadeuterio-PGF1 alpha, 5,6,10,11-tetradeuterio-11-deoxy-PGE1, and 10, 11-dideuterio-11-deoxy-PGE1.

Determination of urinary thiamine by high-pressure liquid chromatography utilizing the thiochrome fluorscent method.

A sensitive, reproducible, and specific method for the determination of urinary thiamine has been established. Unique to the use of high-pressure liquid chromatography (HPLC) to separate the fluorescent thiamine derivative from interfering fluorescent compounds. Urine samples were passed through a Decalso catoin-exchange column, washed with 0.5 M KCl to remove some interfering compounds, and eluted with 3.4 M KCl. The eluted thiamine was converted to the fluorescent derivative, thiochrome, by reaction with alkaline potassium ferricyanide. The reaction mixture was extracted with isobutanol and subjected to HPLC monitored by a fluorescent detector. Within-day and day-to-day coefficients of variation proved to be 2.5% and 1.2% respectively. Recovery of added thiamine (range 0.04 to 2.0 microgram/ml) averaged 99.9 +/- 5.3%. The sensitivity of this method was 0.03 microgram/ml.