Search PubMed⌕ Search

Biomedical subjects

S Symchowicz

Publications and source records attributed to S Symchowicz.

76 records · Page 5Linked to original sources
PubMedDate not supplied

Isolation and identification of a metabolite of rosaramicin in human urine.

A urinary metabolite of rosaramicin in man was isolated and purified by a preparative HPLC method. On the basis of infrared, proton, and 13C magnetic resonance spectroscopic data, and elemental analysis, the metabolite has been identified as 20-bisureidorosaramicin. An authentic 20-bisureidorosaramicin was synthesized and shown to be identical to the urinary metabolite in infrared, 13C magnetic resonance spectral data and elemental analysis. In addition, fast atom bombardment mass spectral data of the metabolite was consistent with the structure of 20-bisureidorosaramicin. In mice receiving orally administered synthetic 20-bisureidorosaramicin, significant concentrations of rosaramicin were found in plasma, indicating the conversion of 20-bisureidorosaramicin to rosaramicin in this species.

Animals↗
PubMedDate not supplied

The disposition and metabolism of a hypnotic benzodiazepine, quazepam, in the hamster and mouse.

The disposition of 14C-quazepam (7-chloro-(2,2,2-trifluoroethyl) [5-14C]-5-o-fluorophenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-thione), a new benzodiazepine hypnotic, was studied in hamsters and mice after iv and po dosing. In both species, quazepam was rapidly absorbed, as indicated by the plasma Cmax being reached within 1 hr of an oral dose (5 mg/kg). Also, radioactivity is essentially completely absorbed in both species, since the percentage of dose excreted in the urine was not dependent on the route of drug administration. Radioactivity was widely distributed in the tissues of both species; however, it was concentrated (relative to plasma) only in the liver and kidneys. In hamsters, 66-77% of the radioactivity was excreted within 48 hr, and 97% within 7 days of dosing (57% found in urine and 40% in feces after iv; 54% in urine and 43% in feces after po dosing). In mice, 86-88% of the radioactivity was excreted within 24 hr, and 98% within 4 days of dosing (43% in urine and 56% in feces after iv, 37% in urine and 61% in feces after po dosing). In both species, plasma levels of quazepam, measured by GLC, accounted for a very small percentage of plasma radioactivity and the elimination half-life was short (2.4 hr in hamster and 1.2 hr in mice), indicating extensive first pass metabolism for this drug. TLC analysis of plasma and urine extracts from both species showed biotransformation of quazepam involved substitution of oxygen for sulfur, followed by: (a) N-dealkylation, 3-hydroxylation, and conjugation or (b) 3-hydroxylation and conjugation.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗