Abstract
The metabolic disposition of two C14-labeled pentaquine salts has been studied in the rhesus monkey. Following injection of pentaquine labeled in the 6-methoxyl group (Pent-Meo) about 49 per cent of the C14 was excreted as C14O2 in the expired air and about 20 per cent in the urine. When pentaquine labeled with C14 in the terminal isopropyl group (Pent-Iso) was injected, 8 per cent of the C14 appeared in the expired air and about 35 per cent was recovered in the urine. About 1 per cent of the pentaquine was excreted in the urine unchanged while 8 to 9 per cent could be accounted for as urinary metabolites which coupled with diazotized sulfanilic acid.
Three radioactive Pent-Meo metabolites and six radioactive Pent-Iso metabolites could be detected when concentrated butanol extracts of treatment urine were chromatographed on cellulose columns. The distribution patterns of the two groups of metabolites were quite different; two of the Pent-Meo like the parent compound were eluted rapidly from the columns whereas the four major Pent-Iso derivatives moved slowly and could be eluted only with polar solvents such as butanol or water.
These data indicate that pentaquine is degraded rapidly in the monkey with the production of at least six metabolic derivatives. They also show that the methoxyl group at position 6 is cleaved with extreme rapidity, while the terminal isopropyl group is more resistant to oxidation. The implications of these findings are discussed and a scheme is proposed to account for the early stages of penta-quine degradation.
Footnotes
- Received July 29, 1955.
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