Metabolism of {alpha}-Olefin Sulfonate (AOS) in Rats

Metabolism of -Olefin Sulfonate (AOS) in Rats. Inoue, S., O'Grodnick,J.S. and Tomizawa, S. (1982). Fundam. Appl. Toxicol. 2:130-138.The metabolic fate of ¹⁴C-AOS (a mixture of ¹⁴C-sodium alkenyl(2)sulfonate and ¹⁴C-sodium 3-hydroxy alkane sulfonate) has beenstudied in rats by a single oral and intravenous injection of100 mg (50 µCi)/kg and 10 mg (5 µCi)/kg, respectively.After oral administration, ¹⁴C-AOS was rapidly absorbed fromthe gastrointestinal tract. The blood level of ¹⁴C-activityreached its peak 3 hr after dosing and then declined. Twenty-fourhr after the dose, about 0.8%/g of the ¹⁴C-AOS given was detectedin cecum content, but in other tissues the figures were under0.02% dose/g. Within 24 hr after the dose, 72% of the dose wasexcreted in the urine and 22% in the feces, while the excretionin the bile was 4.3% within 12 hr. The administered radioactivitywas rapidly eliminated from the whole body within 24 hr. Afterintravenous injection, half of the administered dose of radioactivitywas excreted within 1 hr. In the 0–6 hr interval post-dose,90% of the dose was excreted in the urine. No intact ¹⁴C-AOSwas detected in any of the urine samples after oral and intravenousdoses. The metabolite was apparently more polar than intact¹⁴C-AOS, and results from data of electrophoresis and equilibriumdialysis indicated that intact ¹⁴C-AOS can bind with proteins,while the metabolites cannot. The metabolite was found to containalcoholic, unsaturated and sulfonic acid functionalities. Itis suggested that the metabolite may be a hydroxylated or polyhydroxylatedsulfonic acid of shorter chain length than AOS. These resultssuggest that ¹⁴C-AOS is rapidly absorbed, metabolized and excreted,therefore, no accumulation of ¹⁴C-AOS occurs.