Abstract
1. The absorption, metabolism and excretion of hydroxyethylrutosides in rat and other mammals have been studied. Following oral administration to rats of 3′,4′,7-tri-O-(β-hydroxyethyl)rutoside, 4′,7-di-O-(β-hydroxyethyl)ruto-side and 7-O-(β-hydroxyethyl)rutoside, significant levels of the administered compounds and their conjugates in bile were observed, but 3′,4′,5,7-tetra-O-(β-hydroxyethyl)rutoside was poorly absorbed. The major portion of the dose of each rutoside was excreted as the aglycone in faeces. Urinary excretion of all rutosides was low. 2. Levels of excretion of 14C in the urine of rabbits and rhesus monkeys given 3′,4′,7-tri-O-(β-hydroxy[14C2]ethyl)rutoside and 3′,4′,5,7-tetra-O-(β-hydroxy[14C2]ethyl)rutoside were similar (in vivo and in vitro. The B rings of rutin and 7-O-(β-hydroxyethyl)rutoside give rise to the same phenolic acid metabolites. Mono-O-(β-hydroxyethyl)phloroglucinol is formed from the A ring of 7-O-(β-hydroxyethyl)rutoside. Excretion of these metabolites in urine is suppressed by concurrent administration of neomycin. 4. 3′,4′,7-Tri-O-(β-hydrcxyethyl)rutoside did not undergo cleavage to metabolites other than the aglycone after continuous administration to rats for periods of up to 5 months.