AbstractUpon single oral administration to rats, the mono‐, di‐ and tri‐glucose conjugates of 14C‐3‐phenoxybenzyl alcohol (I) or the mono‐glucose conjugate of 14C‐3‐phenoxybenzoic acid (II) were rapidly hydrolysed and extensively eliminated in the urine mostly as the sulphate conjugate of 3‐(4‐hydroxyphenoxy)benzoic acid (X). The faecal elimination was a minor route, whereas the biliary excretion was about 42 of the dose and the glucuronide conjugates ofI,IIandXwere common major metabolites. The biliary glucuronides were cleaved in the small intestine to the respective aglycones, which were reabsorbed, metabolised further, and excreted in the urine as the sulphate conjugate ofX. Although small amounts of the mono‐, di‐and tri‐glucosides were found in the 0.5‐h blood and liver samples following oral administration of the tri‐glucoside ofI, they were not detected in the urine, bile or faeces. Similarly the sulphate conjugate was one of the major urinary metabolites of germ‐free rats, dosed with the14C‐glucosides via the oral or the intraperitoneal route, although they were excreted unchanged in certain amounts in the urine and faeces. The glucose conjugates were cleavedin vitroby gut microflora and in various rat tissues, including blood, liver, small intestine and small intestinal mucosa. The tissue enzymes showed a different substrate specificity in hydrolysis of the glucosides. However, they were not cleaved in gastric juice
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