METABOLISM OF ROSMARINIC ACID IN RATS

The urine of rats administered rosmarinic acid (7) orally contained se ven metabolites, which were identified as trans-caffeic acid 4-O-sulfa te (1), trans-m-coumaric acid 3-O-sulfate (2), transferulic acid 4-O-s ulfate (3), trans-caffeic acid (4), m-hydroxyphenylpropionic acid (5), trans-m-coumaric acid (6), and unchanged rosmarinic acid (7) by spect roscopic and chemical data. The total cumulative amount of 1-7 excrete d in the urine 48 h after the oral administration of rosmarinic acid w as approximately 31.8% of the dose administered. On the other hand, th e metabolites attributed to rosmarinic acid could not be found in the bile. Orally administered rosmarinic acid may thus be concluded to be excreted in the urine rather than in the bile, with cleavage of eater bonds, selective para-dehydroxylation, methylation, and sulfate-conjug ation. Metabolites 2, 3, 5, and 6 were also detected in the plasma.