Prodrug not its intended target. This reduces adverse or unintended effects of a drug, especially important in treatments like chemotherapy, which can have severe unintended and undesirable side effects. Many herbal extracts historically used in medicine contain glycosides (sugar derivatives) of the active agent, which are hydrolyzed in the intestines to release the active and more bioavailable aglycone. For example, salicin is a β-D-glucopyranoside that is cleaved by esterases to release salicylic acid. Aspirin, acetylsalicylic acid, first made by Felix Hoffmann at Bayer in 1897, is a synthetic prodrug of salicylic acid. However, in other cases, such as codeine and morphine,
I Should Have Known Better I Should Have Known Better "I Should Have Known Better" is a song by English rock band the Beatles composed by John Lennon (credited to Lennon–McCartney), and originally issued on "A Hard Day's Night", their soundtrack for the film of the same name released on 10 July 1964. "I Should Have Known Better" was also issued as the B-side of the US single "A Hard Day's Night" released on 13 July. An orchestrated version of the song conducted by George Martin appears on the North American version of the album, "A Hard Day's Night Original Motion Picture Soundtrack". In January