6. Explain the following observations: (a) One should be extremely cautious when using the results of in vitro biochemic
Posted: Mon May 23, 2022 7:03 am
6. Explain the following observations: (a) One should be extremely cautious when using the results of in vitro biochemical/ medicinal experiments in QSAR analysis. (3 marks) (b) A drug contains an ionized carboxylate group and shows good activity against its target in in vitro tests. When in vivo tests were carried out, the drug showed poor activity when it was administered orally, but good activity when it was administered by intravenous injection. (3 marks) Page 4 of 8 (c) The drug in (b) was converted to an ester, but proved to be inactive in vitro. Despite that, it proved to be active in vivo when it was administered orally. (3 marks) (d) Morphine binds strongly to a receptor in the brain cells to trigger analgesia. In vitro studies show that the quaternary salt of morphine shown below also binds to the same receptor strongly. However, this salt is inactive in vivo when injected intravenously. (3 marks) HO ΔΎ methyl iodide HO quaternary salt of morphine HO morphine