Description: Nitrocaramiphen hydrochloride is a M1 muscarinic (mAChR) antagonist which demonstrates 71-fold selectivity for M 1 over M 2. Nitrocaramiphen binds with high affinity for M1 sites (Ki = 5.5 nM) and with a 71-fold selectivity over M2, and a 10-fold selectivity for the M1 over the M3 subtype.
References: Eur J Pharmacol. 1993 Feb 16;231(3):485-8.