Pharmacological Studies of Norphenyl Hemicholinium 3

Norphenyl HC-3 (NP-HC-3), an analog of HC-3 in which the biphenyl nucleus is replaced by a monophenyl moiety, has been synthesized. NP-HC-3 has been shown to resemble the parent compound in most of its pharmacological properties. Its LD50 in mice was found to range from 45–680 mcg./Kg. NP-HC-3 in low doses induced a slowly progressive respiratory paralysis. In higher doses the neuro-muscular blocking action was antagonized by choline. Neostigmine reversed only the effects observed with low doses of NP-HC-3. NP-HC-3 did not have adrenergic, antihistaminic, analgesic, or local anesthetic activity.