The molecule is an ammonium ion resulting from the protonation of the tertiary amino group of ajmalicine. The major species at pH 7.3. It is a conjugate acid of an ajmalicine.
methyl (1S,15R,16S,20S)-16-methyl-17-oxa-3-aza-13-azoniapentacyclo[11.8.0.02,10.04,9.015,20]henicosa-2(10),4,6,8,18-pentaene-19-carboxylate