(S)-1,10-dimethoxy-2,9-dihydroxyaporphinium chloride (boldine hydrochloride), C19H22NO4+.Cl-

Boldine (5,6,6a,7-tetrahydro-1,10-dimethoxy-6-methyl-4H-dibenzo[de,g]quinoline-2,9-diol) is an aporphine alkaloid noted for its antioxidant properties. A salient feature of the molecule is the non-planarity of the biphenyl system, which exhibits a dihedral angle of 151.1(8)degrees between the least-squares planes of the two benzenoid rings and torsion angles of 25.7 (3), - 150.6 (2), -155.9 (2) and 27.8 (3)degrees about the biphenyl bond. Methoxy C atom C13 lies only 0.195 (4) Angstrom above the mean plane of the ring to which it is attached, with torsion angles about the C10-O2 bond of 168.6 (2) and -11.3 (4)degrees. Methoxy C atom C14 is displaced -1.101 (3)Angstrom from the corresponding ring plane, with torsion angles about the C1-O3 bond of 102.3 (2) and -79.7 (3)degrees. All intramolecular bonds and angles are within the expected range.