Carbon-13 nuclear magnetic resonance spectra of morphine alkaloids

13C-NMR spectra of strychnos alkaloids: brucine and strychnine

The natural abundance 13C-NMR spectra of brucine and strychnine were obtained using the pulse Fourier transform technique. The chemical shifts of various carbon resonances were assigned on the basis of substituent effects on benzene shifts, intesities of signals, multiplicites generated in single-frequency off-resonance-decoupled spectra, and comparisons with the chemical shifts of structurally related compounds.

The enkephalins and opiates: structure-activity relations

The X-ray structures of 9 "opiate" drugs which exhibit a range of pharmacological activity have been examined in detail leading to the theory that one of the reasons why the enkephalins and related peptides possess morphine-like activity is because they have a tyrosine, and hence a "tyramine", residue at the amino terminal position. This residue or a conformationally similar moiety, can be shown to be present in many opiates and analogues.