N-methylputrescine oxidation during cocaine biosynthesis: study of prochiral methylene hydrogen discrimination using the remote isotope method.
[structure: see text] The stereoselectivity of N-methylputrescine (3) oxidation to pyrrolinium ion 4 in Erythroxylum coca during cocaine (1) biosynthesis was studied. The remote isotope method was used to advantage. Each enantiomer of 4-monodeuterated N-methylputrescine served as a precursor for plant feeding. To facilitate mass-spectrometric analysis of products, a 2H3 13C-methyl group was also incorporated into the 4-deuterio-N-methylputrescines. Oxidative deamination of N-methylputrescine was found to be stereoselective; the pro-S hydrogen atom is removed with 6-10:1 selectivity.
Hoye
T R
TR
Department of Chemistry, University of Minnesota, Minneapolis 55455, USA. hoye@chem.umn.edu
Bjorklund
J A
JA
Koltun
D O
DO
Renner
M K
MK
D002247:Carbon Isotopes; D003041:Coca / Q000378:metabolism*; D003042:Cocaine / Q000096:biosynthesis*; D003903:Deuterium; D013058:Mass Spectrometry; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010946:Plants, Medicinal; D011700:Putrescine / Q000031:analogs & derivatives* / Q000378:metabolism; D013237:Stereoisomerism
D002247:Carbon Isotopes; D003903:Deuterium; D003042:Cocaine; D011700:Putrescine