The biosynthesis of Lobelia alkaloids. Part III. Intermediates in the biosynthesis of lobeline; biosynthesis of 8,10-diethyl-lobelidione

Abstract

Cinnamic acid and 3-hydroxy-3-phenylpropanoic acid are incorporated into lobeline{2-[6-(β-hydroxyphenethyl)-1-methyl-2-piperidyl]acetophenone} in Lobelia inflata. Lysine, pentane-1,5-diamine (cadaverine), and 3,4,5,6-tetrahydropyridine are also incorporated into lobeline; their relative incorporations show that pentane-1,5-diamine is not an intermediate in the biosynthesis of this alkaloid from lysine. 8,10-Diethyl-lobelidione [1,1′-(1-methylpiperidine-2,6-diyl)di(butan-2-one)] is shown, by tracer experiments, to be derived from lysine and acetate in L. inflata plants.