THE BIOGENESIS OF ALKALOIDS: XXII. SOME INTERMEDIATE STEPS IN THE TRANSFORMATION OF TRYPTOPHAN TO GRAMINE

Abstract

In germinating barley it is known that tryptophan is converted into gramine. In an attempt to find the intermediate steps in this conversion, it has been established that neither 3-indolylacetic acid, 3-indolylglyoxylic acid, 3-indolylaldehyde, nor 3-indolylacetamide (all labelled with 14C in the side chain) was a precursor of gramine. It has been shown, however, that both 3-indolylpyruvic acid and 3-indolylacrylic acid gave rise to radioactive gramine when fed to germinating barley. It is likely that these two acids constitute two intermediates in the pathway tryptophan–gramine.