Characterization of Alkaloids in Palatable and Unpalatable Clones of Phalaris arundinacea L1

Reed canarygrass genotypes that differ in palatability to lambs also differ in their alkaloid profiles. Unpalatable clones contained an average of 0.78% crude alkaloids on a dry-matter basis, about three times the 0.26% found in palatable clones. The compound 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) was on average 18 times more abundant in unpalatable clones. Other identified alkaloids included gramine, hordenine, and several tryptamine derivatives. The findings suggest that alkaloid concentration, particularly of 5-MeO-DMT, contributes to the palatability differences previously observed in grazing trials.

Study at a glance

Abstract

We determined the types and amounts of alkaloids found in four reed canarygrass ( Phalaris arundinacea L.) genotypes that differed in palatability. The palatability differences had been demonstrated previously in cafeteria grazing trials with lambs. The following alkaloids were identified in reed canarygrass by combinations of gas‐liquid chromatography, thin‐layer chromatography, and mass spectrometry: gramine, hordenine, N‐monomethyltryptamine, N,N‐dimethyltryptamine, 5‐methoxy‐N‐monomethyltryptamine, 5‐methoxy‐N,N‐dimethyltryptamine (5‐MeO‐DMT). Three additional peaks were detected by gas‐liquid chromatography, and work is in progress to determine their structures. The crude alkaloid content of the palatable and unpalatable clones averaged 0.26 and 0.78%, respectively, on a dry‐matter basis. The amount of 5‐MeO‐DMT in the unpalatable clones averaged 18 times the amount found in palatable clones.