The objective of this study was to verify the contents of protein and non-protein nitrogen and ureides (allantoin and allantoic acid) in leaves and roots of comfrey plants (Symphytum officinale L.). The results showed that 12% of the nitrogen was non-protein nitrogen and 28% of which was from ureides. Non-protein nitrogen amounted to 54% of the total nitrogen of the roots, and 71% of which was from ureides. Allantoin contents per leaves and roots were 79% and 92% of the total ureides, respectively.
comfrey; Symphytum officinale L.; ureides; allantoin; allantoic acid