preferred_name: L-leucine + L-arginine => N-amidino-L-leucine + L-ornithine
preferred_name_lc: l-leucine + l-arginine => n-amidino-l-leucine + l-ornithine
label: L-leucine + L-arginine => N-amidino-L-leucine + L-ornithine
label_lc: l-leucine + l-arginine => n-amidino-l-leucine + l-ornithine