preferred_name: (S)-S-adenosyl-L-methionine <=> (R)-S-adenosyl-L-methionine
preferred_name_lc: (s)-s-adenosyl-l-methionine <=> (r)-s-adenosyl-l-methionine
label: (S)-S-adenosyl-L-methionine <=> (R)-S-adenosyl-L-methionine
label_lc: (s)-s-adenosyl-l-methionine <=> (r)-s-adenosyl-l-methionine