emodin + S-adenosyl-L-methionine <=> physcion + S-adenosyl-L-homocysteine
emodin + s-adenosyl-l-methionine <=> physcion + s-adenosyl-l-homocysteine
emodin + S-adenosyl-L-methionine <=> physcion + S-adenosyl-L-homocysteine
emodin + s-adenosyl-l-methionine <=> physcion + s-adenosyl-l-homocysteine