6-O-desmethylmycophenolate + S-adenosyl-L-methionine <=> mycophenolate + S-adenosyl-L-homocysteine + H(+)
6-o-desmethylmycophenolate + s-adenosyl-l-methionine <=> mycophenolate + s-adenosyl-l-homocysteine + h(+)