label: 3',4',5,6-tetrahydroxy-3,7-dimethoxyflavone + S-adenosyl-L-methionine <=> 3',4',5-trihydroxy-3,6,7-trimethoxyflavone + S-adenosyl-L-homocysteine
label_lc: 3',4',5,6-tetrahydroxy-3,7-dimethoxyflavone + s-adenosyl-l-methionine <=> 3',4',5-trihydroxy-3,6,7-trimethoxyflavone + s-adenosyl-l-homocysteine