7,9,10-trihydroxy-3-(2-oxopropyl)-1H-benzo[g]isochromen-1-one + S-adenosyl-L-methionine <=> 9,10-dihydroxy-7-methoxy-3-(2-oxopropyl)-1H-benzo[g]isochromen-1-one + S-adenosyl-L-homocysteine + H(+)
7,9,10-trihydroxy-3-(2-oxopropyl)-1h-benzo[g]isochromen-1-one + s-adenosyl-l-methionine <=> 9,10-dihydroxy-7-methoxy-3-(2-oxopropyl)-1h-benzo[g]isochromen-1-one + s-adenosyl-l-homocysteine + h(+)