label: trans-resveratrol + 2 S-adenosyl-L-methionine => pterostilbene + 2 S-adenosyl-L-homocysteine + 2 H(+)
label_lc: trans-resveratrol + 2 s-adenosyl-l-methionine => pterostilbene + 2 s-adenosyl-l-homocysteine + 2 h(+)