1,7-dimethylxanthine + S-adenosyl-L-methionine <=> caffeine + S-adenosyl-L-homocysteine + H(+)
1,7-dimethylxanthine + s-adenosyl-l-methionine <=> caffeine + s-adenosyl-l-homocysteine + h(+)
1,7-dimethylxanthine + S-adenosyl-L-methionine <=> caffeine + S-adenosyl-L-homocysteine + H(+)
1,7-dimethylxanthine + s-adenosyl-l-methionine <=> caffeine + s-adenosyl-l-homocysteine + h(+)