label: 1,3,3'-tri-O-methyl-4alpha-mannobiose + S-adenosyl-L-homocysteine + H(+) => 3,3'-di-O-methyl-4alpha-mannobiose + S-adenosyl-L-methionine
label_lc: 1,3,3'-tri-o-methyl-4alpha-mannobiose + s-adenosyl-l-homocysteine + h(+) => 3,3'-di-o-methyl-4alpha-mannobiose + s-adenosyl-l-methionine