Lactose(乳糖) 4-0-B-D-Galactopyranosyl-a-D-Glucopyranose 4-0-B-D-Galactopyranosyl-B-D-Glucopyranose CH OH CH,OH OH OH OHLactose（乳糖） 4-0-β-D-Galactopyranosyl-α-D- Glucopyranose 4-0-β-D-Galactopyranosyl-β-D-Glucopyranose O OH OH CH2OH O OH OH CH2OH O OH OH