6 CH,OH CH,OH 5 H H H0二CH0 H 4 OH OH H HO OH H OH 吡喃 3 呋喃 H OH H OH α-D-吡喃葡萄糖 o-D-呋喃葡萄糖 H CH,OH HOH,C CH,OH 5 HO HO OH H OH 4 OH H OH H α-D-吡喃果糖 o-D-呋喃果糖 吡喃型和呋喃型的D-葡萄糖和D-果糖(Haworth式) 吡喃型和呋喃型的D-葡萄糖和D-果糖（Haworth式） 吡喃 呋喃 -D-吡喃葡萄糖 -D-吡喃果糖 -D-呋喃葡萄糖 -D-呋喃果糖