-CH CH HC- CH NH 吡咯 卟吩 CH CH=CH2 CH3 CH3 H CH=CH2 CH Fe++ 亚铁血红素 CH3 CH CH3 CH2CH2COOH CH2CH2COOHHC—CH || || HC—CH \ / NH 吡咯 CH CH CH CH 卟吩 CH CH CH CH CH3 CH3 CH3 CH=CH2 CH3 CH=CH2 CH2CH2COOH CH2CH2COOH Fe++ 亚铁血红素