CH CH R 叶绿素a(R=CH3) 叶绿素b(R=CHO) CH CH2 CH2 CO2CH3 CH3 CH CH CH3N N N N Mg CO2CH3 CH2 O CH H3C H3C R CH2CH3 CH3 CH2 CH2 C O O CH3 CH3 CH3 CH3 CH3 叶 绿 素 a (R=CH3 ) 叶 绿 素 b (R=CHO)