Tamiaki Hitoshi, Kichishima Saki
Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, 525-8577 Japan.
Plant Cell Physiol. 2025 Feb 28;66(2):153-167. doi: 10.1093/pcp/pcae094.
Oxygenic phototrophs use chlorophylls (Chls) as photosynthetically active pigments. A variety of Chl molecules have been found in photosynthetic organisms, including green plants, algae and cyanobacteria. Here, we review their molecular structures with stereochemistry, occurrence in light-harvesting antennas and reaction centers, biosyntheses in the late stage, chemical stabilities and visible absorption maxima in diethyl ether. The observed maxima are comparable to those of semisynthetic Chl analogs, methyl pyropheophorbides, in dichloromethane. The effects of their peripheral substituents and core π-conjugation on the maxima of the monomeric states are discussed. Notably, the oxidation along the molecular x-axis in Chl-a produces its accessory pigments, Chls-b/c, and introduction of an electron-withdrawing formyl group along the y-axis perpendicular to the x-axis affords far-red light absorbing Chls-d/f.
产氧光合生物利用叶绿素（Chls）作为光合活性色素。在光合生物中已发现多种叶绿素分子，包括绿色植物、藻类和蓝细菌。在此，我们综述它们的分子结构（包括立体化学）、在光捕获天线和反应中心中的存在情况、后期生物合成、化学稳定性以及在乙醚中的可见吸收最大值。观察到的最大值与二氯甲烷中半合成叶绿素类似物焦脱镁叶绿酸甲酯的最大值相当。讨论了它们的外围取代基和核心π共轭对单体态最大值的影响。值得注意的是，叶绿素a沿分子x轴的氧化产生其辅助色素叶绿素b/c，而沿垂直于x轴的y轴引入吸电子甲酰基则得到吸收远红光的叶绿素d/f。
