An Approach from Organic Synthesis Toward Elucidating the Mechanism of Super Energy Transfer Efficiencies of Carotenoids in Photosynthesis

多甲藻黄素和岩藻黄质是海洋光合作用中具有代表性的辅助捕光色素。在分别用这些类胡萝卜素、叶绿素和蛋白质构建的超级复合物中，已经报道了从类胡萝卜素到叶绿素的异常高的（>85%）能量转移效率。这种高效率被认为与类胡萝卜素的独特结构有关，它具有丙二烯和羰基功能。然而，这些类胡萝卜素的结构特征与其超强的能量传递能力之间的关系还没有研究。然后，我们专注于这些功能如何在异常高的能量转移中发挥作用的主题。我们成功地合成了这些天然类胡萝卜素及其在丙二烯和共轭多烯上的修饰衍生物。超快时间分辨光谱和Stark光谱的测量结果表明，这两种类胡萝卜素的结构特征决定了它们具有超强的能量传递能力。

Peridinin and fucoxanthin are known as representative auxiliary light harvesting pigments for photosynthesis in the sea. In the super complexes constructed with these carotenoids, chlorophyll and protein, respectively, exceptionally high (>85%) energy transfer efficiencies from the carotenoids to chlorophyll have been reported. This high efficiency is thought to be related to the unique structure of the carotenoids, which possesse allene and carbonyl functions. There are, however, no studies on the relation between the structural features of these carotenoids and their super ability of the energy transfer. We then focused on the subjects of how these functions play a role in the exceptionally highly energy transfer. We have achieved the efficient syntheses of these natural carotenoids and their modified derivatives on allene and conjugated polyene. Measurements of their ultrafast time resolved spectra and Stark spectra have strongly suggested that the structural feature of the both carotenoids has essentially contributed to their super ability of the energy transfer.