Biosynthesis of chlorophyl studied by time-resolved Raman spectroscopy

本项目的主要目标有两个：（1）通过对皮秒至微秒时间分辨吸收光谱的详细研究，发现叶绿素生物合成过程中新的中间体，并从动力学研究中确定叶绿素生物合成过程的时间常数。（2）通过对中间产物的时间分辨共振拉曼谱的分析，确定了中间产物的结构，对第一个目标产物，改进了实验装置，重复实验，发现其生物合成过程为：PClide-650-&gt; PClide（S_1）-&gt;^< PS>X-B -&gt;^&lt;<plus-minus>0.2 <micrn>S&gt;X-690 -&gt;^&lt;<plus-minus>20 <micrn>S&gt;X-684 -&gt;^&lt;<plus-minus>0.5 <micrn>S&gt; Chlide-678-&gt;^&lt;5 <plus-minus>2.0 <micrn>S&gt;Chla，所有中间产物均与低温产物相对应，对第二个目标产物，新发现的中间体和其它中间体的时间分辨共振拉曼光谱由于荧光强度很低而很难观察到。在现阶段，我们还没有成功地得到拉曼光谱。然而，为时间分辨拉曼光谱构建的装置被用于通过使用宽带染料激光基于非相干光方法观察汽车或CSRS来确定飞秒振动相位弛豫。并将其推广到电子退相时间的测量，得到了广大科研工作者的高度评价。首席调查员被邀请在国际会议上演讲六次以上，并被要求撰写三份以上的特邀论文。

There were two targets of this project: (1)By detailed study of picosecond to microsecond time-resolved absorption spectroscopy, new intermediates in the biosynthetic processes of chlorophyl in the time region were to be discovered and from the dynamical study, the time constants of the processes were to be determined. (2)From the time-resolved resonance Raman spectra of the intermediates, the structure were expected to be determined.Concerning the first target, after improving the apparatus, and repeating the experiment the biosynthetic process was found to be described as:PChlide-650->PChlide(S_1)->^^^< PS>X-B ->^^^<<plus-minus>0.2<micrn>S>X-690 ->^^^<<plus-minus>20<micrn>S>X-684 ->^^^<<plus-minus>0.5<micrn>S> Chlide-678->^^^<5<plus-minus>2.0<micrn>S>Chla.All the intermesiates were found to be correspondent with those at low temperature.Concerning the second targer, it was very difficult to observe the timeresolved resonance Raman spectra of the newly found and other intermediates because of the very in tense fluorescence. At the present stage, we have not yet succeeded in getting the Raman spectra. However, the apparatus constructed for the time-resolved Raman spectra was used for the determination of femtosecond vibrational phase relaxation by observing CARS or CSRS using broad band dye laser on the basis of incoherent light method. The work was extendod to the electronic dephasing time measurement and these works were highly evaluated by many scientific research people. The head investigator was invited more than six times to give talks at the international conferences and was asked to write more than three invited papers.