Versatile Synthesis of Chlorophylls and Bacteriochlorophylls for Fundamental Studies in Photosynthesis

在化学系化学合成(SYN)计划的支持下，北卡罗来纳州立大学的乔纳森·S·林赛教授正在开发在实验室中从简单的原料中创建叶绿素和细菌叶绿素的方法。(细菌)叶绿素的化学合成从来不是从简单的起始材料完全完成的，尽管已经完成了通往叶绿素a的非常长的途径的各个步骤。这项研究的目标将允许以直截了当的方式创建叶绿素及其类似物。最终寻求的类似物(及其影响范围)将使人们更深入地了解光合作用中的能量流动(生物物理学、植物科学)、代谢分解产物的性质(生态学、全球碳平衡)以及此类化合物的性质(营养、药物)。该项目位于有机化学的核心，但也将影响科学的各个领域，包括对光合作用的理解。因此，该项目非常适合各级科学家的教育。林赛教授的团队也处于有利地位，可以为科学界代表性不足的学生提供最高水平的教育和培训。涉及北卡罗来纳州教师的外联活动也将是资助项目的一部分。叶绿素和细菌叶绿素是光合作用生物中的主要色素，包括植物、蓝藻和缺氧光合细菌。缺乏制备(细菌)叶绿素及其类似物的合成方法构成了光合作用科学中的智力和技术缺陷。林赛实验室建议通过开发合成这种有价值的大环的可靠方法来填补这一鸿沟。合成(细菌)叶绿素的特殊挑战包括(1)吡咯环上取代基的立体化学(S)，(2)第五个(同环)环上的取代基，以及(3)排列在大环周围的取代基。这项工作的学术价值涉及关键光合色素及其类似物合成路线的开发；后者具有广泛的影响(超出本拨款的范围)，包括光合作用中的量子一致性和生态学中的分解代谢的研究。一个关键的成果是在杂环化学中制备与光合作用的(细菌)叶绿素相关的吡咯、吡咯烷和氢二吡咯的方法学。更广泛的影响包括高中科学教师的专业发展，以改善学校的光合作用教学(通过基于叶绿素的实验)，并激励高中生学习科学、技术、工程和数学(STEM)，从而扩大代表不足的群体的参与。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

With the support of the Chemical Synthesis (SYN) program in the Division of Chemistry, Professor Jonathan S. Lindsey at North Carolina State University is developing methods to create chlorophylls and bacteriochlorophylls in the laboratory from simple starting materials. The chemical synthesis of (bacterio)chlorophylls has never been fully accomplished from simple starting materials, although individual steps of a very long pathway to chlorophyll a have been achieved. The goal of this research will allow chlorophylls and analogues to be created in a straightforward manner. The analogues ultimately sought (and their impact areas) will afford a much deeper understanding of energy flow in photosynthesis (biophysics, plant sciences), the nature of metabolic breakdown products (ecology, global carbon balance), and the properties of such compounds (nutrition, medicine). The project lies at the heart of organic chemistry but will also impact diverse areas of science including understanding of photosynthesis. Thus, the project is well suited for the education of scientists at all levels. Professor Lindsey's group is also well positioned to provide the highest level of education and training for students underrepresented in science. Outreach activities involving North Carolina teachers will also be part of the funded project. Chlorophylls and bacteriochlorophylls are the chief pigments in photosynthetic organisms, including plants, cyanobacteria, and anoxygenic photosynthetic bacteria. The lack of synthetic methods for preparing (bacterio)chlorophylls and analogues constitutes an intellectual and technical deficit in the photosynthetic sciences. The Lindsey lab proposes to fill this chasm by developing robust methods for synthesis of such valuable macrocycles. The particular challenges in synthesizing (bacterio)chlorophylls include (1) the stereochemistry of substituents in the pyrroline ring(s), (2) the fifth (isocyclic) ring, and (3) substituents arrayed about the perimeter of the macrocycle. The intellectual merit of the work concerns the development of routes for the synthesis of the key photosynthetic pigments and analogues; the latter have broad impact (beyond the scope of the present grant) encompassing studies of quantum coherence in photosynthesis and catabolism in ecology. A key outcome is a methodology in heterocyclic chemistry for preparing pyrroles, pyrrolines, and hydrodipyrrins relevant to the (bacterio)chlorophylls of photosynthesis. The broader impacts entail professional development of high school science teachers to improve teaching of photosynthesis (via a chlorophyll-based experiment) in schools and to inspire high school students to science, technology, engineering, and mathematics (STEM), thereby broadening the participation of underrepresented groups.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.