CAREER: Chemoenzymatic Synthesis of Complex Polycyclic Alkaloids Enabled by A-Ketoglutarate Dependent Iron Enzymes

在化学系化学合成项目的支持下，布兰代斯大学的Chi Ting正在研究合成一类天然分子的新策略，这些分子被称为生物碱。其中许多分子很难从天然来源中分离出来，导致可用于研究的数量有限。具体来说，这项工作将有机合成与酶学（生物催化）相结合，以制备足够数量的生物碱，以供进一步研究，特别是用于治疗目的的研究。Ting小组正在研究的生物催化修饰了相对复杂的分子中间体，通过这样做，他们可以直接接触到生物碱。除了研究计划外，还计划向马萨诸塞州沃尔瑟姆市的中学生介绍有机化学。这些活动将展示日常生活中天然产物的存在，并向学生介绍分子结构。这些活动的首要目标是让学生尽早接触化学，特别是有机化学，从而激发他们对专业科学研究的兴趣。Ting实验室通过在后期将酶催化反应纳入其全合成工作，使复杂的多环生物碱的全合成成为可能。他们的方法不仅在概念上不同于传统的全合成，因为生物催化在合成设计中的重要性。该方法也不同于大多数化学酶合成方法，因为这些方法通常涉及生物催化剂促进的早期合成模块的合成，通常控制绝对立体化学。目前，化学生物学和药物化学界对将后期功能化扩展到化学酶合成中有很大的兴趣。例如，许多活性都是针对后期酶促卤化。这里提出的工作超越了这些转变，以更充分地发展后期过氧化的领域。这种策略对于生成复杂的、具有生物活性的分子，特别是那些含有相对敏感的过氧化物功能的分子具有很高的潜力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

With support of the Chemical Synthesis program in the Division of Chemistry, Chi Ting of Brandeis University is studying the development of new strategies for the synthesis of a class of naturally occurring molecules that are referred to as alkaloids. Many of these molecules are challenging to isolate from natural sources, resulting in limited quantities being available to study. Specifically, this work will couple organic synthesis with enzymology (biocatalysis) to prepare alkaloids in sufficient quantities for their further study, particularly their study for therapeutic purposes. The biocatalysis that the Ting group is examining modifies relatively complex molecular intermediates and by doing so, allows them to directly access the alkaloids. In addition to the research plan, outreach activities are planned to introduce organic chemistry to middle school students in Waltham, Massachusetts. These activities will showcase the presence of natural products in everyday life, and introduce students to molecular structure. The overarching goal of these activities is to engage students early on in chemistry and especially organic chemistry in so doing, initiate interest in pursuing science professionally. The Ting lab is enabling the total synthesis of complex, polycyclic alkaloids by incorporating enzyme-catalyzed reactions at a late stage into their total synthesis efforts. Their approach is not only conceptually different than traditional total synthesis efforts because of the importance of biocatalysis in the synthetic design. The approach also differs from most chemoenzymatic synthetic methods in that these typically involve the biocatalyst-facilitated synthesis of earlier stage synthetic building blocks, often with control of absolute stereochemistry. There is currently great interest in chemical biology and medicinal chemistry circles in expanding the use of late stage functionalization into the repertoire of chemoenzymatic synthesis. Much activity has been directed at late stage enzymatic halogenation, for example. The work proposed here goes beyond such transformations to develop more fully the area of late stage peroxidation. This strategy has the potential to be highly enabling for the generation of complex, bioactive molecules, especially those that contain relatively sensitive peroxide functionalities.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.