The Development of Computational Methods to Study the Chemical Structural Evolution of Organic Macromolecules with Diagenesis

研究成岩有机大分子化学结构演化的计算方法进展

• 批准号: 9614352
• 负责人: George Cody
• 金额: $ 11.06万
• 依托单位: Carnegie Institution of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-01-15 至 2000-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9614352&HistoricalAwards=false
• 关键词: Development; Computational; Methods; Study; Chemical

9614352 Cody Organic Reactions that modify the chemical structure of biomacromolecules are controlled, in part by the long range topology of the macromolecule. Understanding the role of macromolecular structure on monomer scale reactivity has important implications regarding our ability to assess the probability for preservation of ancient biomacromolecules (e.g. kerogen as a function of T, P, and fluid composition. The work defined in this proposal sets out to develop a methodology for computational organic geochemistry. A step-wise approach is outlined that starts with a statistical mechanical model of macromolecular topology (the Rotational Isomeric State Model). The rotational isomeric states are characterized through semi-empirical quantum mechanical calculations of the inter-segmental rotational energy surface. These calculations lead to the generation of a large scale, "coarse-grained" macromolecular model that includes the effects of over 10000, monomers. Construction of the macromolecular model is constrained by the RIS calculations; from the initial configuration, using a structure building algorithm, to the final equilibrium state obtained via Monte-Carlo methods. Two macromolecular systems are selected as initial problems. These are the diagenesis of lignin, a principle biomacromolecular component of the xylem tissue of wood, and the diagenesis of sporopollenin, a particularly resistant biopolymeric component of plant spores and seeds. The developed computational methods will be applied to assess the energetic penalties (or gains) of various proposed diagenetic reaction pathways in the two systems based on consideration of the total energy of the macromolecular system. The methodology obtained from the work outlined in this proposal will be exportable to a wide range of problems in organic geochemistry.

9614352修饰生物乳清分子化学结构的Cody有机反应受到大分子的远距离拓扑的控制。 了解大分子结构在单体尺度反应性中的作用具有重要的意义，这对我们评估保存古代生物剧分分子的可能性的能力具有重要意义（例如，在此提案中定义的t，p，p和液体组成的函数的函数。 （旋转异构态模型）。算法，通过蒙特卡洛方法获得的最终平衡状态。 选择两个大分子系统作为初始问题。 这些是木质素的成岩蛋白，木质素是木质木质部组织的原理生物ac骨分子成分，也是孢子囊成岩蛋白的成岩蛋白，孢子蛋白是植物孢子和种子的特别耐药性生物聚合物成分。 根据对大分子系统的总能量的考虑，将采用开发的计算方法来评估两种系统中各种提出的成岩反应途径的能量惩罚（或收益）。 从本提案中概述的工作中获得的方法将出口到有机地球化学的各种问题。