Defined chemical transformation in Lignin, enabling to access shell-core-functionalized Lignin-colloids for selective ion binding.

木质素中定义的化学转化，能够获得壳核功能化的木质素胶体以进行选择性离子结合。

• 批准号: 494591814
• 负责人: Professor Dr. Hans Gerhard Börner
• 金额: --
• 依托单位: Institut für Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/494591814?language=en
• 关键词: Defined; chemical; transformation; Lignin; enabling

Objective of the research proposal is to investigate a defined two-step chemical reaction to selectively activate important aromatic core structures in the complex structural network of lignin. The reaction will be utilized to access shell-stabilized and core-functionalized lignin colloids, that should be investigated on their capabilities to specifically bind heavy metal ions from complex ion mixtures.Lignins are constituting a renewable resource that offers enormous potential for sustainable material solutions, as raw lignin is an inexpensive “waste” product from paper pulp production. The use of lignin provides various opportunities. However, modern material applications often require chemical derivatization of lignin, where limitations result from the inhomogeneous structure and strong batch-to-batch variations.In contrast to rather unselective reactions that are often used for lignin derivatization, the project is investigating the possibilities of a discrete two-step reaction for the selective manipulation of both, the 4-hydroxy-3-methoxybenzene-(G)-type and p-Hydroxyphenyl-(H)-type structural elements of lignin. The G- and H-type aromatics will be oxidized by 2-iodoxybenzoic acid (IBX) in a metal-free manner to yield ortho-quinones. These react as Michael acceptors with various thiols and can be converted rapidly and cleanly to thiol-catechols.The chemistry provides the possibility of introducing functional thiols, such as Cys-containing di- and tripeptides but also thiol-end functional polymers, such as mPEG-SH, Cys-peptide-PEG conjugates or PNIPAm-SH. Exploiting the diffusion limitations in the lignin network, shell-core lignins will be accessed. The functional lignin core should be adapted to the needs of specific binding of heavy metal ions and the colloidal stability will be adjusted independently of the lignin core via the shell.The IBX activation of lignin with subsequent quinone/thiol-Michael addition not only preserves the phenolic OH-groups that are important for ion binding. Moreover, thiol-catechols are generated as derivatives of the potent 1,2-dihydroxybenzene chelate ligand, which can be functionalized or fine-tuned via the thiol substituents.The project investigates the potential of a precise chemical activation of lignin for the synthesis of lignin-colloids and their use to gain basic understanding of the ion-specific complexation of heavy metal ions from more complex ion mixtures. The investigation utilizes systematic substance libraries of shell-core lignins, to study metal-ion binding, illuminating effects of the polymer shell, the lignin core and the functionalities implemented there including peptide-based binding domains for specific heavy metal ions.

研究方案的目的是研究一种明确的两步化学反应，选择性地激活木质素复杂结构网络中的重要芳香族核心结构。该反应将用于获得壳层稳定和核功能化的木质素胶体，应研究其特定结合复杂离子混合物中重金属离子的能力。木质素构成了一种可再生资源，为可持续材料解决方案提供了巨大的潜力，因为原始木质素是纸浆生产中廉价的“废物”产品。木质素的使用提供了各种机会。然而，现代材料应用经常需要木质素的化学衍生化，这是由于木质素的结构不均匀和批次之间的强烈差异造成的。与通常用于木质素衍生化的相当不选择性的反应不同，该项目正在研究离散的两步反应的可能性，以选择性地操纵木质素的4-羟基-3-甲氧基苯-(G)型和对羟基苯基-(H)型结构元素。G型和H型芳烃将被2-碘氧基苯甲酸(IBX)以无金属的方式氧化生成邻苯二酚。这些化合物作为Michael受体与各种硫醇反应，可以快速、清洁地转化为硫醇儿茶酚。这种化学提供了引入功能性硫醇的可能性，如含半胱氨酸的二肽和三肽，但也提供了硫醇末端的功能聚合物，如mpeg-SH、半胱氨酸-肽-聚乙二醇偶联物或PNIPAM-SH。利用木质素网络中的扩散限制，将访问壳核木质素。功能木素核应适应特定结合重金属离子的需要，胶体稳定性将通过壳层独立于木质素核进行调节。木素的IBX活化与后续的苯酚/硫醇-迈克尔加成反应不仅保留了对离子结合重要的酚羟基。此外，硫醇儿茶酚是1，2-二羟基苯络合物的衍生物，可以通过硫醇取代基来功能化或微调。该项目研究了木质素精确化学活化合成木质素胶体的可能性，以及它们的用途，以基本了解重金属离子从更复杂的离子混合物中的离子特异性络合。本研究利用壳核木质素的系统物质库，研究了金属离子与金属离子的结合、聚合物壳层、木素核的发光效应以及所实现的功能，包括特定重金属离子的多肽结合域。