Synthesis of Carbohydrate-Phthalocyanine Conjugates for Biomedical Applications

项目摘要 酞菁是大环化合物，满足有效光敏剂的所有标准，包括吸收 在700- 1100 nm之间的近红外区域，用于深层组织穿透和高单线态氧生成 最大限度地杀死细胞然而，使酞菁成为理想光敏剂的相同性质， 但是生物物理学观点限制了它们在生物系统中的治疗应用。酞菁是已知的 在水中表现出有限的溶解度，倾向于在生物流体中聚集，并表现出有限的对 目标组织。已经使用了几种一般方法来改善药物的药理学特征。 酞菁，包括用硫酸盐或其它水溶性的化合物官能化异吲哚（外）环， 部分如季胺。虽然这些方法已经取得了一些成功，但他们的准备工作仍然 在关键的合成步骤中存在低效的化学反应，导致低产量的反应混合物， 难以分离和评价药理活性。此外，目前制备这些化合物的方法， 酞菁不容易调节（例如，来建立图书馆来研究它们在生物学中的应用 系统）。它们具有挑战性的合成也限制了可能用于增强 这些化合物的总选择性。本建议通过模块综合解决这些问题 糖基共轭酞菁（GPc's）。除了提供增强的溶解度之外， 瞄准能力（例如，通过直接结合在细胞表面过表达的凝集素，或通过 在代谢过程中起关键作用的碳水化合物结合酶的参与）可用于 提高选择性。我们的创新方法，这将使我们能够准备GPc的库，依赖于 容易获得的基于酞菁的溴代二氢吡喃酮的合成， 带有用于糖缀合的功能柄的接头。以这种方式，连接体和碳水化合物两者都可以被连接。 以针对所需的生物学应用调整系统。在本提案中，我们还探讨了 我们综合GPc来解决与NIH倡议一致的两个全球公共卫生问题：肝细胞 癌症和肺结核。鉴于我们的经验，长期的成功合作， 专业知识和资源，我们，作为来自戴维森学院和南加州大学北部的多个PI，是唯一有资格， 共同领导这项工作，这将是我们共同发起的第二个R15倡议。本R15区域提案将支持 为每个机构的多名本科生提供卓越的研究经验，并培养下一个 合成化学家的一代。

PROJECT SUMMARY Phthalocyanines are macrocycles that meet all the criteria for an effective photosensitizer including absorption in the near infrared region between 700-1100nm for deep tissue penetration, and high singlet oxygen generation for maximum cell killing. However, the same properties that make phthalocyanines ideal photosensitizers from a photophysical perspective limit their therapeutic applications in biological systems. Phthalocyanines are known to exhibit limited solubility in water, tend to aggregate in biological fluids, and exhibit limited selectivity toward the targeted tissues. Several general approaches have been used to improve the pharmacological profile of phthalocyanines, including functionalization of the isoindole (outer) rings with sulfates or other water-soluble moieties such as quaternary amines. While these approaches have shown some success, their preparation still suffers from inefficient chemistries at key synthetic steps leading to low yielding reaction mixtures that can be difficult to separate and evaluate for pharmacological activity. In addition, the current methods for preparing these phthalocyanines are not readily amenable to tuning (e.g., to create libraries to study their applications in biological systems). Their challenging synthesis has also limited the installation of groups that might be used to enhance the overall selectivity of these compounds. This proposal addresses these issues through the modular synthesis of glycoconjugated phthalocyanines (GPc’s). In addition to providing enhanced solubility, carbohydrates with targeting ability (e.g., through the direct binding of lectins that are overexpressed on cell surface, or through the engagement of carbohydrate binding enzymes that play key roles in metabolic processes) can be used to enhance selectivity. Our innovative methodology, which will allow us to prepare libraries of GPc’s, relies on the synthesis of readily accessible phthalocyanine-based bromosynthons which can be selectively substituted with linkers bearing functional handles for glycoconjugation. In this way, both the linker and carbohydrate can be exchanged to tune the system for a desired biological application. In this proposal we also explore the ability of the GPc’s we synthesize to address two global public health issues in line with NIH initiatives: hepatocellular carcinoma and tuberculosis. Given our experience, long-standing successful collaboration, and combined expertise and resources, we, as multiple PIs from Davidson College and USC-Upstate, are uniquely qualified to co-lead this effort, which will be our second R15 initiative together. This R15 AREA proposal will support an exceptional research experience for multiple undergraduates at each institution and foster the training of the next generation of synthetic chemists.