I-Corps: Selectively convert biomass-derived carbohydrates through a thermochemical process

这个i-Corps项目更广泛的影响/商业潜力在于可持续发展、绿色化学和先进制造领域。生物质衍生的非食品型碳水化合物是一种丰富的、可再生的碳来源，但它们很难加工成任何有用的燃料、化学品或材料产品。拟议的活动寻求开发一种新的热方法，将碳水化合物转化为高价值的化学品和化学前体，特别是那些无法轻易从石油或天然气中生产的化学品和化学前体。被广泛研究的称为热解的热过程的主要局限性是生成的产品太多，无法有效和经济地进行净化。尽管热解本身存在浪费，但通过小规模的碳水化合物热解仍可产生一类非常理想的化合物，称为无氢糖。特别是，名为左旋葡聚糖或LGA的脱水糖化合物是合成几类天然产品的原料，比如重要的抗寄生虫药阿维菌素和抗生素。LGA的更大可及性和可负担性将导致最终药物的可获得性和可负担性更高。这个i-Corps项目最初专注于左旋葡聚糖(LGA)作为展示改进的热解技术的测试案例。这项技术是基于最新研究的锁环概念，即糖分子在热解之前进行化学修饰。当烷氧基或苯氧基连接到葡萄糖环上的特定位置时，葡萄糖生成LGA成为主导反应(1，6-消除途径)。取代基抑制葡萄糖环的开环和裂解成非脱水糖产物(开环途径)。换句话说，糖环经过化学修饰后，开环比1，6-消除具有更高的活化势垒。化学改性糖热解后，对LGA的选择性从2%提高到90%以上。这种改进的热解技术也可以应用于其他糖和复杂的碳水化合物。

The broader impact/commercial potential of this I-Corps project lie in the areas of sustainability, green chemistry, and advanced manufacturing. Biomass-derived, non-food-based carbohydrates are an abundant and renewable source of carbon, but they are very difficult to process into any useful fuel, chemical or materials products. The proposed activity seeks the development of a new thermal approach to convert carbohydrates into high-value chemicals and chemical precursors, especially those that cannot be readily produced from petroleum or natural gas. The main limitation of the widely studied thermal process known as pyrolysis is that the generated products are too numerous to purify efficiently and economically. In spite of the wastefulness inherent in pyrolysis, one highly desirable class of compounds called anhydrosugars is still produced through carbohydrate pyrolysis at small scale. In particular, the anhydrosugar compound called levoglucosan, or LGA, is the starting material in the synthesis of several classes of natural products, like the important antiparasitic drug Avermectin and antibiotics. Greater accessibility and affordability of LGA would lead to greater accessibility and affordability of the eventual drug or medication.This I-Corps project initially focuses on levoglucosan (LGA) as the test case for demonstrating the improved pyrolysis technology. This technology is based on the newly researched concept of ring-locking, in which a sugar molecule is chemically modified prior to pyrolysis. LGA formation from glucose becomes the dominant reaction (1,6-elimination pathway) when an alkoxy or phenoxy group is attached to a specific location on the glucose ring. The substituent group inhibits the glucose ring from opening and fragmenting into non-anhydrosugar products (ring-opening pathway). In other words, ring-opening has a much higher activation barrier than 1,6-elimination, after the sugar ring is chemically modified. The selectivity to LGA increases from 2% to greater than 90% after pyrolysis of the chemically modified sugar. This improved pyrolysis technology can be applied to other sugars and complex carbohydrates.