School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul, Korea.
Korea Institute of Energy Research, 152, Gajeong-ro, Yuseong-gu, Daejeon, Korea.
ChemSusChem. 2017 Dec 22;10(24):4891-4898. doi: 10.1002/cssc.201701860. Epub 2017 Nov 29.
Alginic acid, a major constituent of macroalgae, iss hydrogenated into sugar alcohols over carbon-supported noble metals for the first time. Mannitol and sorbitol are the major products of the catalytic hydrogenation of alginic acid, which consists of two epimeric uronic acids. The main reaction pathway is the consecutive hydrogenations of the aldehyde and carboxyl ends of alginic acid dimers, followed by the cleavage of the C-O-C linkage into monomeric units by hydrolysis. The highest yield of C sugar alcohols is 61 % (sorbitol: 29 %; mannitol: 28 %; galactitol: 4 %). The low sorbitol/mannitol ratio is in contrast to that from cellulose hydrogenation, owing to the composition of alginic acid and isomerization between sugar alcohols under the catalytic system. This new green route to producing sugar alcohols from alginic acid might provide opportunities to diversify biomass resources.
藻酸是大型藻类的主要成分，首次在负载碳的贵金属上被氢化生成糖醇。在藻酸的催化氢化中，甘露醇和山梨醇是主要产物，它由两种差向异构的糖醛酸组成。主要的反应途径是藻酸二聚体的醛基和羧基端的连续加氢，然后通过水解将 C-O-C 键断裂成单体单元。C 型糖醇的最高收率为 61%（山梨醇：29%；甘露醇：28%；半乳糖醇：4%）。与纤维素加氢相比，糖醇的低山梨醇/甘露醇比例归因于藻酸的组成和催化体系中糖醇之间的异构化。这种从藻酸生产糖醇的新型绿色途径可能为生物质资源的多样化提供机会。
