Isolation of hemicelluloses and lignin in high yield and purity from mild ball-milled Periploca sepium

CELL 277

Feng Xu, xfx315@163.com, College of Materials Science and Technology, Beijing Forestry University, Beijing, China, Qinghua North Road 35, Beijing, 100083, China, Runcang Sun, College of Materials Science and Technology, Beijing Forestry University, Beijing 100083, China, Beijing 100083, China, Beijing, 100083, China, JinXia Sun, src888@126.com, College of Forestry, The North-Western Science and Technology University of Agriculture and Forestry, JinTai Road, Yangling, 712100, China, and Meizhi Zhai, mzzhai@126.com, College of Forestry, The North-Western University of Agricultural and Forest Sciences and Technology, JinTai Road, Yangling, 712100, China.
The sequential treatments of the mild ball-milled Periploca sepium with 80% aqueous dioxane containing 0.05 M HCl at 85°C for 4 h, DMSO at 85°C for 4 h, and 8% NaOH at 50°C for 3 h resulted in a total release of over 85% of the original hemicelluloses and 86% of the original lignin. In particular, approximate 36% of the original hemicelluloses and 50% of the original lignin were obtained during the first mild acidolytic hydrolysis process after low intensity milling. The structure of the acidic dioxane-, DMSO-, and alkali-soluble hemicellulosic and lignin fractions were elucidated using wet chemical analysis, FT-IR, and solution-state 1H, 13C, and 31P NMR techniques. Results showed that both the mild ball milling and the mild acidolysis under the conditions given did not affect the isolated lignin macromolecular structure.It was found that the acidic dioxane-soluble hemicelluloses mainly contained more branched and less acidic arabinoxylans, and the 8% NaOH-soluble hemicellulosic fraction H3 was both less branched and less acidic in structure, whereas the DMSO-soluble hemicelluloses were more acidic but less branched and consisted mainly of 4-O-methylglucuronoarabinoxylan.