title: Structure elucidation of an immunostimulatory arabinoxylan-type polysaccharide prepared from young barley leaves (Hordeum vulgare L.).
abstract: We recently isolated an immunostimulating polysaccharide (BLE-P-I), which possesses a large proportion of arabinoxylan, from young barley leaves. In the present study, to elucidate the structural details of BLE-P-I, it was fractionated into enzyme-resistant fraction (BLE-P-I-X1) and arabinoxylan-rich oligosaccharide fraction (BLE-P-I-X2) after endo-xylanase hydrolysis. Commercial wheat arabinoxylan was also fractionated into WAX-XI and WAX-X2 after the same treatment. BLE-P-I-X2 consisted of arabinose and xylose, including 11 types of neutral glycosidic linkages, whereas WAX-X2 had less, with 6 types of linkages. Mass spectrometric results indicated that WAX-X2 was composed of a xylan backbone bearing only arabinose. In contrast, BLE-P-I-X2 consisted of a xylan backbone with acetate, arabinose, galactose, glucuronic acid, and 4-O-methylglucuronic acid, resembling structural characteristics as glucuronoarabinoxylan. Macrophage-stimulatory activity showed that BLE-P-I-X2 has a role in the expression of the activity. These results indicate that the structural complexity of arabinoxylan seems to be responsible for the immunomodulatory activity in barley leaf.
authors.affiliation: Department of Food Science and Biotechnology, Kyonggi University, San 94-6, Ieu-dong, Youngtong-gu, Suwon, Gyeonggi-do 443-760, Republic of Korea; Department of Integrated Biomedical and Life Science, Korea University, Anam-ro 145, Seongbuk-gu, Seoul 136-701, Republic of Korea.
authors.forename: Hoon
authors.initials: H
authors.lastname: Kim
authors.affiliation: Korea Food Research Institute, Sungnam, Gyeonggi-do 462-746, Republic of Korea.
authors.forename: Hee-Do
authors.initials: HD
authors.lastname: Hong
authors.affiliation: Department of Food Science and Biotechnology, Kyonggi University, San 94-6, Ieu-dong, Youngtong-gu, Suwon, Gyeonggi-do 443-760, Republic of Korea. Electronic address: ksshin@kyonggi.ac.kr.
authors.forename: Kwang-Soon
authors.initials: KS
authors.lastname: Shin
mesh_terms: D000276:Adjuvants, Immunologic / Q000737:chemistry* / Q000302:isolation & purification; D001089:Arabinose / Q000737:chemistry; D001467:Hordeum / Q000737:chemistry*; D006868:Hydrolysis; D018515:Plant Leaves / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification; D014908:Triticum / Q000737:chemistry; D014990:Xylans / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D000276:Adjuvants, Immunologic; D011134:Polysaccharides; D014990:Xylans; C085118:arabinoxylan; D001089:Arabinose
keywords: Arabinoxylan; Barley leaf; Immunostimulatory activity; Structural elucidation; endo-Xylanase