Lignin-xylan ester linkage in jute fiber (corchorus capsularis)
作者:Narendra Nath Das、Sankar Chandra Das、Adiya Sekhar Dutt、Ashimanandra Roy
DOI:10.1016/s0008-6215(00)85597-4
日期:1981.7
(containing 77% of the original lignin) and a water-soluble, lignin-carbohydrate complex ( III ). On hydrolysis, both II and III furnished a new sugar, viz ., 4- O -methyl- d -glucose, in admixture with the same acidic and neutral sugar component as those of I . Alkaline extraction of holocelluloses prepared from I and II afforded crude d -xylans which, on fractional with aqueous barium hydroxide, yielded two
KANIE, OSAMU;TAKEDA, TADAHIRO;OGIHARA, YUKIO, CARBOHYDR. RES., 190,(1989) N, C. 53-64
作者:KANIE, OSAMU、TAKEDA, TADAHIRO、OGIHARA, YUKIO
DOI:——
日期:——
Fungal Glucuronoyl Esterases and Substrate Uronic Acid Recognition
作者:Miroslava ĎURANOVÁ、Ján HIRSCH、Katarína KOLENOVÁ、Peter BIELY
DOI:10.1271/bbb.90486
日期:2009.11.23
Glucuronoyl esterases are enzymes involved in microbial plant cell-wall degradation. In this study we purified and characterized two recombinant Phanerochaete chrysosporium glucuronoyl esterases, PcGE1 and PcGE2. The catalytic activity of these and previously described glucuronoyl esterases was investigated on new synthetic substrates, methyl esters of uronic acids and their glycosides, prepared by esterification with ethereal diazomethane.The data obtained indicate that the enzymes hydrolyzed efficiently not only esters of 4-O-methyl-d-glucuronic acid, but also methyl esters of d-glucuronic acid carrying a 4-nitrophenyl aglycon. Moreover, the fact that they did not recognize the 4-epimers of these compounds, the d-galacturonic acid derivatives, supports the hypothesis that these carbohydrate esterases attack ester linkages between 4-O-methyl-d-glucuronic acid of glucuronoxylan and lignin alcohols.
Synthesis of a precursor of 3-O-(2-acetamido-2-deoxy-3-O-methyl-α-d-galactopyranosyl)-4-O-(4-O-methyl-β-d-glucopyranosyluronic acid)-l-fucose
作者:Osamu Kanie、Tadahiro Takeda、Yukio Ogihara
DOI:10.1016/0008-6215(89)84146-1
日期:1989.7
schlegelii , have a unique structure containing one or two mannosyl residues, novel linkages including an internal fucopyranosyl residue, as well as terminal xylosyl and 4- O -methyl- d -glucopyranosyluronic acid groups. The trisaccharide derivatives that constitute the partial structure of lipid IV were synthesized as follows. Condensation of 4,6-di- O -acetyl-2-azido-2-deoxy-3- O -methyl-α- d -galactopyranosyl