Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, 845 38, Bratislava, Slovak Republic.
Chembiochem. 2023 May 2;24(9):e202200743. doi: 10.1002/cbic.202200743. Epub 2023 Mar 30.
A chemical synthesis of two novel phenyl glycosides of trisaccharides related to acetylarabinoxylan is described. The trisaccharides bear acetyl and arabinofuranosyl moieties at the non-reducing-end xylopyranosyl residue, which is substituted at positions 2 and 3. Both compounds were treated with various xylan deacetylases classified in different carbohydrate esterase (CE) families and significant differences between the families were found. While the arabinosylation hampers deacetylation by CE2-CE5 and CE12 family members, both epitopes are deesterified by CE1 and in particular CE6 enzymes. The 3-O-acetylated 2-O-arabinosylated compound is also processed by CE7 and majority of CE16 esterases, but not by a hitherto non-classified Flavobacterium johnsoniae acetylxylan esterase. The data suggests that a slow deesterification of the 2-O-acetylated 3-O-arabinosylated compound may be due to the acetyl group migration followed by deacetylation of this migration product.
描述了两种新型苯基糖苷的化学合成，这些糖苷与乙酰阿拉伯木聚糖有关，是由非还原末端木吡喃糖基残基上的乙酰基和阿拉伯呋喃糖基组成，该残基在 2 位和 3 位被取代。两种化合物都用不同的木聚糖脱乙酰酶进行处理，这些酶被分类为不同的碳水化合物酯酶（CE）家族，并且在家族之间发现了显著的差异。虽然阿拉伯糖基化会阻碍 CE2-CE5 和 CE12 家族成员的脱乙酰作用，但这两个表位都被 CE1，特别是 CE6 酶脱去酯化。3-O-乙酰化 2-O-阿拉伯糖基化的化合物也被 CE7 和大多数 CE16 酯酶处理，但不能被一种迄今未分类的黄杆菌属乙酰木聚糖酯酶处理。这些数据表明，2-O-乙酰化 3-O-阿拉伯糖基化化合物的脱酯化速度较慢可能是由于乙酰基迁移，随后迁移产物脱乙酰化。
