One-step lactosylation of hydrophobic alcohols by nonaqueous biocatalysis
One-step lactosylation of hydrophobic alcohols by nonaqueous biocatalysis
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非水生物催化疏水醇的一步乳糖基化
DOI：
10.1002/cctc.201000051
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发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Wariishi H
中科院分区：
文献类型：
--
作者：
Okutani Y.;Egusa S.;Ogawa Y.;Kitaoka T.;Goto M.;Wariishi H
随着糖蛋白和糖脂在所有生命系统中发挥重要作用，糖蛋白和糖脂的简便合成引起了人们对具有生物功能的新型生物材料的研究和开发的极大关注。特别是，由亲水性碳水化合物和疏水性脂类组成的一系列不同的糖脂参与了各种细胞通讯。[1，2]这种碳水化合物存在于细胞膜磷脂双层之外，并通过对凝集素和其他碳水化合物的特异性识别参与细胞与细胞之间的相互作用。在各种功能糖结合物的候选糖中，乳糖(Lac，β-D-Gal-1，4-D-Glc)由于其典型的和普遍存在的结构而成为这类生物过程中的核心兴趣。因此，Lac是糖材料工程的主要碳水化合物之一。施密特·埃塔尔。报道了一种含有Lac低聚物的仿生糖脂的化学合成，以及在糖萼中发现的独特的类似聚合物的膨胀行为。[6]然而，传统的化学合成糖偶联物通常需要复杂和精确的控制，例如对许多等价羟基的逐步保护和去保护。正因为如此，酶促合成方法已成为设计功能糖共轭化合物的简便和理想方法的焦点。最近报道了一条以4，6-二甲氧基-1，3，5-三氮基-2-基-β-乳糖苷为糖基供体，在内切-β-葡聚糖酶催化下一步合成寡糖的灵巧路线。森等人。报道了一种利用脂膜β-D-半乳糖苷酶的两相(有机-水相)糖基化反应，使半乳糖(Gal)与可溶于有机相的疏水受体偶联。然而，它需要极长的反应时间(如8天)，而且效率不够高。还报道了各种类似乳胶神经酰胺的糖脂的合成，
Facile synthesis of carbohydrate conjugates is attracting much attention for research and development of novel biomaterials with biological functions, as it has become increasingly clear that glycoproteins and glycolipids play essential roles in all living systems. In particular, a diverse array of glycolipids composed of hydrophilic carbohydrates and hydrophobic lipids are involved in various cellular communications.[1, 2] Such carbohydrates exist outside the phospholipid bilayers of cell membranes, and are involved in cell–cell interactions via specific recognition of lectins and other carbohydrates. Of various candidate sugars for functional glycoconjugates, lactose (Lac, β-D-Gal-1, 4-D-Glc) has become of central interest, due to its typical and ubiquitous structure in such bioprocesses.[3, 4] Hence, Lac is one of the major carbohydrates for glycomaterial engineering.[5]Many types of artificial Lac conjugates and synthesis routes have been developed. Schmidt etal. reported the chemical synthesis of a biomimetic glycolipid containing Lac oligomers, and the unique “polymer-like” swelling behavior that is found in glycocalyx.[6] However, conventional chemical synthesis of glycoconjugates in general requires complex and precise control, for example, stepwise protection and deprotection of many equivalent hydroxy groups. For that reason, enzymatic synthesis approaches have become the focus for facile and desirable methods for the design of functional glycoconjugates.[7] Tanaka etal. recently reported a smart one-step synthetic route for the endo-β-glucanase-catalyzed synthesis of oligosaccharides from 4, 6-dimethoxy-1, 3, 5-triazin-2-yl-β-lactoside as a glycosyl donor, which is synthesized insitu.[8] This approach may provide a solution for aqueous glycosynthesis, but it is difficult to apply to glycoconjugation of hydrophobic compounds. Mori etal. reported a two-phase (organic–aqueous) transglycosylation using lipid-coated β-D-galactosidase, enabling the conjugation of galactose (Gal) to hydrophobic acceptors soluble in an organic phase.[9] In this system, the yield of products was higher than for the conventional enzymatic method. However, it requires extremely long reaction times (eg, 8 days) and is not sufficiently efficient. Various syntheses of Lac-ceramide-mimetic glycolipids have also been reported,