Complex oligosaccharide chains formation

It is believed that the apiofiiranose (Api residue of side chain A, but not that of side-chain B, is involved in RG-II dimerization. Recently mutant Arabidopsis murl strains, which are defective in L-fucose biosynthesis, have been shown to result in small changes in chain A of RG-II the L-fucose residue is replaced by L-galactose. This seemingly minor modification in a complex oligosaccharide structure results in a significant reduction in RG-II dimer formation and has a dramatic impact of plant morphology(/P). It is not yet clear which structural features of RG-II are key to borate ester formation and stability. 

Committed Steps in the Formation of Complex-Type Oligosaccharide Chains and Branching... 

Catalytic aldol reactions are among the most useful synthetic methods for highly stereo-controlled asymmetric synthesis. In this account we discuss the recent development of a novel synthetic technique which uses tandem enzyme catalysis for the bi-directional chain elongation of simple dialdehydes and related multi-step procedures. The scope and the limitations of multiple one-pot enzymatic C-C bond formations is evaluated for the synthesis of unique and structurally complex carbohydrate-related compounds that may be regarded as metabolically stable mimetics of oligosaccharides and that are thus of interest because of their potential bioactivity. 

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