Single-step bioconversion for the preparation of l-gulose and l-galactose

Production of monosaccharides and bio-active compounds derived from marine polysaccharides using subcritical water hydrolysis

“…Gulose has been reported to be a building block in the synthesis of nucleoside analogues, which are useful as potential anticancer compounds (Gumina, Song, & Chu, 2001;Sugiura et al, 2007), and a starting material for antiviral medications (Jeong et al, 1993;Tang, 2012). The limited availability of rare sugars have led to estimated costs for R&D efforts and basic research of $900/g and $240/g, respectively (Woodyer, Christ, & Deweese, 2010). Mannose is a type of sugar most commonly used as a source for bio-ethanol production (Saeman, 1945).…”

Enzymes for the biocatalytic production of rare sugars

“…The advantages of the L-enantiomer are increased antiviral activity, better metabolic stability, and more favorable toxicological profiles. Since the discovery of lamivudine (2 0 ,3 0 -dideoxy-3 0 -thiacytidine, mostly referred to as 3TC), an increasing number of L-nucleoside analogues are undergoing clinical trials and/or preclinical studies, while several other L-sugars can be used to produce L-nucleosides, such as L-gulose, L-xylose, and L-galactose [30,69,113]. L-Sugars can also be used as an active compound on their own, for instance as glycosidase inhibitors [56] or as insecticides [1].…”

“…Starting material for glycoconjugate vaccines against diseases caused by Shigella sonnei [56] Cytostatic and cytotoxic properties with regards to neoplastic cells (cancer therapy) [1] L-Gulose Building block of bleomycin A 2 , a glycopeptide antibiotic (potential anticancer agent) [18,113] Synthesis of nucleosides that exhibit very potent activity against HBV and HIV [18] Starting material for the production of L-nucleoside-based antiviral medications [113] L-Idose Derivatives are required in the synthesis of sensitive substrates for a-L-iduronidase [18] Derivatives are used as glycosyl donors in the synthesis of heparin oligosaccharides [108] L-Lyxose Component of the antibiotic avilamycin A [33] Potential L-fucosidase inhibitor [11] L-Mannose Component of steroid glycosides [38] L-Psicose…”

“…Starting material for branched pentoses (useful in pharmaceutical chemistry) [37] L-Allose Therapeutic agent for diseases involving vasculogenesis [110] L-Altrose Component of biologically important oligo-and polysaccharides [38] L-Fructose Potential inhibitor of various glucosidases [56] Mixture of L-and D-fructose kills ants and house flies [1] L-Galactose Potential in synthesis of L-nucleoside-based antiviral medications [113] Component of saponins, with applications in food, cosmetics, and pharmaceuticals [83,113] L-Glucose…”

Biosynthesis of rare hexoses using microorganisms and related enzymes

“…L-Galactose was also directly synthesized by oxidizing galactitol using D-galactose oxidase [89], including the previously mentioned immobilized galactose oxidase [83–84], but the yields were generally low. In contrast, whole cells of recombinant Escherichia coli carrying a unique mannitol dehydrogenase (EC 1.1.1.255) represent a more scalable system [90] for oxidizing galactitol (Scheme 15). Alternatively, it was reported that L-galactose could be biosynthesized by epimerizing D-glucose through a novel but rare metabolic pathway during the biosynthesis of a sulfated L-galactan in the ascidian tunic, requiring a triple epimerization which brings about inversion of the configuration of carbon 2, 3, and 5 [91].…”