Chemoenzymatic syntheses of naturally occurring β-glucosides

Akita, Hiroyuki; Kurashima, Katsumi; Nakamura, Takuya; Kato, Kanefusa

doi:10.1016/s0957-4166(99)00228-1

Cited by 25 publications

(7 citation statements)

References 15 publications

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“…Epidermin [3-(b-D-glucopyranosyloxy)-3-methylbutanenitrile] (b-HNG) and dihydroosmaronin [3(S)-4-(b-D-glucopyranosyloxy)-3-methylbutanenitrile] (c-HNG) were chemically synthesized by glucosylation of the corresponding aglucones 3-hydroxy-3-methybutanenitrile (commercially available from Sigma-Aldrich) and 3(S)-4-hydroxy-3methylbutanenitrile prepared from (R)-(À)-3-bromo-2-methyl-1propanol (commercially available from Sigma-Aldrich, St. Louis, MO, USA) by conventional procedures for conversion of halides into nitriles with inversion of configuration with 2,3,4,6-tetra-Oacetyl-D-glucopyranosyl fluoride as the glucosyl donor using boron trifluoroetherate as catalyst followed by chromatographic purification and deprotection to achieve the desired molecules (Zagrobelny et al, 2014). Osmaronin [(Z)-4-(b-D-glucopyranosyloxy)-3methylbut-2-enenitrile] (c-HNG) and sutherlandin [(Z)-4-(b-D-glucopyranosyloxy)-3-hydroxymethylbut-2-enenitril] (c-HNG) were synthesized as previously described (Akita et al, 1999). All the synthesized compounds were characterized, and their identity verified using electronspray ionization mass spectrometry and 1 H-and 13 C-NMR.…”

Section: Chemical Synthesis Of the Hngsmentioning

confidence: 99%

Biosynthesis of the leucine derived α‐, β‐ and γ‐hydroxynitrile glucosides in barley (Hordeum vulgare L.)

et al. 2016

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Barley (Hordeum vulgare L.) produces five leucine-derived hydroxynitrile glucosides (HNGs), of which only epiheterodendrin is a cyanogenic glucoside. The four non-cyanogenic HNGs are the β-HNG epidermin and the γ-HNGs osmaronin, dihydroosmaronin and sutherlandin. By analyzing 247 spring barley lines including landraces and old and modern cultivars, we demonstrated that the HNG level varies notably between lines whereas the overall ratio between the compounds is constant. Based on sequence similarity to the sorghum (Sorghum bicolor) genes involved in dhurrin biosynthesis, we identified a gene cluster on barley chromosome 1 putatively harboring genes that encode enzymes in HNG biosynthesis. Candidate genes were functionally characterized by transient expression in Nicotiana benthamiana. Five multifunctional P450s, including two CYP79 family enzymes and three CYP71 family enzymes, and a single UDP-glucosyltransferase were found to catalyze the reactions required for biosynthesis of all five barley HNGs. Two of the CYP71 enzymes needed to be co-expressed for the last hydroxylation step in sutherlandin synthesis to proceed. This observation, together with the constant ratio between the different HNGs, suggested that HNG synthesis in barley is organized within a single multi-enzyme complex.

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Section: Chemical Synthesis Of the Hngsmentioning

confidence: 99%

Biosynthesis of the leucine derived α‐, β‐ and γ‐hydroxynitrile glucosides in barley (Hordeum vulgare L.)

et al. 2016

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“…Incomplete regioselectivity with glucosyltransferases results in mixtures of regioisomers that are difficult to separate (1–3 or 1–6 glycosidic bond compond) . The second kind of enzymes are glycosidases, which catalyze the formation of the glycosidic bond by the reverse reaction of hydrolysis . The major problem with glycosidases is the competition between the synthesis of product and the hydrolysis of substrate.…”

Section: Introductionmentioning

confidence: 99%

A new family‐3 glycoside hydrolase from Penicillium oxalicum BL 3005 catalyzing tyrosol glucosylation to form salidroside

Yang

Wang

Yan

et al. 2016

Biotech and App Biochem

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A glycoside hydrolase from Penicillium oxalicum BL 3005 was purified to apparent homogeneity. Its molecular mass was estimated to be 90 kDa by SDS-PAGE. The enzyme was identified to be a new member of family-3 by peptide sequence. High transglycosylation activity was found in the hydrolytic reaction of cellobiose. In the reaction, salidroside (4-hydroxyphenethyl O-β-d-glucopyranoside) was formed by adding tyrosol as the glycosyl acceptor. The optimum reaction pH and temperature were pH 6.5 and 55 °C, respectively. The maximum yield of salidroside was almost 20 g/L. These results indicated that the β-glucosidase of P. oxalicum can be considered as a very promising catalyst for the synthesis of salidroside.

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“…As an alternative chemo-enzymatic glycosidations have been suggested [21][22][23][24] . These reactions proceed very slowly, and they rarely give acceptable yields 25 . Furthermore, the glycosidases responsible for the creation of the glycosidic bond are not readily commercially available or have to be identified as far as they are yet unknown.…”

Section: Resultsmentioning

confidence: 99%