480-10-4Relevant articles and documents
Phlomisflavosides A and B, new flavonol bisglycosides from Phlomis spinidens
Takeda, Yoshio,Isai, Natsuko,Masuda, Toshiya,Honda, Gisho,Takaishi, Yoshihisa,Ito, Michiho,Otsuka, Hideaki,Ashurmetov, Ozodbek A.,Khodzhimatov, Olimjon K.
, p. 1039 - 1041 (2001)
From the aerial parts of Phlomis spinidens, two new flavonol bisglycosides, phlomisflavosides A (1) and B (2), were isolated together with the known compounds, astragalin, isoquercitrin, lamiridoside, phlomoside A, shanzhiside methyl ester, 8-O-acetylshanzhiside methyl ester, phlorigidoside C, rodioloside (=salidroside), forsythoside B, citroside A and lariciresinol-4′-O-β-D-glucoside. The structures of the new compounds were elucidated based on spectral and chemical evidence.
STRUCTURES AND ACCUMULATION PATTERNS OF SOLUBLE AND INSOLUBLE PHENOLICS FROM NORWAY SPRUCE NEEDLES
Strack, Dieter,Heilemann, Juergen,Wray, Victor,Dirks, Herbert
, p. 2071 - 2078 (1989)
Key Word Index - Picea abies; Pinaceae; Norway spruce; phenolics; identification; seasonal accumulation pattern; turnover; translocation; cell wall localization; flavonol glucosyltransferase. - Abstract - Twenty-two soluble phenolics have been isolated from Norway spruce needles and their structures elucidated on the basis of chromatographic (TLC, HPLC), chemical (hydrolysis), enzymic and spectroscopic (UV, NMR, MS) techniques.These phenolics have been quantified by HPLC during the first year of needle development from a forest near Bad Muenstereifel (F.R.G.) and showed a differential accumulation pattern.Kaempferol 3-O-glucoside showed an interesting metabolism, indicating rapid turnover and/or translocation from a soluble to an insoluble (cell wall bound) pool.The enzyme involved in the formation of this flavonoid, UDP-glucose:flavonol glucosyltransferase, showed a marked transient increase in activity that correlated with the possible kaempferol 3-O-glucoside translocation.
Functional Characterization and Protein Engineering of a Triterpene 3-/6-/2′-O-Glycosyltransferase Reveal a Conserved Residue Critical for the Regiospecificity
Bao, Yang-Oujie,Gao, Bai-Han,Li, Fu-Dong,Qiao, Xue,Shi, Xiao-Meng,Su, Hui-Fei,Wang, Hai-Dong,Ye, Min,Yi, Yang,Zhang, Meng
supporting information, (2022/01/06)
Engineering the function of triterpene glucosyltransferases (GTs) is challenging due to the large size of the sugar acceptors. In this work, we identified a multifunctional glycosyltransferase AmGT8 catalyzing triterpene 3-/6-/2′-O-glycosylation from the medicinal plant Astragalus membranaceus. To engineer its regiospecificity, a small mutant library was built based on semi-rational design. Variants A394F, A394D, and T131V were found to catalyze specific 6-O, 3-O, and 2′-O glycosylation, respectively. The origin of regioselectivity of AmGT8 and its A394F variant was studied by molecular dynamics and hydrogen deuterium exchange mass spectrometry. Residue 394 is highly conserved as A/G and is critical for the regiospecificity of the C- and O-GTs TcCGT1 and GuGT10/14. Finally, astragalosides III and IV were synthesized by mutants A394F, T131V and P192E. This work reports biocatalysts for saponin synthesis and gives new insights into protein engineering of regioselectivity in plant GTs.
Ep7GT, a glycosyltransferase with sugar donor flexibility from: Epimedium pseudowushanense, catalyzes the 7- O -glycosylation of baohuoside
Feng, Keping,Chen, Ridao,Xie, Kebo,Chen, Dawei,Liu, Jimei,Du, Wenyu,Yang, Lin,Dai, Jungui
, p. 8106 - 8114 (2019/09/19)
Icariin (1a), a 7-O-glycosylated flavonoid glycoside, is recognized as the major pharmacologically active ingredient of Epimedium plants, which have been used in traditional Chinese medicine for thousands of years. However, no glycosyltransferase (GT) responsible for the 7-O-glycosylation of flavonoids has been identified from Epimedium plants to date. Herein, a GT, Ep7GT, was identified from E. pseudowushanense B. L. Guo, which can regiospecifically transfer a glucose moiety to baohuoside (1) at 7-OH to form icariin (1a). Ep7GT showed a rare broad donor substrate spectrum, including UDP-glucose, UDP-xylose, UDP-N-acetylglucosamine, UDP-rhamnose, UDP-galactose, UDP-glucuronic acid and TDP-glucose. Moreover, two new derivatives of icariin (1a), 7-O-β-d-[2-(acetylamino)-2-deoxy-glucopyranosyl]-baohuoside (1b) and 7-O-β-d-xylosyl-baohuoside (1c), were biosynthesized by using Ep7GT in vitro. Engineered Escherichia coli harbouring Ep7GT was constructed, and 10.1 μg mL-1 icariin (1a) was yielded by whole-cell biotransformation with baohuoside (1) as the substrate. The present work not only characterizes the GT responsible for the 7-O-glycosylation in the biosynthesis of icariin in Epimedium plants, but also indicates the significant potential of an enzymatic approach for the production of glycosylated baohuoside derivatives with different sugar moieties. What's more, these findings also provide a promising alternative for producing natural/unnatural bioactive flavonoid glycosides by metabolic engineering.
