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.
Highly Promiscuous Flavonoid 3- O-Glycosyltransferase from Scutellaria baicalensis
Wang, Zilong,Wang, Shuang,Xu, Zheng,Li, Mingwei,Chen, Kuan,Zhang, Yaqun,Hu, Zhimin,Zhang, Meng,Zhang, Zhiyong,Qiao, Xue,Ye, Min
supporting information, p. 2241 - 2245 (2019/03/19)
A highly regio-specific and donor-promiscuous 3-O-glycosyltransferase, Sb3GT1 (UGT78B4), was discovered from Scutellaria baicalensis. Sb3GT1 could accept five sugar donors (UDP-Glc/-Gal/-GlcNAc/-Xyl/-Ara) to catalyze 3-O-glycosylation of 17 flavonols, and the conversion rates could be >98%. Five new glycosides were obtained by scaled-up enzymatic catalysis. Molecular modeling and site-directed mutagenesis revealed that G15 and P187 were critical catalytic residues for the donor promiscuity. Sb3GT1 could be a promising catalyst to increase structural diversity of flavonoid 3-O-glycosides.