65549-68-0Relevant academic research and scientific papers
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.
Efficient Synthesis of Crocins from Crocetin by a Microbial Glycosyltransferase from Bacillus subtilis 168
Ding, Fangyu,Liu, Feng,Shao, Wenming,Chu, Jianlin,Wu, Bin,He, Bingfang
, p. 11701 - 11708 (2018/11/21)
Crocins are the most important active ingredient found in Crocus sativus, a well-known "plant gold". The glycosyltransferase-catalyzed glycosylation of crocetin is the last step of biosynthesizing crocins and contributes to their structural diversity. Crocin biosynthesis is now hampered by the lack of efficient glycosyltransferases with activity toward crocetin. In this study, two microbial glycosyltransferases (Bs-GT and Bc-GTA) were successfully mined based on the comprehensive analysis of the PSPG motif and the N-terminal motif of the target plant-derived UGT75L6 and Cs-GT2. Bs-GT from Bacillus subtilis 168, an enzyme with a higher activity of glycosylation toward crocetin than that of Bc-GTA, was characterized. The efficient synthesis of crocins from crocetin catalyzed by microbial GT (Bs-GT) was first reported with a high molecular conversion rate of 81.9%, resulting in the production of 476.8 mg/L of crocins. The glycosylation of crocetin on its carboxyl groups by Bs-GT specifically produced crocin-5 and crocin-3, the important rare crocins.
Molecular cloning and biochemical characterization of two UDP-glycosyltransferases from poplar
Veljanovski, Vasko,Constabel, C. Peter
, p. 148 - 157 (2013/07/27)
Two pathogen-induced uridine diphosphate glycosyltransferases (UGTs) identified previously via co-expression with induced proanthocyanidin (PA) synthesis in poplar were cloned and characterized. Phylogenetic analysis grouped both genes with other known flavonoid UGTs that act on flavonols and anthocyanins. Recombinant enzymes were produced in order to test if they could glycoslate flavonoids. PtUGT78L1 accepted the flavonols quercetin and kaempferol as well as cyanidin, and used UDP-galactose as a sugar donor. PtUGT78M1 did not accept any of the flavonoids tested as a substrate, but did transfer glucose from UDP-glucose to the universal substrate 2,4,6-trichlorophenol. However, neither enzyme acted on the flavan-3-ols catechin or epicatechin, intermediates in the PA biosynthetic pathway.
Functional characterization of a UDP-glucose:flavonoid 3-O- glucosyltransferase from the seed coat of black soybean (Glycine max (L.) Merr.)
Kovinich, Nik,Saleem, Ammar,Arnason, John T.,Miki, Brian
experimental part, p. 1253 - 1263 (2011/04/22)
The seed coats of black soybean (Glycine max (L.) Merr.) accumulate red (cyanidin-), blue (delphinidin-), purple (petunidin-), and orange (pelargonidin-based) anthocyanins almost exclusively as 3-O-glucosides; however, the responsible enzyme has not been identified. In this study, the full-length cDNA which encodes the enzyme that catalyzes the final step in anthocyanin biosynthesis, namely UDP-glucose:flavonoid 3-O-glucosyltransferase (UGT78K1), was isolated from the seed coat tissue of black soybean using rapid amplification of cDNA ends (RACE). Of the 28 flavonoid substrates tested, the purified recombinant protein glucosylated only anthocyanidins and flavonols, and demonstrated strict 3-OH regiospecificity. Galactose could also be transferred with relatively low activity to the 3-position of cyanidin or delphinidin in vitro. These findings are consistent with previous reports of mainly 3-O-glucosylated and minor amounts of 3-O-galactosylated anthocyanins in the seed coat of black soybean. The recombinant enzyme exhibited pronounced substrate inhibition by cyanidin at 100 μM acceptor concentration. Transfer of UGT78K1 into the Arabidopsis T-DNA mutant (ugt78d2) deficient in anthocyanidin and flavonol 3-O-glucosyltransferase activity, restored the accumulation of anthocyanins and flavonols, suggesting the in vivo function of the enzyme as a flavonoid 3-O-glucosyltransferase. Genomic and phylogenetic analyses suggest the existence of three additional soybean sequences with high similarity to UGT78K1. RT-PCR confirmed the co-expression of one of these genes (Glyma08g07130) with UGT78K1 in the seed coat of black soybean, suggesting possible functional redundancies in anthocyanin biosynthesis in this tissue.
Cloning and functional characterisation of two regioselective flavonoid glucosyltransferases from Beta vulgaris
Isayenkova, Judith,Wray, Victor,Nimtz, Manfred,Strack, Dieter,Vogt, Thomas
, p. 1598 - 1612 (2008/02/12)
Two full-length cDNAs encoding flavonoid-specific glucosyltransferases, UGT73A4 and UGT71F1, were isolated from a cDNA library of Beta vulgaris (Amaranthaceae) cell suspension cultures. They displayed high identity to position-specific betanidin and flavonoid glucosyltransferases from Dorotheanthus bellidiformis (Aizoaceae) and to enzymes with similar substrate specificities from various plant families. The open reading frame of the sequences encode proteins of 476 (UGT73A4) and 492 (UGT71F1) amino acids with calculated molecular masses of 54.07 kDa and 54.39 kDa, and isoelectric points of 5.8 and 5.6, respectively. Both enzymes were functionally expressed in Escherichia coli as His- and GST-tagged proteins, respectively. They exhibited a broad substrate specificity, but a distinct regioselectivity, glucosylating a variety of flavonols, flavones, flavanones, and coumarins. UGT73A4 showed a preference for the 4′- and 7-OH position in the flavonoids, whereas UGT71F1 preferentially glucosylated the 3- or the 7-OH position. Glucosylation of betanidin, the aglycone of the major betacyanin, betanin, in B. vulgaris was also observed to a low extent by both enzymes. Several O-glycosylated vitexin derivatives isolated from leaves of young B. vulgaris plants and rutin obtained from B. vulgaris tissue culture are discussed as potential endogenous products of UGT73A4 and UGT71F1. The results are analyzed with regard to evolution and specificity of plant natural product glucosyltransferases.
