Total synthesis of apigenin 7,4′-di-O-β-glucopyranoside, a component of blue flower pigment of Salvia patens, and seven chiral analogues
摘要:
We have succeeded in the first total synthesis of apigenin 7,4'-di-O-beta-D-glucopyranoside (1a), a component of blue pigment, protodelphin, from naringenin (2). Glycosylation of 2 according to Koenigs-Knorr reaction provided a monoglucoside 4a in 80% yield, and this was followed by DDQ oxidation to give apigenin 7-O-glucoside (12a). Further glycosylation of 4'-OH of 12a with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl fluoride (5a) was achieved using a Lewis acid-and-base promotion system (BF3.Et2O, 2,6-di-tert-butyl-4-methylpyridine, and 1,1,3,3-tetramethylguanidine) in 70% yield, and subsequent deprotection produced 1a. Synthesis of three other chiral isomers of 1a, with replacement Of D-glucose at 7 and/or 4'-OH by L-glucose (1b-d), and four chiral isomers of apigenin 7-O-beta-glucosides (6a,b) and 4'-O-beta-glucosides (7a,b) also proved possible. (C) 2004 Elsevier Ltd. All rights reserved.
Exploring the aglycon promiscuity of a new glycosyltransferase from Pueraria lobata
作者:Lili Sun、Dawei Chen、Ridao Chen、Kebo Xie、Jimei Liu、Lin Yang、Jungui Dai
DOI:10.1016/j.tetlet.2016.02.088
日期:2016.3
Enzymatic glycosylation catalyzed by glycosyltransferases has great potential for creating bioactive glycosylated small-molecule compounds. Here, we highlight the aglyconpromiscuity of a new glycosyltransferase (PlGT7) from Pueraria lobata. PlGT7 exhibited the capability to glycosylate 26 structurally diverse drug-like scaffolds and simple phenolics with UDP-glucose to form O-, S-, and N-glycosides
Functional Characterization and Protein Engineering of a Triterpene 3‐/6‐/2′‐
<i>O</i>
‐Glycosyltransferase Reveal a Conserved Residue Critical for the Regiospecificity
We characterized the first plant cycloartane glycosyltransferase AmGT8 from A. membranaceus. Its mutants A394F, A394D, and T131V were discovered using semi-rational design, which showed specific 6-O, 3-O, and 2′-O glycosylation activities, respectively. This study uncovered a conservedresiduecritical for the regiospecificity of plant glycosyltransferases.
Extract of the aerial parts of Lawsonia inermis and its preparation method
申请人:PIERRE FABRE DERMO-COSMETIQUE
公开号:US11207265B2
公开(公告)日:2021-12-28
The invention relates to an extract of the aerial parts of Lawsonia inermis, as well as its preparation method and the extract that can be obtained by said method. The invention also relates to a cosmetic dye composition comprising such an extract. The invention finally concerns a cosmetic method for dying keratin fibers comprising the application of such a composition.
The chirality of the sugar moiety is responsible for the chiral molecular recognition on formation of a metalloanthocyanin from Salvia patens. This mechanism was revealed by using the synthetic apigenin 7,4'-diglucosides derived from D- or L-glucose. The supermolecule consists of six malonylawobanin molecules (blue) coordinated to two Mg2+ ions (red) with an M-helical arrangement of six 7,4'-diglucoside molecules (yellow) intercalated.
LITVINENKO, V. I.;BUBENCHIKOVA, V. N., XIMIYA PRIROD. SOED.,(1988) N, S. 792-795