- Prenylated flavonoids with potential antimicrobial activity: Synthesis, biological activity, and in silico study
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Prenylated flavonoids are an important class of naturally occurring flavonoids with important biological activity, but their low abundance in nature limits their application in medicines. Here, we showed the hemisynthesis and the determination of various biological activities of seven prenylated flavonoids, named 7–13, with an emphasis on antimicrobial ones. Compounds 9, 11, and 12 showed inhibitory activity against human pathogenic fungi. Compounds 11, 12 (flavanones) and 13 (isoflavone) were the most active against clinical isolated Staphylococcus aureus MRSA, showing that structural requirements as prenylation at position C-6 or C-8 and OH at positions C-5, 7, and 4′ are key to the antibacterial activity. The combination of 11 or 12 with commercial antibiotics synergistically enhanced the antibacterial activity of vancomycin, ciprofloxacin, and methicillin in a factor of 10 to 100 times against drug-resistant bacteria. Compound 11 combined with ciprofloxacin was able to decrease the levels of ROS generated by ciprofloxacin. According to docking results of S enantiomer of 11 with ATP-binding cassette transporter showed the most favorable binding energy; however, more studies are needed to support this result.
- Osorio, Mauricio,Carvajal, Marcela,Vergara, Alejandra,Butassi, Estefania,Zacchino, Susana,Mascayano, Carolina,Montoya, Margarita,Mejías, Sophia,Martín, Marcelo Cortez-San,Vásquez-Martínez, Yesseny
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- GuA6DT, a regiospecific prenyltransferase from glycyrrhiza uralensis, catalyzes the 6-prenylation of flavones
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GuA6DT, a flavonoid prenyltransferase, was identified from Glycyrrhiza uralensis, and it was found that this enzyme regiospecifically transfers a dimethylallyl moiety to apigenin at the C-6 position. A further substrate specificity investigation indicated that the existence of hydroxyls at both the C-5 and C-7 positions of the flavone skeleton is critical for the prenylation. However, substitutions on the B-ring had negligible influence on the prenylation. A comparison of GuA6DT expression in different organs revealed that mRNA is mainly expressed in the aerial parts. Moreover, the GuA6DT mRNA was found to be regulated at the transcriptional level, because methyl jasmonate induced upregulation in cultured cells. GuA6DT is the first identified flavone prenyltransferase to exhibit strict substrate specificity and regiospecificity.
- Li, Jianhua,Chen, Ridao,Wang, Ruishan,Liu, Xiao,Xie, Dan,Zou, Jianhua,Dai, Jungui
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p. 1673 - 1681
(2014/08/05)
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- C-isoprenylation of flavonoids enhances binding affinity toward P-glycoprotein and modulation of cancer cell chemoresistance
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Previous studies have shown that flavones bind to P-glycoprotein (Pgp) with higher affinity than isoflavones, flavanones, and glycosylated derivatives. In the present work, a series of C- or O-substituted hydrophobic derivatives of chrysin were synthesized to further investigate structural requirements of the A ring toward Pgp modulation. Increasing hydrophobicity at either position 6, 8, or 7 increased the affinity of in vitro binding to a purified cytosolic domain of Pgp, but only benzyl and 3,3-dimethylallyl C-substitution produced a high maximal quenching of the protein intrinsic fluorescence. Inhibition of membrane Pgp within leukemic cells, characterized by intracellular drug accumulation, was specifically produced by isoprenylated derivatives, with 8-(3,3-dimethylallyl)chrysin being even more efficient than the commonly used cyclosporin A.
- Comte,Daskiewicz,Bayet,Conseil,Viornery-Vanier,Dumontet,Di Pietro,Barron
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p. 763 - 768
(2007/10/03)
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- Mechanism on one-sided Wessely-Moser rearrangement reaction
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Wessely-Moser rearrangement reaction of 5,7-dihydroxychromone derivatives with an isopentyl side chain at C-6 or C-8 position was examined. All reactions gave 8-isopentylchromone derivative predominantly as rearrangement product. Kinetic analysis of the o
- Shinomiya, Kazuki,Hano, Yoshio,Nomura, Taro
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p. 877 - 886
(2007/10/03)
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