An efficient synthesis of the phytoestrogen 8-prenylnaringenin from isoxanthohumol with magnesium iodide etherate

Abstract:The objective of this study was to evaluate the antimicrobial activity of structural analogues of xanthohumol 1, a flavonoid compound found in hops (Humulus lupulus). The agar-diffusion method using filter paper disks was applied. Biological tests performed for selected strains of Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria, fungi (Alternaria sp.), and yeasts (Rhodotorula rubra, Candida albicans) revealed that compounds with at least one hydroxyl group-all of them have it at the C-4 position-demonstrated good activity. Our research showed that the strain S. aureus was more sensitive to chalcones than to the isomers in which the heterocyclic ring C is closed (flavanones). The strain R. rubra was moderately sensitive to only one compound: 4-hydroxy-4'-methoxychalcone 8. Loss of the hydroxyl group in the B-ring of 4'-methoxychalcones or its replacement by a halogen atom (´Cl,´Br), nitro group (´NO 2 ), ethoxy group (´OCH 2 CH 3 ), or aliphatic substituent (´CH 3 ,´CH 2 CH 3 ) resulted in the loss of antimicrobial activity towards both R. rubra yeast and S. aureus bacteria. Xanthohumol 1, naringenin 5, and chalconaringenin 7 inhibited growth of S. aureus, whereas 4-hydroxy-4 1 -methoxychalcone 8 was active towards two strains: S. aureus and R. rubra.

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“…Xanthohumol was obtained according to the method described earlier [36]. Spectral data of 1 were consistent with the literature [35].…”

Section: Xanthohumol and Chalconaringeninmentioning

confidence: 56%

Antimicrobial Activity of Xanthohumol and Its Selected Structural Analogues

Stompor

Żarowska

2016

Molecules

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“…Flavonoids used in these studies were previously isolated from spent hops, or synthesized. Methods of obtaining these compounds and their spectroscopic data are described in earlier publications [ 32 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. Xanthohumol ( 1 ) was isolated from spent hops according to the procedure described by Tronina et al [ 37 ].…”

Section: Methodsmentioning

confidence: 99%

Antimicrobial Properties of Spent Hops Extracts, Flavonoids Isolated Therefrom, and Their Derivatives

et al. 2018

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Hop cones preparations possess a wide range of biological activities including antimicrobial properties. In this work, we evaluated the effect of various organic extracts obtained from spent hops, as well as six hops flavonoids and their twenty natural and synthetic derivatives on human and plant microbial pathogens. Methylene chloride, acetone, ethyl acetate, and methanol were used as extractants. Seven flavonoids, among them two natural (α,β-dihydroxanthohumol and 8-prenylnaringenin) showed significant activity against methicillin sensitive and resistant Staphylococcus aureus and Staphylococcus epidermidis strains with the lowest MIC80 value of 0.5 µg/mL. The crude ethyl acetate, acetone, and methanol extracts from the spent hops exhibited antifungal activity against Fusarium oxysporum, F. culmorum, and F. semitectum with the lowest MIC50 of 0.5 mg/mL, while the methylene chloride extract exerted antifungal activity against Botrytis cinerea with the MIC50 of 1 mg/mL. The preparation obtained after the removal of xanthohumol from the spent hops crude extracts retained up to 95% of activity. These findings suggest that various spent hops extracts may be effective agents for the control of plant pathogens of economic importance, like Botrytis cinerea and Fusarium oxysporum, while some compounds from spent hops or their derivatives may become useful for staphylococcal infections.

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“…The experiments on the biotransformation of 8-prenylnaringenin were conducted in a Sabouraud medium. Anioł et al (2008), The purifi cation of 1 was as described by Bartmańska et al (2010).…”

Section: Generalmentioning

confidence: 99%