We studied the polyphenol composition and antioxidant activity of the ethanolic and ethyl acetate extracts of Hypericum connatum (Guttiferae), in addition to their antimicrobial and antiquorum-sensing (AQS) properties. The extracts exhibited a similar polyphenol content and a notable antioxidant activity, which was stronger in the ethanolic extract (EC50=3.2 μg/mL). Ultrahigh-performance liquid chromatography analyses revealed different polyphenol profiles, with rutin and apigen being the main components of the ethanolic extract and caffeic acid, (-)-epicatechin and p-coumaric acid being abundant in the ethyl acetate extract. The ethyl acetate extract exhibited a more effective antimicrobial activity than the ethanolic extract against the pathogens Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Pseudomonas aeruginosa. For the first time, AQS activity was detected in H. connatum: the ethanolic extract inhibited the production of violacein, a quorum-sensing-regulated pigment, in a Chromobacterium violaceum tester strain, without interfering with its growth.

Biochemical Composition, Antimicrobial Activities,and Anti-Quorum-Sensing Activities of Ethanol and Ethyl Acetate Extracts from Hypericum connatumLam. (Guttiferae)

DE FEO, Vincenzo;DE MARTINO, LAURA
2013

Abstract

We studied the polyphenol composition and antioxidant activity of the ethanolic and ethyl acetate extracts of Hypericum connatum (Guttiferae), in addition to their antimicrobial and antiquorum-sensing (AQS) properties. The extracts exhibited a similar polyphenol content and a notable antioxidant activity, which was stronger in the ethanolic extract (EC50=3.2 μg/mL). Ultrahigh-performance liquid chromatography analyses revealed different polyphenol profiles, with rutin and apigen being the main components of the ethanolic extract and caffeic acid, (-)-epicatechin and p-coumaric acid being abundant in the ethyl acetate extract. The ethyl acetate extract exhibited a more effective antimicrobial activity than the ethanolic extract against the pathogens Staphylococcus aureus, Bacillus cereus, Escherichia coli, and Pseudomonas aeruginosa. For the first time, AQS activity was detected in H. connatum: the ethanolic extract inhibited the production of violacein, a quorum-sensing-regulated pigment, in a Chromobacterium violaceum tester strain, without interfering with its growth.
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11386/4239653
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? 7
  • Scopus 28
  • ???jsp.display-item.citation.isi??? 29
social impact