Interactions of galloylated polyphenols with a simple gram-negative bacterial membrane lipid model

Coones, R. T. ORCID: https://orcid.org/0000-0001-6651-4707, Karonen, M. ORCID: https://orcid.org/0000-0002-9964-6527, Green, R. J. ORCID: https://orcid.org/0000-0001-6783-549X and Frazier, R. ORCID: https://orcid.org/0000-0003-4313-0019 (2024) Interactions of galloylated polyphenols with a simple gram-negative bacterial membrane lipid model. Membranes, 14 (2). 47. ISSN 2077-0375 doi: 10.3390/membranes14020047

Abstract/Summary

Differential scanning calorimetry (DSC) was used to explore the interactions of isolated polyphenolic compounds, including (-)-epigallocatechin gallate ((-)-EGCg), tellimagrandins I and II (Tel-I and Tel-II), and 1,2,3,4,6-penta-O-galloyl-D-glucose (PGG), with a model Gram-negative bacterial membrane with a view to investigating their antimicrobial properties. The model membranes comprised 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (DPPE) and 1,2-dipalmitoyl-sn-glycero-3-phospho-(1’-rac-glycerol) (DPPG), fabricated to mimic the domain formation observed in natural membranes, as well as ideally mixed lipid vesicles for the interaction with (-)-EGCg. Polyphenols induced changes in lipid mixing/de-mixing depending on the method of vesicle preparation, as was clearly evidenced by alterations in the lipid transition temperatures. There was a distinct affinity of the polyphenols for the DPPG lipid component, which was attributed to the electrostatic interactions between the polyphenolic galloyl moieties and the lipid headgroups. These interactions were found to operate through either the stabilization of the lipid headgroups by the polyphenols or the insertion of the polyphenols into the membrane itself. Structural attributes of the polyphenols, including the number of galloyl groups, the hydrophobicity quantified by partition coefficients (logP), and structural flexibility, exhibited a correlation with the temperature transitions observed in the DSC measurements. This study furthers our understanding of the intricate interplay between the structural features of polyphenolic compounds and their interactions with model bacterial membrane vesicles towards the exploitation of polyphenols as antimicrobials.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/115159
Identification Number/DOI	10.3390/membranes14020047
Refereed	Yes
Divisions	Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Thermal Analysis (CAF) Life Sciences > School of Chemistry, Food and Pharmacy > School of Pharmacy > Pharmaceutics Research Group Life Sciences > School of Chemistry, Food and Pharmacy > Department of Food and Nutritional Sciences > Food Research Group
Publisher	MDPI
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