Molecular Aspects of Tannin-Anthelmintic Interactions as Revealed by NMR Spectroscopy
: Sillanpää, Mimosa; Tähtinen, Petri; Karonen, Maarit
Publisher: American Chemical Society
: WASHINGTON
: 2025
: ACS Omega
: ACS Omega
: ACS OMEGA
: 10
: 29
: 32174
: 32188
: 15
: 2470-1343
: 2470-1343
DOI: https://doi.org/10.1021/acsomega.5c03937
: https://doi.org/10.1021/acsomega.5c03937
: https://research.utu.fi/converis/portal/detail/Publication/499246888
The interactions between plant polyphenols and commercial anthelmintics remain largely unexplored, despite the benefits of understanding these interactions for mitigating anthelmintic resistance. This study investigated the interactions of flavan-3-ols, dimeric proanthocyanidins, and selected hydrolyzable tannins with two anthelmintics, ivermectin (IVM) and thiabendazole (TBZ), at various polyphenol to anthelmintic molar ratios using nuclear magnetic resonance (NMR) spectroscopy. Chemical shift changes (Delta delta s), indicating interaction, were observed for specific regions of the compounds and at all polyphenol to anthelmintic molar ratios. For IVM interactions with polyphenols, downfield Delta delta s were observed and were primarily associated with hydroxyl groups within the structures of the anthelmintic and polyphenols, suggesting that the interactions involved hydrogen bond formation. For TBZ interactions with polyphenols, however, both upfield and downfield Delta delta s were observed, suggesting that both hydrogen bonding and hydrophobic interactions were involved. All of the studied polyphenols interacted more strongly with TBZ than with IVM.
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Members of the Natural Chemistry Research Group are thanked for LC-MS instrument maintenance and general discussion. Turku Centre for Chemical and Molecular Analytics is acknowledged for the maintenance of the NMR instruments and for their technical support. This research was funded by the Research Council of Finland (LipidET project, decision 310549), Doctoral Programme in Physical and Chemical Sciences (PCS), Doctoral Programme in Exact Sciences (EXACTUS), University of Turku Joint Research Grant Fund, The Finnish Concordia Fund, Orion Research Foundation, and TOP Foundation.
