A spectroscopic and quantum chemical calculation method for the characterisation of metal ions complexed with propyl gallate and procyanidins
Abstract The deprotonation mechanism for the phenolic hydroxyl and the complexing of metal ions with a commonly used food additive, propyl gallate (PG) were studied theoretically and experimentally. The interaction of procyanidins [PC, epicatechin16 (4 → 8) catechin], and its basic monomeric unit ca...
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| Format: | Article |
| Language: | English |
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Nature Portfolio
2023-02-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-023-30186-x |
| _version_ | 1827984138051780608 |
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| author | Liangliang Zhang Qinhao Guan He Zhang Lihua Tang Man Xu |
| author_facet | Liangliang Zhang Qinhao Guan He Zhang Lihua Tang Man Xu |
| author_sort | Liangliang Zhang |
| collection | DOAJ |
| description | Abstract The deprotonation mechanism for the phenolic hydroxyl and the complexing of metal ions with a commonly used food additive, propyl gallate (PG) were studied theoretically and experimentally. The interaction of procyanidins [PC, epicatechin16 (4 → 8) catechin], and its basic monomeric unit catechin (CA) with metal ions was studied by the fluorescence quenching spectra. The results showed that the 9-OH quinoid PG was formed at higher pH (10.9) by the oxidization of phenolic hydroxyl. The binding affinities (K a) and stoichiometry of these metal ions with PG were determined. The Al3+ in PG-Al complex [Al(PG)(H2O)2Cl2]- was coordinated at the 8,9-OH doubly deprotonated catechol site with double chloride ions (Cl-) and double water molecules (H2O). The fluorescence quenching titration with Sn2+, Zn2+, Cu2+, Al3+ and Fe3+ revealed that the stoichiometries of metal-bound PC were 1:1, 2:3, 2:3, 2:3 and 1:1, respectively. The presence of bovine serum albumin (BSA) could enhance the complexing strength of PC with metal ions. |
| first_indexed | 2024-04-09T22:56:12Z |
| format | Article |
| id | doaj.art-77cd960951b943c0a28a259ae20d3d5d |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-04-09T22:56:12Z |
| publishDate | 2023-02-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-77cd960951b943c0a28a259ae20d3d5d2023-03-22T11:14:47ZengNature PortfolioScientific Reports2045-23222023-02-0113111310.1038/s41598-023-30186-xA spectroscopic and quantum chemical calculation method for the characterisation of metal ions complexed with propyl gallate and procyanidinsLiangliang Zhang0Qinhao Guan1He Zhang2Lihua Tang3Man Xu4Academy of Advanced Carbon Conversion Technology, Huaqiao UniversityInstitute of Chemical Industry of Forest Products, CAFInstitute of Biomedical Health Technology and Engineering, Shenzhen Bay LaboratoryInstitute of Chemical Industry of Forest Products, CAFInstitute of Chemical Industry of Forest Products, CAFAbstract The deprotonation mechanism for the phenolic hydroxyl and the complexing of metal ions with a commonly used food additive, propyl gallate (PG) were studied theoretically and experimentally. The interaction of procyanidins [PC, epicatechin16 (4 → 8) catechin], and its basic monomeric unit catechin (CA) with metal ions was studied by the fluorescence quenching spectra. The results showed that the 9-OH quinoid PG was formed at higher pH (10.9) by the oxidization of phenolic hydroxyl. The binding affinities (K a) and stoichiometry of these metal ions with PG were determined. The Al3+ in PG-Al complex [Al(PG)(H2O)2Cl2]- was coordinated at the 8,9-OH doubly deprotonated catechol site with double chloride ions (Cl-) and double water molecules (H2O). The fluorescence quenching titration with Sn2+, Zn2+, Cu2+, Al3+ and Fe3+ revealed that the stoichiometries of metal-bound PC were 1:1, 2:3, 2:3, 2:3 and 1:1, respectively. The presence of bovine serum albumin (BSA) could enhance the complexing strength of PC with metal ions.https://doi.org/10.1038/s41598-023-30186-x |
| spellingShingle | Liangliang Zhang Qinhao Guan He Zhang Lihua Tang Man Xu A spectroscopic and quantum chemical calculation method for the characterisation of metal ions complexed with propyl gallate and procyanidins Scientific Reports |
| title | A spectroscopic and quantum chemical calculation method for the characterisation of metal ions complexed with propyl gallate and procyanidins |
| title_full | A spectroscopic and quantum chemical calculation method for the characterisation of metal ions complexed with propyl gallate and procyanidins |
| title_fullStr | A spectroscopic and quantum chemical calculation method for the characterisation of metal ions complexed with propyl gallate and procyanidins |
| title_full_unstemmed | A spectroscopic and quantum chemical calculation method for the characterisation of metal ions complexed with propyl gallate and procyanidins |
| title_short | A spectroscopic and quantum chemical calculation method for the characterisation of metal ions complexed with propyl gallate and procyanidins |
| title_sort | spectroscopic and quantum chemical calculation method for the characterisation of metal ions complexed with propyl gallate and procyanidins |
| url | https://doi.org/10.1038/s41598-023-30186-x |
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