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NMR, ESI/MS, and MALDI-TOF/MS analysis of pear juice polymeric proanthocyanidins with potent free radical scavenging activity.
J Agric Food Chem. 2006 Sep 20; 54(19):6969-77.JA

Abstract

The structure of a polymeric proanthocyanidin fraction isolated from pear juice was characterized by NMR, ESI/MS, and MALDI-TOF/MS analyses, and its antioxidant activity was investigated using the DPPH free radical scavenging method. The results obtained from 13C NMR analysis showed the predominance of signals representative of procyanidins. Typical signals in the chemical shift region between 70 and 90 ppm demonstrated the exclusive presence of epicatechin units. The results obtained through negative ESI/MS analysis showed singly and doubly charged ions corresponding to the molecular mass of procyanidins with a degree of polymerization up to 22. The spectra obtained through MALDI-TOF/MS analysis revealed the presence of two series of tannin oligomers. Supporting the observations from NMR spectroscopy, the first series consists of well-resolved tannin identified as procyanidin polymers units with chain lengths of up to 25. A second series of monogalloyl flavan-3-ols polymers with polymerization degree up to 25 were also detected. This is the first mass spectrometric evidence confirming the existence of galloylated procyanidin oligomers in pear fruits. Within each of these oligomers, various signals exist suggesting the presence of several oligomeric tannins. The antioxidant properties of the polymeric fraction were investigated through reduction of the DPPH free radical, and the results obtained showed that the polymeric fraction exhibited a higher antioxidant power compared to those of (+)-catechin and B3 procyanidin dimer.

Authors+Show Affiliations

Unité de Phytopharmacie et Médiateurs Chimiques, INRA, Route de Saint-Cyr, 78026 Versailles Cedex, France. nouressafi@yahoo.frNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

16968050

Citation

Es-Safi, Nour-Eddine, et al. "NMR, ESI/MS, and MALDI-TOF/MS Analysis of Pear Juice Polymeric Proanthocyanidins With Potent Free Radical Scavenging Activity." Journal of Agricultural and Food Chemistry, vol. 54, no. 19, 2006, pp. 6969-77.
Es-Safi NE, Guyot S, Ducrot PH. NMR, ESI/MS, and MALDI-TOF/MS analysis of pear juice polymeric proanthocyanidins with potent free radical scavenging activity. J Agric Food Chem. 2006;54(19):6969-77.
Es-Safi, N. E., Guyot, S., & Ducrot, P. H. (2006). NMR, ESI/MS, and MALDI-TOF/MS analysis of pear juice polymeric proanthocyanidins with potent free radical scavenging activity. Journal of Agricultural and Food Chemistry, 54(19), 6969-77.
Es-Safi NE, Guyot S, Ducrot PH. NMR, ESI/MS, and MALDI-TOF/MS Analysis of Pear Juice Polymeric Proanthocyanidins With Potent Free Radical Scavenging Activity. J Agric Food Chem. 2006 Sep 20;54(19):6969-77. PubMed PMID: 16968050.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - NMR, ESI/MS, and MALDI-TOF/MS analysis of pear juice polymeric proanthocyanidins with potent free radical scavenging activity. AU - Es-Safi,Nour-Eddine, AU - Guyot,Sylvain, AU - Ducrot,Paul-Henri, PY - 2006/9/14/pubmed PY - 2006/11/3/medline PY - 2006/9/14/entrez SP - 6969 EP - 77 JF - Journal of agricultural and food chemistry JO - J. Agric. Food Chem. VL - 54 IS - 19 N2 - The structure of a polymeric proanthocyanidin fraction isolated from pear juice was characterized by NMR, ESI/MS, and MALDI-TOF/MS analyses, and its antioxidant activity was investigated using the DPPH free radical scavenging method. The results obtained from 13C NMR analysis showed the predominance of signals representative of procyanidins. Typical signals in the chemical shift region between 70 and 90 ppm demonstrated the exclusive presence of epicatechin units. The results obtained through negative ESI/MS analysis showed singly and doubly charged ions corresponding to the molecular mass of procyanidins with a degree of polymerization up to 22. The spectra obtained through MALDI-TOF/MS analysis revealed the presence of two series of tannin oligomers. Supporting the observations from NMR spectroscopy, the first series consists of well-resolved tannin identified as procyanidin polymers units with chain lengths of up to 25. A second series of monogalloyl flavan-3-ols polymers with polymerization degree up to 25 were also detected. This is the first mass spectrometric evidence confirming the existence of galloylated procyanidin oligomers in pear fruits. Within each of these oligomers, various signals exist suggesting the presence of several oligomeric tannins. The antioxidant properties of the polymeric fraction were investigated through reduction of the DPPH free radical, and the results obtained showed that the polymeric fraction exhibited a higher antioxidant power compared to those of (+)-catechin and B3 procyanidin dimer. SN - 0021-8561 UR - https://www.unboundmedicine.com/medline/citation/16968050/NMR_ESI/MS_and_MALDI_TOF/MS_analysis_of_pear_juice_polymeric_proanthocyanidins_with_potent_free_radical_scavenging_activity_ L2 - https://dx.doi.org/10.1021/jf061090f DB - PRIME DP - Unbound Medicine ER -