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Relationships between degree of polymerization and antioxidant activities: a study on proanthocyanidins from the leaves of a medicinal mangrove plant Ceriops tagal.

Zhou HC, Tam NF, Lin YM, Ding ZH, Chai WM, Wei SD - PLoS ONE (2014)

Bottom Line: Tannins from the leaves of a medicinal mangrove plant, Ceriops tagal, were purified and fractionated on Sephadex LH-20 columns. 13C nuclear magnetic resonance (13C-NMR), reversed/normal high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDT-TOF MS) analysis showed that the tannins were predominantly B-type procyanidins with minor A-type linkages, galloyl and glucosyl substitutions, and a degree of polymerization (DP) up to 33.Thirteen subfractions of the procyanidins were successfully obtained by a modified fractionation method, and their antioxidant activities were investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity and ferric reducing antioxidant power (FRAP) method.All these subfractions exhibited potent antioxidant activities, and eleven of them showed significantly different mean DP (mDP) ranging from 1.43±0.04 to 31.77±1.15.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen, China; Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR, China; Futian-CityU Mangrove R&D Centre, City University of Hong Kong Shenzhen Research Institute, Shenzhen, China.

ABSTRACT
Tannins from the leaves of a medicinal mangrove plant, Ceriops tagal, were purified and fractionated on Sephadex LH-20 columns. 13C nuclear magnetic resonance (13C-NMR), reversed/normal high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDT-TOF MS) analysis showed that the tannins were predominantly B-type procyanidins with minor A-type linkages, galloyl and glucosyl substitutions, and a degree of polymerization (DP) up to 33. Thirteen subfractions of the procyanidins were successfully obtained by a modified fractionation method, and their antioxidant activities were investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity and ferric reducing antioxidant power (FRAP) method. All these subfractions exhibited potent antioxidant activities, and eleven of them showed significantly different mean DP (mDP) ranging from 1.43±0.04 to 31.77±1.15. Regression analysis demonstrated that antioxidant activities were positively correlative with mDP when around mDP <10, while dropped and then remained at a level similar to mDP = 5 with around 95 µg ml(-1) for DPPH scavenging activity and 4 mmol AAE g(-1) for FRAP value.

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Reflectron mode MALDI-TOF mass spectra for tannin subfraction F4 (a) to F9 (f).Degree of polymerization (DP) of the predominant polymers and largest polymer in each mass spectrum of subfraction are labeled.
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pone-0107606-g003: Reflectron mode MALDI-TOF mass spectra for tannin subfraction F4 (a) to F9 (f).Degree of polymerization (DP) of the predominant polymers and largest polymer in each mass spectrum of subfraction are labeled.

Mentions: For the first step, ten subfractions (F1-F9) were obtained by fractionation on Sephadex LH-20 as described in methods section. After analysis by MALDI-TOF MS, fractions F1-F3 showed a cluster of unresolved peak lower than 500 Da (data not shown), which could be the sugars and other impurities. The spectra obtained by reflectron modes of the seven collected subfractions from fractions F4 (Figure 3a) to F9 (Figure 3f) clearly displayed the distinct predominant polymers and polymer range. The signals of lower oligomers were firstly detected in fraction F4 dominated by dimers (Figure 3a). Fractionation of the lower oligomers that could lead to the saturation of detector can significantly enhance the sensitivity of the detection of large polymers of proanthocyanidins under MALDI-TOF analysis [17]. Therefore, the last subfraction (F9) detected in the present study reached as high as DP19 polymer (Figure 3f), which demonstrated that the fractionation method could improve the detection of high DP polymers compared with the spectra of Fp (Figure 2d), even though it did not completely overcome the discrimination of high molecular weight polymers [17].


Relationships between degree of polymerization and antioxidant activities: a study on proanthocyanidins from the leaves of a medicinal mangrove plant Ceriops tagal.

Zhou HC, Tam NF, Lin YM, Ding ZH, Chai WM, Wei SD - PLoS ONE (2014)

Reflectron mode MALDI-TOF mass spectra for tannin subfraction F4 (a) to F9 (f).Degree of polymerization (DP) of the predominant polymers and largest polymer in each mass spectrum of subfraction are labeled.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4196849&req=5

pone-0107606-g003: Reflectron mode MALDI-TOF mass spectra for tannin subfraction F4 (a) to F9 (f).Degree of polymerization (DP) of the predominant polymers and largest polymer in each mass spectrum of subfraction are labeled.
Mentions: For the first step, ten subfractions (F1-F9) were obtained by fractionation on Sephadex LH-20 as described in methods section. After analysis by MALDI-TOF MS, fractions F1-F3 showed a cluster of unresolved peak lower than 500 Da (data not shown), which could be the sugars and other impurities. The spectra obtained by reflectron modes of the seven collected subfractions from fractions F4 (Figure 3a) to F9 (Figure 3f) clearly displayed the distinct predominant polymers and polymer range. The signals of lower oligomers were firstly detected in fraction F4 dominated by dimers (Figure 3a). Fractionation of the lower oligomers that could lead to the saturation of detector can significantly enhance the sensitivity of the detection of large polymers of proanthocyanidins under MALDI-TOF analysis [17]. Therefore, the last subfraction (F9) detected in the present study reached as high as DP19 polymer (Figure 3f), which demonstrated that the fractionation method could improve the detection of high DP polymers compared with the spectra of Fp (Figure 2d), even though it did not completely overcome the discrimination of high molecular weight polymers [17].

Bottom Line: Tannins from the leaves of a medicinal mangrove plant, Ceriops tagal, were purified and fractionated on Sephadex LH-20 columns. 13C nuclear magnetic resonance (13C-NMR), reversed/normal high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDT-TOF MS) analysis showed that the tannins were predominantly B-type procyanidins with minor A-type linkages, galloyl and glucosyl substitutions, and a degree of polymerization (DP) up to 33.Thirteen subfractions of the procyanidins were successfully obtained by a modified fractionation method, and their antioxidant activities were investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity and ferric reducing antioxidant power (FRAP) method.All these subfractions exhibited potent antioxidant activities, and eleven of them showed significantly different mean DP (mDP) ranging from 1.43±0.04 to 31.77±1.15.

View Article: PubMed Central - PubMed

Affiliation: Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystems, Xiamen University, Xiamen, China; Department of Biology and Chemistry, City University of Hong Kong, Hong Kong SAR, China; Futian-CityU Mangrove R&D Centre, City University of Hong Kong Shenzhen Research Institute, Shenzhen, China.

ABSTRACT
Tannins from the leaves of a medicinal mangrove plant, Ceriops tagal, were purified and fractionated on Sephadex LH-20 columns. 13C nuclear magnetic resonance (13C-NMR), reversed/normal high performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI MS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDT-TOF MS) analysis showed that the tannins were predominantly B-type procyanidins with minor A-type linkages, galloyl and glucosyl substitutions, and a degree of polymerization (DP) up to 33. Thirteen subfractions of the procyanidins were successfully obtained by a modified fractionation method, and their antioxidant activities were investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity and ferric reducing antioxidant power (FRAP) method. All these subfractions exhibited potent antioxidant activities, and eleven of them showed significantly different mean DP (mDP) ranging from 1.43±0.04 to 31.77±1.15. Regression analysis demonstrated that antioxidant activities were positively correlative with mDP when around mDP <10, while dropped and then remained at a level similar to mDP = 5 with around 95 µg ml(-1) for DPPH scavenging activity and 4 mmol AAE g(-1) for FRAP value.

Show MeSH
Related in: MedlinePlus