Antioxidant Properties and Hyphenated HPLC-PDA-MS Profiling of Chilean Pica Mango Fruits (Mangifera indica L. Cv. piqueño) - PDF

Description
Molecules 2014, 19, ; doi: /molecules Article OPEN ACCESS molecules ISSN Antioxidant Properties and Hyphenated HPLC-PDA-MS Profiling of Chilean

Please download to get full document.

View again

of 21
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Information
Category:

Music

Publish on:

Views: 8 | Pages: 21

Extension: PDF | Download: 0

Share
Transcript
Molecules 2014, 19, ; doi: /molecules Article OPEN ACCESS molecules ISSN Antioxidant Properties and Hyphenated HPLC-PDA-MS Profiling of Chilean Pica Mango Fruits (Mangifera indica L. Cv. piqueño) Javier E. Ramirez 1, Ricardo Zambrano 1, Beatriz Sepúlveda 2 and Mario J. Simirgiotis 1, * 1 2 Laboratorio de Productos Naturales, Facultad de Ciencias Básicas, Universidad de Antofagasta, Avenida Universidad de Antofagasta 02800, Antofagasta , Chile; s: (J.E.R.); (R.Z.) Departamento de Ciencias Químicas, Universidad Andrés Bello, Campus Viña del Mar, Los Fresnos N 52, Viña del Mar , Chile; * Author to whom correspondence should be addressed; Tel.: ; Fax: Received: 12 November 2013; in revised form: 22 December 2013 / Accepted: 23 December 2013 / Published: 31 December 2013 Abstract: Antioxidant capacities and polyphenolic contents of two mango cultivars from northern Chile, one of them endemic of an oasis in the Atacama Desert, were compared for the first time. Twenty one phenolic compounds were detected in peel and pulp of mango fruits varieties Pica and Tommy Atkins by HPLC-PDA-MS and tentatively characterized. Eighteen compounds were present in Pica pulp (ppu), 13 in Pica peel (ppe) 11 in Tommy Atkins pulp (tpu) and 12 in Tommy Atkins peel (tpe). Three procyanidin dimers (peaks 6, 9 and 10), seven acid derivatives (peaks 1 4, 11, 20 and 21) and four xanthones were identified, mainly mangiferin (peak 12) and mangiferin gallate, (peak 7), which were present in both peel and pulp of the two studied species from northern Chile. Homomangiferin (peak 13) was also present in both fruit pulps and dimethylmangiferin (peak 14) was present only in Tommy pulp. Pica fruits showed better antioxidant capacities and higher polyphenolic content (73.76/32.23 µg/ml in the DPPH assay and 32.49/72.01 mg GAE/100 g fresh material in the TPC assay, for edible pulp and peel, respectively) than Tommy Atkins fruits (127.22/46.39 µg/ml in the DPPH assay and 25.03/72.01 mg GAE/100 g fresh material in the TPC assay for pulp and peel, respectively). The peel of Pica mangoes showed also the highest content of phenolics (66.02 mg/100 g FW) measured by HPLC-PDA. The HPLC generated fingerprint can be used to authenticate Pica mango fruits and Pica mango food products. Molecules 2014, Keywords: Pica mango fruits; Tommy Atkins; antioxidant capacities; HPLC-PDA-ESI-ToF-MS; local Chilean plants; nutraceuticals; mangiferin; xanthones; flavonoids; phenolic acids 1. Introduction San José de Pica (from aboriginal quechua language: piqai, flower in the sand) is a small town and oasis in a remote part of the Atacama Desert located in the region of Tarapacá (I region of Chile), 114 km southeast of the city of Iquique. Pica has a lush greenery and thriving agriculture due to underground water sources surfacing in the middle of the Atacama Desert. Due to its water supply Pica has been inhabited for millennia, and it was a vital point on the Inca road system south from Peru. The Oasis of Pica is well known for the plentiful amounts of typical mango fruits and lemons that grow there, particularly the Limon de Pica (Pica lemon) and Mango de Pica (Pica mango) the first one a small and tart lemon that is famous throughout Chile. The mango (Mangifera indica L.) is a fleshy stone fruit belonging to the genus Mangifera, consisting of numerous tropical fruiting trees in the flowering family of Anacardiaceae in the order Rutales. Mango is one of the most important tropical fruits worldwide [1], it is a fruit with high nutritional value and unique flavors and taste, considered a good source of antioxidants, including vitamin C [2], and different xanthones [3] carotenoids [4], flavonoids [5,6], benzophenones [5], phenolic acids [7,8] and tannins [9,10] with attributed human health benefits [11]. However, there are differences regarding the polyphenolic compounds and dietary fiber present in different varieties of Mangifera indica fruits [12,13] and leaves [12]. Mango de Pica (Mangifera indica cv piqueño or Pica) is a small mango fruit, six or seven times smaller than Mango Tommy Atkins, with an average weight of g and a orange-yellow peel at maturity stage (Figure 1). This fruit contain considerable amounts of dietary fiber with good flavors and aroma which makes the consumers preference inclined to Pica mangoes in northern Chile (I and II regions of Chile). Tommy mangoes are bigger; the average weight is 600 g and the peel is green turning to red in maturity stage (Figure 1), however the pulp has less flavor and aroma than Pica mangoes. Pica and Tommy mango fruits are the two main mango varieties cultivated and consumed in northern Chile [14]. Besides the various benefits of the edible flesh the peels of mango fruits account for 15% 20% of the weight and are byproducts in the production of canned mango fruit and juices [15,16]. Indeed, mango peels showed good amounts of dietary fiber and antioxidant capacity and are considered a rich source of polyphenols, anthocyanin and carotenoids [11,13]. In this work we have analyzed Mango de Pica fruits (Mangifera indica cv piqueño, Figure 1) using HPLC with PDA and ESI-ToF-MS analyzers and made a comparison with Mango Tommy Atkins fruits, (Mangifera indica cv Tommy Atkins) harvested and consumed in northern Chile. Total phenolic content (TPC) and total flavonoid content (TFC) were compared, as well as antioxidant power measured by the bleaching of the DPPH radical, the ferric reducing antioxidant power (FRAP) and superoxide anion scavenging activity (SA), of pulp and peel of the fruits. This is the first report of phenolic constituents and HPLC analysis of Pica mango fruits. Molecules 2014, Figure 1. Photograph of (A) ripe Tommy Atkins Mango Fruit and (B) Pica Mango Fruits. 2. Results and Discussion 2.1. Antioxidant Capacity and Phenolic Content of Mango Fruits from Northern Chile The bleaching of the DPPH radical (DPPH), total phenolic content (TPC), total flavonoid content (TFC), and ferric reducing antioxidant power (FRAP) from pulp and peel of Tommy and Pica mango fruits are shown in Figure 2. We were not able to find any HPLC analysis and identification of phenolic compounds of Pica mango fruits nor comparison with other mango fruits. However, the ethanolic extract of the bark from Pica mango trees was studied regarding antioxidant and analgesic activities and the values were compared with those of the mango varieties Zill, Gloria, Kent, Sensation, Keitt and Tommy Atkins cultivated in the same area (I region) of Chile [14]. Among those seven cultivars the ethanolic extract from Pica mango bark showed the highest antioxidant activity measured by the bleaching of the DPPH radical (around 96% of bleaching of the DPPH radical at mg/ml, close to that of the positive control Trolox, with 99%) [14]. In this work methanolic extracts of peel and pulp from Tommy mango fruits (Mangifera indica L. variety Tommy Atkins) and Pica mango fruits (Mangifera indica L. variety piqueño) collected in the first region of Chile were evaluated for antioxidant power by the DPPH scavenging activity (measured as IC 50 values) and the ferric reducing antioxidant power assay (FRAP) and the results were compared. Both fruits showed moderate to high antioxidant power, but the peel from endemic Pica mango fruits presented the highest activity (Figure 2). Pica mango fruits showed the highest DPPH scavenging activity (IC 50 = ± 2.08 and ± 2.99 µg/ml, for pulp and peel, respectively, Figure 2) and higher ferric reducing antioxidant power ( ± and ± µmol TE (Trolox equivalents)/100 g fresh weight, for pulp and peel, respectively, Figure 2) than Tommy fruits peel and pulp power (127.22/46.39 µg/ml, in the DPPH assay and / µmol TE (Trolox equivalents)/100 g FW, for pulp and peel, respectively, Figure 2). The pulp of Pica mango fruits showed total phenolic content of ± 3.91 mg GAE (gallic acid equivalents) per 100 g fresh material. This value is 1.29 times higher than the content in Tommy fruits (25.03 ± 1.72 mg GAE/100 g fresh material), collected in the Molecules 2014, same location. The peels showed similar trend (Figure 2). For Pica mangoes the total phenolic content of the peel was 2.2 times higher (72.01 ± 2.78 mg GAE/100 g fresh material), than its pulp, while for Tommy mangoes peel was 1.72 times higher (43.17 ± 3.95 mg GAE/100 g fresh material), than its pulp, which make the peels a better source of bioactive compounds. Figure 2. (a) DPPH scavenging activity; (b) Ferric reducing antioxidant power (FRAP); (c) Total Phenolic content (TPC) and (d) Total flavonoid content (TFC) of mango fruit extracts. ppu: Mangifera indica L. variety Pica pulp extract; ppe: Mangifera indica L. variety Pica peel extract; tpu: Mangifera indica L. variety Tommy Atkins pulp extract; tpe: Mangifera indica L. variety Tommy Atkins peel extract. GA: Gallic acid, Q: Quercetin. The content of phenolics in edible pulp of Tommy mangoes was close to that reported for the variety Irwin (20.94 ± 1.69 mg gallic acid/100 g FW) [17] and the Tommy Atkins varieties growing in United States (21.16 mg gallic acid/100 g FW) [18] as well as in Ecuador and Brazil (23.6 mg gallic acid/100 g FW) [19] and the variety Haden cultivated in Mexico (27.7 mg) [19]. However, the pulp from Pica mangoes showed values close to that reported for the Chinese variety Ao (29.45 ± 4.14 mg gallic acid/100 g FW) [17] and the variety Kent from Mexico (32.2 gallic acid/100 g FW) [19], while the peels from Pica mangoes showed values close to that of the varieties Xiaoji (80.50 ± 3.63 mg gallic acid/100 g FW) from China [17] and Ataulfo from Mexico (99.5 mg gallic acid/100 g FW) [19]. Pica mango fruits also showed higher values in total flavonoids (4.74 ± 0.73 mg QE (quercetin equivalents)/100 g fresh material) than Tommy mango fruits (2.32 ± 0.12 mg QE/100 g fresh Molecules 2014, material), while the highest content of flavonoids was found in Pica mango peels (18.07 ± 2.68 mg QE/100 g fresh material), which was close to that reported for the variety Mallika (18.33 ± 6.56 mg rutin/100 g fresh material) [17] Identification of Phenolic Compounds in Mango Fruits by HPLC-DAD and ToF-ESI-MS/MS In this study several compounds (Figure 3) were identified in mango fruits from northern Chile using photodiode array detection (PDA) and negative electrospray ionization-time of flight mass spectrometry (ESI-ToF-MS) in full scan mode and tandem MS/MS fragmentations. The HPLC fingerprint recorded at 280 nm of methanolic extracts from peel and pulp of both mango fruits cultivated in northern Chile is shown in Figure 4. Figure 3. Compounds identified in two mango fruits (varieties Pica and Tommy) from Northern Chile. Using HPLC coupled to a ToF mass analyzer the solvent flow should be less than 0.5 ml per minute and the amount of acid should be very low, since more than 0.1% of trifluoracetic (TFA) or formic acid in the solvent system as currently used in HPLC coupled to PDA detectors can damage the ToF detector. Thus, in this work we have used 0.05% formic acid in the solvent system and a flow rate of 0.4 ml/min. Both positive and negative mass conditions were employed in this work, but the acidic nature of the compounds present in the extracts (phenols) made the ions more abundant and easily detected in negative mode. It was not possible to distinguish unequivocally all detected compounds due to the lack of standard compounds. Therefore the structures of these compounds were proposed based on UV maxima (272 nm for catechin derivatives, 252, 362 nm for ellagic acid derivatives, 240, Molecules 2014, nm for caffeic acid derivatives, 258, 318, 363 nm for mangiferin derivatives, 255, 354 nm for quercetin derivatives and 254, 365 nm for isorhamnetin derivatives, Figure 5) as well as fragmentation pattern thorough ESI-MS-MS experiments. In this work using tandem MS experiments the loss of 162 Daltons is indicative of hexoses (glucose or galactose, the most common sugars found in flavonoids) the loss of 146 Daltons is indicative of rhamnose, the loss of 133 Daltons is indicative of pentoses (xylose or arabinose, the most common pentoses found in natural products) [20], while the losses of 90 and 120 Daltons is indicative of C-glycoside phenolic compounds [21]. Table 1 show retention times of the peaks detected, UV maxima, molecular formula, pseudomolecular ions and MS fragmentation of all compounds detected in two cultivars of mango fruits cultivated in northern Chile plus references to the compounds, while the identification using HPLC hyphenated with PDA-ESI-ToF-MS and MS n experiments of all detected and tentatively characterized compounds is explained above. In this work 21 compounds were detected and tentatively characterized, 18 in Pica pulp (ppu), 13 in Pica peel (ppe) 11 in Tommy Atkins pulp (tpu) and 12 in Tommy Atkins peel (tpe) (Table 2). Figure 4. HPLC UV chromatograms at 280 nm of (a) Tommy Atkins mango fruits pulp extract, (b) Pica mango fruits pulp extract, (c) Tommy Atkins mango fruits peel extract and (d) Pica mango fruits peel extract. Molecules 2014, Table 1. Identification of phenolic compounds in mango pulp and peel by LC-PDA, LC ESI-ToF-MS and MS/MS data. Peak # Rt (min) HPLC-DAD λ max (nm) [M-H] Formula Other MS-MS ions (m/z) Tentative identification Reference Species/Fruit part C 7 H 12 O Quinic acid [22] ppu C 15 H 12 O , Methyl-di-gallate ester [22] tpe , 275sh, C 21 H 10 O (gallic acid) Valoneic acid bilactone [23,24] ppu, ppe tpu, tpe C 8 H 8 O (gallic acid) Methyl gallate [22] tpu, tpe , C 16 H 18 O (caffeic acid) Caffeoyl-quinic acid [25] ppu, ppe C 37 H 28 O (procyanidin dimer), 405.1, Galloyl-A-type procyanidin 284.0, (gallic acid) dimer [26] tpu, tpe ppu, ppe C 30 H 23 O , (catechin), 205.1, A-type-procyanidin dimer [26] ppu, ppe tpu, tpe C 13 H 16 O (gallic acid) Galloyl glucose [27] ppu, ppe tpu, tpe C 30 H 23 O , (catechin) Epiafzelechin-epicatechin dimer [28] ppu, ppe tpu, tpe , 319, C 26 H 22 O (Mangiferin), (gallic acid) Mangiferin gallate [5] ppu, ppe , C 15 H 18 O ([2M-H] ), (caffeic acid) Caffeoyl-glucose [25] ppu, ppe tpu, tpe , 319, C 19 H 18 O ([2M-H] ), ([2M-H] ), Mangiferin * [3] ppu, ppe tpu, tpe , 319, C 20 H 19 O ([2M-H] ), 301.0, ([2M-H] ), Homomangiferin [29] tpu, ppu , 319, C 21 H 22 O ([2M-H] ), 301.0([2M-H] ) Dimethylmangiferin [30] ppu C 14 H 16 O (quinic acid) Galloyl-quinic acid [22] ppe , C 21 H 20 O (quercetin), 179.0, Quercetin-3-O-glucose * [6] ppu, ppe tpu, tpe , 290 sh, C 21 H 20 O (quercetin), 179.0, Quercetin-3-O-rhamnose [6] ppu , 293sh, C 20 H 17 O (quercetin), 179.0, Quercetin-3-O-pentose [3] tpe, ppu , 300sh, C 22 H 22 O (Isorhamnetin), Isorhamnetin-3-O-glucose * [3] ppu, ppe tpu, tpe , C 15 H 8 O , Methyl-ellagic acid [31] ppu, ppe , C 14 H 6 O Ellagic acid * [5] ppu Species and fruit parts: Mangifera indica L. variety piqueño: Pulp (ppu) and peel (ppe); Mangifera indica L. variety Tommy Atkins: Pulp (tpu) and peel (tpe).* identified by spiked experiments with authentic standard. Molecules 2014, Figure 5. PDA spectra of compounds 3, 4, 6, 11, 12, 16 and AU AU nm Peak 6. A type procyanidin dimer nm Peak 4. Methyl gallate AU 1.50 AU nm Peak 3. Valoneic acid bilactone nm Peak 11. Caffeic acid glucoside Peak AU Peak 12. Mangiferin nm 0.30 AU nm Peak 16. Quercetin glucoside AU nm Peak 19. Isorhamnetin glucoside Molecules 2014, Xanthones In this work peaks 10, were tentatively identified as xanthones (Figures 3 and 6). Mangosteen is one of the richest sources of different antioxidant xanthones [32], while mango fruits, specially the Tommy Atkins cultivar showed a few principal components, mainly mangiferin and isomangiferin [3,33]. Peak 12 showed an [M-H] ion at m/z in the ToF-ESI-MS spectra and fragment ions at m/z ([M-H-90 Daltons] and m/z ([M-H-120 Daltons] corresponding to losses of C-glycoside phenolic compounds [21] and was identified as mangiferin [3], its identity being confirmed by spiking experiments using an authentic standard. Peak 14 with a pseudomolecular ion at m/z and daughter ions at m/z and m/z was identified as the xanthone derivative di-methylmangiferin [30]. Peak 13 with a pseudomolecular ion at m/z and MS 2 ions at m/z 315.1, and m/z was identified as the mangiferin monomethyl derivative homomangiferin [29]. Similarly, Peak 10 with an [M-H] ion at m/z and product MS n ions at m/z (mangiferin) and m/z (gallic acid) was tentatively characterized as mangiferin gallate as reported [5]. Figure 6. Structures, fragmentations, full ESI-MS and MS-MS spectra of peaks 10 and Phenolic Acids, tannins and their Derivatives and/or Related Compounds Peak 1 was tentatively identified as quinic acid ([M-H] ion at m/z 191.1, Figure 7) while peak 15 with a [M-H] ion at m/z and a loss of 152 Daltons (galloyl moiety) producing a quinic acid daughter ion at m/z was a identified as galloylquinic acid (Figure 7) [22]. Peak 2 showed an [M-H] ion at m/z and a daughter MS ion at m/z (methyl gallate) and was identified as methyl digallate ester (Figure 7) while the related compound 4 was identified as methyl gallate Molecules 2014, (Figure 7) [22]. Peak 3 showing UV spectral data characteristic of an ellagic acid derivative (Figure 7 and Table 1) with an [M-H] ion at m/z and a daughter gallic acid ion at m/z was identified as the ellagic acid derivative valoneic acid bilactone (Figure 7) [23,24]. Peak 4 showed a pseudomolecular ion at m/z and daughter MS ion at m/z (gallic acid) and was identified as the gallic acid derivative methyl gallate [22]. Peak 8 with an [M-H] ion at m/z and MS daughter ion at m/z was identified as galloyl glucose (Figure 8) [27]. Peak 5 showed an [M-H] ion at m/z (Figure 8) and an UV spectrum characteristic of caffeic acid (Table 1). A loss in the ESI MS-MS experiment resulting in a peak at m/z (caffeic acid) prompted the identification of this compound as caffeoyl-quinic acid [25]. Similarly, peak 11 with an [M-H] ion at m/z and a MS 2 ion at m/z was identified as caffeoylglucose (Figure 8) [25]. Peak 20 with a pseudomolecular anion at m/z and daughter ions at m/z and was identified as methyl ellagic acid (Figure 8) [31]. Peak 21 with a pseudomolecular ion at m/z and eluting very late in the chromatogram as reported [5] was identified as free ellagic acid (Figure 8) [5,20]. Figure 7. Structures, fragmentations, full ESI-MS and MS-MS spectra of peaks 1, 2, 3, 4, 5, and 15. Molecules 2014, Figure 8. Structures, fragmentation, full ESI-MS and MS-MS spectra of peaks 8, 11, 20 and Flavonoids Peak 16 showed an [M-H] ion at m/z and a MS 2 fragment at m/z [6] which produced quercetin MS 3 ions at m/z and [20] and was identified and confirmed as the flavonoid isoquercitrin (quercetin 3-O-glucoside, (Figure 9) [6], by spiking experiment with authentic standard. Similarly, peaks 17 and 18 with molecular ions at m/z and were identified as quercetin-3-o-pentoside and quercetin-3-o-rhamnoside respectively (Figure 9) [20]. Peak 19 with a molecular anion at m/z and MS 2 ion at m/z (isorhamnetin) was identified as isorhamnetin 3-O-glucoside (Figure 9) [3]. Molecules 2014, Figure 9. Structures, fragmentation, full ESI-MS and MS-MS spectra of peaks 16, 17, 18 and Procyanidins The monomer procyanidins (+)catechin and ( )epicatechin were identified in mango fruits in previous reports [17,34,35]. In this work minor peaks 6, 7, and 9 were identified as procyanidins (Figure 10). Peak 7 with an [M-H] ion at m/z and product daughter ions at m/z (RDA, Retro Diels Alder product) and (epicatechin monomer) was identified as a procyanidin A dimer, (epi)catechin-(epi)catechin) [26]. Similarly, peak 9 with a molecular anion at m/z and MS 2 ions at m/z product ion from RDA cleavage) and m/z (epicatechin) was identified as a procyanidin A dimer with an epiafzelechin monomer constituent, (epiafzelechin-epicatechin) as reported [28]. Peak 6 with an [M-H] ion at m/z and MS n ions at m/z 405.1, (epicatechin) and m/z (gallic acid) was identified as a galloylated A type
Related Search
Similar documents
View more...
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks