HPLC-UV-MS Profiles of Phenolic Compounds and Antioxidant Activity of Fruits from Three Citrus Species Consumed in Northern Chile

Abstract

Peels and edible pulp from three species of citrus including Citrus aurantifolia (varieties pica and sutil) and Citrus x lemon var. Genova widely cultivated and consumed in Northern Chile (I and II region) were analyzed for phenolic compounds and antioxidant activity for the first time. A high performance electrospray ionization mass spectrometry (HPLC-UV-ESI-MS) method was developed for the rapid identification of phenolics in extracts from peels and juices of all species. Several flavonoids including one kaempferol-O-hexoside (peak 16) and one hesperidin derivative (peak 22) three quercetin derivatives (peaks 4, 19 and 36), five isorhamnetin derivatives (peaks 5, 23, 24, 26 and 29) four luteolin derivatives (peaks 14, 25, 27 and 40), seven apigenin derivatives (peaks 2, 3, 12, 20, 34, 35 and 39), seven diosmetin derivatives (peaks 7-9, 17, 21, 31 and 37), three chrysoeriol derivatives (peaks 10, 18 and 30), and four eryodictiol derivatives (peaks 6, 13, 15 and 38) were identified in negative and positive mode using full scan mass measurements and MS n fragmentations. Ascorbic acid content was higher in the pulps of OPEN ACCESSMolecules 2014, 19 17401 the varieties Genova and Sutil (60.13 ± 1.28 and 56.53 ± 1.06 mg ascorbic acid per g dry weight, respectively) while total phenolic content was higher in Pica peels followed by Sutil peels (34.59 ± 0.81 and 25.58 ± 1.02 mg/g GAE dry weight, respectively). The antioxidant capacity was also higher for Pica peels (10.34 ± 1.23 µg/mL in the DPPH assay and 120.63 ± 2.45 µM trolox equivalents/g dry weight in the FRAP assay). The antioxidant features together with the high polyphenolic contents can support at least in part, the usage of the peel extracts as nutraceutical supplements, especially to be used as anti-ageing products.

Flavonoid Constituents of Phlomis (Lamiaceae) Species Using Liquid Chromatography Mass Spectrometry

“…The fragmentation of the ion at m / z 301 indicates a neutral loss of 162 AMU (glucose) (Reed, ; Falcao et al ., ; Chen et al ., ; Vagiri et al ., ). Moreover, other fragment ions of MS/MS spectra at m / z 268, 179 (RT = 17.766), 283, 257.7 (RT = 13.015, 13.023), 179, 283 (RT = 13.023), 151, 121.9 (RT = 13.015) and 121 (RT = 14.233) also corresponded to quercetin in structure (Pereira, ; Lin et al ., ; Brito et al ., ). This compound is suggested as quercetin‐3‐ O‐ glucoside which is confirmed by reference standards (Pereira, ; Lin et al ., ).…”

“…The fragment ions at m / z 243.4, 239.8, 225, 205.2, 150, 115.4, 91.9 (RT = 24.669) were also identified. Based on previous reports and reference standards, this flavone was identified as apigenin (Sanchez‐Rabaneda et al ., ; Plazonic et al ., ; Pereira et al ., ; Pereira, ; Brito et al ., ). The presence of apigenin in Ph.…”

“…Successive cleavage of the hexose moiety at 8‐C gave rise to the fragment ion at m / z 489 ([M‐H‐120]). This data led to the identification of this flavone as luteolin‐6,8‐di‐ C ‐hexoside (Brito et al ., ; Taamalli et al ., ). This luteolin derivative is first reported here in Ph.…”

“…In the MS/MS spectra, this compound showed base peak ions at m / z 315.2 (−308 Da), 478.4 and 316.4 (RT = 17.316; peak no. 49) which corresponds to that of isorhamnetin‐3‐ O ‐rutinoside (Figures E, B, B) (Krasteva and Nikolov, ; Lin et al ., ; Vagiri et al ., ; Brito et al ., ; Chen et al ., ). The structure of this compound was assigned based on interpretation of their fragmentation pathways observed in MS/MS spectra.…”

Pharmacokinetics of Cymbopogon Citratus Infusion in Rats after Single Oral Dose Administration

“…L7G, L3'S, LUT, CHR and DIO were identified by HPLC-PDA-ESI/MSn. All compounds presented UV spectra characteristic of luteolin de- [36,37]. Since the method was not validated to L3'S due to the unavailability of standard, this analyte was quantified expressing the results in equivalents of L7G.…”