HPLC–DAD–ESI-MS/MS screening of bioactive components from Rhus coriaria L. (Sumac) fruits

HPLC–DAD–ESI-MS/MS screening of bioactive components from Rhus coriaria L. (Sumac) fruits Ibrahim M. Abu-Reidah a,b,c , Mohammed S. Ali-Shtayeh a, ⇑ , Rana M. Jamous a , David Arráez-Román b,c , Antonio Segura-Carretero b,c, ⇑ a Biodiversity & Environmental Research Center (BERC), Til, Nablus POB 696, Palestine b Department of Analytical Chemistry, Faculty of Sciences, University of Granada, Avda. Fuentenueva, 18071 Granada, Spain c Functional Food Research and Development Centre (CIDAF), PTS Granada, Avda. del Conocimiento, Edificio Bioregión, 18016 Granada, Spain article info Article history: Received 25 March 2014 Received in revised form 29 May 2014 Accepted 3 June 2014 Available online 12 June 2014 Keywords: Palestinian sumac Anacardiaceae Hydrolysable tannins Flavonoids Mediterranean diet HPLC–DAD–ESI-MS/MS abstract Rhus coriaria L. (sumac) is an important crop widely used in the Mediterranean basin as a food spice, and also in folk medicine, due to its health-promoting properties. Phytochemicals present in plant foods are in part responsible for these consequent health benefits. Nevertheless, detailed information on these bioactive compounds is still scarce. Therefore, the present work was aimed at investigating the phytochemical components of sumac fruit epicarp using HPLC–DAD–ESI-MS/MS in two different ionisation modes. The proposed method provided tentative identification of 211 phenolic and other phyto-constituents, most of which have not been described so far in R. coriaria fruits. More than 180 phytochemicals (tannins, (iso)flavonoids, terpenoids, etc.) are reported herein in sumac fruits for the first time. The obtained results highlight the importance of R. coriaria as a promising source of functional ingredients, and boost its potential use in the food and nutraceutical industries. Ó2014 The Authors. Published by Elsevier Ltd. This is anopen access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). 1. Introduction Sumac, Rhus coriaria L. (Anacardiaceae), is a wild edible plant growing in the Mediterranean region, has long been used as a seasoning spice, either in pure form or in combination with other spices (Ali-Shtayeh, & Jamous, 2008), sauce, appetizer, drink, and as a souring agent in food recipes. R. coriaria L. is an important and the most widely used species of the genus Rhus in the Mediterranean region since antiquity. Recently, the consumption of sumac fruits has been increasing around the world as an important economic crop (Kizil, & Turk, 2010). In folk medicine and traditional Arabic Palestinian herbal medicine, this plant has been used in the treatment of cancer, stroke, diarrhoea, hypertension, dysentery, haematemesis, ophthalmia, stomach ache, diuresis, diabetes, atherosclerosis, measles, smallpox, liver disease, aconuresis, teeth and gum ailments, headaches, animal bites, dermatitis, and liver disease (Ali-Shtayeh, & Jamous, 2008; Shafiei, Nobakht, & Moazzam, 2011). Furthermore, R. coriaria is known to possess non-mutagenic, fever-reducing, DNA protective, antiseptic, antifungal, antibacterial, antioxidant, anti-ischaemic, hypouricemic, hypoglycaemic, and hepatoprotective properties, which support its traditional uses (Anwer et al., 2013; Chakraborty et al., 2009; Madihi et al., 2013; Shafiei et al., 2011). Among 56 Palestinian plants tested, sumac was found to have the greatest antimicrobial effect against Probionibacterium acnes (MIC 6 mg/ml, MBC 6 mg/ml), Staphylococcus aureus (MIC 4 mg/ ml, MBC 6 mg/ml), Escherichia coli (MIC 6 mg/ml, MBC 8 mg/ml) and Pseudomonas aeruginosa (MIC 4 mg/ml and MBC 6 mg/ml) (Ali-Shtayeh, Al-Assali, & Jamous, 2013). The literature lacks detailed information on R. coriaria chemical composition. Previous works have reported sumac to contain phenolic compounds, such as hydrolysable tannins, anthocyanins and also organic acids such as malic and citric acids (Kosar, Bozan, Temelli, & Baser, 2007; Kossah, Nsabimana, Zhang, & Chen, 2010). Interestingly, the acidic and astringent tastes, may be due to indigenous organic acids (mainly, malic acid) and tannins. Many compounds have been identified from different parts of sumac, such as phenolics, organic acids, proteins, fibre, volatile oils, fatty acids, vitamins, and minerals (Anwer et al., 2013; Özcan, & Haciseferogullari, 2004). Only a few studies have been carried out on the chemical composition of R. coriaria leaves (Regazzoni et al., 2013; Van Loo, De Bruyn, & Verzele, 1988) and little is known about the phytochemical composition of the plant’s fruit epicarps. http://dx.doi.org/10.1016/j.foodchem.2014.06.011 0308-8146/Ó2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). ⇑ Corresponding authors. Tel.: +970 92536406 (M.S. Ali-Shtayeh). Address: Functional Food Research and Development Center (CIDAF), PTS Granada, Avda. del, Conocimiento, Edificio Bioregión, 18016 Granada, Spain. Tel.: +34 958248435 (A. Segura-Carretero). E-mail addresses: [email protected] (M.S. Ali-Shtayeh), [email protected] (A. Segura-Carretero). Food Chemistry 166 (2015) 179–191 Contents lists available at ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem Although R. coriaria is a particularly rich source of phenolic compounds (Kossah et al., 2010), the phenolic constituents of sumac fruit’s epicarp remains so far incompletely investigated. Thus, detailed and extended profiling of the phytochemicals of sumac fruits using high sensitive tools is necessary. Consequently, suitable methods need to be established for the identification of phytochemicals in plant food matrices (Abu-Reidah, Contreras, Arráez-Román, Fernández-Gutiérrez, & Segura-Carretero, 2014). Mass spectrometry coupled to high-performance liquid chromatography (HPLC–MS) has been increasingly used in the structural characterisation of complex matrices and has proved to be the tool of choice to identify phenolic compounds (Abu-Reidah, Arráez-Román, Lozano-Sánchez, Segura-Carretero, & FernándezGutiérrez, 2013; Abu-Reidah, Arráez-Román, Segura-Carretero, & Fernández-Gutiérrez, 2013; Lee, Zweigenbaum, & Mitchell, 2013). Therefore, the objective of the present study was to investigate the phytochemical composition of hydro-methanolic extracts of R. coriaria fruits cultivated in Palestine, by using high-performance liquid chromatography-diode array detector-hyphenated with tandem mass spectrometry (HPLC–DAD–ESI-MS/MS) as a potent analytical technique. 2. Materials and methods 2.1. Chemicals Acetonitrile and methanol of analytical or HPLC grade were purchased from Labscan (Dublin, Ireland). Acetic acid of analytical grade (assay >99.5%) was purchased from Fluka (Switzerland). Water was purified by using a Milli-Q system (Millipore, Bedford, USA). 2.2. Sample preparation Sumac is commercially obtainable in local markets in readyto-use ground form. In our present study, for quality control considerations, sumac samples were harvested in their mature stage from the wild habitat mountains of Nablus (Qusra village) in summer of 2012 and were identified by Prof. Mohammad S. Ali-Shtayeh from BERC. Collected sumac samples were dried, and then epicarps of R. coriaria L. fruits were liberated from kernels and ground into powder using a household mill and stored at room temperature until they were used for extraction. 2.3. Extraction of phenolic compounds The extraction procedure was performed following Abu-Reidah, Arráez-Román, Segura-Carretero, and Fernández-Gutiérrez (2013), with some modifications. Portions of the dried and ground Sumac fruit epicarps (0.5 g) were extracted using methanol (80% v/v) and sonicated for 30 min at room temperature. The mixture was centrifuged for 15 min at 3800gand the supernatant was collected into a round-bottom flask. The extraction process was repeated three times. To get rid of the non-polar fraction that could be extracted by 80% methanol, the supernatant was mixed twice with 5 mL of n-hexane. The solvent was evaporated using a rotary evaporator under vacuum at 40 °C and the dry residue was dissolved in aqueous methanol. Finally, the extract was centrifuged again and the supernatant was filtered through a 0.2l m syringe filter and stored at 20 °C until analysis. 2.4. HPLC–DAD/QTOF-MS analysis Separation of phenolic compounds from sumac extract was performed on an Agilent 1200 series Rapid Resolution LC (Agilent Technologies, Santa Clara, CA) consisting of a vacuum degasser, an auto-sampler, a binary pump and diode-array detector (DAD). This instrument was equipped with an Agilent Zorbax C18 column (4.6 150 mm, 5 l m) from Agilent Technologies. Acidified water (0.5% acetic acid, v/v) and acetonitrile were used as mobile phases A and B, respectively. The gradient was programmed as follows: 0 min, 0% B; 20 min, 20% B; 30 min, 30% B; 40 min, 50% B; 50 min, 75% B; 60 min, 100% B; 62 min 0% B, and finally, the initial conditions were held for 8 min as a re-equilibration step. The flow rate was set at 0.80 mL/min throughout the gradient. The flow from the HPLC system into the ESI-Q-TOF-MS detector was 0.2 mL/min. The injection volume was 10 l L and the column temperature was maintained at 25 °C. The HPLC system was coupled to a quadrupole-time-of-flight (micrOTOF-Q™, Bruker Daltonik GmbH, Bremen, Germany) orthogonal accelerated Q-TOF mass spectrometer, equipped with an electrospray ionisation source (ESI). Parameters for analysis were set using negative and positive ion modes, with spectra acquired over a mass range from m/z50 to 1100. The optimum values of the ESI-MS parameters were: capillary voltage, 3.5 and +4.0 kV; drying gas temperature, 190 °C; drying gas flow, 9.0 L/ min; nebulising gas pressure, 29 psi; collision RF, 150 Vpp; transfer time 70 l s, and pre-pulse storage, 5 l s. Moreover, automatic MS/ MS experiments were performed adjusting the collision energy values as follows: m/z100, 20 eV; m/z500, 30 eV; m/z1000, 35 eV, using nitrogen as collision gas. The MS data were processed through Data Analysis 4.0 software (Bruker Daltonics, Bremen, Germany) which provided a list of possible elemental formulas by using the Generate Molecular Formula™ editor. The editor uses a CHNO algorithm, which provides standard functionalities, such as maximum/minimum elemental range, and a sophisticated comparison of the theoretical with the measured isotope pattern (mSigma value), for increasing the confidence in the suggested molecular formula. The widely accepted accuracy for confirmation of elemental compositions has been established as 5 ppm. At some stage in the HPLC method development, an external apparatus calibration was performed using a Cole Palmer syringe pump (Vernon Hills, IL) directly linked to the interface, passing a solution of sodium acetate. Using this method, an exact calibration curve based on numerous cluster masses each differing by 82 Da (C 2 H 3 NaO 2 ) was obtained. Due to the compensation of temperature drift in the Q-TOF, this external calibration provided accurate mass values for a complete run without the need for a dual sprayer set up for internal mass calibration. 3. Results and discussion 3.1. Characterisation of the phenolics and other phytochemical derivatives 3.1.1. General Table 1 shows the list of 211 compounds tentatively identified through HPLC–DAD–ESI-MS/MS experiments along with their retention times (t R ), detected accurate mass (ionisation modes either negative and/or positive, molecular formula, error in ppm (between the mass found and the accurate mass) of each phytochemical, as well as the MS/MS fragment ions and the bibliographic references used in the characterisation process. In the present work, a qualitative analysis of the phenolic composition from the hydro-methanol extract of sumac fruits (epicarps) has been carried out using HPLC–DAD–ESI-MS/MS in negative and positive ionisation modes. The method was used to detect and characterise 211 phytochemical compounds, of which 188 were tentatively characterised for the first time in sumac (R. coriaria) fruits. Fig. 1A–C correspond to the base peak 180 I.M. Abu-Reidah et al. / Food Chemistry 166 (2015) 179–191 Table 1 Phytochemical compounds detected and characterised in R. coriaria L. fruits by using HPLC–DAD/QTOF-MS in positive and negative ionisation modes. Peak No. Tentative assignment t R (min.) [M+H] + (m/z) [MH]  (m/z) Error (ppm) mSigma Molecular formula MS2/MS fragment ions b Reference 1 Quinic acid I 2.35 193.0708 191.0566 2.8 1.4 C 7 H 12 O 6 173.0442(4), 109.0302(4) a – 2 Malic acid I 2.69 – 133.0144 1.2 1.8 C 4 H 6 O 5 115.0034(100) a – 3 Malic acid hexoside I 2.91 – 295.0663 1.3 7.6 C 10 H 16 O 10 133.0140(100),115.0030(63) a Ley et al. (2006) 4 Malic acid hexoside II 3.16 – 295.0673 0.8 7.3 C 10 H 16 O 10 133.0137(100),115.0030(41) a Ley et al. (2006) 5 Malic acid hexoside III 3.36 – 295.0671 0.2 0.9 C 10 H 16 O 10 133.0136(100), 115.0044(48) a Ley et al. (2006) 6 Oxydisuccinic acid 4.32 251.0410 249.0262 3.9 7.3 C 8 H 10 O 9 133.0141(100),115.0036(52) a – 7 Malic acid II 4.37 135.0284 133.0143 0.4 1.7 C 4 H 6 O 5 115.0024(100) a – 8 Malic acid III 4.82 135.0281 133.0140 1.7 2.9 C 4 H 6 O 5 115.0024(100) a – 9 Quinic acid II 5.71 193.0365 191.0555 3.5 1.8 C 7 H 12 O 6 173.0409(100) a – 10 O-Succinoyl-di-Ocaffeoylquinic acid 5.75 – 615.1383 4.5 10 C 29 H 28 O 15 307.0675(15), 191.0569(100) a – 11 Malic acid derivative 6.52 – 289.0569 1.5 10.3 C 11 H 14 O 9 173.0466(26),155.0369(4), 133.0141(100),115.0034(22) a – 12 Caftaric acid 6.75 – 311.0354 8.5 21 C 13 H 12 O 9 133.0135(100), 115.0031(37) a – 13 Galloylhexose I 7.44 – 331.0647 4.3 3.8 C 13 H 16 O 10 169.0158(100) a Fröhlich et al. (2002) 14 Galloylhexose II 9.09 – 331.0669 0.6 14.8 C 13 H 16 O 10 169.0148(100) a Fröhlich et al. (2002) 15 Levoglucosan gallate I 9.50 315.0717 – 2 1.3 C 13 H 14 O 9 153.0196(100),109.0270(6) – 16 Galloylhexose III 9.86 – 331.0673 0.8 13.4 C 13 H 16 O 10 271.0470(100),211.0255(47), 169.0142(55) a Fröhlich et al. (2002) 17 Levoglucosan gallate II 10.68 315.0730 – 6.1 7.5 C 13 H 14 O 9 153.0186(100),125.0219(6), 109.0252(2) – 18 Galloylhexose IV 11.00 – 331.0671 0.1 0.3 C 13 H 16 O 10 271.0462(100),211.0252(46), 169.0144(38) a Fröhlich et al. (2002) 19 O-galloylnorbergenin i 11.01 467.0803 – 3.7 7.2 C 20 H 18 O 13 171.0278(2),153.0184(100) – 20 Digalloyl-hexoside I 11.40 – 483.0772 1.8 4.7 C 20 H 20 O 14 331.067(25), 169.0143(56) a Fröhlich et al. (2002) 21 Galloylhexose derivative I 11.42 – 505.0606 3.5 10.3 C 22 H 18 O 14 445.0404(6), 331.0665(6), 169.0102(10) a – 22 O-galloylnorbergenin ii 11.54 467.0816 – 1 13 C 20 H 18 O 13 171.0291(2),153.0181(100) – 23 Digalloyl-hexoside II 11.92 – 483.0773 1.2 1.8 C 20 H 20 O 14 331.0671(20),313.0560(6), 169.0144(52) a Fröhlich et al. (2002) 24 Galloylhexose derivative II 11.94 – 505.0625 0.2 13.4 C 22 H 18 O 14 331.0650(9), 169.0134(11) a – 25 Protocatechuic acid hexoside 12.21 – 315.0717 1.5 10.1 C 13 H 16 O 9 153.0169(50), 152.0108(100), 109.0286(14), 108.0215(39) a – 26 Gallic acid dihexose 12.56 – 493.1191 1.5 41.8 C 19 H 26 O 15 313.0561(100) a – 27 Galloylhexose malic acid I 12.73 – 447.0777 0.8 8.2 C 17 H 20 O 14 331.0666(100),271.0481(10), 169.0153(14) a – 28 Galloylhexose V 12.86 – 331.0672 0.5 7.1 C 13 H 16 O 10 169.0146(100),125.0244(11) a Fröhlich et al. (2002) 29 Galloylhexose malic acid II 13.00 – 447.0782 0.4 4.8 C 17 H 20 O 14 331.0673(100),169.0147(19), 133.0146(6) a – 30 Unknown 13.33 309.0632 307.0469 3.3 7.5 C 14 H 12 O 8 289.0339(50), 245.0457(35), 201.0571(100) a – 31 Protocatechoic acid 13.47 – 153.0194 0.6 4.1 C 7 H 6 O 4 109.0293(100) a Shabana et al. (2011) 32 Galloylshikimic acid I 13.49 – 325.0567 0.6 2.4 C 14 H 14 O 9 169.0145(100),153.0200(13), 125.0244(20) a – 33 Digalloyl-hexose-malic acid I 13.55 – 599.0901 2 14.4 C 24 H 24 O 18 483.0794(48),465.0621(6), 447.0773(8),313.0548(3), 169.0142(22) a – 34 Gallic acid hexose derivative 13.62 – 487.1082 2.2 27 C 20 H 24 O 14 331.0618(28),169.0152(70) a – 35 Syringic acid hexoside 13.77 – 359.0977 1.7 12.8 C 15 H 20 O 10 197.0425(7) a – 36 Gallic acid O-malic acid 13.80 – 285.0261 3.1 1.8 C 11 H 10 O 9 169.0153(5),133.0141(100) a Zhang et al. (2004) 37 Galloylshikimic acid II 13.94 – 325.0572 2.2 5.4 C 14 H 14 O 9 169.0152(100),125.0236(14) a – 38 Digalloyl-hexose malic acid II 14.26 – 599.0891 0.1 11.4 C 24 H 24 O 18 483.0779(39),447.0756(21), 313.0680(1),169.0146(19) a – 39 Unknown 14.46 583.0937 – 1.3 14.1 C 24 H 22 O 17 171.0332(3),154.0203(9), 127.0371(13),109.0265(6), 97.0286(21) – 40 Galloylquinic acid I 14.71 – 343.0691 5.8 45.8 C 14 H 16 O 10 191.0626(12), 169.0156(83) a – 41 O-galloylnorbergenin iii 15.04 467.0828 – 1.7 31.4 C 20 H 18 O 13 153.0191(100) – 42 Digalloyl-hexose malic acid III 15.35 – 599.0881 1.5 5.2 C 24 H 24 O 18 599.0875(100),483.0771(12), 447.0772(14),169.0143(11) a – 43 Coumaryl-hexoside 15.77 – 325.0924 1.5 10.8 C 15 H 18 O 8 163.0398(100), 119.0491(60) a – 44 Digalloyl-hexoside III 16.10 485.0949 483.0793 2.6 12 C 20 H 20 O 14 423.0570(37), 331.0665(12), 169.0143(17) a Fröhlich et al. (2002) 45 O-galloylnorbergenin iv 16.25 476.0837 – 3.6 11.8 C 20 H 18 O 13 303.0561(20),153.0193(100) – 46 Digalloyl-hexoside IV 16.49 485.0809 483.0774 1.2 4.9 C 20 H 20 O 14 423.0581(3), 331.0699(6), 169.0149(25) a Fröhlich et al. (2002) 47 Galloylquinic acid II 16.62 – 343.0675 1.3 16.6 C 14 H 16 O 10 191.0570(33), 169.0139(100) a – 48 Trigalloyllevoglucosan I 16.67 619.0961 – 5 2.2 C 27 H 22 O 17 153.0183(100),109.0309(1) Chen, and Bergmeier (2011) (continued on next page) I.M. Abu-Reidah et al. / Food Chemistry 166 (2015) 179–191 181 Table 1 (continued) Peak No. Tentative assignment t R (min.) [M+H] + (m/z) [MH]  (m/z) Error (ppm) mSigma Molecular formula MS2/MS fragment ions b Reference 49 Digalloyl-hexose malic acid IV 16.68 – 599.0884 1 5.5 C 24 H 24 O 18 483.0784(40), 447.0757(6), 331.0664(5), 313.0537(2), 169.0138(18) a – 50 Kaempferol hexoside or Luteolin hexoside I 16.92 449.1048 – 6.8 65 C 21 H 20 O 11 287.0571(100) Buziashvili, Komissarenko, and Kolesnikov (1970) and Shrestha, et al. (2012) 51 Tri-galloyl-hexoside I 16.94 637.1110 635.0896 0.9 4.1 C 27 H 24 O 18 483.0759(23), 465.0699(9), 169.0128(9) a Regazzoni et al. (2013) 52 Penstemide 17.16 – 443.1917 1.3 7.1 C 21 H 32 O 10 101.0229(2) a Rodríguez-Pérez et al. (2013) 53 Digallic acid I 17.18 323.0403 321.0260 2.4 6.4 C 14 H 10 O 9 169.0139(100), 125.0240(18) a El Sissi et al. (1972) 54 Digalloyl-hexoside V 17.50 – 483.0775 1.1 3.5 C 20 H 20 O 14 331.0681(4), 169.0144(19) a Fröhlich et al. (2002) 55 Kaempferol hexoside or Luteolin hexoside II 17.55 449.1082 – 0.9 4.7 C 21 H 20 O 12 287.0576(100) Buziashvili, Komissarenko, and Kolesnikov(1970) and Shrestha et al. (2012) 56 O-galloylnorbergenin v 17.75 467.0826 – 1.1 15.8 C 20 H 18 O 13 153.0187(100) – 57 Methyl gallate 18.24 185.0441 183.0302 1.5 1.7 C 8 H 8 O 5 168.0076(28), 140.0112(64), 124.0170(39) a Shabana et al. (2011) 58 Trigalloyllevoglucosan II 18.40 619.0945 – 2.4 3.3 C 27 H 22 O 17 303.0531(3),153.0180(100) Chen, and Bergmeier (2011) 59 Tri-galloyl-hexoside II 18.57 637.1106 635.0886 0.6 2.7 C 27 H 24 O 18 331.0699(1), 169.0128(8) a Regazzoni et al. (2013) 60 Digallic acid II 18.71 323.0408 321.0257 1.1 2.7 C 14 H 10 O 9 169.0164(100),125.0243(18) a El Sissi et al. (1972) 61 Coumaric acid 18.72 – 163.0403 1.3 3.9 C 9 H 8 O 3 119.0507(100) a Min-Young, Ill-Min, Deog-Cheon, and HeeJuhn (2009) 62 Trigalloyllevoglucosan III 18.81 619.0950 – 2.4 3.3 C 27 H 22 O 17 153.0186(100) Chen, and Bergmeier (2011) 63 Galloylpyrogallol 18.82 279.0512 – 4.5 5.8 C 13 H 10 O 7 153.0190(100) – 64 Isorhamnetin hexoside I 18.94 479.1167 – 3.5 13 C 22 H 22 O 12 317.0671(100) – 65 Apigenin glucoside I 18.96 433.1149 – 4.6 13.4 C 21 H 20 O 10 271.0617(100) Shabana et al. (2011) 66 Tri-galloyl-hexoside III 19.04 637.1100 635.0882 1.3 2 C 27 H 24 O 18 483.0774(7), 465.0658(4), 169.0147(3) a Regazzoni et al. (2013) 67 Isorhamnetin hexoside II 19.14 479.1189 – 1.1 7.6 C 22 H 22 O 12 317.0664(100) – 68 Kaempferol-hexose malic acid I 19.16 565.1194 – 1.1 14 C 25 H 24 O 15 287.0558(100) Perestrelo et al. (2012) 69 Hydroxymethoxyphenyl-O-(Ogalloyl)-hexose 19.45 – 453.1053 3.1 40.4 C 20 H 22 O 12 313.0573(15), 179.0414(9), 169.0153(13) a – 70 Cyanidin-3-O- (2 00 galloyl)-galactoside 19.65 601.1186 599.1039 0.6 30 C 28 H 24 O 15 285.0405(100) a Kirby et al. (2013) 71 Trigalloyllevoglucosan IV 20.23 619.0935 – 0.9 3.4 C 27 H 22 O 17 153.0183(100) Chen, and Bergmeier (2011) 72 Tri-galloyl-hexoside IV 20.37 – 635.0895 0.8 4.4 C 27 H 24 O 18 483.0777(7), 465.0675(4), 169.0147(3) a Regazzoni et al. (2013) 73 7-O-Methyldelphinidin-3-O-(2 00 galloyl)-galactoside I 20.38 631.1301 – 1.3 17 C 29 H 26 O 16 317.0650(100), 233.0448(3), 153.0195(27) Kirby et al. (2013) 74 Kaempferol-hexose malic acid II 20.39 565.1193 – 0.8 41 C 25 H 24 O 15 287.0549(100) Perestrelo et al. (2012) 75 7-O-Methyldelphinidin-3-O-(2 00 galloyl)-galactoside II 20.57 631.1304 – 1.3 17 C 29 H 26 O 16 317.0665(100), 233.0425(2), 153.0183(10) Kirby et al. (2013) 76 Spinochrome A 20.92 265.1465 263.0217 7.4 13.2 C 12 H 8 O 7 245.0085(30), 235.0277(30), 219.0267(24), 207.0309(22), 191.0391(19) a – 77 Apigenin-7-O-(6 00 -Ogalloyl)-b-Dglucopyranoside 20.97 585.1241 – 6 20.6 C 28 H 24 O 14 271.0618(100), 153.0187(10) Tian et al., 2010 78 O-Galloyl arbutin 21.04 425.1066 – 2.8 30.5 C 19 H 20 O 11 273.0707(4) Shi & Zuo, (1992) 79 Coumaryl-hexose malic acid 21.06 – 441.1037 0.3 8.5 C 19 H 22 O 12 325.0926(13), 163.0405(100), 119.0509(5) a – 80 Methyldihydroquercetin hexoside 21.64 – 479.1190 1 4.2 C 22 H 24 O 12 317.0701(26), 299.0574(100) a – 81 7-O-Methyl-cyanidin3-O-galactoside 21.66 463.1231 461.1090 0.1 11.8 C 22 H 22 O 11 299.0562(61), 298.0480(100) a Kirby et al. (2013) 82 Caffeoylquinic acid 21.88 355.1040 – 4.6 48 C 16 H 18 O 9 193.0494(100) – 83 Trigalloyllevoglucosan V 22.03 619.0959 – 4.7 12 C 27 H 22 O 17 153.0183(100) Chen, and Bergmeier (2011) 84 Chrysoriol-hexose 22.08 579.1361 – 2.8 4.2 C 26 H 26 O 15 301.0705(100) – 182 I.M. Abu-Reidah et al. / Food Chemistry 166 (2015) 179–191 Table 1 (continued) Peak No. Tentative assignment t R (min.) [M+H] + (m/z) [MH]  (m/z) Error (ppm) mSigma Molecular formula MS2/MS fragment ions b Reference malic acid 85 Myricetin hexose-malic acid I 22.13 – 595.1297 1.3 12.6 C 26 H 28 O 16 479.1180(100), 369.0832(29), 317.0687(7), 299.0570(34) a – 86 Tri-galloyl-hexoside V 22.15 – 635.0888 0.2 12 C 27 H 24 O 18 465.0620(21), 483.0748(12), 169.0147(4) a Regazzoni et al. (2013) 87 Eriodictyol hexoside or Dihydrokaempferol hexoside I 22.18 – 449.1087 0.5 21 C 21 H 22 O 11 287.0570(86), 269.0448(54), 259.0603(66) a – 88 Ampeloptin 22.27 – 319.0470 3.4 13.6 C 15 H 12 O 8 193.0153(100), 179.0005(35), 153.0181(45), 125.0251(68) a – 89 Myricetin galloylhexoside 22.72 – 631.1306 0.2 6.8 C 29 H 28 O 16 317.0675(100) a – 90 7-O-Methyl-cyanidin3-O-(2 00 galloyl)- galactoside 22.74 615.1358 613.1196 0.5 2.5 C 29 H 26 O 15 299.0568(100) a Kirby et al. (2013) 91 Myricetin-hexose malic acid II 22.85 – 595.1303 0.2 16.5 C 26 H 28 O 16 479.1181(100), 369.0824(28), 317.0683(35), 299.0572(42) a – 92 Di-O-galloyl-3,4-(S)- hexahydroxydiphenoyl protoquercitol I 23.00 619.0950 – 3.3 8.1 C 27 H 22 O 17 301.0716(100) Nishimura, Nonaka, and Nishioka (1984) 93 Di-O-galloyl-2,3-(S)- hexahydroxydiphenoylscyllo-quercitol II 23.05 771.1092 – 6.8 4.8 C 34 H 26 O 21 153.0177(100) Nishimura et al. (1984) 94 Tetra-O-galloylhexoside I 23.07 789.1208 787.1008 1 4.9 C 34 H 28 O 22 635.0872(8), 169.0109(1) a Regazzoni et al. (2013) 95 Eriodictyol xyloyldeoxyhexose 23.41 – 565.1197 0.4 18.7 C 25 H 26 O 15 287.0553(76) a – 96 Umbelliferone 23.46 163.0391 161.0241 2.2 9.4 C 9 H 6 O 3 133.0299(100), 117.0341(61), 105.0332(10) a – 97 Trigalloyllevoglucosan VI 23.62 619.0945 – 2.4 33 C 27 H 22 O 17 301.0713(37), 153.0182(100) Chen, and Bergmeier (2011) 98 Isorhamnetin hexoside III 23.66 – 477.1030 1.7 32 C 22 H 22 O 12 314.0576(8),313.0561(50) a – 99 Tetra-O-galloyl-scylloquercitol 23.74 731.1477 – 3.2 2.8 C 33 H 30 O 19 301.0716(100),153.0179(7) Nishimura et al. (1984) 100 Glycitein 7-O-glucoside 23.76 447.1282 – 0.8 23.7 C 22 H 22 O 10 285.0768(100) – 101 Myricetin Orhamnosylglucose 23.86 627.1577 625.1409 0.3 6.1 C 27 H 30 O 17 317.0311(3), 316.0198(5) a Regazzoni et al. (2013) 102 Ampelopsin glucoside 23.88 – 481.0995 1.6 16.7 C 21 H 22 O 13 319.0460(65), 301.0360(40), 193.0144(100) a Yeom et al. (2003) 103 Quercetin glucoside I 24.09 465.1017 – 2.3 13.8 C 21 H 20 O 12 303.0512(100) Regazzoni et al. (2013) 104 Myricetin-hexose malic acid III 24.11 597.1081 – 0.9 18.8 C 25 H 24 O 17 319.0454(100) – 105 Myricetin-3-Oglucuronide 24.20 495.0766 493.0625 0.2 3.2 C 21 H 18 O 14 317.0308(100) a Regazzoni et al. (2013) 106 Myricitin derivative 24.21 – 515.0451 3.2 11 C 23 H 16 O 14 339.0125(23), 317.0307(100) a – 107 Myricitin derivative 24.23 657.1317 – 5.9 19.8 C 27 H 28 O 19 319.0478(100) – 108 Myricetin-3-Oglucoside 24.40 481.0970 479.0826 1.1 6.6 C 21 H 20 O 13 317.0291(28), 316.0243(76), 169.0144(26) a Regazzoni et al. (2013) 109 Trigallic acid 24.43 – 473.0362 0.2 2.4 C 21 H 14 O 13 321.0262(22), 169.0147(100) a Nishimura et al. (1984) 110 Myricetin-hexose malic acid IV 24.48 597.1077 – 1.5 18.9 C 25 H 24 O 17 319.0466(100) – 111 Trigalloyllevoglucosan VII 25.12 619.0945 – 2.4 33 C 27 H 22 O 17 301.0707(3), 153.0185(100) Chen, and Bergmeier (2011) 112 Benzoic acid, 3,4,5– trihydroxy-2-oxo-1,3propanediyl ester 25.14 – 393.0449 3.6 41.9 C 17 H 14 O 11 317.0402(49), 241.0355(100), 169.0144(76), 125.0240(9) a – 113 Tetra-O-galloylhexoside II 25.15 789.1224 787.0992 0.9 2.3 C 34 H 28 O 22 635.0871(5), 169.0130(1) a Regazzoni et al. (2013) 114 Horridin 25.25 595.1669 – 238 C 27 H 30 O 15 433.1152(48), 301.0714(100) – 115 Pentagalloyl-hexoside I 25.39 941.1328 939.1081 3 9.5 C 41 H 32 O 26 787.1001(4), 617.0767(6), 465.0660(4), 393.0444(81), 317.0402(100), 241.0367(24), 169.0148(27) a Regazzoni et al. (2013) 116 Trigalloyllevoglucosan VIII 25.47 619.0973 617.0833 7.9 41.6 C 27 H 22 O 17 465.0710(6), 393.0458(73), 317.0407(100), 241.0356(22), 169.0150(33) a Chen, and Bergmeier (2011) 117 Mingjinianuronide B 25.55 563.1402 – 1.1 25.8 C 26 H 26 O 14 301.0720(100) Tan and Zuo (1994) 118 Apiin I 25.74 565.1577 563.1385 3.7 13.0 C 26 H 28 O 14 443.1033(8),413.0890(100) a Abu-Reidah et al. (2013) 119 Trigalloyllevoglucosan IX 25.77 619.0961 – 5.1 6.7 C 27 H 22 O 17 301.0698(14),237.0422(4), 153.0186(100) – 120 Apigenin neohesperidoside I 25.82 579.1710 – 0.2 45.6 C 27 H 30 O 14 433.1151(100),271.0606(4) Matsuda (1966) (continued on next page) I.M. Abu-Reidah et al. / Food Chemistry 166 (2015) 179–191 183 Table 1 (continued) Peak No. Tentative assignment t R (min.) [M+H] + (m/z) [MH]  (m/z) Error (ppm) mSigma Molecular formula MS2/MS fragment ions b Reference 121 Quercetin-3-O-(6 00 -3hydroxy-3methylglutaroyl)-âgalactoside 25.84 593.1552 – 8.5 45.0 C 27 H 28 O 15 301.0721(100) Sari, Heikki, Sampo, and Ari (2006) 122 Spicoside E 25.86 615.1353 – 1.3 168.3 C 29 H 26 O 15 303.0516(100),153.0196(70) Albach, Grayer, Kite, and Jensen (2005) 123 Apiin II 25.97 565.1577 – 4.4 8.9 C 26 H 28 O 14 433.1116(99),271.0643(6) Abu-Reidah et al. (2013) 124 Rutin 26.01 611.1627 609.1441 3.3 6.1 C 27 H 30 O 17 303.0512(100) Olchowik et al. (2012) 125 Pentagalloyl-hexoside II 26.19 941.1325 939.1095 1.4 37.1 C 41 H 32 O 26 787.1003(5),393.0445(42), 169.0154(2) a – 126 Isovitexin 26.23 433.1116 – 3 37 C 21 H 20 O 10 415.1022(6),343.0762(10), 313.0719(100) – 127 Petunidin-3-Oglucoside pyruvate 26.30 – 545.0892 8 30 C 21 H 20 O 12 463.0878, 316.0227(100) a Sáenz-navajas et al. (2010) 128 Myricetin-3-Orhamnoside 26.38 465.1027 – 0.1 5.6 C 21 H 20 O 12 319.0460(100) Regazzoni et al. (2013) 129 Digalloyl-hexoyl-ellagic acid 26.43 767.1437 765.0955 1.3 11.1 C 35 H 26 O 20 463.0869(25), 300.9994(100) a Wu et al. (2013) 130 Ellagic acid 26.44 303.0158 – 7.6 5.1 C 14 H 6 O 8 303.0149(42),285.0055(39), 275.0207(69),257.0087(100), 247.0288(35), 229.0161(51), 201.0187(33), 173.0241(12) El Sissi et al. (1972) 131 Chrysoeriol-6-O-acetyl4 0 -b-d-glucoside 26.51 505.1331 – 1.8 30.7 C 24 H 24 O 12 301.0732(100) Chandrashekar et al. (2005) 132 Trigalloyllevoglucosan IX 26.53 619.0966 – 3.7 24.8 C 20 H 26 O 22 301.0692(2), 153.0187(100) – 133 Quercetin-hexose malic acid I 26.56 581.1153 579.0984 1.3 7.2 C 25 H 24 O 16 463.0864(100), 301.0339(6) a Shabana et al. (2011) and Regazzoni et al. (2013) 134 Eriodictyol hexoside or Dihydrokaempferol hexoside II 26.68 – 449.1076 2.9 59.3 C 21 H 22 O 11 287.0560(100), 151.0029(30) a – 135 Quercetin glucoside II 26.71 465.1026 – 0.4 4.7 C 21 H 20 O 12 303.0511(100) Regazzoni et al. (2013) 136 Quercetin glucuronide 26.88 479.0825 477.0670 0.9 6.6 C 21 H 18 O 13 301.0358(100) a Al Sayed et al. (2010) 137 Kaempferol hexoside or Luteolin hexoside I 27.03 449.1086 447.0928 1.1 16.2 C 21 H 20 O 11 285.0415(50) a Buziashvili et al. (1970) 138 Quercetin-hexose malic acid II 27.05 581.1151 579.0982 1.7 10 C 25 H 24 O 16 463.0879(100), 301.0360(9) a Shabana et al. (2011) and Regazzoni et al. (2013) 139 Quercetin glucoside III 27.12 465.1028 – 0.2 21.4 C 21 H 20 O 12 303.0514(100) Regazzoni et al. (2013) 140 Pentagalloyl-hexoside III 27.13 941.1320 939.1096 1.4 34.5 C 41 H 32 O 26 769.0887(6), 617.0777(11), 447.0572(7), 393.0444(22), 317.0402(25), 169.0142(100) a Regazzoni et al. (2013) 141 Kaempferol rutinoside I 27.45 595.1660 – 0.4 52.6 C 27 H 30 O 15 287.0567(100) Ding et al. (2009) 142 Kaempferol-hexose malic acid III 27.49 565.1208 563.1031 2.1 11.1 C 25 H 24 O 15 447.0930(100), 285.0409(4) a Perestrelo et al. (2012) 143 Chrysoriol derivative 27.64 657.1482 – 4.8 11.5 C 31 H 28 O 16 301.0726(100) – 144 Mangiferitin 27.84 261.0394 259.0240 3.3 82.1 C 13 H 8 O 6 191.0312(30) a – 145 Pentagalloyl-hexoside IV 27.86 939.1098 – 1.2 9.8 C 41 H 30 O 26 393.0376(1), 169.0142(100) Regazzoni et al. (2013) 146 1,5-di-O-galloyl-3,4- (S)- hexahydroxydiphenoyl protoquercitol 27.89 771.1085 – 5.9 4.8 C 34 H 26 O 21 153.0186(100) Nishimura et al. (1984) 147 Myricetin-rhamnose malic acid 28.16 581.1149 579.0990 2.6 19 C 25 H 24 O 16 463.0873(100), 316.0223(3), 301.0345(1) a – 148 Dihydroxybenzoic acetate-digallate I 28.18 – 545.0544 5.3 42.7 C 24 H 18 O 15 393.0454(100), 317.0408(11), 169.0136(3) a Hahn and Fekete, 1954 149 Pentagalloyl-hexoside V 28.30 941.1317 939.1088 2.3 9.5 C 41 H 32 O 26 393.0443(22), 169.0135(3) a Regazzoni et al. (2013) 150 Kaempferol rutinoside II 28.31 595.1640 – 2.9 15.7 C 27 H 30 O 15 287.0581(100), 153.0223(8) Ding et al. (2009) 151 Methyl digallate I 28.33 – 335.0403 0.4 7.2 C 15 H 12 O 9 183.0302(100) a Shabana et al. (2011) 152 Kaempferol hexoside or Luteolin hexoside II 28.38 449.1086 447.0930 0.5 9.6 C 21 H 20 O 11 285.0381(29), 284.0318(77) a Buziashvili et al. 1970 and Shrestha et al. (2012) 153 Quercetin arabinoside 28.40 435.0942 433.0760 3.6 18.8 C 20 H 18 O 11 301.0324(39), 300.0261(100) a Buziashvili et al. (1970) 154 Apigenin neohesperidoside II 28.43 579.1717 577.1534 5.1 37.5 C 27 H 30 O 14 269.0452(44) a Matsuda (1966) 155 Methyl digallate II 28.75 337.0578 335.0412 1 1.8 C 15 H 12 O 9 183.0303(100) a Shabana et al. (2011) 156 Kaempferol-hexose malic acid IV 28.96 565.1210 563.1010 5.8 21.2 C 25 H 24 O 15 447.0904(100),285.0426(12) a Perestrelo et al. (2012) 157 Kaempferol 3glucuronide 29.25 463.0902 – 6.7 10.0 C 21 H 18 O 12 287.0574(100) Al Sayed et al. (2010) 184 I.M. Abu-Reidah et al. / Food Chemistry 166 (2015) 179–191 Table 1 (continued) Peak No. Tentative assignment t R (min.) [M+H] + (m/z) [MH]  (m/z) Error (ppm) mSigma Molecular formula MS2/MS fragment ions b Reference 158 Quercetin rhamnoside 29.30 449.1097 447.0925 1.9 3.5 C 21 H 20 O 11 301.0350(100) a Regazzoni et al. (2013) 159 Dihydroxybenzoic acetate-digallate II 29.32 – 545.0546 5 32.1 C 24 H 18 O 15 469.0489(100), 393.5454(21), 169.0144(44) a Hahn and Fekete, 1954 160 Hexagalloyl-hexoside 29.42 – 1091.1192 2.4 3.9 C 48 H 36 O 30 939.0980(1), 769.0780(12), 617.0649, 393.0443(39), 169.0140(34) a Regazzoni et al. (2013) 161 Kaempferol-hexose malic acid V 29.58 565.1152 – 3.7 11.0 C 25 H 24 O 15 287.0549(100) Perestrelo et al. (2012) 162 Dihydroxybenzoic acetate-digallate III 29.62 – 545.0556 3.2 38.7 C 24 H 18 O 15 469.0493(100), 393.5466(15), 169.0147(34) a Hahn and Fekete, 1954 163 Apigenin glucuronide 29.90 447.0928 445.0765 1.5 143.0 C 21 H 20 O 11 271.0613(100) a – 164 Apigenin glucoside II 29.92 433.1143 431.0953 3.2 62.8 C 21 H 22 O 10 271.0618(100) a Shabana et al. (2011) 165 Camellianin A 30.81 621.1855 – 6.7 28 C 29 H 32 O 15 433.1153(100), 313.0726(63), 271.0648(8) – 166 Genistein-hexose malic acid 31.08 549.1265 – 1.7 177.0 C 25 H 24 O 14 271.0605(100) – 167 Galloyl-valoneic acid bilactone 31.11 623.1887 621.0596 2.4 26.6 C 22 H 22 O 21 469.5507(46), 393.5454(2), 169.0139(3) a Sanz et al. (2010) 168 Quercetin-rhamnose malic acid I 31.13 565.1089 563.1024 3.3 4.2 C 25 H 24 O 15 447.0917(100), 301.0354(10) a – 169 Quercetin-rhamnose malic acid II 31.40 565.0903 – 4.4 9.0 C 28 H 20 O 13 303.0520(100) – 170 Myricetin 31.41 319.0457 317.0300 0.8 28.3 C 15 H 10 O 8 287.0218(38), 271.0222(4), 178.9985(85), 151.0036(87), 137.0240(34) a Regazzoni et al. (2013) 171 Dihydroxybenzoic acetate-digallate IV 31.42 – 545.0542 5.7 46.3 C 24 H 18 O 15 393.0465(100), 169.0151(94) a Hahn and Fekete, 1954 172 Quercetin glucoside IV 31.48 465.1026 – 0.3 9.3 C 21 H 20 O 12 303.0520(100), 129.0545(32) Regazzoni et al. (2013) 173 Quercetin-hexose malic acid III 31.62 581.1151 – 2.4 45.4 C 25 H 24 O 16 303.0691(100) – 174 Myricitrin O-gallate 31.80 617.1164 615.0988 0.6 30.5 C 28 H 24 O 16 469.5507(33), 393.0439(10), 317.0299(2), 169.0134(3) a Moharram et al. (2006) 175 Kaempherol rhamnoside 31.92 433.1153 – 5.6 15.7 C 21 H 20 O 10 287.0571(100) Shabana et al. (2011) 176 Quercetin I 32.14 - 301.0346 2.5 12.8 C 15 H 10 O 7 217.0060(2), 191.0389(1), 151.0054(2) a Shabana et al. (2011) and Kosar et al. (2007) 177 Quercetin-hexose malic acid IV 32.20 581.1132 – 0.8 46.4 C 25 H 24 O 16 303.0524(100) – 178 Isorhamentin hexosemalic acid 33.60 595.1376 – 13 49 C 26 H 26 O 16 317.0700(100) – 179 Kaempferol rhamnosemalic acid 33.80 – 547.1060 6.1 31.0 C 25 H 24 O 14 431.0974(100), 285.0396(43) a – 180 Homoprotocatechuic acid 34.15 169.0497 – 1.2 6.0 C 8 H 8 O 4 141.0615(36), 126.0261(56), 108.0218(100), 95.0393(50) – 181 Unknown 34.52 – 593.1327 4.4 31.3 C 30 H 26 O 13 513.1687(18), 441.1239(36) a – 182 Quercitrin 2 00 O-gallate 34.77 – 599.1008 5.8 25.0 C 28 H 24 O 15 301.0358(100) a Moharram et al. (2006) 183 Isorhamnetin hexoside IV 34.81 – 477.1012 5.6 14.7 C 22 H 22 O 12 315.0506(58), 314.0438(80) a – 184 Di-benzopyranofuranacetic acid deriv. 35.31 – 515.0429 7.4 52.0 C 23 H 16 O 14 469.0477(34), 384.0422(42), 303.0118(38), 169.0129(100) a – 185 Luteolin 36.30 287.0562 285.0406 0.6 7.1 C 15 H 10 O 6 217.0486(2), 199.0418(2), 175.0387(1), 151.0038(3), 133.0288(3) a Kim, Chung, Choi, and Park (2009) 186 Quercetin II 36.57 303.0520 301.0352 0.6 2.3 C 15 H 10 O 7 273.0399(13), 229.0504(3), 178.9983(48), 151.0029(100), 121.0292(15) a Shabana et al. (2011) and Kosar et al. (2007) 187 Quercetin dimer 36.59 – 603.0760 3.4 25 C 30 H 20 O 14 301.0354(100) a – 188 Isorhamnetin hexoside V 36.60 – 477.1030 1.8 22.4 C 22 H 22 O 12 315.0517(100), 271.0590(26) a – 189 Afzelin O-gallate 37.11 585.1265 583.1072 3.7 17.2 C 28 H 24 O 14 297.0596(40), 285.0411(100), 169.0108(7) a Moharram et al. (2006) 190 Butein 38.91 273.0773 – 5.7 13.0 C 15 H 12 O 5 142.9542(28), 163.0369(16), 137.0232(100) Lee et al. (2008) 191 Chrysoriol 40.16 301.0692 – 3.0 49.2 C 16 H 12 O 6 286.0470(100), 258.0545(81) – 192 Kaempferol 40.22 287.0556 285.0404 0.3 10.0 C 15 H 10 O 6 257.0437(1), 229.0526(1), 213.0525(1), 201.0348(1), 151.0027(2) a Shabana et al. (2011) 193 Hinokiflavone or Amenthoflavone or Agathisflavone I 41.46 539.0992 537.0822 1.1 4.7 C 30 H 18 O 10 541.2242(13), 425.2128(14), 417.0566(3), 375.0507(13) a Van Loo et al. (1988) 194 Ascorbyl monomyristate 41.60 387.2393 – 4 5.8 C 20 H 34 O 7 121.1006(100) – 195 Dihydroxypalmitic acid 41.92 289.2393 287.2231 6.7 11.1 C 16 H 34 O 4 147.1175(49), 133.1016(73), 121.1025(67), 109.1001(100) a – (continued on next page) I.M. Abu-Reidah et al. / Food Chemistry 166 (2015) 179–191 185 chromatogram (BPC) in positive and negative ionisation modes together with the UV chromatogram at 280 nm in aqueous methanol extract of R. coriaria L. The compounds detected in this work were tentatively characterised by means of MS data, together with the interpretation of the observed MS/MS spectra in comparison with those found in the literature. The formerly identified phytochemicals from the same botanical family or species have been also utilised in the identification when applicable. In the identification process, the following public databases were consulted: ChemSpider (http:// www.chemspider.com), SciFinder Scholar (https://scifinder.cas.org), Kegg Ligand Database (http://www.genome.jp/kegg/ ligand.html), and Phenol-Explorer (www.phenol-explorer.eu). Commercial standards were not available for all the sumac phenolics and phytochemical compounds detected in this work. 3.1.2. Organic acids At the beginning of analysis, several very polar compounds such as malic acid isomers and derivatives have been detected, in accordance with the literature; malic acid was reported to be the most abundant organic acid in R. coriaria (Kossah, Nsabimana, Zhang, Chen, 2010). Thus, compounds 2,7and 8were proposed as malic acid isomers, while 3,4, and 5were suggested as glycosides of malic acid (Ley et al., 2006). 3.1.3. Phenolic acids and derivatives In the present work we were able to characterise 9 phenolic acid derivatives, 3 of which (25,35,43) were detected in negative ionisation mode and show the neutral loss of a hexose moiety. Based on QTOF-MS analysis and MS/MS fragmentation pattern, these compounds were proposed as protocatechuic acid hexoside, syringic acid hexoside and coumaryl-hexoside, respectively. In positive ionisation mode a compound with a major fragment at m/z355.1040 was assigned as caffeoylquinic acid (Fig. 2a), relying on the neutral loss of caffeic acid moiety (162 Da) and the a product ion at m/z193.0494 (quinic acid). Compound 12 (t R 6.75 min), is suggested as caftaric acid. 3.1.4. Phenolic compounds conjugated with malic acid derivatives For the first time, in the present work, the methodology used allowed us to identify 26 unusual phenolics conjugated with glycoside-malic acid. This fragmentation pattern was previously described by Perestrelo et al. (2012). From MS and MS/MS fragmentation pattern data, a dominant neutral loss of 287 Da was observed, which may be attributed to the loss of hexose-malic acid moiety in all 26 detected compounds in both positive and negative ionisation modes. Compounds 27 and 29, with a precursor ion [MH]  at m/z447.0777 and with the identical formula C 17 H 19 O 14 , have been assigned as galloyl-hexose-malic acid Table 1 (continued) Peak No. Tentative assignment t R (min.) [M+H] + (m/z) [MH]  (m/z) Error (ppm) mSigma Molecular formula MS2/MS fragment ions b Reference 196 Hexadecadienoic acid 41.94 253.2180 – 7 1.6 C 16 H 28 O 2 142.9508(100), 132.9601(58), 109.1001(45), 95.0848(88) – 197 Deacetylforskolin 42.12 369.2284 – 3.3 1.3 C 20 H 32 O 6 253.2123(12), 235.2088(14), 217.1924(18) Zhang et al. (2009) 198 Hinokiflavone or Amenthoflavone or Agathisflavone II 42.33 539.0996 537.0818 1.7 12 C 30 H 18 O 10 425.2064(13) a Van Loo et al. (1988) 199 Rhamnetin I 42.43 – 315.0505 0.5 17 C 16 H 12 O 7 179.0352(100),164.0099(32) a Wollenweber (1974) 200 Unknown 42.54 405.2497 403.2315 3.4 5.8 C 20 H 38 O 8 323.2266(13), 305.2146(8), 253.2189(100), 235.2055(87), 217.1956(53) a – 201 Rhamnetin II 43.29 317.0675 315.0511 0.1 6.1 C 16 H 12 O 7 300.0279(27), 193.0141(17), 165.0195(100), 121.0285(17) a Wollenweber (1974) 202 Hinokiflavone or Amenthoflavone or Agathisflavone III 46.86 539.0998 – 4.8 30.5 C 30 H 18 O 10 –Van Loo et al. (1988) 203 Vapiprost 50.57 478.2952 – 0.0 35 C 30 H 39 NO 4 337.2748(100),306.2805(29) – 204 Sespendole 50.77 520.3416 – 0.9 36.4 C 33 H 45 NO 4 184.0743(100),104.1077(31) – 205 Linoleic acid amide 51.17 280.2647 – 4.4 10.4 C 18 H 33 NO 109.1001(59),95.0837(100) – 206 Unknown 52.67 522.3587 – 0.7 33 C 33 H 47 NO 4 184.0736(100) – 207 Linoleylhydroxamate I 53.04 296.2598 – 4.7 3.2 C 18 H 33 NO 2 169.1235(100),95.0840(75) – 208 Unknown 53.17 522.3581 – 0.7 33 C 18 H 33 NO 4 184.0743(100),104.1076(29) – 209 Linoleylhydroxamate II 53.44 296.2584 – 4.7 3.4 C 18 H 33 NO 2 169.1235(100),95.0840(75) – 210 Betunolic acid I 55.12 455.3518 – 0.4 27.8 C 30 H 46 O 3 437.3483(12), 419.3347(17), 295.2454(12), 189.1606(45), 139.1118(100),121.0998(54) Shabana et al. (2011) 211 Triterpenoid derivative 55.44 663.4616 – 0.5 51.7 C 42 H 62 O 6 551.3333(80), 495.2626(100), 439.2103(35) – 212 Moroctic acid 55.66 277.2177 – 5.4 50.8 C 18 H 28 O 2 149.0229(100) – 213 Vebonol 57.17 453.3384 – 4.7 9.1 C 30 H 44 O 3 435.3301(32), 213.1652(27), 201.1641(100) – 214 Betunolic acid II 57.97 455.3535 – 3.3 2.5 C 30 H 46 O 3 201.1633(100),187.1465(66), 161.1301(87), 133.1010(81), 121.1001(79), 109.1015(55) Shabana et al. (2011) 215 Deoxycorticosterone glucoside 58.73 493.2809 –– 2.7 5.3 C 27 H 40 O 8 337.2781(43), 263.2339(31), 109.0987(70), 95.0850(100) – 216 Dihydroisovaltrate 59.17 425.2170 – 0.0 15.6 C 22 H 32 O 8 425.2103(38), 365.1975(64), 281.1337(24) – 217 Oxoglycyrrhetinic acid 59.70 469.3320 – 1.7 13.6 C 30 H 44 O 4 337.2849(3), 221.1595(3), 137.0970(100), 175.1419(8) – Rt: retention time. I, II, III... stand for isomers. a Fragmentation pattern in negative ionization mode. b Between parenthesis (relative intensity %). 186 I.M. Abu-Reidah et al. / Food Chemistry 166 (2015) 179–191 isomers. QTOF-MS analysis showed a product ion at m/z331.0666, [MH116]  , implying the loss of malic acid (C 4 H 4 O 4 ) to give a galloylhexose moiety, and a product ion at m/z169.0153 representing gallic acid. Four digalloyl-hexose malic acid isomers (t R 13.55, 14.26, 15.35, and 16.68 min) were detected in ESImode. Loss of malic acid [MH116]  from the precursor ion at m/z 483.0794 occurred giving a product ion at m/z169.0142 (gallic acid). The QTOF-MS analysis revealed the presence of five isomers of kaempferol hexose-malic acid in the ESIand ESI + modes with ions at m/z563.1010 and 565.1210, respectively. The appearance of fragment ions at m/z447.0904, [MH116]  and a product ion at m/z285.0426 corresponded to kaempferol (Perestrelo et al., 2012). Four isomers of myricetin-hexose malic acid (C 25 H 24 O 17 ) were observed, as shown by the appearance of product ions at m/z319.0466/317.0687, and corresponded to myricetin in structure after the neutral loss of 287 Da (hexose-malic acid moiety loss). At 26.56, 27.05, 31.62 and 32.20 min pseudomolecular ions at m/z581.1151/579.0982 were observed. In the MS/MS spectra, product ions at m/z301.0360/303.0520 (quercetin) were observed. These isomers were assigned as quercetin-hexose malic acid. The product ion at m/z463.0879 was proposed as quercetin hexose, in keeping with a previous report on sumac (Regazzoni et al., 5 Ints. 81, 82 90 126, 128 2.5 5 x10 81, 82 90 128 204 A 2.0 138140 158 158 1.5 105 , 92 144 186 197, 198 203 207 1.0 72-74 8 4- , 107 113 144 - 146 170, 172 186 195, 196 200 203 207 214 0.5 19 58 60, 62, 63 8 88 113 , 114 175 201 214 0.0 0.5 Ints. 58 5 x10 I n t s. 14 2,-4 127 134 144, 148 176, 179 160 167, 168, 170 B 3 113 127 , 134 158 173175 181160 , 162 198 , B 3 23 7 72 92158 , 159 183 , 199 2 23 , 24 2022 36, 37 6062 66 72 94 184 186 195 200 1 3134 62 8991 57 80, 81 105107 184 186 - 188 200 1 40 91 81 201 0 Ints. [ AU ] 14 167 148 600 [ m AU ] 167 , 168 176 C 1 6 2 176 , 179 181183 400 72 112 6 163 183 27 36, 37 0632 66 91 184 124 185 200 18, 20 33 41 47 89 91 124 185 0 38 43 89 0 0 10 20 30 40 50 Time [min] Fig. 1. HPLC–DAD/QTOF-MS base peak chromatograms (BPC) of: (A) MS in positive ion mode, (B) MS in negative ion mode, and (C) UV at 280 nm, for the hydro-methanol extract of sumac fruits. 193.0494 355.1039 0 1000 2000 3000 4000 50 100 150 200 250 300 350 400 450 m/z a. (82) Caffeoylquinic acid O O OH OH HO 2 C OH HO OH [M+H]+ 319.0461 481.0968 0 500 1000 1500 2000 2500 3000 Ints. 300 350 400 450 500 550 600 m/z OHO OH O O OH OH OH O HO OH HO OH b. (102) Ampelopsinglucoside [M-H]- 183.0302 335.0403 0 2000 4000 6000 150 200 250 300 350 400 m/z COOMe OH OH O HO HO OH O e. (151, 155) Methyl digallate [M-H]- [M-H-152]- 287.0581 595.1641 0 1000 2000 3000 4000 100 200 300 400 500 600 700 m/z c. (120, 154) Kaempferol rutinoside O HO OH OH O O O OH O O HO Me OH OH HO HO [M+H]+ [M+H-308]+303.0508 611.1584 0.0 0.5 1.0 1.5 2.0 2.5 4 x10 100 200 300 400 500 600 700 800 900 m/z OH OH O OH HO O O O OH HO HO O O Me HO HO HO d. (124) Rutin [M+H]+ [M+H-308]+ [M+H-162]+ [M-H-162]- Ints. Ints. Ints. Ints. Fig. 2. MS 2 spectra and structure of new phenolics detected in R. coriaria by QTOF-MS in NIM and PIM. I.M. Abu-Reidah et al. / Food Chemistry 166 (2015) 179–191 187