Hplc∓Dad∓ESI-MS/MS Screening of Bioactive Components
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Food Chemistry 166 (2015) 179–191 Contents lists available at ScienceDirect Food Chemistry journal homepage: www.elsevier.com/locate/foodchem 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 abstract Article history: Rhus coriaria L. (sumac) is an important crop widely used in the Mediterranean basin as a food spice, and Received 25 March 2014 also in folk medicine, due to its health-promoting properties. Phytochemicals present in plant foods are in Received in revised form 29 May 2014 part responsible for these consequent health benefits. Nevertheless, detailed information on these Accepted 3 June 2014 bioactive compounds is still scarce. Therefore, the present work was aimed at investigating the Available online 12 June 2014 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 Keywords: phyto-constituents, most of which have not been described so far in R. coriaria fruits. More than 180 Palestinian sumac phytochemicals (tannins, (iso)flavonoids, terpenoids, etc.) are reported herein in sumac fruits for the first Anacardiaceae Hydrolysable tannins time. The obtained results highlight the importance of R. coriaria as a promising source of functional Flavonoids ingredients, and boost its potential use in the food and nutraceutical industries. Mediterranean diet Ó 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license HPLC–DAD–ESI-MS/MS (http://creativecommons.org/licenses/by-nc-nd/3.0/). 1. Introduction is known to possess non-mutagenic, fever-reducing, DNA protec- tive, antiseptic, antifungal, antibacterial, antioxidant, anti-ischae- Sumac, Rhus coriaria L. (Anacardiaceae), is a wild edible plant mic, hypouricemic, hypoglycaemic, and hepatoprotective growing in the Mediterranean region, has long been used as a properties, which support its traditional uses (Anwer et al., 2013; seasoning spice, either in pure form or in combination with other Chakraborty et al., 2009; Madihi et al., 2013; Shafiei et al., 2011). spices (Ali-Shtayeh, & Jamous, 2008), sauce, appetizer, drink, and Among 56 Palestinian plants tested, sumac was found to have as a souring agent in food recipes. R. coriaria L. is an important the greatest antimicrobial effect against Probionibacterium acnes and the most widely used species of the genus Rhus in the (MIC 6 mg/ml, MBC 6 mg/ml), Staphylococcus aureus (MIC 4 mg/ Mediterranean region since antiquity. Recently, the consumption ml, MBC 6 mg/ml), Escherichia coli (MIC 6 mg/ml, MBC 8 mg/ml) of sumac fruits has been increasing around the world as an and Pseudomonas aeruginosa (MIC 4 mg/ml and MBC 6 mg/ml) important economic crop (Kizil, & Turk, 2010). (Ali-Shtayeh, Al-Assali, & Jamous, 2013). In folk medicine and traditional Arabic Palestinian herbal med- The literature lacks detailed information on R. coriaria chemical icine, this plant has been used in the treatment of cancer, stroke, composition. Previous works have reported sumac to contain phe- diarrhoea, hypertension, dysentery, haematemesis, ophthalmia, nolic compounds, such as hydrolysable tannins, anthocyanins and stomach ache, diuresis, diabetes, atherosclerosis, measles, small- also organic acids such as malic and citric acids (Kosar, Bozan, pox, liver disease, aconuresis, teeth and gum ailments, headaches, Temelli, & Baser, 2007; Kossah, Nsabimana, Zhang, & Chen, animal bites, dermatitis, and liver disease (Ali-Shtayeh, & Jamous, 2010). Interestingly, the acidic and astringent tastes, may be due 2008; Shafiei, Nobakht, & Moazzam, 2011). Furthermore, R. coriaria 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 ⇑ Corresponding authors. Tel.: +970 92536406 (M.S. Ali-Shtayeh). Address: acids, vitamins, and minerals (Anwer et al., 2013; Özcan, & Functional Food Research and Development Center (CIDAF), PTS Granada, Avda. Haciseferogullari, 2004). Only a few studies have been carried del, Conocimiento, Edificio Bioregión, 18016 Granada, Spain. Tel.: +34 958248435 out on the chemical composition of R. coriaria leaves (Regazzoni (A. Segura-Carretero). E-mail addresses: [email protected] (M.S. Ali-Shtayeh), [email protected] et al., 2013; Van Loo, De Bruyn, & Verzele, 1988) and little is known (A. Segura-Carretero). about the phytochemical composition of the plant’s fruit epicarps. http://dx.doi.org/10.1016/j.foodchem.2014.06.011 0308-8146/Ó 2014 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/). 180 I.M. Abu-Reidah et al. / Food Chemistry 166 (2015) 179–191 Although R. coriaria is a particularly rich source of phenolic Technologies, Santa Clara, CA) consisting of a vacuum degasser, compounds (Kossah et al., 2010), the phenolic constituents of an auto-sampler, a binary pump and diode-array detector (DAD). sumac fruit’s epicarp remains so far incompletely investigated. This instrument was equipped with an Agilent Zorbax C18 column Thus, detailed and extended profiling of the phytochemicals of (4.6 Â 150 mm, 5 lm) from Agilent Technologies. Acidified water sumac fruits using high sensitive tools is necessary. Consequently, (0.5% acetic acid, v/v) and acetonitrile were used as mobile phases suitable methods need to be established for the identification of A and B, respectively. The gradient was programmed as follows: phytochemicals in plant food matrices (Abu-Reidah, Contreras, 0 min, 0% B; 20 min, 20% B; 30 min, 30% B; 40 min, 50% B; Arráez-Román, Fernández-Gutiérrez, & Segura-Carretero, 2014). 50 min, 75% B; 60 min, 100% B; 62 min 0% B, and finally, the initial Mass spectrometry coupled to high-performance liquid chroma- conditions were held for 8 min as a re-equilibration step. The flow tography (HPLC–MS) has been increasingly used in the structural rate was set at 0.80 mL/min throughout the gradient. The flow characterisation of complex matrices and has proved to be the from the HPLC system into the ESI-Q-TOF-MS detector was tool of choice to identify phenolic compounds (Abu-Reidah, 0.2 mL/min. The injection volume was 10 lL and the column Arráez-Román, Lozano-Sánchez, Segura-Carretero, & Fernández- temperature was maintained at 25 °C. Gutiérrez, 2013; Abu-Reidah, Arráez-Román, Segura-Carretero, & The HPLC system was coupled to a quadrupole-time-of-flight Fernández-Gutiérrez, 2013; Lee, Zweigenbaum, & Mitchell, 2013). (micrOTOF-Q™, Bruker Daltonik GmbH, Bremen, Germany) Therefore, the objective of the present study was to investigate orthogonal accelerated Q-TOF mass spectrometer, equipped with the phytochemical composition of hydro-methanolic extracts of R. an electrospray ionisation source (ESI). Parameters for analysis coriaria fruits cultivated in Palestine, by using high-performance were set using negative and positive ion modes, with spectra liquid chromatography-diode array detector-hyphenated with acquired over a mass range from m/z 50 to 1100. The optimum val- tandem mass spectrometry (HPLC–DAD–ESI-MS/MS) as a potent ues of the ESI-MS parameters were: capillary voltage, À3.5 and analytical technique. +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 2. Materials and methods time 70 ls, and pre-pulse storage, 5 ls. Moreover, automatic MS/ MS experiments were performed adjusting the collision energy 2.1. Chemicals values as follows: m/z 100, 20 eV; m/z 500, 30 eV; m/z 1000, 35 eV, using nitrogen as collision gas. The MS data were processed Acetonitrile and methanol of analytical or HPLC grade were pur- through Data Analysis 4.0 software (Bruker Daltonics, Bremen, chased from Labscan (Dublin, Ireland). Acetic acid of analytical Germany) which provided a list of possible elemental formulas grade (assay >99.5%) was purchased from Fluka (Switzerland). by using the Generate Molecular Formula™ editor. The editor uses Water was purified by using a Milli-Q system (Millipore, Bedford, a CHNO algorithm, which provides standard functionalities, such USA). as maximum/minimum elemental range, and a sophisticated com- parison of the theoretical with the measured isotope pattern (mSigma value), for increasing the confidence in the suggested 2.2. Sample preparation molecular formula. The widely accepted accuracy for confirmation of elemental compositions has been established as 5 ppm. Sumac is commercially obtainable in local markets in ready- At some stage in the HPLC method development, an external to-use ground form. In our present study, for quality control apparatus calibration was performed using a Cole Palmer syringe considerations, sumac samples were harvested in their mature pump (Vernon Hills, IL) directly linked to the interface, passing a stage from the wild habitat mountains of Nablus (Qusra village) solution of sodium acetate. Using this method, an exact calibration in summer of 2012 and were identified by Prof. Mohammad curve based on numerous cluster masses each differing by 82 Da S. Ali-Shtayeh from BERC. Collected sumac samples were dried, (C2H3NaO2) was obtained. Due to the compensation of tempera- and then epicarps of R. coriaria L. fruits were liberated from kernels ture drift in the Q-TOF, this external calibration provided accurate and ground into powder using a household mill and stored at room mass values for a complete run without the need for a dual sprayer temperature until they were used for extraction.