Anal Bioanal Chem DOI 10.1007/s00216-016-9376-4 RESEARCH PAPER Comparative metabolite profiling and fingerprinting of genus Passiflora leaves using a multiplex approach of UPLC-MS and NMR analyzed by chemometric tools Mohamed A. Farag1 & Asmaa Otify 1 & Andrea Porzel2 & Camilia George Michel1 & Aly Elsayed1 & Ludger A. Wessjohann2 Received: 9 December 2015 /Revised: 19 January 2016 /Accepted: 28 January 2016 # Springer-Verlag Berlin Heidelberg 2016 Abstract Passiflora incarnata as well as some other those of C-flavonoids including isovitexin-2″-O-xyloside, Passiflora species are reported to possess anxiolytic and sed- luteolin-C-deoxyhexoside-O-hexoside, schaftoside, ative activity and to treat various CNS disorders. The medic- isovitexin, and isoorientin. P. inc arn ata was found most inal use of only a few Passiflora species has been scientifical- enriched in C-flavonoids, justifying its use as an official drug ly verified. There are over 400 species in the Passiflora genus within that genus. Compared to NMR, LC-MS was found worldwide, most of which have been little characterized in more effective in sample classification based on genetic and/ terms of phytochemical or pharmacological properties. or geographical origin as revealed from derived multivariate Herein, large-scale multi-targeted metabolic profiling and fin- data analyses. Novel insight on metabolite candidates to me- gerprinting techniques were utilized to help gain a broader diate for Passiflora CNS sedative effects is also presented. insight into Passiflora species leaves’ chemical composition. Nuclear magnetic resonance spectroscopy (NMR) and mass Keywords Passiflora . C-glycosides . Chemotaxonomy . spectrometry (MS) spectra of extracted components derived Biomarkers . Flavonoids . Multivariate data analysis . from 17 Passiflora accessions and from different geographical UPLC-MS . NMR origins were analyzed using multivariate data analyses. A total of 78 metabolites were tentatively identified, that is, 20 C- flavonoids, 8 O-flavonoids, 21 C, O-flavonoids, 2 cyanogenic Introduction glycosides, and 23 fatty acid conjugates, of which several flavonoid conjugates are for the first time to be reported in Passifloraceae is a family of flowering plants, including over Passiflora spp. To the best of our knowledge, this study pro- 700 species classified in around 25 genera [1]. They are most- vides the most complete map for secondary metabolite distri- ly found in tropical and temperate regions including ornamen- bution within that genus. Major signals in 1H-NMR and MS tal plants such as Passiflora incarnata L., Passiflora foetida spectra contributing to species discrimination were assigned to L. as well as commercialized species as Passiflora edulis Sims and Passiflora laurifolia L., both widely cultivated for their edible fruits. The genus Passiflora from the Passifloraceae Electronic supplementary material The online version of this article plant family comprises about 400 dicotyledonous species, (doi:10.1007/s00216-016-9376-4) contains supplementary material, and the genus is considered the largest and namesake of the which is available to authorized users. Passifloraceae family [2]. Several species have a long history * Mohamed A. Farag in traditional herbal medicine, though the medicinal use has [email protected]; [email protected] been scientifically verified only for very few Passiflora spe- cies to varied extents. Aerial parts of Passiflora species have been traditionally used to treat anxiety, insomnia, and ner- 1 Pharmacognosy Department, College of Pharmacy, Cairo University, vousness [3]. In particular, P. incarnata L. (passion flower) Kasr el Aini St., Cairo P.B. 11562, Egypt is regarded as the most common species used in contemporary 2 Department of Bioorganic Chemistry, Leibniz Institute of Plant Western phytotherapy for the treatment of anxiety disorders Biochemistry, Weinberg 3, 06120 Halle (Saale), Germany [4]. Other reported biological activities include antioxidant, M.A. Farag et al. antihypertensive, anti-inflammatory, antitumor, and antimi- Plant material crobial effects [5]. P.incarnata L. is indeed listed as an official plant drug in the 1970s and 1990s in several pharmacopoeias Leaves from 17 different species within the genus Passiflora [6–8]. Passion extracts are worldwide distributed in health (a total of 20 samples) were collected from different geograph- stores and often formulated with other herbal drugs as cham- ical origins (Table 1). omile, hops, kava, skullcap, and valerian in nutraceuticals used as sedatives. Several Passiflora species have been ana- Chemicals and reagents lyzed with respect to their flavonoid composition, being a rich source of the otherwise rare C-glycosyl flavones [9, 10]. Methanol-d4 (99.80 % D), acetone-d6 (99.80 % D), and Nevertheless, several metabolites, i.e., maltol [11], alkaloids hexamethyldisiloxane (HMDS) were provided from Deutero [12], and essential oil [13, 14], have also been proposed to GmbH (Kastellaun, Germany). Acetonitrile and formic acid mediate for Passiflora pharmacological effects. The active (LC-MS grade) were purchased from J. T. Baker principles have not yet been fully identified which warrants (The Netherlands); Milli-Q water was used for LC analysis. for a more detailed, initially untargeted type of analysis to Vitexin, isovitexin, harmine, orientin, and isoorientin were provide better insight on the global chemical composition of purchased from Chromadex (Wesel, Germany). All other that genus. Metabolomics is defined as the comprehensive chemicals and standards were provided by Sigma-Aldrich analysis of thousands of metabolites (metabolome), providing (St. Louis, MO, USA). a way for accurate analysis and or standardization of herbal products. The metabolomic technique enables large numbers Extraction procedure and sample preparation for NMR of samples to be processed quickly and simultaneously “glob- and MS analyses al approach”; in an untargeted manner, such approach often utilizes hyphenated analytical techniques most commonly liq- A one pot extraction protocol developed in Farag et al. [20] uid chromatography (LC) coupled to mass spectrometry (MS) was used for extraction of Passiflora specimens. Dried and or direct analysis using nuclear magnetic resonance spectros- deep frozen Passiflora leaves were ground with a pestle in a copy (NMR). Such technologies have great potential for ac- mortar using liquid nitrogen. The powder (120 mg) was ho- curate analyses or standardization of herbal products. mogenized with 5 ml 100 % MeOH containing 10 μg/ml Successful examples for the use of metabolomics in quality umbelliferone (an internal standard for relative quantification control of herbal drugs involve analyses of licorice [15], ephe- using UPLC-MS) using a Turrax mixer (11,000 RPM) for five dra [16], hops [17, 18], or St. John’sWort[19]. Combination 20-s periods. To prevent heating, a period of 1 min separated of the complementary advantages of both platforms, i.e., pow- each mixing period. Extracts were then vortexed vigorously erful NMR structural elucidation accuracy and MS high sen- and centrifuged at 3000×g for 30 min to remove plant debris. sitivity and peak resolution, was employed to profile metabo- For NMR analysis, 3 ml was aliquoted using a syringe and the lites in 17 different Passiflora species. Our aim is to explore solvent was evaporated under a stream of nitrogen to dryness. variation in secondary metabolites from a wide range of Dried extracts were resuspended with 800 μl100%methanol- Passiflora species in terms of genotypes and geographical d4 containing HMDS. After centrifugation (13,000×g for origins to provide a detailed map for metabolite pattern- 1 min), the supernatant was transferred to a 5-mm NMR tube. based taxonomy, quality control analysis, and to help identify All 1H-NMR spectra for multivariate data analysis were ac- alternatives for the official drug P. incarnata. To achieve our quired consecutively within a 48-h time interval with samples goal, metabolite profiling and fingerprinting using ultra per- prepared immediately before data acquisition. Repeated con- formance liquid chromatography (UPLC)-MS in parallel to trol experiments after 48 h showed no additional variation. For NMR techniques were employed for the analysis of the offi- UPLC-MS analyses, 500 μl was aliquoted and placed on a cial P. in carn ata leaves from three geographical origins. (500 mg) C18 cartridge preconditioned with methanol and Additionally, metabolic profiles of 16 other different water. Samples were then eluted using 6 ml methanol, the Passiflora leaf extracts (Table 1) were performed to help iden- eluent was evaporated under a nitrogen stream, and the ob- tify a substitute candidate and for drug quality control analysis tained dry residue was resuspended in 1 ml methanol. Three and or adulteration detection. microliters was used for UPLC-MS analysis. For each speci- men, three biological replicates were provided and extracted in parallel under identical conditions. Experimental High resolution UPLC-PDA-MS and MS/MS analysis Materials and methodology used in this study were applied Chromatographic separations were performed on an Acquity following the protocol of Farag et al. [20]. UPLC system (Waters) equipped with a HSS T3 column Comparative metabolite profiling and fingerprinting of Passiflora leaves Table 1 Origin of Passiflora leaf samples used in this study Species Country Herbarium voucher Passiflora ambigua Hemsl. Germany, Botanische Gärten der Universität