title: Determination of polyphenolic compounds by liquid chromatography-mass spectrometry in Thymus species.
abstract: Polyphenolic compounds represent a wide group of phytochemicals, including well-known subgroups of phenolic acids, flavonoids, natural dyes, lignans etc., which are produced by plants. These natural bioactive compounds possess a variety of beneficial effects including antioxidant and anticarcinogenic activities, protection against coronary diseases as well as antimicrobial properties. Thymus species have already been reported as sources of different phenolic acids and flavonoids. Moreover, the composition and content of flavonoids in Thymus species play important role as taxonomic markers providing distinction of species. High-performance liquid chromatography (HPLC) coupled with diode array detector (DAD) and on-line mass spectrometry (ESI-MS) method was used for analysis. The method was evaluated for a number of validation characteristics (repeatability and intermediate precision, LOD, LOQ, calibration range, and recovery). The polyphenolic pattern of five native Hungarian Thymus species (T. glabrescens Willd., T. pannonicus All., T. praecox Opiz, T. pulegioides L., and T. serpyllum L.) was characterized. The dominant compound was rosmarinic acid, which ranged between 83.49 μg g(-1) and 1.436 mg g(-1). Other phenolic acids (ferulic acid, caffeic acid and its other derivatives, chlorogenic acid and p-coumaric acids) were present in every examined Thymus species, as well as flavanones: naringenin, eriodictyol and dihydroquercetin; flavones: apigenin and apigenin-7-glucoside, flavonols: quercetin and rutin. The polyphenolic pattern was found to be a useful additional chemotaxonomic tool for classification purposes and determination of the locality of origin.
authors.affiliation: Department of Analytical and Environmental Chemistry, Faculty of Science, University of Pécs, Ifjúság útja 6, H-7624 Pécs, Hungary.
authors.forename: Borbála
authors.initials: B
authors.lastname: Boros
authors.forename: Silvia
authors.initials: S
authors.lastname: Jakabová
authors.forename: Agnes
authors.initials: A
authors.lastname: Dörnyei
authors.forename: Györgyi
authors.initials: G
authors.lastname: Horváth
authors.forename: Zsuzsanna
authors.initials: Z
authors.lastname: Pluhár
authors.forename: Ferenc
authors.initials: F
authors.lastname: Kilár
authors.forename: Attila
authors.initials: A
authors.lastname: Felinger
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005419:Flavonoids / Q000032:analysis*; D010636:Phenols / Q000032:analysis*; D010936:Plant Extracts / Q000032:analysis*; D059808:Polyphenols; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D046930:Thymus Plant / Q000737:chemistry*
chemical_list: D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; D059808:Polyphenols