Plants produce a great number of metabolites with potentially useful biological activities. Species from the genus Globularia (Plantaginaceae) are known as sources of different phenolic and iridoid compounds. Globularia alypum L. is a medicinal plant used as a healing agent in many Mediterranean countries. Similarities in phytochemical composition are often observed for related species. For Globularia spp., such findings were mostly based on identification of several isolated compounds from distinct species. To our knowledge, this is the first study that enables simultaneous comparison of phytochemical profiles from several members of the genus Globularia. Liquid chromatography-photodiode array detection-electrospray ionization-tandem mass spectrometry was used for the analysis of methanolic extracts of aerial parts obtained from four Globularia species (G. alypum, G. punctata, G. cordifolia and G. meridionalis). In total, 85 compounds were identified or tentatively identified based on comparison of their retention time, UV and MS (up to MS ) spectra to those of standard compounds and/or to literature data. Among these, high relative amounts of bioactive molecules such as globularin, globularifolin, asperuloside and verbascoside (acteoside) were found. Apart from providing new insights into the phytochemistry and chemotaxonomy of selected Globularia species, results of this study complement existing MS/MS spectral data and could enable easier mass spectrometric profiling of certain bioactive compounds such as iridoids and phenylethanoids in related plant species, genera and families. Copyright © 2016 John Wiley & Sons, Ltd.

Research background. Mastic tree (Pistacia lentiscus L.) of the Anacardiaceae family is an evergreen shrub from Mediterranean countries where it is used in traditional medicine. Analysis of P. lentiscus leaf, stem, fruit and root extracts showed high concentrations of principal groups of secondary metabolites (flavonoids, phenolic acids and tannins), suggesting the plant possesses great biological potential. Therefore, the aim of this research is to evaluate the impact of environmental parameters and the extraction solvent type on the concentration of phenols in mastic tree leaf extracts grown at four different locations along the Adriatic coast (Barbariga, Lun, Hvar and Vela Luka) during three phenological stages (early flowering, early fruiting and late fruiting). Experimental approach. Since mastic tree plant has phenolic compounds with different structures and chemical properties, ethanolic and methanolic leaf extracts were analysed using high-performance liquid chromatography (HPLC) coupled with UV/Vis PDA detector. Phenolic compounds were identified by comparing the retention times and spectral data with those of standards at 280 and 340 nm. Results and conclusions. In all samples, phenolic acids and flavonol glycosides were quantified, while catechin was quantified only in methanolic extracts. The 5-O-galloylquinic acid was determined as a predominant phenolic compound in all samples followed by monogalloyl glucose, 3,5-di-O-galloylquinic acid, 3,4,5-tri-O-galloylquinic acid and gallic acid, respectively. Myricetin-3-O-rhamnoside was found to be the predominant flavonol glycoside followed by myricetin-3-O-glucoside, myricetin-3-O-glucuronide, quercetin-3-O-rhamnoside and derivative of flavonol glycoside. The mass concentration of these compounds significantly varied during different phenological stages, at different growing locations and used extraction solvents. The highest phenolic mass concentration was determined in the samples harvested at Hvar growing location and extracted in 80 % methanol. The highest total phenolic acid mass concentration was obtained in the samples harvested during the flowering phenological stage and the highest total flavonoid mass concentration in the samples harvested during the early fruiting stage. Novelty and scientific contribution. The obtained data provide a better understanding of the P. lentiscus species phenolic concentration, which can lead to further investigations regarding the valorisation of mastic tree leaves as pharmaceutical products or as food products with added value.

Total phenolic, flavonoid, condensed tannin and iridoid content, as well as antioxidant capacityin vitro,were determined spectrophotometrically in methanolic extracts of different plant parts of the Mediterranean medicinal plantGlobularia alypumL. and three widespread European species of the same genus:G. cordifoliaL.,G. meridionalis(Podp.) O. Schwarz andG. punctataLapeyr. In order to consider possible environmental influences on the production of specialized metabolites, each species, exceptG. alypum, was collected from three different natural populations. Great variations in the amounts of specialized metabolites were observed among different plant parts and species. For example, total phenolic content ranged from 10.13 (G. punctata, flowers) to 44.90 (G. cordifolia, flower stems) mg gallic acid equivalent g−1dry weight. Moreover, great differences, attributed to location-specific environmental factors, were observed among different populations of the same species. For example, a strong positive correlation was observed among mean monthly temperatures and total phenolic contents in the leaves of studiedGlobulariaspp. (r = 0.75, p = 0.019). However, despite these differences, all species were rich in bioactive substances when compared toG. alypum, especially in their aerial parts. A very good positive correlation was observed between total phenolic content and DPPH radical scavenging capacity (r = 0.86, p < 0.001)/ABTS radical scavenging capacity (r = 0.83, p < 0.001). The results obtained show thatG. cordifolia,G. meridionalisandG. punctataare rich in bioactive substances, providing support for their pharmaceutical utilization. Further investigations are needed to verify the possibility of their medicinal use.

Species from the genus Globularia L. have been used as healing agents for various ailments, with utilization of Globularia alypum L. being most frequently reported. The aim of this study was to evaluate the antidiabetic, antioxidant, anti-inflammatory, antibacterial and anticancer potential of G. alypum and three related species, G. punctata Lapeyr., G. cordifolia L. and G. meridionalis (Podp.) O.Schwarz, in relation to their phytochemical compositions. Globularin and verbascoside were identified using LC-PDA-ESI-MSn as the major metabolites of G. alypum with known biological activities. G. alypum demonstrated the greatest α-glucosidase inhibitory activity and DPPH radical scavenging activity (IC50 = 17.25 μg/mL), while its anti-inflammatory activity was not significantly different from those of related species. All investigated species showed considerable antibacterial activity against methicillin-resistant Staphylococcus aureus in the broth microdilution method (MIC = 1.42–3.79 mg/mL). G. punctata also showed antibacterial activities against Escherichia coli (MIC = 1.42 mg/mL), Bacillus subtilis (MIC = 1.89 mg/mL), B. cereus (MIC = 2.84 mg/mL) and Enterococcus faecalis (MBC = 5.68 mg/mL). G. punctata, G. cordifolia and G. meridionalis showed greater anticancer potential than G. alypum. Obtained results indicate investigated Globularia species could serve as sources of diverse bioactive molecules, with G. punctata having the greatest antibacterial potential.

Qualitative phytochemical analyses of eight species from the genus Galium (G. corrudifolium, G. cruciata, G. divaricatum, G. lucidum, G. mollugo, G. palustre, G. parisiense, and G. verum), followed by spectrophotometric evaluation of their total phenolic, flavonoid and iridoid content, as well as antiradical capacity, were conducted. G. cruciata contained the greatest amount of total phenolics (111.00 mg gallic acid equivalents g-1 dry extract), while G. verum had the greatest amount of flavonoids (23.11 mg quercetin equivalents g-1 dry extract) and iridoids (461.30 mg aucubin equivalents g-1 dry extract). The best antioxidant (antiradical) activity was shown by G. cruciata (IC50 (ABTS) = 30.30 µg mL-1 ; IC50 (DPPH) = 27.62 µg mL-1), followed by G. divaricatum, G. verum and G. palustre. The same species were rich in various bioactive constituents and would be appropriate for inclusion in further investigations considering their biomedical potential.