Development and Validation of an Analytical Methodology Based on Liquid Chromatography-Electrospray Tandem Mass Spectrometry for the Simultaneous Determination of Phenolic Compounds in Olive Leaf Extract

Application of Liquid Chromatography-Ion Mobility Spectrometry-Mass Spectrometry-Based Metabolomics to Investigate the Basal Chemical Profile of Olive Cultivars Differing in Verticillium dahliae Resistance

The limited effectiveness of current strategies to control Verticillium wilt of olive (VWO) prompts the need for innovative approaches. This study explores the basal metabolome of 43 olive cultivars with varying resistance levels to Verticillium dahliae, offering alternative insights for olive crossbreeding programmes. The use of an innovative UHPLC-ESI-TimsTOF MS/MS platform enabled the annotation of more than 70 compounds across different olive organs (root, stem, and leaf) and the creation of a preliminary compilation of TIMSCCSN2 experimental data for more reliable metabolite annotation. Moreover, it allowed the documentation of numerous isomeric species in the studied olive organs by resolving hidden compounds. Multivariate statistical analyses revealed significant metabolome variability between highly resistant and susceptible cultivars, which was further investigated through supervised PLS-DA. Key markers indicative of VWO susceptibility were annotated and characteristic compositional patterns were established. Stem tissue exhibited the highest discriminative capability, while root and leaf tissues also showed significant predictive potential.

Secondary Metabolites and Antioxidant Activity against Moko Disease as a Defense Mechanism of Musa spp. from the Ecuadorian Coast Area

The Musa spp. represents the most commonly produced, transitioned, and consumed fruit around the globe, with several important applications in the biotechnology, pharmaceutical, and food industries. Moko disease is produced by Ralstonia solanacearum-a factor with a high impact on all crops in Ecuador, representing one of the biggest phytosanitary problems. Four of the most common varieties of Musa spp. were tested to identify the metabolic reaction of plants facing Moko disease. The phenolic and flavonoid content has been evaluated as a defense system, and the α-diphenyl-α-picrylhydrazyl free-radical-scavenging method (DPPH), free-radical-scavenging activity (ABTS), ferric-reducing antioxidant power (FRAP) assays, and liquid chromatography and mass spectrometry (LC-MS) have been adapted to analyze the active compounds with the antioxidant capacity necessary to counteract the pathogenic attack. Our results indicate that all the studied varieties of Musa spp. react in the same way, such that the diseased samples showed a higher accumulation of secondary metabolites with antioxidant capacity compared with the healthy ones, with high active compound synthesis identified during the appearance of Moko disease symptoms. More than 40 compounds and their derivatives (from kaempferol and quercetin glycosides) with protective roles demonstrate the implication of the Musa spp. defense system against R. solanacearum infection.

Phenolic Compound Profiles, Cytotoxic, Antioxidant, Antimicrobial Potentials and Molecular Docking Studies of Astragalus gymnolobus Methanolic Extracts

Since Astragalus is a genus with many important medicinal plant species, the present work aimed to investigate the phytochemical composition and some biological activities of Astragalus gymnolobus. The methanolic fractions of four organs (stems, flowers, leaves, root and whole plant) were quantified and identified by Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (LC-ESI-MS/MS) analysis. Hesperidin, hyperoside, p-hydroxybenzoic acid, protocatechuic acid and p-coumaric acid were identified as main compounds among the extracts. Among all cells, leaf methanol (Lm) extract had the highest cytotoxic effect on HeLa cells (IC50 = 0.069 μg/mL). Hesperidin, the most abundant compound in A. gymnolobus extract, was found to show a strong negative correlation with the cytotoxic effect observed in HeLa cells according to Pearson correlation test results and to have the best binding affinity to targeted proteins by docking studies. The antimicrobial activity results indicated that the most susceptible bacterium against all extracts was identified as Streptococcus pyogenes with 9-11 mm inhibition zone and 8192 mg/mL MIC value. As a result of the research, it was suggested that A. gymnolobus could be considered as a promising source that contributes to the fight against cancer.

Characterization of the Metabolic Profile of Olive Tissues (Roots, Stems and Leaves): Relationship with Cultivars' Resistance/Susceptibility to the Soil Fungus Verticillium dahliae

Verticillium wilt of olive (VWO) is one of the most widespread and devastating olive diseases in the world. Harnessing host resistance to the causative agent is considered one of the most important measures within an integrated control strategy of the disease. Aiming to understand the mechanisms underlying olive resistance to VWO, the metabolic profiles of olive leaves, stems and roots from 10 different cultivars with varying levels of susceptibility to this disease were investigated by liquid chromatography coupled to mass spectrometry (LC-MS). The distribution of 56 metabolites among the three olive tissues was quantitatively assessed and the possible relationship between the tissues' metabolic profiles and resistance to VWO was evaluated by applying unsupervised and supervised multivariate analysis. Principal component analysis (PCA) was used to explore the data, and separate clustering of highly resistant and extremely susceptible cultivars was observed. Moreover, partial least squares discriminant analysis (PLS-DA) models were built to differentiate samples of highly resistant, intermediate susceptible/resistant, and extremely susceptible cultivars. Root models showed the lowest classification capability, but metabolites from leaf and stem were able to satisfactorily discriminate samples according to the level of susceptibility. Some typical compositional patterns of highly resistant and extremely susceptible cultivars were described, and some potential resistance/susceptibility metabolic markers were pointed out.

Optimization of Ultrasound- and Microwave-Assisted Extraction for the Determination of Phenolic Compounds in Peach Byproducts Using Experimental Design and Liquid Chromatography-Tandem Mass Spectrometry

The conversion of plant byproducts, which are phenolic-rich substrates, to valuable co-products by implementing non-conventional extraction techniques is the need of the hour. In the current study, ultrasound- (UAE) and microwave-assisted extraction (MAE) were applied for the recovery of polyphenols from peach byproducts. Two-level screening and Box-Behnken design were adopted to optimize extraction efficiency in terms of total phenolic content (TPC). Methanol:water 4:1% v/v was the extraction solvent. The optimal conditions of UAE were 15 min, 8 s ON-5 s OFF, and 35 mL g^-1, while MAE was maximized at 20 min, 58 °C, and 16 mL g^-1. Regarding the extracts' TPC and antioxidant activity, MAE emerged as the method of choice, whilst their antiradical activity was similar in both techniques. Furthermore, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated to determine chlorogenic acid and naringenin in byproducts' extracts. 4-Chloro-4'-hydroxybenzophenone is proposed as a new internal standard in LC-MS/MS analysis in foods and byproducts. Chlorogenic acid was extracted in higher yields when UAE was used, while MAE favored the extraction of the flavonoid compound, naringenin. To conclude, non-conventional extraction could be considered as an efficient and fast alternative for the recovery of bioactive compounds from plant matrices.

Phytochemical Analysis, Antioxidant, and Antimicrobial Activities of Ducrosia flabellifolia: A Combined Experimental and Computational Approaches

Ducrosia flabellifolia Boiss. is a rare desert plant known to be a promising source of bioactive compounds. In this paper, we report for the first time the phytochemical composition and biological activities of D. flabellifolia hydroalcoholic extract by using liquid chromatography-electrospray tandem mass spectrometry (ESI-MS/MS) technique. The results obtained showed the richness of the tested extract in phenols, tannins, and flavonoids. Twenty-three phytoconstituents were identified, represented mainly by chlorogenic acid, followed by ferulic acid, caffeic acid, and sinapic acid. The tested hydroalcoholic extract was able to inhibit the growth of all tested bacteria and yeast on agar Petri dishes at 3 mg/disc with mean growth inhibition zone ranging from 8.00 ± 0.00 mm for Enterococcus cloacae (E. cloacae) to 36.33 ± 0.58 mm for Staphylococcus epidermidis. Minimal inhibitory concentration ranged from 12.5 mg/mL to 200 mg/mL and the hydroalcoholic extract from D. flabellifolia exhibited a bacteriostatic and fungistatic character. In addition, D. flabellifolia hydroalcoholic extract possessed a good ability to scavenge different free radicals as compared to standard molecules. Molecular docking studies on the identified phyto-compounds in bacterial, fungal, and human peroxiredoxin 5 receptors were performed to corroborate the in vitro results, which revealed good binding profiles on the examined protein targets. A standard atomistic 100 ns dynamic simulation investigation was used to further evaluate the interaction stability of the promising phytocompounds, and the results showed conformational stability in the binding cavity. The obtained results highlighted the medicinal use of D. flabellifolia as source of bioactive compounds, as antioxidant, antibacterial, and antifungal agent.

Extraction of Polyphenols from Olive Leaves Employing Deep Eutectic Solvents: The Application of Chemometrics to a Quantitative Study on Antioxidant Compounds

The extraction of phenolic compounds from olive leaves was optimized using three glycerol-based deep eutectic solvents (DESs) with lysine, proline, and arginine. A three-level Box–Behnken design was used to examine the influence of the liquid/solid ratio, concentration of DESs, and extraction temperature on the yield of the extraction process. A second-order polynomial model was used for predicting the polyphenol extraction yield. The optimal predicted conditions were used for extractions and they provided the highest total phenol yields with the glycerol–lysine exhibiting the best performance. Quantification of tyrosol, hydroxytyrosol, oleuropein, luteolin-7-O-glucoside, and rutin in the extracts showed high content in tyrosol in all DESs, particularly with glycerol–lysine and relatively similar contents with other studies for the other phenolic compounds. Finally, a linear relationship between tyrosol content and the total phenolic content of the extracts was observed.

Innovative Extraction Technologies for Development of Functional Ingredients Based on Polyphenols from Olive Leaves

Olive tree (Olea europea L.) leaves represent around 10% of the total weight of olives arriving at any given mill, which are generally discarded, causing economic and environmental issues. However, these are rich sources of natural bioactive compounds (i.e., polyphenols), which have health-promoting potential. Thus, the valorization of olive leaves by recovering and reusing their components should be a must for food sustainability and circular economy. This review provides an insight into the principal polyphenols present in olive leaves, together with agronomic variables influencing their content. It also summarizes the recent advances in the application of novel extraction technologies that have shown promising extraction efficacy, reducing the volume of extraction solvent and saving time and cost. Moreover, potential industrial uses and international patents filed in the pharmaceutic, food, and cosmetic sectors are discussed.

Determination of the Chemical Composition, Antioxidant, and Enzyme Inhibitory Activity of Onosma mollis DC

Onosma species have long been used traditionally for respiratory tract infections, abdominal pain, wound treatment, burns, and constipation. This study aims to investigate the chemical composition and in vitro antioxidant and enzyme inhibitory activities of ethyl acetate (EtOAc), methanol (MeOH), and water extracts of Onosma mollis DC. MeOH extract was richer in both phenolics and flavonoids than other extracts (44.06 mg GAEs/g and 41.57 mg QEs/g, respectively). The findings obtained from the results of the chromatographic analysis also supported the results of the spectrophotometric analysis. The MeOH extract was the richest in terms of most of the phytochemicals screened. Apigenin 7-glucoside, luteolin 7-glucoside, rosmarinic acid, vanillic acid, and pinoresinol were over 1000.0 μg/g in MeOH extract. The extract in question showed the highest activity in phosphomolybdenum, DPPH, and ABTS radical scavenging and CUPRAC and FRAP reducing power activity assays (2.01, 3.33, 2.30, 1.48, and 0.79 mg/ml, respectively). The water extract presented the highest activity in the ferrous ion chelating assay (1.01 mg/ml). While EtOAc extract showed high activity in acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glucosidase inhibitory activity tests (1.11, 1.49, and 1.07 mg/ml, respectively), MeOH extract showed significant efficacy in tyrosinase and α-amylase inhibitory activity assays (2.94 and 2.08 mg/ml, respectively). There was a high correlation between the total phenolics/flavonoids of the extracts and their antioxidant activities (correlation coefficients were over 0.9). In addition, the phytochemicals mentioned above were found to contribute significantly to the antioxidant activity. It was concluded that a more detailed analysis should be done to determine the compounds responsible for the enzyme inhibitory activities of the extracts.

Phytochemical Composition, Antioxidant, and Enzyme Inhibition Activities of Methanolic Extracts of Two Endemic Onosma Species

Onosma species have been used as a dye for hundreds of years due to their dark red pigments. These species have also been used by mankind in the treatment of various diseases since ancient times. This work analyzed the phytochemical composition in methanol extract of two endemic Onosma species (O. lycaonica and O. papillosa). Methanolic extract of these species varied in the content of flavonoids and phenolics. The flavonoids were found higher in O. papillosa [32.9 ± 0.3 mg QEs (quercetin equivalent)/g extracts] while the phenolics were higher in O. lycaonica [43.5 ± 1.5 mg GAEs (gallic acid equivalent)/g extracts]. ESI-MS/MS (electrospray ionization-mass spectrometry) revealed the presence of 25 compounds in O. lycaonica and 24 compounds in O. papillosa. The former was richer than the latter for apigenin, luteolin, eriodictyol, pinoresinol, apigenin 7-glucoside, rosmarinic acid, luteolin 7-glucoside, ferulic acid, vanillin, caffeic acid, 4-hydroxybenzoic acid, (+)-catechin3,4-dihydroxyphenylacetic acid. The O. papillosa exhibited low EC₅₀ (1.90 ± 0.07 mg/mL) which indicated its strong phosphomolybdenum scavenging activity as compared to O. lycaonica. However, the O. lycaonica showed low IC₅₀ or EC₅₀ for 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS+), cupric reducing antioxidant power (CUPRAC), ferric reducing antioxidant power (FRAP) and ferrous ion chelating activity, as compared to O. papillosa. The results proved the presence of potent antioxidant compounds in O. lycaonica. Further, the plant extracts significantly varied for enzyme inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), but the plant extracts did not significantly differ for inhibition of α-glucosidase, α-amylase, and tyrosinase. Onosma species deserve further research towards developing novel drugs to treat oxidative diseases.

Bioactive Compounds in Waste By-Products from Olive Oil Production: Applications and Structural Characterization by Mass Spectrometry Techniques

In recent years, a remarkable increase in olive oil consumption has occurred worldwide, favoured by its organoleptic properties and the growing awareness of its health benefits. Currently, olive oil production represents an important economic income for Mediterranean countries, where roughly 98% of the world production is located. Both the cultivation of olive trees and the production of industrial and table olive oil generate huge amounts of solid wastes and dark liquid effluents, including olive leaves and pomace and olive oil mill wastewaters. Besides representing an economic problem for producers, these by-products also pose serious environmental concerns, thus their partial reuse, like that of all agronomical production residues, represents a goal to pursue. This aspect is particularly important since the cited by-products are rich in bioactive compounds, which, once extracted, may represent ingredients with remarkable added value for food, cosmetic and nutraceutical industries. Indeed, they contain considerable amounts of valuable organic acids, carbohydrates, proteins, fibers, and above all, phenolic compounds, that are variably distributed among the different wastes, depending on the employed production process of olive oils and table olives and agronomical practices. Yet, extraction and recovery of bioactive components from selected by-products constitute a critical issue for their rational valorization and detailed identification and quantification are mandatory. The most used analytical methods adopted to identify and quantify bioactive compounds in olive oil by-products are based on the coupling between gas- (GC) or liquid chromatography (LC) and mass spectrometry (MS), with MS being the most useful and successful detection tool for providing structural information. Without derivatization, LC-MS with electrospray (ESI) or atmospheric pressure chemical (APCI) ionization sources has become one of the most relevant and versatile instrumental platforms for identifying phenolic bioactive compounds. In this review, the major LC-MS accomplishments reported in the literature over the last two decades to investigate olive oil processing by-products, specifically olive leaves and pomace and olive oil mill wastewaters, are described, focusing on phenolics and related compounds.

LC-MS/MS Profiles and In Vitro Biological Activities of Extracts of an Endemic Species from Turkey: Stachys cretica ssp. anatolica

Background: Genus Stachys is one of the largest of the Lamiaceae family, having around 300 different plant species inhabiting areas with temperate and warm climates. The Stachys species in Turkey are represented with 81 taxa; 51 of them being endemic. Plants of the Stachys genus have been known for their biological activity and their use in ethnomedicine. Methods: The dominant components of S. cretica ssp. anatolica aqueous and methanol extracts were studied with the LC-MS/MS technique. Results: Chlorogenic acid, apigenin-7-glucoside and verbascoside present as the dominant polyphenols found in studied extracts. The prominent biological activity of the studied S. cretica ssp. anatolica methanol and aqueous extracts showed strong antioxidant activity and inhibition of enzymes tyrosinase and α-amylase, involved in skin disorders and diabetes mellitus type II. Conclusions: This study has proven that the aqueous and methanol extracts of S. cretica ssp. anatolica have prominent antioxidant activity, due to a high abundance of polyphenols. The strong antioxidant properties of S. cretica ssp. anatolica extracts show promising application for the pharmaceutical, food, and cosmetics industries.

Chemical Composition, Antioxidant and Enzyme Inhibitory Activities of Onosma bourgaei and Onosma trachytricha and in Silico Molecular Docking Analysis of Dominant Compounds

The aim of this study was to investigate the chemical composition, antioxidant and enzyme inhibitory activities of methanol (MeOH) extracts from Onosma bourgaei (Boiss.) and O. trachytricha (Boiss.). In addition, the interactions between phytochemicals found in extracts in high amounts and the target enzymes in question were revealed at the molecular scale by performing in silico molecular docking simulations. While the total amount of flavonoid compounds was higher in O. bourgaei, O. trachytricha was richer in phenolics. Chromatographic analysis showed that the major compounds of the extracts were luteolin 7-glucoside, apigenin 7-glucoside and rosmarinic acid. With the exception of the ferrous ion chelating assay, O. trachytricha exhibited higher antioxidant activity than O. bourgaei. O. bourgaei exhibited also slightly higher activity on digestive enzymes. The inhibitory activities of the Onosma species on tyrosinase were almost equal. In addition, the inhibitory activities of the extracts on acetylcholinesterase (AChE) were stronger than the activity on butyrylcholinesterase (BChE). Molecular docking simulations revealed that luteolin 7-glucoside and apigenin 7-glucoside have particularly strong binding affinities against ChEs, tyrosinase, α-amylase and α-glucosidase when compared with co-crystallized inhibitors. Therefore, it was concluded that the compounds in question could act as effective inhibitors on cholinesterases, tyrosinase and digestive enzymes.

Campanula macrostachya: biological activity and identification of phenolics using a liquid chromatography electrospray ionization tandem mass spectrometry system

It is known that some Campanula species are traditionally used because of their anti-allergic, spasmolytic, antiphlogistic, antioxidant, and antiviral properties. This study was designed to evaluate the phytochemical composition, antioxidant, α-amylase, and tyrosinase inhibitory activity of ethyl acetate, methanol, and water extracts of Campanula macrostachya Waldst. & Kit. ex Willd. Chemical compositions were analyzed by spectrophotometric and chromatographic methods. Antioxidant activities of the samples were tested by using five different test systems. Enzyme inhibitory activities of the extracts were also studied. As a result of the LC-ESI-MS/MS analyses, chlorogenic acid, hesperidin, and hyperoside were found to be the major compounds of the extracts, especially the MeOH extract (6559.59, 2499.22, and 2047.66 μg/g extract, respectively). Antioxidant activity tests have proven that MeOH extract showed higher activity than others (DPPH: 4.15 mg/mL, ABTS: 2.05 mg/mL, CUPRAC: 1.80 mg/mL, FRAP: 0.83 mg/mL, phosphomolybdenum: 1.69 mg/mL). Ferrous ion chelating activity of the water extract was 1.03 mg/mL. In α-amylase and tyrosinase inhibitory assays, EtOAc (IC₅₀: 2.54 mg/mL) and MeOH (IC₅₀: 1.51 mg/mL) extracts showed higher activity than the others did. In phosphomolybdenum, CUPRAC, FRAP, and tyrosinase inhibitory assays, the activity was strongly correlated with flavonoids, chlorogenic acid, hesperidin, and hyperoside. On the other hand, phenolic compounds have been found to contribute more to radical scavenging activity. Pearson correlation analysis showed that phenolics and flavonoids were not responsible for the α-amylase inhibitory activity of EtOAc extract.

Phytochemical screening and antioxidant activity of some medicinal plants' crude juices

Leaves of fig, guava, olive and pomegranate and peels of ripe pomegranate fruits were mechanically pressed to obtain the crude juices. The resultant crude juices were subjected to the estimation of certain phytochemicals, i.e. total phenols, flavonoids, tannins and anthocyanins by HPLC. The assessment of their antioxidant activities were performed by three methods, i.e. DPPH, reducing power and metal chelating assays. The results indicated that the amounts of polyphenols, flavonoids, tannins and anthocyanins in crude pomegranate peels juices were markedly higher than those of other medicinal plants crude juices. The polyphenolic constituents in fig leaves, pomegranate leaves and peels, guava leaves and olive leaves were distinguished using HPLC. The major compounds found in all crude juices were gallic acid, ellagic acid, naringenin, ferulic acid and methyl gallate, respectively. Pomegranate peels crude juice exhibited the highest antioxidant activity assessed by the aforementioned methods in comparison with other medicinal plants crude juices.

Target and Suspect HRMS Metabolomics for the Determination of Functional Ingredients in 13 Varieties of Olive Leaves and Drupes from Greece

The huge interest in the health-related properties of foods to improve health has brought about the development of sensitive analytical methods for the characterization of natural products with functional ingredients. Greek olive leaves and drupes constitute a valuable source of biophenols with functional properties. A novel ultra-high-performance liquid chromatography-quadrupole time of flight tandem mass spectrometry (UHPLC-QTOF-MS) analytical method was developed to identify biophenols through target and suspect screening in Greek olive leaves and drupes of the varieties: Koroneiki, Throumbolia, Konservolia, Koutsourelia, Kalamon, Petrolia, Amigdalolia, Megaritiki, Mastoeidis, Agouromanakolia, Agrilia, Adramitiani and Kolovi. The method's performance was evaluated using the target compounds: oleuropein, tyrosol and hydroxytyrosol. The analytes demonstrated satisfactory recovery efficiency for both leaves (85.9-90.5%) and drupes (89.7-92.5%). Limits of detection (LODs) were relatively low over the range 0.038 (oleuropein)-0.046 (hydroxytyrosol) and 0.037 (oleuropein)-0.048 (hydroxytyrosol) for leaves and drupes, respectively For leaves, the precision limit ranged between 4.7 and 5.8% for intra-day and between 5.8 and 6.5% for inter-day experiments, and for drupes, it ranged between 3.8 and 5.2% for intra-day and between 5.1 and 6.2% for inter-day experiments, establishing the good precision of the method. The regression coefficient (r²) was above 0.99 in all cases. Furthermore, the preparation of herbal tea from olive leaves is suggested after investigating the optimum infusion time of dried leaves in boiling water. Overall, 10 target and 36 suspect compounds were determined in leaves, while seven targets and thirty-three suspects were identified in drupes, respectively.

Polyphenol Profile and Biological Activity Comparisons of Different Parts of Astragalus macrocephalus subsp. finitimus from Turkey

The members of the genus Astragalus have great interest as traditional drugs in several folk systems including Turkey. In this sense, the present paper was aimed to explore the biological properties and chemical profiles of different parts (aerial parts, leaves, flowers, stems, and roots) of A. macrocephalus subsp. finitimus. Antioxidant (radical quenching, reducing power, and metal chelating) and enzyme inhibitory (α-amylase and tyrosinase) effects were investigated for biological properties. Regarding chemical profiles, individual phenolic compounds were detected by LC-MS, as well as total amounts. The leaves extract exhibited the strongest antioxidant abilities when compared with other parts. However, flowers extract had the best metal chelating ability. Hyperoside, apigenin, p-coumaric, and ferulic acids were identified as main compounds in the tested parts. Regarding enzyme inhibitory properties, tyrosinase inhibitory effects varied from IC₅₀: 1.02 to 1.41 mg/mL. In addition, the best amylase inhibition effect was observed by leaves (3.36 mg/mL), followed by aerial parts, roots, stems, and flowers. As a result, from multivariate analysis, the tested parts were classified in three cluster. Summing up the results, it can be concluded that A. macrocephalus subsp. finitimus could be a precious source of natural bioactive agents in pharmaceutical, nutraceutical, and cosmeceutical applications.

Enzyme and Biological Activities of the Water Extracts from the Plants Aesculus hippocastanum, Olea europaea and Hypericum perforatum That Are Used as Folk Remedies in Turkey

Phenolic compounds are secondary metabolites that are found ubiquitously in plants, fruits, and vegetables. Many studies have shown that regular consumption of these compounds could have a positive effect on our health. The aim of this study was to compare the phytochemical contents of the water extracts from three different plants used as folk remedies in Turkey: Aesculus hippocastanum, Olea europaea, and Hypericum perforatum. A liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) analysis was performed to explore the phenolic profiles. The biological activities of these extracts were also evaluated in terms of their antioxidant activities (2,2-diphenyl-1-picrylhydrazyl DPPH, 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid ABTS, Ferric Reducing Antioxidant Power Assay FRAP, cupric ion reducing antioxidant capacity CUPRAC, β-carotene, phosphomolybdenum, and metal chelating) and enzyme inhibitory properties (against acetylcholinesterase, butyrylcholinesterase, and tyrosinase). The aqueous extract of H. perforatum showed the highest levels of total phenolic, flavonoid, and saponin contents. Protocatechuic acid, vanillic acid, verbascoside, hesperidin, hyperoside, apigenin 7-hexosides, and quercetin were the most common compounds found in this species. The results confirm that A. hippocastanum, O. europaea, and H. perforatum represent a potential source of natural-derived molecules with positive properties that could be used as valid starting point for new food supplements, and drugs in the pharmaceutical, cosmetic, and food industries.

Phenolic Profile and Bioactivities of Sideritis perfoliata L.: The Plant, Its Most Active Extract, and Its Broad Biological Properties

Sideritis, also named “ironwort,” “mountain tea,” or “shepherd's tea,” is a genus of flowering plants used as herbal medicine in traditional Mediterranean-area medicine systems, and these plants are generally consumed as a herbal tea. Its use as herbal tea and in traditional herbal medicine is quite popular. There are currently few studies on Sideritis perfoliata L., and only one reports the use of a liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MSⁿ) profile and the content of phenolic compounds without considering a possible correlation with its biological activities. This paper aims to investigate the antioxidant activities by means of several different biological/biochemical assays (radical scavenging, reducing power, ferrous ion chelating, and total antioxidant by phosphomolybdenum and β-carotene bleaching methods) as well as analyze the enzyme inhibitory activities (against AChE (acetylcholinesterase), BChE (butyrylcholinesterase), tyrosinase, α-glucosidase, and α-amylase) as well as the total phenolics, flavonoids, and condensed tannins. The reported results on Sideritis perfoliata highlighted that methanol and water extracts generally showed higher radical scavenging and reducing power activities. A similar trend could be observed for phosphomolybdenum and ferrous ion chelating activities. Methanol extracts showed lower activity only for the β-carotene bleaching assay.

Ganoderma carnosum and Ganoderma pfeifferi: Metal concentration, phenolic content, and biological activity

Medicinal Ganoderma mushrooms have long tradition in Asia, and recently they began to be consumed in Europe as well. Among hundreds of Ganoderma species, only a few of them are intensively investigated, i.e., G. lucidum and G. applanatum, whereas the chemistry and bioactivities of the other species, especially of European origin, still remain unknown. This study comprises detailed chemical analysis of two Ganoderma species growing wild in Turkey, G. pfeifferi and G. carnosum. Metal composition of both species shows high concentrations of biogenic metals. Phenolic composition of the isolated extracts of G. carnosum and G. pfeifferi shows that these species are rich in simple phenolic acids, such as 2,5-dihydroxybenzoic acid and vanillic acid, but also in flavonoids. These compounds are found to be carriers of the antioxidant activity but also enzyme inhibition activity of the analyzed extracts. Overall results indicate that these two Ganoderma species have strong potential to be used for medicinal purposes.

Study on the Chemical Composition, Enzyme Inhibition and Antioxidant Activity of Ziziphora taurica subsp. cleonioides

Ziziphora is a plant used in Turkish and Iran traditional medicine for its antibacterial activity, sedative and stomach soothing properties. Although the chemical profile of the essential oil of different Ziziphora species is well documented, data regarding plant extracts are incomplete. In this study extracts from Ziziphora taurica subsp. cleonioides were obtained using ethyl acetate, methanol and water and the chemical profile of the aerial part of the plant was elucidated. Among the compounds identified, rosmarinic acid was the most abundant (3375.67 ± 38.02 μg/mL), at the extract of methanol, followed by chlorogenic acid (3225.10 ± 16.44). Enzyme inhibition activity against α-amylase and tyrosinase was also estimated. The ethyl acetate extract showed the highest α-amylase activity (1.95 ± 0.04 mg/mL), while the best anti-tyrosinase activity was calculated for the methanolic extract (1.25 ± 0.01 mg/mL). In addition, total phenolic, flavonoid content and antioxidant activity were evaluated. According to our results, bioactivity of the plant is of great interest, nonetheless, at the same time, it is strongly depended on the solvent used during the extraction process. Our data suggest that the plant under study may be an important source to consider against metabolic, skin pigmentation and oxidative stress related disorders.

Analytical methods to analyze pesticides and herbicides

Presented in this paper is an annual review of literatures published in 2018 on topics relating to analytical methods for pesticides and herbicides. According to the different techniques, this review is divided into six sections, including extraction methods; chromatographic or mass spectrometric techniques; electrochemical techniques; spectrophotometric techniques; chemiluminescence and fluorescence methods; and biochemical assays. PRACTITIONER POINTS: Totally 134 relevant research articles are summarized. The review is divided into six parts according to the techniques. Chromatographic and mass spectrometric methods are the most widely used.

Ziziphora taurica subsp. taurica: Analytical Characterization and Biological Activities

The Lamiaceae family comprises many flowering plants classified into about 236 genera. The genus Ziziphora is one of the well-known genera of this family and its species are important in different fields of pharmaceutical, chemical, traditional, and folk medicines. The phytochemicals present in Ziziphora include monoterpenic essential oils, triterpenes, and phenolic substances. The aim of this paper was to study the phytochemical profile of Ziziphora taurica subsp. taurica and compare and evaluate the biological activities of its ethyl acetate (ZTT-EtOAc), methanolic (ZTT-MeOH), and aqueous (ZTT-W) extracts based on their enzyme inhibition and antioxidant capacities. Determination of total phenolic (TPC) and total flavonoid (TFC) contents as well as biological activities were determined using spectrophotometric procedures. Subsequently, the individual phenolic compounds were detected by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). In total, twenty-two different phenolic compounds were identified, including apigenin, ferulic acid, and luteolin which were the most common. ZTT-MeOH extract showed the best antioxidant activity, whereas ZTT-EtOAc extract was the most effective against tyrosinase and α-amylase. Ziziphora taurica subsp. taurica represents a potential source of natural compounds with positive effects on human health.

Establishing the Phenolic Composition of Olea europaea L. Leaves from Cultivars Grown in Morocco as a Crucial Step Towards Their Subsequent Exploitation

In Morocco, the recovery of olive agro-industrial by-products as potential sources of high-added value substances has been underestimated so far. A comprehensive quantitative characterization of olive leaves’ bioactive compounds is crucial for any attempt to change this situation and to implement the valorization concept in emerging countries. Thus, the phenolic fraction of olive leaves of 11 varieties (‘Arbequina’, ‘Hojiblanca’, ‘Frantoio’, ‘Koroneiki’, ‘Lechín’, ‘Lucque’, ‘Manzanilla’, ‘Picholine de Languedoc’, ‘Picholine Marocaine’, ‘Picual’ and ‘Verdal’), cultivated in the Moroccan Meknès region, was investigated. Thirty eight phenolic or related compounds (including 16 secoiridoids, nine flavonoids in their aglycone form, seven flavonoids in glycosylated form, four simple phenols, one phenolic acid and one lignan) were determined in a total of 55 samples by using ultrasonic-assisted extraction and liquid chromatography coupled to electrospray ionization-ion trap mass spectrometry (LC-ESI-IT MS). Very remarkable quantitative differences were observed among the profiles of the studied cultivars. ‘Picholine Marocaine’ variety exhibited the highest total phenolic content (around 44 g/kg dry weight (DW)), and logically showed the highest concentration in terms of various individual compounds. In addition, chemometrics (principal components analysis (PCA) and stepwise-linear discriminant analysis (s-LDA)) were applied to the quantitative phenolic compound data, allowing good discrimination of the selected samples according to their varietal origin.

Chemical, biological and molecular modelling analyses to probe into the pharmacological potential of Antidesma madagascariense Lam.: A multifunctional agent for developing novel therapeutic formulations

Antidesma madagascariense Lam. (AM), an indigenous medicinal plant to the Mascarene Islands, is used for the treatment of several diseases. We endeavoured to validate its use via evaluating the kinetics of inhibition of crude aqueous extract (CAE) and crude methanol extract (CME) of AM against key metabolic enzymes (pancreatic lipase, cholesterol esterase [CEase], acetylcholinesterase [AChE], and urease). In vitro antiglycation, antioxidant, cytotoxicity using iCELLigence real time cell analysis system and WST-1 methods, were used. LC-ESI-MS/MS was employed to determine the phenolic composition of the extracts and interaction of selected compounds to the studied enzymes was determined using in silico docking. AChE was inhibited by the CME of AM and CEase by the CAE. Both extracts were active inhibitors of urease and pancreatic lipase. Hyperoside (271.97 μg/g extract), present in large amount in the CME, docked to the enzymatic pocket of urease and CEase. The extracts showed competitive and mixed inhibition of urease and pancreatic lipase, respectively. The antioxidant capacity of the CME (6.61 μg GAE/mg crude extract) was higher compared to CAE (2.20 μg GAE/mg crude extract). AM extracts were significantly (p <  0.05) less potent than aminoguanidine in preventing advanced glycation end products formation. Toxicological screening revealed that both extracts were non-toxic on HEK-293 cells. AM crude extracts at concentrations ranging from 78 to 312 μg/ml did not cause a visible change in cell morphology compared to control. This study supports the safe use of AM as a biomedicine for the management and/or treatment of common non-communicable diseases.