Analysis of underivatized oligosaccharides by liquid chromatography/electrospray ionization tandem mass spectrometry with post-column addition of formic acid

Nematicidal activity of paucimannose-type glycoconjugates from acacia honey

Natural honey contains glycoconjugates as minor components. We characterized acacia honey glycoconjugates with molecular masses in the range of 2-5 kDa. The glycoconjugates were separated by RP-HPLC into three peaks (termed RP-2-5 k-I, RP-2-5 k-II, and RP-2-5 k-III) which demonstrated paralyzing effects on the model nematode C. elegans (ED50 of 50 ng glycoconjugates/μL). To examine molecular mechanisms underlying the nematicidal effects of honey glycoconjugates, expressional analyses of genes that are essential for the growth, development, reproduction, and movement of C. elegans were carried out. Quantitative PCR-based assays showed that these molecules moderately regulate the expression of genes involved in the citric acid cycle (mdh-1 and idhg-1) and cytoskeleton (act-1 and act-2). MALDI-ToF-MS/MS analysis of RP-HPLC peaks revealed the presence of paucimannose-like N-glycans which are known to play important roles in invertebrates e.g., worms and flies. These findings provided novel information regarding the structure and nematicidal function of honey glycoconjugates.

Casuarina glauca branchlets' extract as a potential treatment for ulcerative colitis: chemical composition, in silico and in vivo studies

Ulcerative colitis (UC) is an inflammatory bowel disease that is often resistant to current treatment options, leading to a need for alternative therapies. Herbal products have shown promise in managing various conditions, including UC. However, the potential of Casuarina glauca branchlets ethanolic extract (CGBRE) in treating UC has not been explored. This study aimed to analyze the chemical composition of CGBRE and evaluate its efficacy in UC treatment through in silico and in vivo experiments. LC-ESI-MS/MS was used to identify 86 compounds in CGBRE, with 21 potential bioactive compounds determined through pharmacokinetic analysis. Network pharmacology analysis revealed 171 potential UC targets for the bioactive compounds, including EGFR, LRRK2, and HSP90 as top targets, which were found to bind to key CGBRE compounds through molecular docking. Molecular docking findings suggested that CGBRE may be effective in the prevention or treatment of ulcerative colitis mediated by these proteins, where key CGBRE compounds exhibited good binding affinities through formation of numerous interactions. In vivo studies in rats with acetic acid-induced UC demonstrated that oral administration of 300 mg/kg CGBRE for 6 days reduced UC symptoms and colonic expression of EGFR, LRRK2, and HSP90. These findings supported the therapeutic potential of CGBRE in UC and suggested the need for further preclinical and clinical investigation.

Nutritional and chemical composition of Alpinia zerumbet leaves, a traditional functional food

Alpinia zerumbet, a species of the Zingiberaceae family, is a common plant in tropical and subtropical areas used in traditional medicine to treat various diseases and also included as food in the traditional Okinawan diet (Japan). The leaves and rhizomes of this plant are used as spice and flavoring in foods such as rice, meats, and pasta. Studies of the chemical and nutritional characteristics of fresh leaves and of leaves submitted to thermal treatments such as boiling and steaming are lacking. In the current study, the leaves of A. zerumbet were subjected to boiling or steaming for 10, 20, and 30 min as part of the thermal treatments. The study also provides noteworthy results regarding the proximate composition, physical-chemical data, minerals, phenolic compounds, antioxidant activity, volatile compounds, and LC-MS chromatographic profiles of the extracts produced with fresh leaves and with thermal treatments. The carbohydrate content of A. zerumbet leaves improved during the thermal treatments, showing an increase after steaming (18.86 to 19.79%) and boiling for 30 min (25.85%). After boiling treatment for 20 min, a significant amount of protein was found (6.79%) and all heat treatments resulted in low content of lipid (<1.0%). The boiling treatment for 10 min (BT10) resulted in the highest concentrations of total phenolic components (TPC), 339.5 mg/g, and flavonoids (TF), 54.6 mg/g, among the three thermal treatments (BT10, BT20 and BT30). The results of the steaming treatments (ST 10, 20, and 30 min) differed, with ST20 leading to higher TPC (150.4 mg/g) and TF (65.0 mg/g). The quantity of total phenolics and flavonoids, as well as the antioxidant activity, were significantly affected by the cooking method and the length of time of sample exposure to heat. The samples boiled for 30 and 10 min had higher concentrations of antioxidant activity as measured by the phosphomolybdenum and DPPH methods (151.5 mg/g of extract and 101.5 μg/mL, respectively). Thirty-eight volatile organic compounds (VOCs) were identified by chromatographic analysis of fresh and thermally treated leaves of A. zerumbet. Terpenoids were the predominant class of volatile compounds in the fresh leaves and in all thermal treatments. p-Cymene, 1,8-cineole, 4-terpineol, linalool, α-copaene and β-bisabolene have the greatest impact on overall aroma perception, with odor activity values (OAV) greater than five. Among the phenolic compounds identified by LC-HRMS in the extracts of fresh and thermally treated leaves were proanthocyanidins, (+) catechin, (-) epicatechin, quercetin-3-O-glucoronide, isorhamnetin-3-O-glucoronide, kaempferol-3-O-rutinoside, pinocembrin, alpinetin, pinostrobin, and other compounds. The present results support the traditional use of this plant as a potential food with properties that certainly contribute to health improvement.

Understanding the Chemical Composition and Biological Activities of Different Extracts of Secamone afzelii Leaves: A Potential Source of Bioactive Compounds for the Food Industry

Secamone afzelii (Roem. & Schult.) K. Schum (family Asclepiadaceae) is a creeping woody climber used to treat ailments in many traditional medicine systems. The present study aims to examine the antioxidant and enzyme inhibition activities of S. afzelii leaf using different compositions of methanol-water mixture as an extraction solvent. The extracts were characterized by HPLC-ESI-MSⁿ in terms of chemical compounds. The in silico results show that compound 23 (quercitrin) has the higher docking scores among the selected substances and the MD simulation revealed that the interactions with the enzymatic pocket are stable over the simulation time and strongly involve the tyrosinase catalytic Cu atoms. All together the results showed that both 80% and 100% methanolic extracts contained significantly (p < 0.05) the highest total phenolics content while the highest content of total flavonoids was significantly (p < 0.05) extracted by 100% methanol. About 26 compounds were tentatively identified by HPLC-ESI-MSⁿ and 6 of them were quantified using standards. Results showed that the extracts were rich in flavonoids with a relatively high abundance of two kaempferol glycosides comprising 60% of quantified compounds. The 100% and 80% methanol extracts recorded significantly (p < 0.05) the highest total antioxidant, DPPH and ABTS activity as well as tyrosinase and ⍺-amylase inhibitory activities. The best significant (p < 0.05) cholinesterase inhibitory activity and reducing capacity of Fe⁺⁺⁺ and Cu⁺⁺ was recorded from the 80% methanolic extract while 100% ethanolic extract gave the highest significant (p < 0.05) butyrylcholinesterase inhibitory activity. The best glucosidase activity was observed in the 50% and 80% methanolic extracts. Although the water extract displayed the least total phenolics and flavonoids content and consequently the lowest antioxidant and enzyme inhibition activity, it displayed significantly (p < 0.05) the highest chelating power. In conclusion, these results demonstrated the richness of S. afzelii leaf as a potential source of bioactive compounds for the food industry, for the preparation of food supplements and functional foods.

Phenolics Profiling by HPLC-DAD-ESI/MSn of the Scientific Unknown Polygonum hydropiperoides Michx. and Its Antioxidant and Anti-Methicillin-Resistant Staphylococcus aureus Activities

Polygonum hydropiperoides Michx. is an Asian native plant species that is also widely distributed in the Americas. Despite its traditional uses, P. hydropiperoides is scarcely scientifically exploited. This study aimed to chemically characterize and investigate the antioxidant and antibacterial activities of hexane (HE-Ph), ethyl acetate (EAE-Ph), and ethanolic (EE-Ph) extracts from aerial parts of P. hydropiperoides. The chemical characterization was performed through HPLC-DAD-ESI/MSⁿ. The antioxidant activity was assessed by the phosphomolybdenum reducing power, nitric oxide inhibition, and the β-carotene bleaching assays. The antibacterial activity was determined by the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration followed by the classification of the antibacterial effect. Chemical characterization revealed the expressive presence of phenolic acids and flavonoids in EAE-Ph. An increased antioxidant capacity was revealed in EAE-Ph. Regarding antibacterial activity, EAE-Ph showed weak to moderate property against 13 strains tested with MIC values ranging from 625 to 5000 µg/mL, with bactericidal or bacteriostatic effects. Glucogallin and gallic acid stand out as the most relevant bioactive compounds. These results suggest that P. hydropiperoides is a natural source of active substances, supporting this species' traditional use.

Preliminary Phytochemical Screening and Antioxidant Activity of Commercial Moringa oleifera Food Supplements

Moringa oleifera has been reported to possess a high number of bioactive compounds; hence, several food supplements are commercially available based on it. This work aimed to analyze the phytochemical composition and antioxidant activity of commercial food supplements. The phenolic composition of methanolic extracts was determined by using high-performance liquid chromatography with diode-array and electrospray ionization mass spectrometric detection (HPLC-DAD-ESI-MSⁿ), and the antioxidant activity was assessed by ABTS^·+ and DPPH assays. Thirty-three compounds were identified, and all the main compounds were quantified, observing that the main contribution to the phenolic profile was due to kaempferol and quercetin glucosides. The antioxidant activity in both assays agreed with the phenolic content: the higher the phenolic levels, the higher the antioxidant activity. The obtained results were compared with those previously published regarding Moringa oleifera leaves to establish the potential benefits of food supplement consumption in the diet.

Novel Perceptions on Chemical Profile and Biopharmaceutical Properties of Mentha spicata Extracts: Adding Missing Pieces to the Scientific Puzzle

Mentha spicata is one of the most popular species in the genus, and it is of great interest as a gastrointestinal and sedative agent in the folk medicine system. In this study, different M. spicata extracts, obtained by the use of four solvents (hexane, chloroform, acetone and acetone/water) were chemically characterized using HPLC-ESI-MS n, which allowed for identification of 27 phenolic compounds. The extracts' antioxidant and enzyme inhibitory properties were investigated. In addition, neuroprotective effects were evaluated in hypothalamic HypoE22 cells, and the ability of the extracts to prevent the hydrogen peroxide-induced degradation of dopamine and serotonin was observed. The best antioxidant effect was achieved for all the extraction methods using acetone/water as a solvent. These extracts were the richest in acacetin, eriodictyol, hesperidin, sagerinic acid, naringenin, luteolin, chlorogenic acid, chrysoeriol and apigenin. The intrinsic antioxidant and enzyme inhibition properties of the acetone/water extract could also explain, albeit partially, its efficacy in preventing prostaglandin E2 overproduction and dopamine depletion (82.9% turnover reduction) in HypoE22 cells exposed to hydrogen peroxide. Thus, our observations can provide a scientific confirmation of the neuromodulatory and neuroprotective effects of M. spicata.

Shedding Light into the Connection between Chemical Components and Biological Effects of Extracts from Epilobium hirsutum: Is It a Potent Source of Bioactive Agents from Natural Treasure?

Epilobium hirsutum is extensively used as a traditional remedy in folk medicine, especially against prostate inflammation. Therefore, we evaluated the chemical profiles and biopharmaceutical potentials of different extracts of E. hirsutum aerial parts and roots. Metabolomic, antioxidant, and enzyme inhibitory profiles were investigated. Human prostate cancer PC3 cells were exposed to the extracts to evaluate antiproliferative effects. Gene expression and bioinformatics analyses were performed to investigate anti-inflammatory mechanisms. Oenothein B and myricetin were prominent compounds in the extracts. In scavenging/reducing assays, the methanol, infusion, and methanol/water extracts exhibited similar activities. We also observed the reduction of PC3 viability occurring following exposure to methanol and methanol/water extracts. According to bioinformatics analysis, myricetin was predicted to interact with COX-2 and TNFα. The interaction between TNFα and oxo-dihydroxy-octadecenoic acid was predicted as well. Intriguingly, the gene expression of COX-2 and TNFα was reduced in PC3 cells after exposure to methanol and methanol/water extracts. These effects were paralleled by the decreased gene expression of IL-8 and NFkB and the inhibition of PGE2 release. Therefore, the present findings suggest the potential use of E. hirsutum for the management of the burden of inflammation and oxidative stress occurring in lower urinary tract diseases, including prostatitis.

Insight into the Secondary Metabolites of Geum urbanum L. and Geum rivale L. Seeds (Rosaceae)

The present study aimed at the identification and quantitation of phenolic compounds, fatty acids, and further characteristic substances in the seeds of Geum urbanum L. and Geum rivale L. For this purpose, individual components of extracts recovered with MeOH, CH₂Cl₂, and by cold-pressing, respectively, were characterized by HPLC-DAD/ESI-MSⁿ and GC/MS and compared with reference compounds. For both Geum species, phenolic compounds, such as flavonoids and gallic acid derivatives, and triterpenes, such as saponins and their aglycones, were detected. Surprisingly, both Geum species revealed the presence of derivatives of the triterpenoid aglycons asiatic acid and madecassic acid, which were characterized for the first time in the genus Geum. Furthermore, the fatty acids of both species were characterized by GC–MS after derivatization. Both species showed a promising fatty-acid profile in terms of nutritional properties because of high proportions of unsaturated fatty acids. Linoleic acid and linolenic acid were most abundant, among other compounds such as palmitic acid and stearic acid. In summary, the present study demonstrates the seeds of G. urbanum and G. rivale to be a valuable source of unsaturated fatty acids and bioactive phenolics, which might be exploited for nutritional and cosmetic products and for phytotherapeutic purposes.

Anti-inflammatory, hypoglycemic, hypolipidemic, and analgesic activities of Plinia cauliflora (Mart.) Kausel (Brazilian grape) epicarp

ETHNOPHARMACOLOGICAL RELEVANCE

Plinia cauliflora (Mart.) Kausel, known in Brazil as jabuticaba or jaboticaba has been used by Brazilian native populations for medicinal purposes, including those related to inflammatory conditions, such as asthma, diarrhea, disorders in female genitourinary tract, and tonsillitis. Inflammation has emerged as a main factor for the oxidative stress, hyperglycemia, and dyslipidemia present in chronic noncommunicable diseases (NCDs). Such disturbances have been a leading cause of death worldwide for decades, despite significant efforts in developing new therapies. Therefore, strengthening the relevance of ethnobotanic approaches, as P. cauliflora has the potential to become a natural, native, and traditional product to prevent and treat inflammation-associated diseases more effectively for more people.

AIM OF THE STUDY

Evaluate anti-inflammatory, hypoglycemic, hypolipidemic, and analgesic properties of hydroethanolic extract of P. cauliflora epicarps (PcE).

MATERIALS AND METHODS

Phytochemical compound from the PcE were identified through HPLC-DAD-ESI-MSⁿ analysis. Antioxidant activity was determined by measuring 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging. The anti-inflammatory potential was investigated by carrageenan-induced paw edema and peritonitis in mice. Analgesic effect was assessed, in mice, though hot plate test and acetic acid-induced abdominal writhing. Antidiabetic and hypolipidemic potential were evaluated using alloxan-induced diabetic mice.

RESULTS

Tannins, phenolic acids, and their derivatives were the predominant phytochemicals found. Overall, PcE showed different properties related to the treatment of clinical conditions associated with chronic diseases as a potent antioxidant activity, demonstrating a radical scavenging action similar to gallic acid. PcE oral administration also significantly reduced inflammation induced by paw edema and partially blocked leukocyte migration. Moreover, PcE produced peripheral and central analgesic effects, as evaluated in the writhing model and hot plate tests. Treatment with PcE significantly improved glucose levels and lipid markers in diabetic mice.

CONCLUSIONS

P. cauliflora fruits are rich sources of secondary metabolites, mainly tannins and phenolic acids with high biological potential, which can effectively contribute to the approach of preventing and controlling chronic NCDs.

Comparative Analysis of Glycosidic Aroma Compound Profiling in Three Vitis vinifera Varieties by Using Ultra-High-Performance Liquid Chromatography Quadrupole-Time-of-Flight Mass Spectrometry

Glycosidic aroma compounds are the important precursors of volatile aroma in grapes, and they can be added with odorous aglycones via enzyme- or acid-catalyzed hydrolysis during wine fermentation and storage. Developing an analytical method for intact glycosides can provide the possibility to study the accumulation of these aroma precursors in grape berries. For this purpose, a Tandem Mass Spectrometry (MS/MS). database based on ultra-high-performance liquid chromatography quadrupole-time-of-flight mass spectrometry was built, covering multiple aglycone classes. Subsequently, the profiles of glycosidic aroma compounds in Vitis vinifera L. cv. Muscat Blanc, Riesling, and Chardonnay berries during maturation were investigated. Pentosyl-hexosides were the most abundant glycosides in all three varieties. Both composition and concentration of glycosidic aroma compounds varied obviously among grape varieties. Except for monoterpenol pentosyl-hexosides, most glycosides were kept almost stable in their concentrations during berry maturation. This research provides an approach to understand the variation of glycosidic aroma components from the perspective of aglycones and glycosides.

Bloodwood: the composition and secreting-site of the characteristic red exudate that gives the name to the Swartzia species (Fabaceae)

The Swartzia species are commonly known as bloodwood due to the red exudate released from the stem after injury. This exudate has aroused great interest, and an integrative study is essential to describe it in detail. Thus, this work aimed to identify the red exudate's secreting-site in S. flaemingii and S. langsdorffii, and determine if it is a latex or a resin. Samples of the stem bark and the secondary xylem were prepared for histological analysis. Fresh exudates were dissolved in deuterated methanol and analyzed by ¹H-NMR; other samples were resuspended in MeOH:H₂O (9:1), partitioned with organic solvents and analyzed by direct infusion mass spectrometry. Total phenolic and total flavonoid contents were determined spectrophotometrically, and antioxidant capacity was determined using ferric reducing antioxidant power assay. The results showed that the exudate is a red latex produced by articulated laticifers located among the phloem cells. The latex is composed of sucrose, catechin glucosides, chlorophyll derivatives, and hederagenin-type saponins. Both samples of S. flaemingii and S. langsdorffii presented high amounts of phenolics and flavonoids, as well as a strong antioxidant capacity. The anatomical study showed that the secreting-site of the Swartzia red exudates were laticifers. This finding allows us to exclude other substances such as resin or oleoresin, generally produced by secretory cavities or ducts. Furthermore, since laticifers are rare in Fabaceae, this finding is significant, and represents an essential taxonomic feature. The showy red color is due to the large amounts of flavonoids. This latex probably has a protective role against microorganisms and photodamage. The bioactive potential of this exudate inspires further studies, which may boost the economic importance of Swartzia.

Stingless bee honey, a novel source of trehalulose: a biologically active disaccharide with health benefits

Stingless bee (Meliponini) honey has long been considered a high-value functional food, but the perceived therapeutic value has lacked attribution to specific bioactive components. Examination of honey from five different stingless bee species across Neotropical and Indo-Australian regions has enabled for the first time the identification of the unusual disaccharide trehalulose as a major component representing between 13 and 44 g per 100 g of each of these honeys. Trehalulose is an isomer of sucrose with an unusual α-(1 → 1) glucose-fructose glycosidic linkage and known acariogenic and low glycemic index properties. NMR and UPLC-MS/MS analysis unambiguously confirmed the identity of trehalulose isolated from stingless bee honeys sourced across three continents, from Tetragonula carbonaria and Tetragonula hockingsi species in Australia, from Geniotrigona thoracica and Heterotrigona itama in Malaysia and from Tetragonisca angustula in Brazil. The previously unrecognised abundance of trehalulose in stingless bee honeys is concrete evidence that supports some of the reported health attributes of this product. This is the first identification of trehalulose as a major component within a food commodity. This study allows the exploration of the expanded use of stingless bee honey in foods and identifies a bioactive marker for authentication of this honey in associated food standards.

Chemical characterization, computational analysis and biological views on Daphne gnidioides Jaub. & Spach extracts: Can a new raw material be provided for biopharmaceutical applications?

The scientific world tends to turn to natural products such as medicinal and aromatic plants because of the inadequacy of commercially available synthetic drugs as antibiotics or anticancer, and their adverse effects on healthy tissues. One of these plants is Daphne gnidioides Jaub. & Spach, which belongs to the Thymelaeaceae family, and there is no data in the literature on its biological activity. This study is aimed to elucidate the chemical profiles and in vitro anticancer, antibacterial and DNA protection and enzyme inhibitory properties of methanol extracts of root, stem, and leaf of D. gnidioides Jaub. & Spach. Polyphenolic components of the extracts were characterized by HPLC-MS/MS. The highest phenolic content was detected in the leaf extract (TIPC = 43.5 ± 0.5 mg/g DE), followed by stem (TIPC = 27.3 ± 0.7 mg/g DE) and root (TIPC = 18.3 ± 0.2 mg/g DE) extracts. Vicenin-2 and 3-O-p-coumaroyl-5-O-caffeoylquinic acid were the main identified compounds in leaf and both root and stem extracts, respectively. The extracts did not show any protective effect on DNA against experimental Fenton's reagent. The minimum inhibitory concentration and the minimum bactericidal concentration values for the root and leaf extracts against tested bacterial strains ranged from 31.25 to 500 μg/mL. After 48 h interaction of the cancer cell lines with the extracts, only the stem extract had significant cytotoxicity on HeLa cells (IC50 = 86.16 μg/mL). No remarkable activity of the extracts, which was tested against MDA-MB-231, was detected (IC50 > 1000 μg/mL). These data showed that D. gnidioides Jaub. & Spach stem extract inhibited the survival of HeLa cells in a time-dependent manner. After the treatment of IC50 concentration of stem extract with HeLa cells, an increase in LC3-II autophagic gene expression was detected. Also, the extracts exhibited significant tyrosinase inhibitory effects which were confirmed by molecular docking. To sum up, the tested extracts could be used as a starting point for the development of new multifunctional drugs.

Coumaroyl Flavonol Glycosides and More in Marketed Green Teas: An Intrinsic Value beyond Much-Lauded Catechins

Marketed green teas (GTs) can highly vary in their chemical composition, due to different origins, processing methods, and a lack of standardization of GT-based products. Consequently, biological activities become difficult to correlate to the presence/content of certain constituents. Herein, ultra-high-performance liquid chromatography (UHPLC) combined with high-resolution tandem mass spectrometry (HR MS/MS) was successfully applied to six commercial GT products, extracted by ethanol sonication, to disclose their polyphenol profile beyond the well-known catechins. The relative abundance of each class of metabolites was correlated to antiradical and antilipoperoxidant data through hierarchical clustering analysis, since it reasonably affects the beneficial properties of the product that reaches the consumer. The thiobarbituric acid reactive substances (TBARS) assay demonstrated that GT extracts effectively counteracted the UV-induced lipoperoxidation of hemp oil, which is highly rich in Polyunsaturated Fatty Acids (PUFAs), and therefore highly unstable. The Relative Antioxidant Capacity Index (RACI) comprehensively emphasized that gunpower and blend in filter GTs appeared to be the less active matrices, and except for a GT-based supplement, the Sencha GT, which was particularly rich in flavonol glycosides, was the most active, followed by Bancha GT.

Phenolic Profile, Antioxidant Activity, and Enzyme Inhibitory Properties of Limonium delicatulum (Girard) Kuntze and Limonium quesadense Erben

In this work, we report the phytochemical composition and bioactive potential of methanolic and aqueous extracts of leaves from Limonium delicatulum (Girard) Kuntze and Limonium quesadense Erben. The characterization and quantitation of individual phytochemicals were performed with liquid chromatography with diode array and electrospray-tandem mass spectrometry detection. Myricetin glycosides were abundant in L. delicatulum, whereas L. quesadense was rich in gallo(epi)catechin-O-gallate. Total phenolics, flavonols, and flavonoids were assayed with conventional methods. Antioxidant and radical scavenging assays (phosphomolybdenum, DPPH, ABTS, CUPRAC, FRAP, and metal chelating activity), as well as enzyme inhibitory assays (acetylcholinesterase, butyrylcholinesterase, tyrosinase, amylase, glucosidase, and lipase), were performed to evaluate the potential bioactivity. The methanolic extracts of both species presented higher phenolic content and bioactivity than the aqueous extracts. Overall, L. quesadense extracts exhibited the most potent activity for most assays, representing a potential source of bioactive compounds for the pharmaceutical and food industries.

Chemical profiling of Centaurea bornmuelleri Hausskn. aerial parts by HPLC-MS/MS and their pharmaceutical effects: From nature to novel perspectives

Ethnobotanical evidences substantiate the use of several Centaurea species to treat and/or manage several human ailments. In the present study, the phytochemical profile of the ethyl acetate, methanol, and aqueous extracts (prepared by infusion and decoction) of Centaurea bornmuelleri Hausskn. aerial parts was established. The enzyme inhibitory and antioxidant properties were also determined by in vitro bioassays. Methanol extract (38.58 mg gallic acid equivalent/g extract) and ethyl acetate extract (38.83 mg rutin equivalent/g extract) possessed the highest concentration of phenolics and flavonoids, respectively. Aqueous extract prepared following traditional infusion method showed potent DPPH (38.54 mg TE/g extract) and ABTS (57.75 mg TE/g extract) scavenging abilities. The methanol extract (101.46 mg TE/g extract) of C. bornmuelleri exhibited potent reducing activity in the CUPRAC assay while the aqueous extract obtained by infusion was more active in the FRAP assay (69.81 mg TE/g extract). Ethyl acetate extract of C. bornmuelleri inhibited both acetylcholinesterase (1.14 mg galantamine equivalent [GALAE]/g extract), butyrylcholinesterase (0.63 mg GALAE/g extract), tyrosinase (69.84 mg kojic acid equivalent/g extract), amylase (19.90 mg acarbose equivalent [ACAE]/g extract), and glucosidase (33.12 mg ACAE/g extract). The phytochemical profile of C. bornmuelleri has been characterized and the main components quantified in order to provide scientific base to design innovative products including pharmaceuticals, cosmetics or nutraceuticals although further investigation concerning the isolation of the main bioactive compounds would be required.

Fast LC-MS quantitation of glucose and glycerol via enzymatic derivatization

Glucose and glycerol are important circulating metabolites. Due to poor ionization and/or ion suppression, the liquid chromatography-mass spectrometry (LC-MS) detection of glucose and glycerol presents challenges. Here, we propose an efficient LC-MS method of quantitative glucose and glycerol detection via enzymatic derivatization to glucose-6-phosphate and sn-glycerol-3-phosphate, respectively. This derivatization protocol can be used to measure the concentrations of glucose production in a plethora of sample types for metabolic analysis and is compatible with the general metabolomics workflow. This novel approach allows us to quantitatively study glucose and glycerol metabolism using stable isotope tracers in vivo.

Use of a Continuous Stirred Tank Reactor for the Determination of Electrospray Response Factors and Its Application to Underivatized Sugars Under Various Solvent Parameters

The relationship between the electrospray ionization (ESI)-mass spectrometric (MS) response of an analyte and its concentration has been well studied for permanently charged and basic analytes in the positive ionization mode, but there has been a lack of research effort for other analytes, and for the negative ionization mode, in general. In this study, this relationship was investigated for various adducts and deprotonated species of glucose, sucrose, and raffinose using a continuous stirred tank reactor (CSTR) coupled with ESI-tandem MS to obtain a continuum of response factors across a wide concentration range in both the positive and negative ionization modes with a single injection under 18 different combinations of solvents and additives. Profiles of response factors vs. concentrations varied widely and were dependent upon the analyte and solvent parameters. The use of ammonium trifluoroacetate resulted in the highest response factors for methanol-based and acetonitrile-based solvents in the positive and negative ionization modes, respectively. Ammonium acetate, ammonium formate, and sodium chloride in 80:20 acetonitrile:water in the negative ionization mode resulted in good linearities, useful for quantitative analysis. In the positive ionization mode, response factors tended to increase with an increase in the molecular weight of the analyte, and acetonitrile was generally found to decrease response factors. We have also demonstrated the ability of CSTR-ESI-MS to visualize ionization suppression in the presence of co-analytes. These data should be useful for liquid chromatography-ESI-MS method development for sugar analysis, to help guide the choice of mobile phase that will result in high sensitivity and linearity. Graphical Abstract.

Phenolic profile and antioxidant activity of Jasonia glutinosa herbal tea. Influence of simulated gastrointestinal in vitro digestion

In order to value J. glutinosa DC (rock tea), we characterised its phenolic profile and antioxidant activity. The study was performed in aqueous extracts before and after a simulated in vitro digestion to obtain data regarding phenolics bioavailability. Methanolic extracts were also analysed for comparison purposes. Phytochemical profiles were determined by high-performance liquid chromatography with mass spectrometric detection, whereas total phenolic content (TPC) and antioxidant assays were performed by conventional spectrophotometric methods. The most abundant compounds were dicaffeoylquinic acids, representing more than 90% of phenolics in tea infusions. Statistically significant differences were observed for all parameters except for TPC in methanol and aqueous extracts. Both phenolics amount and antioxidant activities were lower after the in vitro digestion of the infusions. However, although phenolics were lost during the simulated digestion, rock tea is still a good source of bioactive compounds with potential applications in the pharmaceutical or nutraceutical industries.

Parentucellia latifolia subsp. latifolia: A potential source for loganin iridoids by HPLC-ESI-MSn technique

This study attempts to compare the pharmaceutical potential (antioxidant and key enzyme inhibition of clinical relevance) of organic and aqueous extracts of Parentucellia latifolia (L.) Caruel subsp. latifolia (L.) Caruel as well as phytochemical composition. The phytochemical compounds were evaluated by spectrophotometric methods (for total amounts) and HPLC-ESI-DAD-MSⁿ (for individual compounds). The extracts were screened for antioxidant abilities by in vitro assays. Inhibition effects were also investigated against a set of enzymes linked to major health problems. Generally, the methanol (MeOH) and aqueous extracts displayed higher scavenging abilities on radicals and reductive effects when compared with the ethyl acetate (EtOAc) extract. On the other hand, the EtOAc extract was the most active inhibitor on cholinesterases (1.81-1.88 mg GALAE/g), amylase (0.70 mmol ACAE/g), glucosidase (2.85 mmol ACAE/g) and lipase (33.24 mg OE/g). The highest TPC was observed in the aqueous extract (25.07 mg GAE/g) while MeOH extract possessed the highest level of TFC (44.15 mg RE/g) and TPAC (3.46 mg CE/g). LC-MSⁿ metabolite profiling indicated that loganin and its isomers, rutin, and luteolin-O-hexoside were the most abundant compounds. Our results suggest that P. latifolia may be valuable source of phyto-agents for the management of noncommunicable diseases.

Chemical profile, antioxidant, and enzyme inhibitory properties of two Scutellaria species: S. orientalis L. and S. salviifolia Benth

OBJECTIVES

This study investigates into the biological effects of solvent extracts (ethyl acetate, methanol, and water) of Scutellaria orientalis L. and Scutellaria salviifolia Benth. based on its enzyme inhibitory activity and antioxidant ability together with the screening of bioactive compounds.

METHODS

Total and individual bioactive components were determined using spectrophotometric and HPLC-ESI-MS methods. Six antioxidant assays were conducted and enzyme inhibition was tested against key enzymes linked to the pathology of common chronic disorders.

KEY FINDINGS

Results revealed that the aqueous extracts of both plants exerted better 2,2'-azino-bis(3-ethylbenzothiazoline)-6-sulfonic acid scavenging, reducing power, metal chelating, and α-glucosidase inhibitory activities. The methanol extracts showed highest tyrosinase inhibition and antioxidant activity in phosphomolybdenum assay while the less polar ethyl acetate extracts showed better acetylcholinesterase, butyrylcholinesterase, and α-amylase inhibition. Phytochemical evaluation by HPLC-ESI-MS revealed the presence of high amounts of flavones.

CONCLUSIONS

Scutellaria orientalis and S. salviifolia are important sources of bioactive agents that warrants further studies.

Determination of the Phenolic Profile and Antioxidant Activity of Leaves and Fruits of SpanishQuercus coccifera

In this work, we report the phytochemical composition and antioxidant activity of methanol extracts of leaves and fruits (acorns) ofQuercus coccifera(kermes oak). Forty-one compounds were characterized using high-performance liquid chromatography with electrospray multistage mass spectrometry (HPLC-ESI-MSn) with an ion trap mass spectrometer. A high percentage of the detected compounds were gallic acid derivatives, although some saccharides and flavonoids were also present. This phytochemical pattern is typical inQuercusspecies, which are rich in gallotannins. These compounds are partially responsible for the cardioprotective effects observed in different food samples containing them. We evaluated the antioxidant activity by ABTS and DPPH assays. In both cases, high antioxidant activity was observed, being higher in acorns than in leaves. The high antioxidant potential of the extracts, which is related to the high total phenolic content, indicates the potential benefit of the use of this species as a source of bioactive compounds.

Effects of solvent parameters on the electrospray ionization tandem mass spectrometry response of glucose

RATIONALE

The importance of saccharides, the most abundant biomolecules on Earth, extends beyond their biological roles and to consumer products and industrial processes. Electrospray ionization tandem mass spectrometry (ESI-MS/MS) is an attractive tool for the analysis of underivatized saccharides (US), but they tend to have relatively low sensitivities due to their low surface activities and lack of easily protonable or deprotonable chemical groups. An understanding of the influences that solvent parameters have on their signal intensities would enhance the usefulness of ESI-MS/MS for their analysis.

METHODS

Solutions of glucose, a model analyte for US, in various combinations of solvent, additive, additive concentration, and pH were analyzed by flow injection analysis ESI-MS/MS in both the positive and negative ionization mode. The blank-corrected signal intensities of the solvent parameter combinations were then compared.

RESULTS

The addition of acetonitrile led to severe ionization suppression in the positive ionization mode through its competition with glucose for cation adduction. High signal intensity was achieved under wide pH and concentration ranges for methanol: water solutions containing ammonium trifluoroacetate in the positive ionization mode. The highest signal intensities for acetonitrile: water solutions were those containing ammonium formate or lithium fluoride in the negative ionization mode.

CONCLUSIONS

An understanding of the influence of solvent parameters on the signal intensity of a given analyte is useful for guiding the selection process of mobile phases/flow solvents that lead to low limits of detection or the minimization of matrix effects by allowing its detection at high dilution factors.

Integration of in vitro and in silico perspectives to explain chemical characterization, biological potential and anticancer effects of Hypericum salsugineum: A pharmacologically active source for functional drug formulations

The genus Hypericum is one of the most popular genera in both traditional medicine and scientific platform. This study is designed to provide conceptual insights on the biological potential and chemical characterization of H. salsugineum, which is endemic to Turkey. The qualitative and quantitative phenolic content of the extracts was characterized by HPLC-ESI-MSn. Biological efficiency was investigated by enzyme inhibitory assays (cholinesterases, tyrosinase, amylase, and glucosidase) and anti-cancer efficacy tests (anti-proliferative activities with the iCELLigence technology, colony formation and wound healing scratch assays). Phenolic acids (3-O-caffeoylquinic, 5-O-caffeoylquinic, and 4-O-caffeoylquinic acids) were the predominant group in the studied extracts, although several flavonoids were also detected and quantified. The extracts exhibited good inhibitory effects on tyrosinase and glucosidase, while they had weak ability against cholinesterases and amylase. Computational studies were also performed to explain the interactions between the major phenolics and these enzymes. The extracts displayed significant anti-cancer effects on breast carcinoma cell lines. Our findings suggest that Hypericum salsugineum could be valued as a potential source of biologically-active compounds for designing novel products.

High Triterpenic Acids Production in Callus Cultures from Fruit Pulp of Two Apple Varieties

INTRODUCTION

Very rarely fruit pulp has been used in in vitro culture to produce secondary metabolites useful in promoting health.

OBJECTIVES

The aims of this work were the study of the best conditions to obtain the callus cultures from the pulp of two varieties of apples, Golden Delicious (GD) and "Mela Rosa Marchigiana" (MRM), and the quali-quantitative analysis of secondary metabolites produced by the two in vitro callus cultures.

METHODOLOGY

Callus was induced on both Murashige and Skoog and Gamborg B5 media containing various combinations of supplements. To achieve the maximum recovery of secondary metabolites produced, preliminary extraction tests were carried out on GD apple culture using two different organic solvents (MeOH and EtOAc). The quali-quantitative analysis of the methanolic extract of both cultures was carried out by ESI-MSⁿ and GC-MS techniques.

RESULTS

The GC-MS analysis revealed the presence of triterpenic acids, in particular, oleanolic, ursolic, maslinic, pomolic, tormentic, corosolic and annurcoic acid along with a phytosterol, β-sitosterol. In addition, GD callus culture produced phloridzin, absent in the MRM culture. In this last culture, however, the total amount of secondary metabolites was markedly higher. The in vivo production of these bioactive compounds were also quantified in the GD and MRM apple pulps.

CONCLUSION

Apple pulps produced higher amounts of triterpenic acids in vitro than in vivo. The present work can be considered a method to amplify the production of important secondary metabolites which exert beneficial effects on human health. Copyright © 2016 John Wiley & Sons, Ltd.

LC-PDA-ESI-MSn analysis of phenolic and iridoid compounds from Globularia spp

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 MSⁿ (up to MS⁴ ) 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.

Profiling monoterpenol glycoconjugation in Vitis vinifera L. cv. Muscat of Alexandria using a novel putative compound database approach, high resolution mass spectrometry and collision induced dissociation fragmentation analysis

In this work we present a novel approach for the identification of plant metabolites using ultrahigh performance liquid chromatography coupled to accurate mass time-of-flight mass spectrometry. The workflow involves developing an in-house compound database consisting of exact masses of previously identified as well as putative compounds. The database is used to screen accurate mass spectrometry (MS) data to identify possible compound matches. Subsequent tandem MS data is acquired for possible matches and used for structural elucidation. The methodology is applied to profile monoterpene glycosides in Vitis vinifera cv. Muscat of Alexandria grape berries over three developmental stages. Monoterpenes are a subclass of terpenes, the largest class of plant secondary metabolites, and are found in two major forms in the plant, "bound" to one or more sugar moieties or "free" of said sugar moieties. In the free form, monoterpenes are noted for their fragrance and play important roles in plant defense and as attractants for pollinators. However, glycoconjugation renders these compounds odorless, and it is this form that the plant uses for monoterpene storage. In order to gain insight into monoterpene biochemistry and their fate in the plant an analysis of intact glycosides is essential. Eighteen monoterpene glycosides were identified including a monoterpene trisaccharide glycoside, which is tentatively identified here for this first time in any plant. Additionally, while previous studies have identified monoterpene malonylated glucosides in other grapevine tissue, we tentatively identify them for the first time in grape berries. This analytical approach can be readily applied to other plants and the workflow approach can also be used for other classes of compounds. This approach, in general, provides researchers with data to support the identification of putative compounds, which is especially useful when no standard is available.

Activity of Vitis vinifera Tendrils Extract Against Phytopathogenic Fungi

The in vitro antifungal activity was determined of an ethanolic extract of Vitis vinifera L. tendrils (TVV) against ten plant pathogenic fungi, using the agar dilution method; activity was shown against all tested fungi. Fusarium species were the most sensitive with MIC values ranging from 250 to 300 ppm, while the basidiomycete fungus Rhizoctonia solani was the most resistant, with a MIC value of 500 ppm. Electrospray ionization tandem mass spectrometry (ESI-MSn) was used to obtain qualitative information on the main components of TVV. The high amount of polyphenolic compounds contained in TVV is likely to contribute significantly to its antifungal activity.

Profiling of grape monoterpene glycosides (aroma precursors) by ultra-high performance-liquid chromatography-high resolution mass spectrometry (UHPLC/QTOF)

A 'suspect screening analysis' method for grape metabolomics by ultra-high performance-liquid chromatography (UHPLC) and high-resolution quadrupole-time of flight (QTOF) mass spectrometry was recently developed. This method was applied to study grape monoterpene glycosides, the main grape aroma precursors. Since standard compounds were not available, they were tentatively identified by overlapping various analytical approaches, in agreement with the indications recommended in mass spectrometry (MS)-based metabolomics. Accurate mass and isotopic pattern, MS/MS fragmentation, correlation between fragments observed and putative structures and between liquid chromatography coupled with mass spectrometry (LC/MS) and gas chromatography/mass spectrometry signals were studied. Seventeen monoterpene glycosides were identified without performing the hydrolytic artifacts commonly used to study these compounds which may affect sample profile. This is the first time that a detailed study of these aroma precursors has been carried out by direct LC/MS analysis.

Quantification of total hexose on dry blood spot by tandem mass spectrometry

BACKGROUND

Because hypoglycemia and hyperglycemia are harmful and not always associated with overt clinical signs, it is necessary to have methods available to screen for glucose levels to detect hypoglycemia and diabetes as early as possible. A new method for such screening and the clinical determination of blood total hexose on a dry blood spot (DBS) using tandem mass spectrometry (MS/MS) was developed.

METHODS

The serum glucose controls and blood were prepared as DBS and then extracted into a methanol solution containing isotope-labeled internal standards. The methanolic extraction was subjected to HPLC, followed by MS/MS in positive ion mode. Multiple-reaction monitoring of m/z 203.1→23 was used to detect hexose, and m/z 209.0→23 was used for 13C6-D-glucose.

RESULTS

The recoveries of blood glucose by MS/MS were 90%-102% with an R(2) value of 0.999 after linear regression (p<0.001). The controls were within an acceptable range, and the coefficients of variation were less than 10%. The blood total hexose in neonates aged 3-7 days (6.41±1.46 mmol/L) was lower than that in neonates aged 8-30 days (6.66±1.38 mmol/L), and it was lower in neonates than in children aged 1-72 months (7.19±1.87 mmol/L).

CONCLUSION

Quantification of total hexose on a dry blood spot by MS/MS is accurate, reliable and feasible for screening and clinical tests.

Phenylalanine derived cyanogenic diglucosides from Eucalyptus camphora and their abundances in relation to ontogeny and tissue type

The cyanogenic glucoside profile of Eucalyptus camphora was investigated in the course of plant ontogeny. In addition to amygdalin, three phenylalanine-derived cyanogenic diglucosides characterized by unique linkage positions between the two glucose moieties were identified in E. camphora tissues. This is the first time that multiple cyanogenic diglucosides have been shown to co-occur in any plant species. Two of these cyanogenic glucosides have not previously been reported and are named eucalyptosin B and eucalyptosin C. Quantitative and qualitative differences in total cyanogenic glucoside content were observed across different stages of whole plant and tissue ontogeny, as well as within different tissue types. Seedlings of E. camphora produce only the cyanogenic monoglucoside prunasin, and genetically based variation was observed in the age at which seedlings initiate prunasin biosynthesis. Once initiated, total cyanogenic glucoside concentration increased throughout plant ontogeny with cyanogenic diglucoside production initiated in saplings and reaching a maximum in flower buds of adult trees. The role of multiple cyanogenic glucosides in E. camphora is unknown, but may include enhanced plant defense and/or a primary role in nitrogen storage and transport.

Positive and negative electrospray ionisation travelling wave ion mobility mass spectrometry and low-energy collision-induced dissociation of sialic acid derivatives

Mono- or oligosaccharide-containing samples, whether they are derived from biological sources or products of chemical synthesis, are often mixtures of spatial or constitutional isomers. The possibility of characterising or performing quality control on such samples by mass spectrometry is hampered because these isomers cannot be separated by their mass-to-charge ratio alone. Therefore, the use of techniques to separate the isobaric sample compounds prior to mass spectrometric characterisation is mandatory. Travelling wave ion mobility separation offers the possibility of separating mixtures based on their compound's collisional cross-sections in the gas phase and can easily be combined with mass spectrometry for further characterisation. Here, we use 5-N-acetylneuraminic acid and several derivatives as model compounds to evaluate the separation power of travelling wave ion mobility spectrometry and present an approach to clearly identify constitutional isomers in mixtures in combination with low-energy collision-induced dissociation (CID) in the negative ion mode even if they cannot be completely separated by ion mobility.

Anomeric discrimination and rapid analysis of underivatized lactose, maltose, and sucrose in vegetable matrices by U-HPLC-ESI-MS/MS using porous graphitic carbon

Lactose intolerance is a common condition caused by intestinal lactase deficiency, and a lactose-free diet represents the simplest way to avoid gastrointestinal symptoms. The emerging use of dietary supplements requires analytical tools that are capable of assessing these analytes, particularly for those based on dry herbal extracts that contain lactose together with maltose and sucrose, because of cross-contamination and/or deliberate addition as excipient. Electrospray ionization mass spectrometry (ESI-MS) and MS/MS are valuable detection methods for underivatized disaccharides; however, the absence of distinctive ions and collision-induced dissociation (CID) fragmentation patterns does not allow discrimination of stereoisomers without good chromatographic resolution. We developed an ultrahigh performance liquid chromatography-ESI (U-HPLC-ESI) approach, based on porous graphitic carbon (PGC) columns, working at 5 °C to separate and detect the disaccharides in their anomeric forms as formate adducts obtained directly in-column by eluting with formate buffer/acetonitrile gradient mixtures. Using a Paul trap, we monitored the adducts [M + HCOO](-) at m/z 387 in ESI negative mode (MS(1)) as well as the CID fragment ion [M - H](-) at m/z 341 (MS(2)) and used MS(3) fragment ions at m/z 178 and 161 to confirm disaccharides identity in complex vegetable matrices. Complete resolution of lactose α- and β-anomers, maltose α- and β-anomers, and sucrose was obtained with R ≥ 2.0 for all peaks and selectivity α = 1.2 between α- and β-anomers of lactose. The limits of detection were in the range of 3-7 µg/l (ppb) for the target disaccharides. Because of the rapidity and good anomeric discrimination, the described method represents an alternative tool to investigate the mutarotation phenomenon for reducing disaccharides.