Identification and Characterization of Kukoamine Metabolites by Multiple Ion Monitoring Triggered Enhanced Product Ion Scan Method with a Triple-Quadruple Linear Ion Trap Mass Spectrometer

A systematic UHPLC Q-ToF MS approach for the characterization of bioactive compounds from freeze-dried red goji berries (L. barbarum L.) grown in Serbia: Phenolic compounds and phenylamides

The aim of this study was to identify and characterise different classes of bioactive compounds from freeze-dried red goji berries (RGB) grown in Serbia, using ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC Q-ToF MS). In addition, this study aims to demonstrate the importance of applying the advanced UHPLC Q-ToF MS technique in the identification of various biocompounds. The analysis showed the presence of 28 phenolic compounds, 3 organic acids, and 26 phenylamides. The 2-O-β-d-glucopyranosyl-l-ascorbic acid (AA-2βG) was identified by UHPLC Q-ToF MS and quantified by standardised UHPLC-DAD method. Most of the compounds detected were derivatives of caffeic acid and ferulic acid, followed by quercetin derivatives. Among the phenylamides, several glucosylated caffeoyl and/or dihydrocaffeoyl derivatives of spermidine and spermine were characterized, confirming their recent characterization. Some glycosylated/non-glycosylated putrescine derivatives and caffeoyl-dihydrocaffeoyl-feruloyl spermidines were identified in goji berriesfor the first time. Their tentative structures and fragmentations were proposed.

Direct infusion-multiple reaction monitoring cubed (DI-MRM3) enables widely targeted bi-omics of Colla Corii Asini (Chinese name: Ejiao)

Food authenticity is extremely important and widely targeted bi-omics is a promising pipeline attributing to incorporating metabolomics and peptidomics. Colla Corii Asini (CCA, Ejiao) is one of the most popular tonic edible materials, with counterfeit and adulterated products being widespread. An attempt was devoted to develop a high-throughput and reliable DI-MRM3 program facilitating widely targeted bi-omics of CCA. Firstly, predictive MRM program captured metabolites and peptides in trypsin-digestive gelatins. After data alignment and structure annotation, primary parameters such as Q1 → Q3 → QLIT, CE, and EE were optimized for all 17 metabolites and 34 peptides by online ER-MS. Though a single run merely consumed 6.5 min, great selectivity was reached for each analyte. Statistical results showed that nine peptides contributed to distinguish CCA from other gelatins. After cross-validation with LC-MRM, DI-MRM3 was justified to be reproducible and high-throughput for widely targeted bi-omics of CCA, suggesting a meaningful tool for food authenticity.

Ultrasound-assisted extraction of bioactive compounds from goji berries: Optimization, bioactivity, and intestinal permeability assessment

Lycium barbarum L. berries have a remarkable chemical composition and extensive biological activities, being a valuable component of health and nutraceutical practices. Nevertheless, a deep insight on the intestinal permeation of the pro-healthy bioactive compounds is urgently needed to predict the real effects on human body. This study attempted, for the first time, to optimize the Ultrasound-Assisted Extraction (UAE) of goji berries using a Response Surface Methodology approach and establish the intestinal permeation of the principal pro-healthy compounds. The optimal extraction conditions were a solid:liquid ratio of 8.75 % for 56.21 min, using an intensity of 59.05 W/m2. The optimal extract displayed a remarkable antioxidant capacity, with LC/DAD-ESI-MS analysis unveiled a diverse phytochemical profile, encompassing different compounds (e.g. glu-lycibarbarspermidine F, 2-glu-kukoamine, rutin, 3,5-dicaffeoylquinic acid). The intestinal co-culture model demonstrated that glu-lycibarbarspermidine F (isomer 2) (73.70 %), 3,5-dicaffeoylquinic acid (52.66 %), and isorhamnetin-3-O-rutinoside (49.31 %) traversed the intestinal cell layer, exerting beneficial health-promoting effects.

The Chemical Profile, and Antidermatophytic, Anti-Inflammatory, Antioxidant and Antitumor Activities of Withania chevalieri A.E. Gonç. Ethanolic Extract

Withania chevalieri, endogenous from Cape Verde, is a medicinal plant used in ethnomedicine with a large spectrum of applications, such as treating skin fungal infections caused by dermatophytes. The aim of this work was to chemically characterize the W. chevalieri crude ethanolic extract (WcCEE), and evaluate its bioactivities as antidermatophytic, antioxidant, anti-inflammatory and anticancer, as well as its cytotoxicity. WcCEE was chemically characterized via HPLC-MS. The minimal inhibitory concentration, minimal fungicidal concentration, time-kill and checkerboard assays were used to study the antidermatophytic activity of WcCEE. As an approach to the mechanism of action, the cell wall components, β-1,3-glucan and chitin, and cell membrane ergosterol were quantified. Transmission electron microscopy (TEM) allowed for the study of the fungal ultrastructure. WcCEE contained phenolic acids, flavonoids and terpenes. It had a concentration-dependent fungicidal activity, not inducing relevant resistance, and was endowed with synergistic effects, especially terbinafine. TEM showed severely damaged fungi; the cell membrane and cell wall components levels had slight modifications. The extract had antioxidant, anti-inflammatory and anti-cancer activities, with low toxicity to non-tumoral cell lines. The results demonstrated the potential of WcCEE as an antidermatophytic agent, with antioxidant, anti-inflammatory and anticancer activity, to be safely used in pharmaceutical and dermocosmetic applications.

Brazilian sunberry (Solanum oocarpum Sendtn): Alkaloid composition and improvement of mitochondrial functionality and insulin secretion of INS-1E cells

Chronic high-glucose levels induce the generation of reactive oxygen species leading to mitochondrial dysfunction, which is one of the pathological triggers in the development of diabetes. This study investigated the alkaloid composition of two fruits of the genus Solanum, fruta-do-lobo (Solanum lycocarpum) and juá-açu (Solanum oocarpum), and their capacity to protect against oxidative damage and defective insulin secretion induced by chronic high-glucose levels. LC-MS and molecular network of fruit crude extracts reveals that juá-açu and fruta-do-lobo contain kukoamines and glycoalkaloids, respectively. Two purification processes were used to enrich those alkaloids. Fruta-do-lobo extract rich in glycoalkaloids showed a strong cytotoxicity effect, however the juá-açu enriched extract was able to protect mitochondrial functionality against glucotoxicity and stimulate insulin secretion even under conditions of hyperglycemia. These results are promising and suggest that juá-açu is a potential source of bioactive compounds for adjuvant/co-adjuvant therapy for diabetes.

Phenolamides: Plant specialized metabolites with a wide range of promising pharmacological and health-promoting interests

Phenolamides constitute a family of metabolites, widely represented in the plant kingdom, that can be found in all plant organs with a predominance in flowers and pollen grains. They represent a large and structurally diverse family, resulting from the association of phenolic acids with aliphatic or aromatic amines. Initially revealed as active compounds in several medicinal plant extracts, phenolamides have been extensively studied for their health-promoting and pharmacological properties. Indeed, phenolamides have been shown to exhibit antioxidant, anti-inflammatory, anti-cancer and antimicrobial properties, but also protective effects against metabolic syndrome and neurodegenerative diseases. The purpose of this review is to summarise this large body of literature, including in vitro and in vivo studies, by describing the diversity of their biological properties and our actual knowledge of the molecular mechanisms behind them. With regard to their considerable pharmacological interest, the question of industrial production is also tackled through chemical and biological syntheses in engineered microorganisms. The diversity of biological activities already described, together with the active discovery of the broad structural diversity of this metabolite family, make phenolamides a promising source of new active compounds on which future studies should be focused.

The Establishment of Tandem Mass Spectrometric Fingerprints of Phytosterols and Tocopherols and the Development of Targeted Profiling Strategies in Vegetable Oils

Phytosterols and tocopherols are essential for plant biochemistry, and they possess beneficial health effects for humans. Evaluating the tandem mass spectrometric (MS/MS) behavior of phytosterols and tocopherols is needed for the development of a qualitative and quantitative method for these biologically active plant metabolites. Herein, the MS/MS dissociation behavior of phytosterols and tocopherols is elucidated to establish generalized MS/MS fingerprints. MS/MS and multistage (MS³) analysis revealed common fragmentation behavior among the four tested phytosterols, namely β-sitosterol, stigmasterol, campesterol, and brassicasterol. Similar analysis was conducted for the tocopherols (i.e., alpha (α), beta (β), gamma (γ), and delta (δ)). As such, a universal MS/MS fragmentation pathway for each group was successfully established for the first time. Based on the generalized MS/MS fragmentation behavior of phytosterols, diagnostic product ions were chosen for the development of profiling methods for over 20 naturally occurring phytosterols. A precursor ion scan-triggered-enhanced product ion scan (PIS-EPI) method was established. Due to enhanced chromatographic peaks, multiple ion monitoring-triggered-enhanced product ion scan (MIM-EPI) was employed for confirmation. The screening approach was applied successfully to identify blinded samples obtained from standard mixtures as well as sesame and olive oils. The oil samples contain other phytosterols, and their successful identification indicates that, the generalized MS/MS fragmentation behavior is applicable to various structures of phytosterols. A similar approach was attempted for tocopherols and was only hindered by the low concentration of these bioactive metabolites present in the oil samples.

Comparative Study of the Chemical Constituents and Bioactivities of the Extracts from Fruits, Leaves and Root Barks of Lycium barbarum

The fruits, leaves and root barks of L. barbarum plant are widely used as functional foods and as ingredients in traditional Chinese prescriptions and patent medicines. They are considered to have different pharmacological activities and health benefits because of their diverse constituents. Here, the chemical constituents of the extracts from fruits, leaves and root barks of L. barbarum were compared by ultra-high performance liquid chromatography coupled with high resolution mass spectrometry (UPLC-HR-MS). A total of 131 compounds were identified and seven of them were quantified. Among them, 98, 28 and 35 constituents were detected in fruits, leaves and root barks respectively. Dicaffeoylspermidine/spermine derivatives were the most detected compounds (74/131); among them, dicaffeoylspermine isomers and propionyl-dicaffeoylspermidine were found in root barks in very large amounts (e.g., kukoamine B = 10.90 mg/g dry powder); dicaffeoyl-spermidine isomers were detected in fruits/leaves in a high amount, and many of their glycosylated derivatives were mainly detected in fruits. In addition, six saponins from L. barbarum fruits were reported for the first time, and 5,6-dihydrosolasonine was reported for the first time in plants. The activity assays showed that the root bark extract possessed the strongest antioxidative activity and cytotoxicity, which was presumed due to the large amount of dicaffeoylspermine/spermidines in root barks. Fourteen potential bioactive components from fruits were identified by a target cell-based screening method. These results will help to understand the different biological activities of these three parts of L. barbarum plant and will benefit the discovery of new functional components.

Metabolic Demethylation and Oxidation of Caffeine during Uptake by Lettuce

Pharmaceuticals can be metabolized after being taken up by plants. The metabolites could manifest similar or equivalent bioactivity to the parent compound, promoting the critical need to understand the metabolism in plants. Caffeine has been frequently detected in agriculture produce; however, little attention is given to its metabolites in vegetables. This study examined uptake and metabolism of caffeine in lettuce in a hydroponic system. Caffeine and its metabolites in aqueous solution and lettuce were identified and quantified using a liquid chromatography coupled to a QTrap tandem mass spectrometry instrument. After 144 h, over 50% of applied caffeine dissipated in the hydroponic lettuce system, and eight caffeine metabolites were identified primarily in the shoots. Caffeine underwent demethylation reactions, which were confirmed with authentic standards, and the total amount accounted for 20% of the initially applied caffeine. Other metabolism pathways included oxidation and hydroxylation, and the amount of metabolites increased over uptake time.

Quality control of Lycium chinense and Lycium barbarum cortex (Digupi) by HPLC using kukoamines as markers

Background

Lycii Cortex (LyC), composed of Lycium chinense and Lycium barbarum cortex and having the Chinese name Digupi, is used to treat chronic diseases like cough, hypertension, and diabetes in Eastern Asia. However, chromatographic methods, such as TLC and HPLC, to determine the phytochemical composition of LyC have not been included in any official compendiums. This study aims to establish a validated HPLC method for quality control of LyC.

Methods

Kukoamines A and B (KA and KB, respectively) were selected as markers for the HPLC method. An acetic acid solution was adopted for sample extraction because it facilitated the release of kukoamines and effectively prevented their degradation. Optimal separation of the kukoamine isomers was achieved on hydrophilic ligand-coated C18 columns with a gradient elution of acetonitrile and 0.1% (v/v) trifluoroacetic acid. The average contents and proposed contents for LyC were calculated with a t test and an uncertainty test based on 16 batches of authentic samples.

Results

The method was validated with linearity (r² = 0.9999 for both KA and KB), precision (RSD = 1.29% for KA and 0.57% for KB), repeatability (RSD = 1.81% for KA and 0.92% for KB), and accuracy (recovery of 90.03–102.30% for KA, and 98.49–101.67% for KB), indicating that the method could offer reliable results for quality control analysis of LyC. At the 95% confidence level, the calculated content limits were 1.45 mg/g for KA and 4.72 mg/g for KB.

Conclusion

Compared with conventional morphological identification, the HPLC method involving KA and KB contents offers precise, objective, and quantitative results for quality control of LyC.

Electronic supplementary material

The online version of this article (doi:10.1186/s13020-016-0121-x) contains supplementary material, which is available to authorized users.

Development and validation of a rapid and sensitive UPLC-MS/MS method for quantification of kukoamine B in human plasma: Application to a clinical pharmacokinetic study

A rapid, accurate and robust method was firstly developed using ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) assay to quantify kukoamine B, which is a novel drug under clinical development for the treatment of sepsis, in human plasma. Solid-phase extraction (SPE) was used to extract kukoamine B from human plasma. The extracts were separated on a Waters Acquity HSS T3 column (2.1×50mm i.d., 1.8μm) with a gradient elution method, using mobile phases of A (formic acid-water (1:1000, v/v)) and B(formic acid-methanol (1:1000, v/v)). Kukoamine B and internal standard (5-deuterated isotope kukoamine B) were detected under the multiple-reaction monitoring mode by an API 5500 triple quadrupole mass spectrometer with electrospray ionization. The method showed good linearity from 0.100 to 50.0ng/mL according to 1/x² weighted linear regression analysis. Inter- and intra-batch precision of kukoamine B were less than 15% and the accuracy was within 85-115%. The extraction recoveries and matrix effect of kukoamine B at three concentration levels were consistent. The sensitivity, specificity and stabilities under various conditions were validated. In conclusion, the validation results showed that this method was rapid, accurate, robust and can successfully fulfill the requirement of clinical pharmacokinetic study of kukoamine B mesylate in Chinese healthy subjects.

Metabolism and bioactivation of the tricyclic antidepressant amitriptyline in human liver microsomes and human urine

Aim: Amitriptyline is a widely used tricyclic antidepressant, but the metabolic studies were conducted almost 20 years ago using high-performance liquid chromatography coupled with ultraviolet detector or radiolabeled methods. Results: First, multiple ion monitoring (MIM)- enhanced product ion (EPI) scan was used to obtain the diagnostic ions or neutral losses in human liver microsome incubations with amitriptyline. Subsequently, predicted multiple reaction monitoring (MRM)-EPI scan was used to identify the metabolites in human urine with the diagnostic ions or neutral losses. Finally, product ion filtering and neutral loss filtering were used as the data mining tools to screen metabolites. Consequently, a total of 28 metabolites were identified in human urine after an oral administration using LC–MS/MS. Conclusion: An integrated workflow using LC–MS/MS was developed to comprehensively profile the metabolites of amitriptyline in human urine, in which five N-acetyl-l-cysteine conjugates were characterized as tentative biomarkers for idiosyncratic toxicity.