Prediction of Transformation Products of Monensin by Electrochemistry Compared to Microsomal Assay and Hydrolysis

The knowledge of transformation pathways and identification of transformation products (TPs) of veterinary drugs is important for animal health, food, and environmental matters. The active agent Monensin (MON) belongs to the ionophore antibiotics and is widely used as a veterinary drug against coccidiosis in broiler farming. However, no electrochemically (EC) generated TPs of MON have been described so far. In this study, the online coupling of EC and mass spectrometry (MS) was used for the generation of oxidative TPs. EC-conditions were optimized with respect to working electrode material, solvent, modifier, and potential polarity. Subsequent LC/HRMS (liquid chromatography/high resolution mass spectrometry) and MS/MS experiments were performed to identify the structures of derived TPs by a suspected target analysis. The obtained EC-results were compared to TPs observed in metabolism tests with microsomes and hydrolysis experiments of MON. Five previously undescribed TPs of MON were identified in our EC/MS based study and one TP, which was already known from literature and found by a microsomal assay, could be confirmed. Two and three further TPs were found as products in microsomal tests and following hydrolysis, respectively. We found decarboxylation, O-demethylation and acid-catalyzed ring-opening reactions to be the major mechanisms of MON transformation.

Validation and Application of Biocrates AbsoluteIDQ® p180 Targeted Metabolomics Kit Using Human Milk

Human-milk-targeted metabolomics analysis offers novel insights into milk composition and relationships with maternal and infant phenotypes and nutritional status. The Biocrates AbsoluteIDQ® p180 kit, targeting 40 acylcarnitines, 42 amino acids/biogenic amines, 91 phospholipids, 15 sphingolipids, and sum of hexoses, was evaluated for human milk using the AB Sciex 5500 QTRAP mass-spectrometer in liquid chromatography-tandem mass-spectrometry (LC-MS/MS) and flow-injection analysis (FIA) mode. Milk (<6 months lactation) from (A) Bangladeshi apparently healthy mothers (body mass index (BMI) > 18.5; n = 12) and (B) Bangladeshi mothers of stunted infants (height-for-age Z (HAZ)-score <-2; n = 13) was analyzed. Overall, 123 of the possible 188 metabolites were detected in milk. New internal standards and adjusted calibrator levels were used for improved precision and concentration ranges for milk metabolites. Recoveries ranged between 43% and 120% (coefficient of variation (CV): 2.4%-24.1%, 6 replicates). Milk consumed by stunted infants vs. that from mothers with BMI > 18.5 was lower in 6 amino acids/biogenic amines but higher in isovalerylcarnitine, two phospholipids, and one sphingomyelin (p < 0.05 for all). Associations between milk metabolites differed between groups. The AbsoluteIDQ® p180 kit is a rapid analysis tool suitable for human milk analysis and reduces analytical bias by allowing the same technique for different specimens. More research is needed to examine milk metabolite relationships with maternal and infant phenotypes.

Molecular Networking Reveals the Chemical Diversity of Selaginellin Derivatives, Natural Phosphodiesterase-4 Inhibitors from Selaginella tamariscina

Selaginellins are unique pigments found in the genus Selaginella, the largest genus of Lycopodiophyta. Recent studies reported that some selaginellin analogues have potent phosphodiesterase-4 (PDE4) inhibitory activity. In this study, the chemical diversity of natural selaginellin derivatives was revealed by an MS/MS molecular networking-based dereplication of the Selaginella tamariscina extract. It led to the prioritization of chromatographic peaks predicted as previously unknown selaginellin derivatives. Targeted isolation of these compounds afforded two unusual selaginellin analogues with a 1H,3H-dibenzo[de,h]isochromene skeleton, namely, selariscins A (1) and B (2), along with eight new diarylfluorene derivatives, selaginpulvilins M-T (3-10), and five known analogues, 11-15. The absolute configurations of 1, 2, and 8-10 were elucidated by spectroscopic data analyses including computational electronic circular dichroism data. Compounds 1 and 3-10 showed PDE4 inhibitory activity with IC₅₀ values in the range of 2.8-33.8 μM, and their binding modes are suggested by a molecular docking study.

Potent Vasodilator and Cellular Antioxidant Activity of Endemic Patagonian Calafate Berries (Berberis microphylla) with Nutraceutical Potential

Hydroalcoholic extracts of Patagonian Calafate berry (Berberis microphylla) contain mono or disaccharide conjugated anthocyanins and flavonols. The Liquid Chromatography-Mass Spectrometry (LC-MS) chemical extract profile identified glycosylated anthocyanidins such as delphinidin-, petunidin- and malvidin-3-glucoside as the major constituents. The predominant flavonols were 3-O substituents quercetin-rutinoside or -rhamnoside. Anthocyanins doubled flavonols in mass (13.1 vs. 6 mg/g extract). Polyphenols vascular actions were examined in the rat arterial mesenteric bed bioassay; extract perfusion elicited concentration-dependent vasodilatation mimicked by conjugated anthocyanins standards. Vascular responses of main glycosylated anthocyanins were endothelium-dependent (p < 0.001) and mediated by NO production (p < 0.05). The anthocyanins antioxidant activity determined in isolated endothelial cells (CAA) showed a reduced redox potential as compared to the extract or quercetin. While in the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, the anthocyanins showed an equivalent quercetin potency, the extract was 15-fold less active, proposing that the anthocyanin-induced vasodilation is not due to an antioxidant mechanism. The extract shows promising commercial nutraceutical potential.

Development and Validation of an HPLC-ESI/MS/MS Method for the Determination of Amoxicillin, Its Major Metabolites, and Ampicillin Residues in Chicken Tissues

A method for the simultaneous analysis of amoxicillin (AMO), amoxicillin metabolites, and ampicillin residues in edible chicken muscle, liver, and kidney samples via high-performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI/MS/MS) was developed and verified. The extraction and purification procedures involved the extraction of the sample using a liquid-liquid extraction method with acetonitrile to eliminate the proteins. The chicken tissue extract was then injected directly onto an HPLC column coupled to a mass spectrometer with an ESI(+) source. The HPLC-ESI/MS/MS method was validated according to specificity, sensitivity, linearity, matrix effects, precision, accuracy, decision limit, detection capability, and stability, as defined by the European Union and Food and Drug Administration. The linearity was desirable, and the determination coefficients (r² values) ranged from 0.9968 and 0.9999. The limits of detection and limits of quantification were 0.10–2.20 μg/kg and 0.30–8.50 μg/kg, respectively. The decision limits were 57.71–61.25 μg/kg, and the detection capabilities were 65.41–72.50 μg/kg, and the recoveries of the four target analytes exceeded 75% at the limits of quantification and exceeded 83% at 25, 50, and 100 μg/kg (n = 6 at each level), confirming the reliability of this method for determining these analytes and providing a new detection technology. For real sample analysis, this experiment tested 30 chicken tissue samples, only one chicken muscle, liver, and kidney sample were contaminated with 5.20, 17.45, and 7.33 μg/kg of AMO values, respectively, while other target compounds were not detected in the 30 tested chicken tissue samples.

Lethal Injection of a Castor Bean Extract: Ricinine Quantification as a Marker for Ricin Exposure Using a Validated LC-MS/MS Method

Ricin is a highly toxic agent derived from the castor bean plant (Ricinus communis). Poisoning occurs commonly by oral ingestion of the beans. Injection of ricin is believed to be more lethal. Ricin is a large glycosylated protein difficult to detect in clinical samples. Instead, ricinine, a small alkaloid found in the same beans, is used as surrogate marker for ricin exposure. We describe a simple LC-MS/MS method for the detection of ricinine in serum, blood and urine, validated according to EMA guidelines and successfully applied to patient samples of a suicidal death after injection of a castor bean extract. A 26-year-old man self-presented to the emergency department with severe abdominal cramps and nausea after injection of a castor bean extract. Due to rapid deterioration of his hemodynamic function despite early aggressive fluid resuscitation, he was transferred to ICU. Abdominal cramps worsened and a fulminant diarrhea developed, resulting in hypovolemic shock and cardiorespiratory collapse. Despite full supportive therapy, the patient died approximately 10 hours after injection due to multiple organ failure. Ricinine was quantified by LC-MS/MS after LLE with diethyl ether using ricinine-D3 as internal standard. Six hours after injection, ricinine concentrations in serum and blood were 16.5 and 12.9 ng/mL, respectively, which decreased to 12.4 and 10.6 ng/mL, 4 hours later. The urinary concentration was 81.1 ng/mL 7 hours after injection, which amply exceeded the levels previously reported in similar cases with lethal outcome. Concentrations of ricinine, compatible with a lethal exposure to castor beans, were detected in serum, blood and urine. Ricinine was also found in bile and liver tissue.

Alteration of Sphingolipids in Biofluids: Implications for Neurodegenerative Diseases

Sphingolipids (SL) modulate several cellular processes including cell death, proliferation and autophagy. The conversion of sphingomyelin (SM) to ceramide and the balance between ceramide and sphingosine-1-phosphate (S1P), also known as the SL rheostat, have been associated with oxidative stress and neurodegeneration. Research in the last decade has focused on the possibility of targeting the SL metabolism as a therapeutic option; and SL levels in biofluids, including serum, plasma, and cerebrospinal fluid (CSF), have been measured in several neurodegenerative diseases with the aim of finding a diagnostic or prognostic marker. Previous reviews focused on results from diseases such as Alzheimer's Disease (AD), evaluated total SL or species levels in human biofluids, post-mortem tissues and/or animal models. However, a comprehensive review of SL alterations comparing results from several neurodegenerative diseases is lacking. The present work compiles data from circulating sphingolipidomic studies and attempts to elucidate a possible connection between certain SL species and neurodegeneration processes. Furthermore, the effects of ceramide species according to their acyl-chain length in cellular pathways such as apoptosis and proliferation are discussed in order to understand the impact of the level alteration in specific species. Finally, enzymatic regulations and the possible influence of insulin resistance in the level alteration of SL are evaluated.

Salivary proteomics of canine oral tumors using MALDI-TOF mass spectrometry and LC-tandem mass spectrometry

Canine oral tumors are relatively common neoplasms in dogs. For disease monitoring and early diagnosis, salivary biomarkers are appropriate because saliva collection is non-invasive and requires no professional skills. In the era of omics, matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry (MALDI-TOF MS) coupled with liquid chromatography-tandem MS (LC-MS/MS) are suitable to identify potential disease-associated peptides and proteins. The present study aimed to use MALDI-TOF MS and LC-MS/MS to search for particular peptide mass fingerprints (PMFs) and conceivable biomarkers in saliva of dogs with early- and late-stage oral melanoma (EOM and LOM, respectively), oral squamous cell carcinoma (OSCC), benign oral tumors (BN), and periodontitis and healthy controls (CP). Pooled saliva samples in each group were used to be representative of population change. Unique PMFs were obtained and specific peptide fragments were sequenced by LC-MS/MS and BLAST-searched with mammalian protein databases. Seven peptide fragments appeared in the tumor groups (EOM, LOM, OSCC and BN) at 1096, 1208, 1322, 1794, 1864, 2354 and 2483 Da, two peptide fragments appeared in the LOM and OSCC groups at 2450 and 3492 Da, and in the CP controls at 2544 and 3026 Da. Also, protein–chemotherapy drug interaction networks were exhibited. Using western blot analysis, the expression of sentrin-specific protease 7 (SENP7), a peptide fragment at 1096 Da, in OSCC was significantly increased, as was the expression of TLR4, a peptide fragment at 3492 Da, in LOM and OSCC, compared with the CP group. The expression of nuclear factor kappa B (NF-κB), a TLR4 partner, was notably increased in OSCC compared with CP, BN and EOM. The expression was also enhanced in LOM compared with EOM. Expressed protein sequences from western blots were verified by LC-MS/MS. Western blots were then performed with individual samples in each group. The results showed the elevated expression of TLR4 in LOM and OSCC, compared with that in CP and BN, the increased expression of NF-κB in LOM and OSCC, compared with CP and in LOM compared with BN, and the enhanced expression of SENP7 in LOM and OSCC, compared with that in CP and BN. In conclusion, discrete clusters of EOM, LOM, OSCC, BN and CP groups and potential protein candidates associated with the diseases were demonstrated by salivary proteomics. Western blot analysis verified SENP7, TLR4 and NF-κB as potential salivary biomarkers of canine oral tumors.

Identification of Auxin Metabolites in Brassicaceae by Ultra-Performance Liquid Chromatography Coupled with High-Resolution Mass Spectrometry

Auxins are signaling molecules involved in multiple stages of plant growth and development. The levels of the most important auxin, indole-3-acetic acid (IAA), are regulated by the formation of amide and ester conjugates with amino acids and sugars. In this work, IAA and IAA amide conjugates with amino acids bearing a free carboxylic group or a methyl ester group, along with some selected IAA metabolites, were studied in positive and negative electrospray ionization (ESI) modes, utilizing high-resolution mass spectrometry (HRMS) as a tool for their structural analysis. HRMS/MS spectra revealed the fragmentation patterns that enable us to identify IAA metabolites in plant extracts from eight vegetables of the Brassicaceae family using a fast and reliable ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QToF-MS) method. The accurate m/z (mass to charge) ratio and abundance of the molecular and fragment ions of the studied compounds in plant extracts matched those obtained from commercially available or synthesized compounds and confirmed the presence of IAA metabolites.

Detection of 13 Ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, Compound K, 20(S)-Protopanaxadiol, and 20(S)-Protopanaxatriol) in Human Plasma and Application of the Analytical Method to Human Pharmacokinetic Studies Following Two Week-Repeated Administration of Red Ginseng Extract

We aimed to develop a sensitive method for detecting 13 ginsenosides using liquid chromatography-tandem mass spectrometry and to apply this method to pharmacokinetic studies in human following repeated oral administration of red ginseng extract. The chromatograms of Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, Rg3, Rh2, F1, compound K (CK), protopanaxadiol (PPD), and protopanaxatriol (PPT) in human plasma were well separated. The calibration curve range for 13 ginsenosides was 0.5-200 ng/mL and the lower limit of quantitation was 0.5 ng/mL for all ginsenosides. The inter- and intra-day accuracy, precision, and stability were less than 15%. Among the 13 ginsenosides tested, nine ginsenosides (Rb1, Rb2, Rc, Rd, Rg3, CK, Rh2, PPD, and PPT) were detected in the human plasma samples. The plasma concentrations of Rb1, Rb2, Rc, Rd, and Rg3 were correlated with the content in red ginseng extract; however, CK, Rh2, PPD, and PPT were detected although they are not present in red ginseng extract, suggesting the formation of these ginsenosides through the human metabolism. In conclusion, our analytical method could be effectively used to evaluate pharmacokinetic properties of ginsenosides, which would be useful for establishing the pharmacokinetic-pharmacodymic relationship of ginsenosides as well as ginsenoside metabolism in humans.

Dissipation Kinetics and the Pre-Harvest Residue Limits of Acetamiprid and Chlorantraniliprole in Kimchi Cabbage Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry

The dissipation behaviors of acetamiprid and chlorantraniliprole in kimchi cabbages were studied under open-field conditions. A simple and rapid analytical method was developed using ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS). The multiple reaction monitoring (MRM) conditions of two pesticides were optimized to quantify and identify the pesticide residues. Sample preparation was performed by the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method. Average recovery rates at the different spiked levels (0.05 and 0.25 mg/kg) were in the range of 103.6-113.9% (acetamiprid) and 80.8-91.2% (chlorantraniliprole), and the relative standard deviations were ≤4.3% for all. The dissipation kinetics were assessed using first-order equations after spraying acetamiprid and chlorantraniliprole individually on kimchi cabbages. The biological half-lives in field 1 and 2 were 5.2 and 6.3 days (acetamiprid) and 10.0 and 15.2 days (chlorantraniliprole), respectively. Based on the dissipation equations, the pre-harvest residue limits (PHRLs) corresponding to each day before harvest were suggested as the guidelines to meet the MRL on harvest day. It was also predicted that the terminal residues observed after multiple sprayings (three and seven days) would be below the MRL when harvested, in compliance with the established pre-harvest intervals.

Saccharomyces cerevisiae and Torulaspora delbrueckii Intra- and Extra-Cellular Aromatic Amino Acids Metabolism

Tryptophan, phenylalanine, and tyrosine play an important role as nitrogen sources in yeast metabolism. They regulate biomass production and fermentation rate, and their catabolites contribute to wine health benefits and sensorial character through the yeast biotransformation of grape juice constitutes into biologically active and flavor-impacting components. A UHPLC-MS/MS method was applied to monitor 37 tryptophan/phenylalanine/tyrosine yeast metabolites both in extra- and intracellular extracts produced by the fermentation of two Saccharomyces cerevisiae strains and one Torulaspora delbrueckii. The results shed light on the intra- and extra-cellular metabolomic dynamics, by combining metabolic needs, stimuli, and signals. Among others, the results indicated (a) the production of 2-aminoacetophenone by yeasts, mainly by the two Saccharomyces cerevisiae; (b) the deactivation and/or detoxification of tryptophol via sulfonation reaction; and (c) the deacetylation of N-acetyl tryptophan ethyl ester and N-acetyl tyrosine ethyl ester by producing the corresponding ethyl esters.

RQ3, A Natural Rebaudioside D Isomer, Was Obtained from Glucosylation of Rebaudioside A Catalyzed by the CGTase Toruzyme 3.0 L

In this study, a monoglucosyl rebaudioside A product was isolated from the mixture of glucosylated rebaudioside A obtained from the most reported and industrial used cyclodextrin glycosyl transferase, Toruzyme 3.0 L (CGTase, Toruzyme 3.0 L). The molecular structure of the monoglucosyl rebaudioside A was characterized using LC-MS/MS and methylation analysis combined with 1D and 2D NMR, indicating that it is 13-[(2-O-(3-α-O-D-glucopyranosyl)-β-D-glucopyranosyl-3-O-β-D-glucopyranosyl-β-D-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid β-D-glucopyranosyl ester (also known as RQ3, which naturally exists in Stevia extract as an isomer of rebaudioside D). This study may help to further understand the reaction mechanism of glucosylation of steviol glycoside assisted by Toruzyme 3.0 L in the aspect of molecule linkage pattern, and also benefit the application of the glucosylated rebaudiosides.

Analyzing a broader spectrum of endocrine active organic contaminants in sewage sludge with high resolution LC-QTOF-MS suspect screening and QSAR toxicity prediction

Endocrine active contaminants (EACs) in environmental samples can pose a range of toxicological threats to ecosystems, especially through their impacts on reproductive pathways mediated by the estrogen receptor. The physicochemical properties of known organic EACs vary greatly and typically require different sample preparation techniques to identify different classes of compounds. EAC sources are similarly diverse, including both endogenous compounds and anthropogenic chemicals found in personal care products, pharmaceuticals, and their transformation products, which are often disposed of to sewers at their end of use. Looking for EACs in sewage sludge proposes a bottom-up, or end-of-use and treatment approach to discover environmentally relevant EACs, since many EACs accumulate in sludges even after application of robust wastewater treatment processes. This study demonstrates an extraction and analytical method capable of detecting a broad spectrum of known and suspected EACs via High Resolution Liquid Chromatography Quadropole Time-of-Flight Mass Spectrometry (LC-QTOF-MS) suspect screening of fourteen California sewage sludge samples. Spike-recovery experiments were performed using twelve carefully selected surrogates to assess different extraction solvents, sample weights, extraction pH values, procedures for combining extracts with different extraction pH's, and solid phase extraction cartridges. Using LC-QTOF-MS, identifications of several other organic compounds in the samples were made, a goal unachievable with unit resolution mass spectrometry. Suspect screening of California sludge samples discovered 118 compounds including hormones, pharmaceuticals, phosphate flame retardants, recreational drugs, antimicrobials, and pesticides. Additionally, 22 of these identified compounds are predicted to interfere with estrogen receptors or other reproductive/developmental pathways based on the VEGA QSAR toxicity prediction model.

Pyrrolizidine Alkaloids of Blue Heliotrope (Heliotropium amplexicaule) and Their Presence in Australian Honey

Blue heliotrope (Heliotropium amplexicaule) is an invasive environmental weed that is widely naturalized in eastern Australia and has been implicated as a source of pyrrolizidine alkaloid (PA) poisoning in livestock. Less well-documented is the potential of such carcinogenic alkaloids to contaminate honey from bees foraging on this plant species. In this study, the PA profile of H. amplexicaule plant material, determined by HRAM LC-MS/MS, revealed the presence of nine PAs and PA-N-oxides, including several PAs and PA-N-oxides of the indicine class, which have not previously been reported. The predominant alkaloid, indicine, represents 84% of the reduced PA content, with minor alkaloids identified as intermedine and the newly reported helioamplexine, constituting 7 and 9%, respectively. NMR analysis confirmed the identity of helioamplexine as a previously unreported indicine homologue. This is the first report of the isolation of intermedine, helioamplexine, and 3'-O-angelylindicine from H. amplexicaule. Also described is the identification of N-chloromethyl analogues of the major alkaloids as isolation-derived artifacts from reactions with dichloromethane. Analysis of regional-market honey samples revealed a number of honey samples with PA profiles analogous to that seen in H. amplexicaule, with measured PA contents of up to 2.0 μg of PAs per gram of honey. These results confirm the need for honey producers to be aware of H. amplexicaule as a potential PA source, most particularly in products where honey is sourced from a single location.

Milk-Derived Amadori Products in Feces of Formula-Fed Infants

Food processing of infant formula alters chemical structures, including the formation of Maillard reaction products between proteins and sugars. We detected early Maillard reaction products, so-called Amadori products, in stool samples of formula-fed infants. In total, four Amadori products (N-deoxylactulosyllysine, N-deoxyfructosyllysine, N-deoxylactulosylleucylisoleucine, N-deoxyfructosylleucylisoleucine) were identified by a combination of complementary nontargeted and targeted metabolomics approaches. Chemical structures were confirmed by preparation and isolation of reference compounds, LC-MS/MS, and NMR. The leucylisoleucine Amadori compounds, which most likely originate from β-lactoglobulin, were excreted throughout the first year of life in feces of formula-fed infants but were absent in feces of breastfed infants. Despite high inter- and intraindividual differences of Amadori products in the infants' stool, solid food introduction resulted in a continuous decrease, proving infant formula as the major source of the excreted Amadori products.

Potential Photoprotective Effect of Dietary Corn Silk Extract on Ultraviolet B-Induced Skin Damage

Ultraviolet B (UVB) irradiation causes adverse effects on the skin. Corn silk contains flavonoids and other bioactive compounds and antioxidants, which may prevent skin photoaging through antioxidant and anti-inflammatory effects. We aimed to investigate the potential photoprotective effects of dietary corn silk on UVB-induced skin damage in mice and the mechanisms behind these effects on human skin cells. Oral administration of corn silk water extract (CS) (2 or 4 g/kg/day) for 19 weeks decreased epidermal thickness, wrinkle formation, and positive staining for PCNA, Ki67, and 8-OHdG, and increased collagen staining in UVB-irradiated SKH-1 hairless mice compared with controls. The pro-inflammatory NF-κB target genes (IL-1β, iNOS, and COX-2) and MMP-9 expressions were lower in the CS groups, and TGF-β/Smad signaling increased. Low skin lipid peroxidation and blood DNA oxidation levels and high blood glutathione were detected. Antioxidant transcription factor Nrf2-related catalase and SOD1 proteins and glutaredoxin mRNA levels increased. The results of CS extract treatment and UVB irradiation in HaCaT cells showed the same results in Nrf2 and NF-κB target genes. An LC-MS/MS analysis showed that the CS extract contained potential antioxidants, which might have contributed to its anti-photoaging effects in tissues and cells. CS extract may reduce UVB-induced skin damage through antioxidant and anti-inflammatory mechanisms.

Investigation of the chemical composition and biological activity of edible grapevine (Vitis vinifera L.) leaf varieties

Chemical composition and bioactivity of eight edible Vitis vinifera L. leaf varieties originating from Fruška Gora, Serbia, including two autochthonous varieties, were evaluated. The LC-MS/MS analysis confirmed the presence of 28 natural products in leaf samples, among which most abundant were glycosylated flavonoids, ellagic and chlorogenic acids. The highest amounts of most of the tested compounds were detected in leaves of autochthonous variety Sila. Bioactivity was assessed by a set of in vitro antioxidant, neuroprotective and cytotoxic assays. Leaves of all examined varieties exhibited average bioactivity, with leaves of autochthonous variety Župljanka standing out as the most promising sample. To conclude, investigated grapevine leaves proved to be a rich source of nutraceuticals, primarily antioxidants, and their further employment as medicinal food in human diet and beneficial raw material for food, pharmaceutical and cosmetic industries should be supported.

Ultrahigh-performance liquid chromatography with tandem mass spectrometry for the determination of 10 alkaloids in beagle plasma after the oral administration of the three Coptidis rhizoma extracts

ETHNOPHARMACOLOGICAL RELEVANCE

Coptidis rhizoma (CR) is the dried rhizome of the ranunculaceous plant CR. For decades in China, this plant has been used to treat hypertension, hyperlipidemia, and chronic diarrhea and has been officially included in the Chinese Pharmacopoeia. The present paper presents a review of the pharmacokinetics of CR.

AIM OF THE STUDY

The pharmacokinetic studies and differences of 10 alkaloids among Coptis deltoidea C. Y. cheng et Hsiao, Coptis chinensis Franch and Coptis teeta Wall. Are seldom reported. This study is the first to determine corydaline, dehydrocorydaline, tetrahydropalmatine, palmatine, magnoflorine, jatrorrhizine, berberine, worenine, berberrubine, and coptisine, which adopted an ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometry, simultaneously.

MATERIALS AND METHODS

Chromatographic separation was performed within 8 min by using an Agilent SB-C₁₈ column (150 mm × 2.1 mm, 1.8 μm) with gradient mobile phase consisting of 0.3% acetic acid water (v/v) and acetonitrile at a flow rate of 0.3 mL/min. Multiple reaction monitoring mode was used to detect the tandem mass spectrum in the positive ionization mode by electrospray ionization source.

RESULTS

The method was fully validated to be linear over a wide concentration (r > 0.9916), and the linear concentration range was 0.195-2260 ng/mL. Intra- and interday precisions were below 14.19% and 18.56% for the 10 analytes, respectively. The accuracy ranged from -9.30% to 6.31%. The extraction recovery of the 10 alkaloids and internal standard ranged from 79.76% to 95.37%. Pharmacokinetic comparative study showed that the C_max and AUC_0-∞ values of dehydrocorydaline, tetrahydropalmatine, palmatine, magnoflorine, jatrorrhizine, berberine, worenine, berberrubine, and coptisine increased significantly (p < 0.05), which was different for beagles after oral administration. The results can help determine the mechanism of action and guide clinical application of these three extracts.

CONCLUSION

This validated method was successfully applied for the pharmacokinetics study of beagle plasma after oral administration of three CR extract types.

Development and validation of a simple, fast, and sensitive LC/MS/MS method for the quantification of oxfendazole in human plasma and its application to clinical pharmacokinetic study

The most popular standard treatments for soil transmitted helminths in humans including mebendazole, albendazole, levamisole, and pyrantel pamoate, show greatly variable efficacy against different species of parasites and have unfavorable pharmacokinetic characteristics, such as short half-life. The transition of oxfendazole, a potent broad-spectrum anthelmintic with long half-life, from veterinary medicine to human use has been considered as a promising approach. However, analytical methods for the quantitative detection of oxfendazole in human matrix are very limited and lack sensitivity. In this study, we have developed a high-performance liquid chromatography-tandem mass spectrometry (LC/MS/MS) method for the quantification of oxfendazole in human plasma using albendazole as an internal standard. The established method was fully validated with lower limit of quantitation (LLOQ) of 0.5 ng/mL and linearity in the range of 0.5-1000 ng/mL; intra-day and inter-day accuracies ranged from 2.6 to 9.5% for 3 quality control levels (1.5 ng/mL, 75 ng/mL, and 750 ng/mL) and LLOQ; intra-day and inter-day precision was ≤13.6% for quality controls and ≤15.1% for LLOQ; matrix factor and extraction recovery were consistent with coefficient of variation of less than 15.0%. Other parameters including matrix selectivity, injection carryover, reinjection reproducibility, hemolysis effect, interference of analyte with internal standard, dilution integrity, freeze/thaw stability, whole blood stability, and stock solution stability were also validated and met the acceptance criteria. The assay was successfully applied to quantify oxfendazole plasma concentration in healthy adult volunteers after the administration of multiple oral doses of oxfendazole.

Spatial and proteomic profiling reveals centrosome-independent features of centriolar satellites

Centriolar satellites are small electron-dense granules that cluster in the vicinity of centrosomes. Satellites have been implicated in multiple critical cellular functions including centriole duplication, centrosome maturation, and ciliogenesis, but their precise composition and assembly properties have remained poorly explored. Here, we perform in vivo proximity-dependent biotin identification (BioID) on 22 human satellite proteins, to identify 2,113 high-confidence interactions among 660 unique polypeptides. Mining this network, we validate six additional satellite components. Analysis of the satellite interactome, combined with subdiffraction imaging, reveals the existence of multiple unique microscopically resolvable satellite populations that display distinct protein interaction profiles. We further show that loss of satellites in PCM1-depleted cells results in a dramatic change in the satellite interaction landscape. Finally, we demonstrate that satellite composition is largely unaffected by centriole depletion or disruption of microtubules, indicating that satellite assembly is centrosome-independent. Together, our work offers the first systematic spatial and proteomic profiling of human centriolar satellites and paves the way for future studies aimed at better understanding the biogenesis and function(s) of these enigmatic structures.

Peptidomic analysis of zebrafish embryos exposed to polychlorinated biphenyls and their impact on eye development

Polychlorinated biphenyls (PCBs), a class of persistent organic pollutant, are closely related to abnormal eye development in children. However, little is known regarding the role of peptides in the development of PCB-induced ocular dysplasia. To characterize the nature of PCB exposure on peptides involved in the development of the ocular system, we used liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) to detect differential expression of peptides between normal and PCB-exposed zebrafish embryos. A total of 7900 peptides were analyzed, 90 of which were differentially expressed, with 29 being up-regulated and 61 down-regulated. These peptides were investigated using ingenuity pathway analysis (IPA) and gene ontology (GO) analysis to explore their role in eye development. This study identified 18 peptides associated with the development of the optic nerve and ocular system in the PCB-exposure group, as well as 10 peptides that are located in the functional domain of their precursor proteins. These peptides provide potential biomarkers for the treatment of ocular dysplasia caused by PCBs and may help us understand the mechanism of abnormal eye development caused by organic pollutants.

Sperm Proteome Analysis and Identification of Fertility-Associated Biomarkers in Unexplained Male Infertility

Up to 30% of men with normal semen parameters suffer from infertility and the reason for this is unknown. Altered expression of sperm proteins may be a major cause of infertility in these men. Proteomic profiling was performed on pooled semen samples from eight normozoospermic fertile men and nine normozoospermic infertile men using LC-MS/MS. Furthermore, key differentially expressed proteins (DEPs) related to the fertilization process were selected for validation using Western blotting. A total of 1139 and 1095 proteins were identified in normozoospermic fertile and infertile men, respectively. Of these, 162 proteins were identified as DEPs. The canonical pathway related to free radical scavenging was enriched with upregulated DEPs in normozoospermic infertile men. The proteins associated with reproductive system development and function, and the ubiquitination pathway were underexpressed in normozoospermic infertile men. Western blot analysis revealed the overexpression of annexin A2 (ANXA2) (2.03 fold change; P = 0.0243), and underexpression of sperm surface protein Sp17 (SPA17) (0.37 fold change; P = 0.0205) and serine protease inhibitor (SERPINA5) (0.32 fold change; P = 0.0073) in men with unexplained male infertility (UMI). The global proteomic profile of normozoospermic infertile men is different from that of normozoospermic fertile men. Our data suggests that SPA17, ANXA2, and SERPINA5 may potentially serve as non-invasive protein biomarkers associated with the fertilization process of the spermatozoa in UMI.

Phytochemical Profile and Antidepressant Effect of Ormosia henryi Prain Leaf Ethanol Extract

The Ormosia henryi Prain leaf (OHPL) is a new bioactive resource with potential antidepressant activity, but few reports have confirmed its chemical composition or antidepressant effect. To investigate the phytochemical profile of OHPL ethanol extract (OHPLE), six flavone C-glycosides and two flavone O-glycosides were purified by high-speed counter-current chromatography combined with preparative high-performance liquid chromatography (HSCCC-prep-HPLC). The eight isolated compounds were identified by NMR and MS. Forty-six flavonoids, including flavones, flavone C-glycosides, flavone O-glycosides, isoflavones, isoflavone O-glycosides, prenylflavones and polymethoxyflavones were definitively or tentatively identified from OHPLE using ultra-performance liquid chromatography/ electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS/MS) on the basis of fragment ions that are characteristic of these isolated compounds. The results of the antidepressant assay suggest that OHPLE significantly improved depression-related behaviors of chronic unpredictable mild stress (CUMS) mice. The observed changes in these mice after OHPLE treatment were an increased sucrose preference index, reduced feeding latency, prolonged tail suspension time, and upregulated expression of brain-derived neurotrophic factor (BDNF). The details of the phytochemicals and the antidepressant effect of OHPLE are reported here for the first time. This study indicates that the OHPL, enriched in flavone C-glycosides, is a new resource that might be potentially applied in the field of nutraceuticals (or functional additives) with depression-regulating functions.

Rapid Characterization of Triterpene Saponins from Zornia brasiliensis by HPLC-ESI-MS/MS

Zornia brasiliensis Vogel (Leguminosae) is a species popularly known in Brazil as “urinária”, “urinana”, and “carrapicho”, it is popularly used as a diuretic and in the treatment of venereal diseases. A specific methodology to obtain a saponin-enriched fraction and high-performance liquid chromatography coupled with diode array detection, ion trap mass spectrometry, and TOF-MS (HPLC-DAD-ESI-MS/MS) was applied for the analysis of triterpene saponins. The MS and MS/MS experiments were carried out by ionization in negative mode. Molecular mass and fragmentation data were used to support the structural characterization of the saponins. Based on retention times, high-resolution mass determination and fragmentation, 35 oleanane-triterpene saponins were tentatively identified in Z. brasiliensis.