High-performance Liquid Chromatography-electrospray Ionization Mass Research Articles

PM10 Organic Aerosol Fingerprints by Using Liquid Chromatography Orbitrap Mass Spectrometry: Urban vs. Suburban in an Eastern Mediterranean Medium-Sized Coastal City

This study compares the PM10 (particulate matter of diameter smaller than 10 μm) organic aerosol composition between urban and suburban stations in Heraklion, Crete, during winter 2024 in order to highlight the impact of local anthropogenic activities on urban atmospheric particulate matter pollution. Using an HPLC-ESI-MS Orbitrap analyzer (High Performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry) in full MS scan mode at a resolution of 140,000, 48 daily aerosol filter extracts were analyzed in both positive and negative modes, resulting in the detection of 2809 and 3823 features, respectively. Features with at least five times higher intensity in the urban environment compared to the suburban, and p < 0.05, were deemed significant. A correlation with black carbon (r > 0.6) was observed for 71% of significant urban features in positive mode. These features showed a predominance of low O:C ratios (<0.2) and the majority were classified as intermediate volatility organic compounds (IVOCs), indicating fresh primary emissions. A clear urban–suburban distinction was shown by PCA of positive mode features, unlike the negative mode features. Regarding the total intensity of the features, urban samples were on average 55% higher than suburban samples in positive mode and 39% higher in negative mode. This study reveals the molecular profile of locally emitted combustion related organics observed in positive mode in an urban environment.

Profiling of regioisomeric triacylglycerols in pistachio nuts by high-performance liquid chromatography-electrospray ionization mass spectrometry

In this contribution, a non-aqueous reversed-phase liquid chromatographic method coupled to electrospray ionization (ESI) tandem mass spectrometry (LC-MS) is used for the identification of triacylglycerol (TAG) down to the regioisomersíc level in pistachio lipids. Furthermore, for effective profiling of TAG, a two-dimensional (2D) map was employed to identify the entire homologous series of TAGs especially, odd-numbered fatty acid and long-chain derivatives. Notably, TAGs were observed as pairs of regioisomers with distinct retention times and tandem mass spectra. Furthermore, more than 100 TAGs containing 26 fatty acids with 51-63 carbon atoms and 0-3 double bonds were identified in different pistachio samples. The developed method is effective and facile for the fast quantification of complex TAGs in pistachio samples at high selectivity.

Ionic Liquid-Dispersive Micro-Extraction and Detection by High Performance Liquid Chromatography-Mass Spectrometry for Antifouling Biocides in Water.

A simple analytical method was developed and evaluated for the determination of two antifouling biocides using an ionic liquid-dispersive liquid-liquid micro-extraction (IL-DLLME) and a high-performance liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) analysis. Irgarol 1051 and Sea-Nine 211 were extracted from deionized water, lake water, and seawater using IL 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIm][PF6]) and ethyl acetate as the extraction solvent and the dispersion solvent. Several factors were considered, including the type and volume of extraction and dispersive solvent, IL amount, sample pH, salt effect, and cooling temperature. The developed method resulted in a recovery range of 78.7-90.3%, with a relative standard deviation (RSD, n = 3) less than 7.5%. The analytes were enriched greater than 40-fold, and the limits of detection (LOD) for two antifouling biocides were 0.01-0.1 μg L-1. The method was effectively applied for the analysis of real samples of freshwater as well as samples of seawater.

Characterization and Comparison of Steroidal Glycosides from Polygonatum Species by High-Performance Liquid Chromatography–Electrospray Ionization Mass Spectrometry

Polygonatum species have been used as traditional medicines and functional foods in Asia and Europe since ancient times. In this study, a fast and simple method based on liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI-MS) was developed to systematically analyze and identify the steroidal glycosides in four major Polygonatum species distributed in Japan, including P. odoratum, P. falcatum, P. macranthum, and P. sibiricum. As a result, 31 steroidal glycosides were tentatively identified, including 18 known and 13 previously unreported glycosides. Their structures were identified by the interpretation of chromatographic behavior and ESI-MS fragmentation patterns. The identification of 31 steroidal glycosides was indicative of a common biogenetic pathway in Polygonatum species. Our study disclosed the chemical profiling of steroidal glycosides in the plants of Polygonatum species, which will benefit better phytochemotaxonomical and phytochemical understanding and quality control for their medicinal usage.

Simultaneous Determination of Glibenclamide and Silymarin Released from Chitosan Microparticles by HPLC-ESI-MS Technique: Method Development and Validation.

The study aim was to develop and validate a high-performance liquid chromatography–electrospray ionization mass spectrometry (HPLC-ESI-MS) method to simultaneously determine glibenclamide (Gli) and silymarin (Sil) released from chitosan (CS) microparticles in aqueous solutions. The CS microparticles were synthesized using an ionic gelation method, and their morphology, swelling degree, encapsulation efficiency and active substance release were investigated. Gli and Sil were loaded in different concentrations, and their identification and quantification were performed using the HPLC-ESI-MS method, which was further validated. The drugs’ characteristic m/z was found in the higher intensity of retention time (Rt) (Gli, 8.909 min; Sil A, 5.41 min; and Sil B, 5.66 min). The method selectivity and precision are very good, and the blank solution proved no interference. The linearity of the answer function is very good for Sil A (R2 = 1), Sil B (R2 = 0.9998) and Gli (R2 = 0.9991). For Gli, we obtained a limit of detection (LOD) = 0.038 mg/mL and limit of quantification (LOQ) = 1.275 mg/mL; for Sil A, a LOD = 0.285 mg/mL and LOQ = 0.95 mg/mL; and for Sil B, a LOD = 0.045 mg/mL and LOQ = 0.15 mg/mL. A high-resolution HPLC-ESI-MS method was developed and validated, which allowed the simultaneous determination of Gli and Sil loaded in CS microparticles, in a concentration range of 0.025–1 mg/mL.

Is selenium beneficial or detrimental to earthworm? Growth and metabolism responses of Eisenia Fetida to Na2SeO3 exposure

Se unevenly distributed in soils due to variations of geology and anthropogenic input, which results in different effects on earthworms. The effects of Se were characterized by analyzing the growth and metabolism responses of earthworms after exposure to three different concentrations of Na2SeO3. The results showed that except the possible growth promotion at 5 mg/kg, low and middle-level exposure to Na2SeO3 (0.3–10 mg/kg) did not significantly affect the growth of earthworms. While a significant inhibition effect on growth was observed in the high-level exposure group (30–70 mg/kg). There was an inflection point for Se performing promotion to inhibition effects on earthworm growth. To investigate the metabolic response of earthworms, a novel HPLC-ESI-MS (High Performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry) method was used to determine sensitive biomarkers. Selenium exposure significantly altered the metabolism of seven essential amino acids, namely tyrosine, leucine, phenylalanine, valine, alanine, glycine, and lysine, and two selenoamino acids, namely selenomethionine and methylselenocysteine. The overall metabolism level of earthworms was not affected at low exposure concentrations, but was affected at medium and high exposure concentrations. The metabolic pathways that integrated the selenocompound metabolism and the tricarboxylic acid cycle from the perspective of energy supply and demand were affected by Na2SeO3 exposure. The derived reactive oxygen species at high exposure concentrations were probably the reason for the growth inhibition effect of Se on earthworms. This study provides biochemical insights into the effects of Na2SeO3 on earthworms and suggests that an Se concentration of about 2.3 mg/kg is appropriate for soil organism health.

Identification of pesticides in water samples by solid-phase extraction and liquid chromatography-electrospray ionization mass spectrometry.

The Contaminants of Emerging Concern (CECs), including pesticides, have been a trending topic and Brazil is the country with the highest usage of pesticides worldwide. This study aimed to measure the presence of pesticide residues in the water from different sources in the city of Porto Alegre. We analyzed 55 samples from drinking water treatment plants, public water sites, and sewage treatment plants from winter 2018 to summer 2020 by solid-phase extraction and high-performance liquid chromatography-electrospray ionization mass spectrometry. Among 184 pesticides evaluated, 107 matched validation criteria (linearity, trueness, accuracy, repeatability, reproducibility) and 15 of them were detected in different water samples, including seven insecticides, five antifungals, and three herbicides, with a wide range of toxicity levels and noticeable seasonal differences. For the worst-case scenario evaluation, 20 out of 22 (90.9%) samples exceeded the Risk Quotient of 1. The sum of pesticide concentrations exceeded 100 ng L-1 in 66.7% of samples in February 19 and in 75% of samples in February 20 and the total pesticide concentration has reached the worrisome mark of 1615 and 954.96 ng L-1 respectively. Therefore, our results make evident the need to promote public policies to achieve better water quality monitoring. PRACTITIONER POINTS: Among 184 pesticides evaluated, 107 matched validation criteria (linearity, trueness, accuracy, repeatability, reproducibility). A total of 55 different water samples were analyzed, and 15 pesticides were detected and five quantified. For the worst-case scenario evaluation, 20 out of 21 samples exceeded the Risk Quotient of 1 on Feb/20. The pesticide concentrations sum exceeded 100 ng L-1 in 66.7% of samples on February 19 and in 75% of samples on February 20. It is mandatory to improve water monitoring to guide the development of public policies concerning its quality.

Secondary metabolic profiles and anticancer actions from fruit extracts of immature pomegranates.

Immature fruits from Punica granatum L. thinning are a neglected side product of pomegranate production with cumbersome disposal costs for farmers. To explore value potential of immature fruits from pomegranate ‘Wonderful’ cultivars, the compositional landscapes and antitumorigenic activities of pomegranate extracts from two different stages of maturation were assessed. Cancer cell proliferation and cytotoxicity was quantified in human lung H1299 and colon HCT116 adenocarcinomas by crystal violet staining, MTS assay and caspase-3 activity. High performance liquid chromatography—diode array detector (HPLC/DAD) and high performance liquid chromatography—electrospray ionization—mass spectrometry (HPLC/ESI-MS) analyses indicate that immature fruits are rich sources of gallotannins and ellagitannins, with the highest amounts contained in immature fruit peels. Biological investigations reveal a robust anticancer activity by those immature P. granatum fruit extracts, which reflected induction of tumor cytotoxicity and cell death mechanisms. Together, present observations suggest P. granatum byproducts from the thinning process may provide unexplored values for virtuous circular economy.

Bioactive Molecules for Discriminating Robinia and Helianthus Honey: High-Performance Liquid Chromatography-Electron Spray Ionization-Mass Spectrometry Polyphenolic Profile and Physicochemical Determinations.

Bioactive molecules from the class of polyphenols are secondary metabolites from plants. They are present in honey from nectar and pollen of flowers from where honeybees collect the “raw material” to produce honey. Robinia pseudoacacia and Helianthus annuus are important sources of nectar for production of two monofloral honeys with specific characteristics and important biological activity. A high-performance liquid chromatography–electro spray ionization–mass spectrometry (HPLC–ESI–MS) separation method was used to determine polyphenolic profile from the two types of Romanian unifloral honeys. Robinia and Helianthus honey showed a common flavonoid profile, where pinobanksin (1.61 and 1.94 mg/kg), pinocembrin (0.97 and 1.78 mg/kg) and chrysin (0.96 and 1.08 mg/kg) were identified in both honey types; a characteristic flavonoid profile in which acacetin (1.20 mg/kg), specific only for Robinia honey, was shown; and quercetin (1.85 mg/kg), luteolin (21.03 mg/kg), kaempferol (0.96 mg/kg) and galangin (1.89 mg/kg), specific for Helianthus honey, were shown. In addition, different phenolic acids were found in Robinia and Helianthus honey, while abscisic acid was found only in Robinia honey. Abscisic acid was correlated with geographical location; the samples collected from the south part of Romania had higher amounts, due to climatic conditions. Acacetin was proposed as a biochemical marker for Romanian Robinia honey and quercetin for Helianthus honey.

Oxidative and Proteolytic Inactivation of Alpha-1 Antitrypsin in Bronchopulmonary Dysplasia Pathogenesis: A Top-Down Proteomic Bronchoalveolar Lavage Fluid Analysis.

The study investigates the role of the oxidative and proteolytic inactivation of alpha-1 antitrypsin (AAT) in the pathogenesis of bronchopulmonary dysplasia (BPD) in premature infants. Bronchoalveolar lavage fluid (BALF) samples were collected on the 3rd day of life from mechanically ventilated neonates with gestational age ≤ 30 weeks and analyzed without previous treatment (top-down proteomics) by reverse-phase high-performance liquid chromatography-electrospray ionization mass spectrometry. AAT fragments were identified by high-resolution LTQ Orbitrap XL experiments and the relative abundances determined by considering the extracted ion current (XIC) peak area. Forty preterm neonates were studied: 20 (50%) did not develop BPD (no-BPD group), 17 (42.5%) developed mild or moderate new-BPD (mild + moderate BPD group), and 3 (7.5%) developed severe new-BPD (severe BPD group). Eighteen fragments of AAT and a fragment of AAT oxidized at a methionine residue were identified: significantly higher values of AAT fragments 25–57, 375–418, 397–418, 144–171, and 397–418 with oxidized methionine were found in the severe BPD group. The significantly higher levels of several AAT fragments and of the fragment 397–418, oxidized in BALF of preterm infants developing BPD, underlie the central role of an imbalance between proteases and protease inhibitors in exacerbating lung injury and inducing most severe forms of BPD. The study has some limitations, and between them, the small sample size implies the need for further confirmation by larger studies.

Brain/blood ratios of methadone and ABCB1 polymorphisms in methadone-related deaths

Methadone is an opioid that often leads to fatalities. Interpretation of toxicological findings can be challenging if no further information about the case history is available. The aims of this study were (1) to determine whether brain/blood ratios can assist in the interpretation of methadone findings in fatalities; (2) to examine whether polymorphisms in the gene encoding the P-glycoprotein (also known as multidrug resistance protein 1 (MDR1) or ATP-binding cassette sub-family B member 1 (ABCB1)), which functions as a multispecific efflux pump in the blood–brain barrier, affect brain/blood ratios of methadone. Femoral venous blood and brain tissue (medulla oblongata and cerebellum) from 107 methadone-related deaths were analysed for methadone by gas chromatography-mass spectrometry. In addition, all the samples were genotyped for three common ABCB1 single nucleotide polymorphisms (SNPs rs1045642, rs1128503, and rs2032582) using ion-pair reversed-phase high-performance liquid chromatography-electrospray ionization mass spectrometry (ICEMS). In nearly all cases, methadone concentrations were higher in the brain than in the blood. Inter-individual brain/blood ratios varied (0.6–11.6); the mean ratio was 2.85 (standard deviation 1.83, median 2.35). Moreover, significant differences in mean brain/blood ratios were detected among the synonymous genotypes of rs1045642 in ABCB1 (p = 0.001). Cases with the T/T genotype had significantly higher brain/blood ratios than cases with the other genotypes (T/T vs. T/C difference (d) = 1.54, 95% CI [1.14, 2.05], p = 0.002; T/T vs. C/C d = 1.60, 95% CI [1.13, 2.29], p = 0.004). Our results suggest that the rs1045642 polymorphisms in ABCB1 may affect methadone concentrations in the brain and its site of action and may be an additional factor influencing methadone toxicity.

Molecular characterization of biomass burning tracer compounds in fine particles in Nanjing, China

Abstract In this work, a sensitive method based on the High Performance Liquid Chromatography-Electrospray Ionization-Mass spectrometry/Mass spectrometry (HPLC-ESI-MS/MS) technique was established and validated, and successfully applied to quantify biomass burning tracer species (in total 20 compounds) in fine aerosol particles (PM2.5) collected during the full year of 2016 in Nanjing, China. The annual levoglucosan concentration was determined to be 328.3 ng m−3, at a similar level as it in other Chinese cities; the concentration peaked in fall, indicating influences of crop/straw burning during harvest periods. Concentrations of other species were a few orders of magnitude lower than that of levoglucosan, with salicylic acid (1.53 ng m−3), cis-pinonic acid (0.60 ng m−3) and vanillic acid (0.51 ng m−3) as the three most abundant ones. Total concentrations of tracers indicative of softwood, hardwood and grass burning were about equal. Seasonal concentrations of these tracers were generally similar, and all peaked in winter, different from that of levolglucosan. Further positive matrix factorization (PMF) identified four types of biomass (cellulose, harwood lignin, softwood lignin and grass). Celluose was dominated in fall, while softwood and hardwood were both dominated in winter, and seasonal contributions (except summer) were relatively even to grass. On an annual basis, softwood, hardwood and grass contributions were almost on par to the selected tracers, in agreement with the results based only on concentrations, but seasonally, grass was the major one in spring, summer and fall, but much less important in winter.

Contamination Level, Distribution Characteristics, and Ecotoxicity of Tetrabromobisphenol A in Water and Sediment from Weihe River Basin, China.

Tetrabromobisphenol A (TBBPA) is a brominated flame retardant, which is widely present in the various environmental and biological media. The knowledge on the contamination of TBBPA in Weihe River Basin is still limited. In order to know the pollution level and distribution of tetrabromobisphenol A (TBBPA) in the Weihe River Basin, a total of 34 sediment samples and 36 water samples were collected from the main stream and tributaries of the WeiHe River Basin, and the concentration of TBBPA in the samples was analyzed by high-performance liquid chromatography–electrospray ionization–mass spectrometry (HPLC-ESI-MS). The detection frequency of TBBPA in sediments and water samples was 61.8% and 27.8%, respectively; the TBBPA concentrations in sediments and water samples were in the range of not detected (N.D.)–3.889 ng/g (mean value of 0.283 ng/g) and N.D—12.279 ng/L (mean value of 0.937 ng/L), respectively. Compared with other areas in China, the residues of TBBPA in the Weihe River Basin were at a relatively low level. The spatial distributions of TBBPA in surface sediments and water indicated that the local point-input was their major source. This is related to the proximity of some sampling sites to industrial areas and domestic sewage discharge areas. The insignificant correlation between TBBPA and total organic carbon (TOC) indicated that TBBPA in sediments is not only influenced by TOC but also affected by atmosphere and land input, wet deposition, and long-distance transmission. The potential risks posed by TBBPA in water and sediment were characterized using the risk quotient (RQ) method. The calculated RQ for TBBPA was less than 0.01, showing that the ecological risk due to TBBPA was quite low for aquatic organisms.

Preliminary Testing of Ultrasound/Microwave-Assisted Extraction (U/M-AE) for the Isolation of Geraniin from Nephelium lappaceum L. (Mexican Variety) Peel

The rambutan peel (RP) is a relevant source of bioactive molecules, which could be used for application in cosmetics, food, and pharmaceutical areas. Total soluble polyphenol content was extracted from Mexican variety rambutan peels using an emergent ultrasound/microwave-assisted extraction (U/M-AE) technology. Five extractions were performed using different mass/volume and ethanol/water ratios; 1:16-0; 1:16-70; 1:8-0; 1:8-70; 1:12-30. Condition 1:16-0 was defined as the best extraction condition with 0% ethanol percentage (only water). The content of total soluble polyphenols was 307.57 mg/g. The total bound polyphenol content was 26.53 mg/g. Besides, two separation processes were made with the soluble fraction; the first one was performed using Amberlite XAD-16 (Sigma-Aldrich, Saint Louis, MO, USA), and seven polyphenolic compounds were obtained. The second one was performed using a preparative HPLC (Varian, Palo Alto, CA, USA) equipment obtained fraction where three compounds were obtained: geraniin (main compound), ellagic acid, and ellagic acid pentoside. The major compound isolated in the two separations was geraniin, according to HPLC/ESI/MS (High Performance Liquid Chromatography/ElectroSpray Ionization/Mass) analysis.

Antioxidant Capacity of Thistle (Cirsium japonicum) in Various Drying Methods and their Protection Effect on Neuronal PC12 cells and Caenorhabditis elegans

The aim of this study was, firstly, to evaluate the phenol profile of thistle (Cirsium japonicum, CJ) by High performance liquid chromatography-electrospray ionization–mass spectrometry (HPLC–ESI–MS), dried by different methods (90 °C hot-air, 70 °C hot-air, shade-, and freeze-drying). Secondly, we aimed to evaluate the relationship between phenolic compounds content and antioxidant properties. CJ contained chlorogenic acid, linarin, and pectolinarin. Total phenolic contents of CJ significantly decreased under hot-air-drying condition, especially chlorogenic acid contents in CJ have been reduced by 85% and 60% for 90 °C and 70 °C hot-air-drying, respectively. We evaluated the protective effect on adrenal pheochromocytoma (PC12) cells and Caenorhabditis elegans using shade-dried CJ, which has the largest phenolic contents and the strongest antioxidant property. CJ-treated PC 12 cells dose-dependently exhibited the protective effects against reactive oxygen species (ROS), while cell viability increases, lactate dehydrogenase release decreases, and ROS formation decreases. Furthermore, CJ has also shown protection against ROS in C. elegans. Consequently, CJ contributed to lifespan extension under ROS stress without influencing the physiological growth.

Nickel(I) salen-catalyzed reduction of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113): CO2-mediated carbon–fluorine bond cleavage

Cyclic voltammetry, controlled-potential (bulk) electrolysis, gas chromatography (GC), gas chromatography–mass spectrometry (GC–MS), and high-performance liquid chromatography–electrospray ionization–mass spectrometry (HPLC–ESI–MS) have been used to investigate the direct and nickel(I) salen-catalyzed reduction of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-113) in both Ar- and CO2-saturated dimethylformamide (DMF) containing 0.10 M tetra-n-butylammonium tetrafluoroborate (TBABF4). Cyclic voltammograms show one irreversible cathodic peak for direct reduction of CFC-113 in CO2-saturated DMF to afford 1-chloro-1,2,2-trifluoroethene (CFC-1113), whereas cyclic voltammograms in Ar-saturated DMF exhibit two irreversible cathodic peaks. Bulk electrolyses of CFC-113 in CO2-saturated DMF at a potential 400 mV more negative than the resolved cathodic peak cause partial reduction of CFC-1113 to yield di-, tri-, and tetrafluoro species. Cyclic voltammograms for reduction of nickel(II) salen in the presence of CFC-113 in CO2-saturated DMF show two cathodic peaks attributable to formation of CFC-1113 and HFC-1123; cyclic voltammograms in Ar-saturated DMF exhibit similar behavior. Bulk electrolyses involving electrogenerated nickel(I) salen in CO2-saturated DMF yield mixtures of HFC-1123, isomers of difluoroethene, and traces of other species. No electrocarboxylation of CFC-113 or its derivatives was seen in the presence of CO2; however, excess CO2 increases the extent of dechlorination of CFC-113 during bulk electrolyses when compared with analogous electrolyses in an Ar-saturated medium. Structural modification of nickel(II) salen during catalytic reduction of CFC-113 in the presence of CO2 was determined with the aid of HPLC–ESI–MS.

In vitro studies on the interactions of blood lipid level-related biological molecules with gallic acid and tannic acid.

To provide the scientific evidence for a possible new mechanism of hypolipidemic effects of gallic acid (GA) and tannic acid (TA), the binding capacity of GA and TA with blood lipid level-related biological molecules, including fat, cholesterol and cholates, were investigated in vitro. Additionally, we attempted to study the interactions of cholates with GA and TA by spectroscopic methods, high-performance liquid chromatography electrospray-ionization mass spectrometry (HPLC-ESI-MS) analysis and molecular modeling studies. Our results demonstrated that both GA and TA were capable of binding with the blood lipid level-related biological molecules in vitro. The fat-binding capacity of TA was 122.1% that of GA when the addition of polyphenol was 90 mg. The inhibitory effects of GA and TA on the cholesterol solubility in mixed micelles and liquid egg yolk exhibited a dose-dependent relationship (0.5-2.0 mg mL-1 ). In cholate-binding tests, TA showed higher affinity for sodium cholate than GA at a concentration of 2.0 mg mL-1 , while no significant difference in the affinity for sodium deoxycholate was found between GA and TA. Moreover, the data of spectroscopic methods, HPLC-ESI-MS analysis and molecular modeling studies indicated that GA and TA might precipitate cholates through hydrophobic interactions and intermolecular hydrogen bonds rather than covalent bonds. The findings of the present study suggested that the binding capacity of GA and TA with blood lipid level-related biological molecules might play a crucial role in their hypolipidemic effects in animals. © 2019 Society of Chemical Industry.

Flabelliferin removal by sodium salts and sodium hydroxide: Pretreatment in Borassus flabellifer mesocarp

The mesocarp of Borassus flabellifer has been proven to be a good potential as a food ingredient; however, the presence of bitterness in it is a deterrent to its acceptable application. Therefore, this study was aimed to determine the effectiveness of sodium hydroxide, sodium chloride, and sodium bicarbonate at 1% to 3% concentrations in reducing the bitter component, flabelliferin, in the mesocarp of B. flabellifer and how the pretreatment could affect the reduction of flabelliferin and phenolics contents. Eleven compounds were identified in the mesocarp by high-performance liquid chromatography-electrospray ionisation mass spectrometry (HPLC-ESI-MS/MS), which consisted of seven types of phenolics, two types of antocyanidins, and two types of steroidal saponins. The highest reduction at 46.2% of flabelliferin was obtained by 3% sodium hydroxide treatment. However, the removal of the bitter component was also concurrently resulted in a decrease of the total phenolic contents (0.16 mg GAE/g) of the sample. Mild treatment such as enzymatic treatment should be employed as the alternative method to preserve the antioxidant content in the mesocarp of B. flabellifer in order to promote its application in the food industry as a potential food ingredient.

Cellular evaluation of the antioxidant activity of U.S. Pecans [Carya illinoinensis (Wangenh.) K. Koch

Clinical trials show an inverse relationship between the consumption of antioxidant-rich tree nuts and the development of chronic diseases. This study examined antioxidant efficacy of U.S. pecans using a modified cellular antioxidant activity (CAA) assay with comparisons to data from in vitro antioxidant assays (hydrophilic-oxygen radical absorbance capacity {H-ORACFL} and ferric reducing antioxidant power {FRAP}). Crude phenolic extracts from both raw and roasted pecans were analyzed. In the CAA assay, pecan phenolics were taken up by human colorectal adenocarcinoma (Caco-2) cells and bestowed CAA, determined by monitoring the fluorescence of 2′,7′-dichlorofluorescein. Phenolics (25–100 μg/mL) demonstrated a reduction in fluorescence by 37–69% for raw and 26–68% for roasted pecans. The primary active phenolic constituents were determined by high-performance liquid chromatography–electrospray ionization–mass spectrometry (HPLC–ESI–MS) to be epi(catechin) dimers and trimers. These oligomeric procyanidins, ranging in size from 560 to 840 g/mol appear to be small enough for cellular uptake, showing pecans are an effective antioxidant in biological systems, regardless of roasting.

Association between plasma α-aminobutyric acid and depressive symptoms in older community-dwelling adults in Japan.

To examine the association between depressive symptoms and plasma amino acid related metaboli in older adults. A total of 152 older adults aged ≥65 years, residing in Niigata, Japan, were used for analysis. We evaluated depressive symptoms using the Geriatric Depression Scale-15, which has been validated in older community-dwelling individuals, and used a cut off score of ≥5 to classify participants as having depressive symptoms. We used high-performance liquid chromatography-electrospray ionization mass spectrometry to measure the concentrations of plasma amino acid-related metabolites, and carried out logistic regression analysis to assess the association between depressive symptoms and plasma amino acid-related metabolites. Of the 119 older adults (mean age 76.3 years) included in the analysis, 22 were classified as having depressive symptoms (depressive group). There were no significant differences in physical and cognitive impairments between participants in the depressive and non-depressive groups. The plasma α-aminobutyric acid (AABA) level was significantly lower in the depressive group than in the non-depressive group (P < 0.001). Logistic regression analysis showed the best-fit model, which included AABA, leucine, threonine, hydroxyl proline and histidine levels (area under the receiver operating characteristic curve 0.8346; 95% confidence interval 0.7365-0.9326). In particular, the plasma AABA level was strongly associated with depressive symptoms. Plasma AABA level is significantly associated with depression symptoms in older community-dwelling adults in Japan. Thus, plasma AABA might serve as a potential marker of depression in older adults aged ≥65 years. Geriatr Gerontol Int 2019; 19: 254-258.