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Ochratoxin A (OTA), which is one of the most important mycotoxins in terms of human health, can be found in cereal products such as bread, “bazlama” (traditional flatbread), and pita bread, as well as cereals such as wheat, barley, and corn. This study aimed to determine the effect of different fermentation times, baking, and storage for various periods on the presence of OTA in sourdough bazlama. Bazlama flour was contaminated with OTA concentrations of 5 and 10 μg/kg. After two different fermentation times (1.5 and 3 h), baking at 300 ± 5°C, and storage at room temperature (25 ± 2°C) for 0, 5, and 10 days, the change in OTA levels of bazlama samples was determined by the high‐performance liquid chromatography with fluorescence detector (HPLC‐FLD) method. The effect of different storage periods on the presence of OTA is insignificant. Although a general decrease in OTA level has been determined, it has been found that long‐term fermentation (at least 3 h) was more effective, especially in flours with a high concentration (10 μg/kg) of OTA contamination. It has been determined that bazlama made from contaminated flours with OTA levels of 5 and 10 μg/kg contained OTA levels exceeding 3 μg/kg when long‐term fermentation was not used. This is the maximum permitted limit set by the Turkish Food Codex and the European Commission, indicating that it is not suitable for consumption in this position. [ABSTRACT FROM AUTHOR]

BACKGROUND: Rosaceae fruits have been used in traditional medicine for the prevention and treatment of diseases. However, these fruits have not extensively been studied regarding their phenolic composition. Thus, this research focuses on the determination of phenolic compounds by high‐performance liquid chromatography electrospray ionization time‐of‐flight mass spectrometry, flavan‐3‐ols by high‐performance liquid chromatography with fluorescence detection, and the antioxidant activity by 2,2‐diphenyl‐1‐picrylhydrazyl, 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid), and ferric reducing antioxidant power of the fruits of five species of genera Crataegus and Sorbus (Rosaceae). RESULTS: We found a total of 71 phenolic compounds from which 30 were identified in these berries for the first time. Crataegus monogyna and Crataegus laciniata revealed higher total phenolic and flavan‐3‐ol contents than the other species and the highest antioxidant activities. CONCLUSIONS: Therefore, the fruits evaluated have demonstrated to be important sources of bioactive compounds with huge potential for being used in nutraceutical or food scopes. Additional studies could be needed to evaluate the influence of the different production areas on the phenolic content. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

A simple, reproducible and sensitive liquid chromatography (HPLC) method has been developed and validated for estimation of bisphenol A (BPA) in human urine. A simple liquid–liquid extraction technique was used in BPA sample preparation. The analyte was chromatographed on a Shimadzu Prominence HPLC system using isocratic mobile phase conditions at a flow rate of 0.500 ml/min and a Hypersil Gold C18 column maintained at 40°C. Quantification was performed on a fluorescence detector set at excitation 275 nm, emission 313 nm and bisphenol B was used as internal standard. The total run time was 8 min. The method was found to have acceptable sensitivity, selectivity, accuracy (98.82–103.64%), precision (1.17–5.36) and stability in the validation experiment carried out as per the USFDA guidelines. The method sensitivity was as low as 0.50 ng/ml. The applicability of the validated analytical method was established in human patient urine samples. The mean human urine BPA concentrations were 1.18 ± 2.11 ng/ml in the control group and 5.76 ± 6.00 ng/ml in the patient group (P < 0.001). Therefore, this method could be considered as an alternative for routine bio‐monitoring of BPA which is less expensive and feasible in resource‐poor settings. [ABSTRACT FROM AUTHOR]

Disorders of certain branched‐chain amino acids may be associated with the occurrence and development of non‐alcoholic fatty liver disease. Measurement of related branched‐chain amino acid levels could provide a reference for the clinical and scientific research of the non‐alcoholic fatty liver disease. An established HPLC–FLD method was used to quantify aspartic acid, glutamate, glutamine, glycine, taurine, tyrosine, 4‐amino butanoic acid, tryptophan, methionine, valine, phenylalanine, isoleucine and leucine in mouse brain tissue. Brain tissue samples mixed with internal standard (3‐aminobutyric acid) were processed, then derivatized with 2‐O‐phthaldialdehyde, and finally separated on an ODS2 column through gradient elution at a flow rate of 1.0 ml·min−1. The excitation and emission wavelengths were set at 340 and 455 nm, respectively. The mobile phase A was 100% methanol and the mobile phase B consisted of 30 mmol·L−1 sodium acetate (pH 6.8). The injection volume was 20 μl and the single run time was 45 min. Several parameters, accuracy, precision, and stability, were verified and the results showed the established method had good sensitivity and resolution for all of the 13 compounds and internal standard in mouse brain. [ABSTRACT FROM AUTHOR]

Accelerated solvent extraction (ASE) and solid‐phase extraction (SPE) conditions were optimized by a high‐performance liquid chromatography‐fluorescence detector (HPLC‐FLD) method for the detection of piperazine in chicken tissues and pork. Piperazine residues were determined by precolumn derivatization with trimethylamine and dansyl chloride. Samples were extracted with 2% formic acid in acetonitrile using an ASE apparatus and purified using a Strata‐X‐C SPE column. The monosubstituted product of the reaction of piperazine with dansyl chloride was 1‐dansyl piperazine (1‐DNS‐piperazine). Chromatographic separations were performed on an Athena C18 column (250 × 4.6 mm, id: 5 μm) with gradient elution using ultrapure water and acetonitrile (5:95, V/V) as the mobile phase. The calibration curves showed good linearity over a concentration range of LOQ‐200.0 μg/kg with a coefficient of determination (R2) ≥ .9992. The recoveries and relative standard deviations (RSD values) ranged from 78.49% to 97.56% and 1.19% to 5.32%, respectively, across the limit of quantification (LOQ) and 0.5, 1, and 2.0 times the maximum residue limit (MRL; μg/kg). The limits of detection (LODs) and LOQs were 0.96 to 1.85 μg/kg and 3.20 to 5.50 μg/kg, respectively. The method was successfully applied for the validation of animal products in the laboratory. [ABSTRACT FROM AUTHOR]

Abstract: We describe a simple, rapid, selective and sensitive HPLC method coupled with fluorescence detection for simultaneous determination of 10 kinds of biogenic amines (BAs: tryptamine, 2‐phenethylamine, putrescine, cadaverine, histamine, 5‐hydroxytryptamine, tyramine, spermidine, dopamine and spermine). BAs and IS were derivated with dansyl chloride. Fluorescence detection (λex/λem = 340/510 nm) was used. A satisfactory result for method validation was obtained. The assay was shown to be linear over the ranges 0.005–1.0 μg/mL for tryptamine, 2‐phenethylamine and spermidine, 0.025–1.0 μg/mL for putrescine, 0.001–1.0 μg/mL for cadaverine, 0.25–20 μg/mL for histamine, 0.25–10 μg/mL for 5–hydroxytryptamine and dopamine, and 0.01–1.0 μg/mL for tyramine and spermine. The limits of detection and the limits of quantification were 0.3–75.0 ng/mL and 1.0–250.0 ng/mL, respectively. Relative standard deviations were ≤5.14% for intra‐day and ≤6.58% for inter‐day precision. The recoveries of BAs ranged from 79.11 to 114.26% after spiking standard solutions of BAs into a sample at three levels. Seven kinds of BAs were found in rat plasma, and the mean values of tryptamine, 2‐phenethylamine, putrescine, cadaverine, histamine, spermidine and spermine determined were 52.72 ± 7.34, 11.45 ± 1.56, 162.56 ± 6.26, 312.75 ± 18.11, 1306.50 ± 116.16, 273.89 ± 26.41 and 41.51 ± 2.07 ng/mL, respectively. [ABSTRACT FROM AUTHOR]

Abstract: A new multiway/multivariate approach is proposed to study and model the spoilage of swordfish with time and temperature of storage through the profiles of putrescine, spermidine, histamine, tyramine, tryptamine, cadaverine, spermine, and 2‐phenylethylamine. The evolution of these biogenic amines in food is a complex process that cannot be characterized by a single parameter but by a modification of the amine profiles. An experimental strategy is designed to determine these profiles in such a way that data are structurally 3‐way. Modeling the joint evolution of the biogenic amines with a PARAFAC model which explains 97.8% of variability (CORCONDIA index equals 100%) leads to estimate the storage time, storage temperature, and biogenic amines profiles. A multiple regression (determination coefficient of 0.98) based on the loadings of the 2 factors of the time profile of the PARAFAC model enables the estimation of the storage time with an error of 0.5 days. [ABSTRACT FROM AUTHOR]

BACKGROUND Ochratoxin A (OTA) is a natural contaminant of food including tea with multiple toxic effects, which poses a threat to human health. In terms of lifestyle, the Turkish population is a frequent visitor of tearooms, and the traditional Turkish tea preparation is one of the most popular ways of preparing tea infusion. RESULTS The aim of this study was to investigate OTA transfer from raw black tea to the tea infusion prepared according to the Turkish tradition. A high-performance liquid chromatography method with a limit of quantification of 0.35 ng g−1 was used for OTA determination. The OTA amount in raw black teas from Turkey ranged from ≤0.35 ng g−1 up to 56.7 ng g−1. An homogenised sample of black tea naturally contaminated with 55.0 ng g−1 was used to prepare infusions. The OTA transfer from the black tea to the infusion was found to be 41.5% ± 7%. CONCLUSION These data are important for the realisation of a 'Total Diet study' (TDS). The TDS can be a complementary tool to estimate the population dietary exposure to OTA across the entire diet by analysing main foods prepared 'as consumed' (tea infusions) and not 'as purchased' (raw tea). © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The determination of amino acids with actions like neurotransmitters or modulators has been increasingly important for diagnosis in many neuropsychiatric diseases. A rapid and simple high-performance liquid chromatography with fluorescence detection method was developed for simultaneous determination of seven amino acids: aspartate (Asp), glutamate (Glu), serine (Ser), glutamine (Gln), glycine (Gly), taurine (Tau) and γ-aminobutyric` acid (GABA). Homoserine was used as an internal standard. The analysis was performed on a BDS column with methanol and 50 m m sodium acetate solution (pH 6.5) using a simple gradient elution. Several parameters of the developed method were validated including linearity, accuracy, precision, extraction recovery and stability, which were within the acceptable range. The method was successfully applied to determination of real samples: hippocampus and cortex in depressed rats exposed to chronically unpredictable stress in order to study if there existed differences in the seven amino acids levels between depressed rats and control. The results showed that Asp, Gly, Tau and GABA significantly decreased with increasing Gln in the hippocampus of depressed rats, compared with that of the control group, among which obviously lower level of Asp and higher level of Gln in cortex were observed. The analytical method and the results could be useful for clinical diagnosis and further insight into pathophysiological mechanism of depression. [ABSTRACT FROM AUTHOR]

BACKGROUND The contents of 18 free amino acids in 87 Chinese honey samples from four botanical origins (linden, acacia, vitex and rape) were determined by developing a high-performance liquid chromatography with fluorescence detector ( HPLC-FLD) method with an in-loop automated pre-column derivatization. The free amino acid profiles of these samples were used to construct a statistical model to distinguish honeys from various floral origins. RESULTS The average contents of all free amino acids in linden honey were lower than in the other three types of honey. Phenylalanine was particularly useful in the present study because its average content in vitex honey was far higher than in any other honey samples. There is no doubt that both phenylalanine and tyrosine can be considered as the marker free amino acid in Chinese vitex honey. Principal component analysis ( PCA) was conducted based on 15 free amino acids and showed significant differences among the honey samples. The cumulative variance for the first two components was 80.62%, and the four principal components can explain 94.18% of the total variance. In the two first component scores, the honey samples can be separated according to their botanical origins. Cluster analysis of amino acid data also revealed that the botanical origins of honey samples correlated with their amino acid content. Back-propagation artificial neural network ( BP-ANN) and naïve Bayes methods were employed to construct the classification models. The results revealed an excellent separation among honey samples according to their botanical origin with 100% accuracy in model training for both BP-ANN and naïve Bayes. CONCLUSION It indicated that the free amino acid profile determined by HPLC-FLD can provide sufficient information to discriminate honey samples according to their botanical origins. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Mycotoxins, which may contaminate peanut and peanut products, are responsible for many diseases to humans. Aflatoxin B1 (AFB1), aflatoxin G1 (AFG1), aflatoxin B2 (AFB2), aflatoxin G2 (AFG2), ochratoxin A (OTA) and zearalenone (ZEN) are considered the most relevant groups of mycotoxins found in food. This work aimed to develop a high-performance liquid chromatography method with a fluorescence detector (HPLC-FLD) combined with dispersive liquid-liquid microextraction (DLLME) method for the simultaneous determination of the six mycotoxins in peanuts. The six mycotoxins were simultaneously determined under their best wavelength by means of changing wavelength. RESULTS Under the optimum conditions, the linear ranges were 1-100 ng mL−1 for AFB1, AFG1 and OTA, 0.3-30 ng mL−1 for AFB2 and AFG2, 5-1000 ng mL−1 for ZEN, with the correlation coefficient ( R2) of 0.9969-0.9997. Limits of detection (LODs) were 0.10, 0.10, 0.30, 0.03, 0.03 and 1.0 µg kg−1, respectively, and the mean recoveries were in the range of 83.1% to 99.3% with RSD < 10% ( n = 6, independent analysis). Thirteen (46%) of these tested samples were contaminated with at least one mycotoxin. CONCLUSION The proposed method was demonstrated to be simple, highly selective, accurate, reliable, and was successfully applied to simultaneously analyse the six mycotoxins in real peanut samples from China. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Currently, commercially prepared complementary foods have become an important part of the diet of many infants and toddlers. But the method for simultaneous analysis of different types of micronutrient remains poorly investigated, which hinders the rapid and comprehensive quality control of infant foods. In the presented study, we first tried to employ the fluorescence labeling strategy combined with high-performance liquid chromatography-fluorescence detection for simultaneous determination of some acidic micronutrients including biotin, nicotinic acid, linolenic acid, eicosapentaenoic acid, docosahexaenoic acid, arachidonic acid and linoleic acid in infant foods. RESULTS 2-(5-Benzoacridine) ethyl- p-toluenesulfonate was used as the fluorescence labeling reagent for simultaneous labeling of the seven components. The labeling conditions were optimized systematically by response surface methodology. The correlation coefficients for the calibration curves of the tested compounds ranged from 0.9991 to 0.9998. Limits of detection were in the range of 1.99-3.05 nmol L−1. Relative standard deviation values of retention time and peak area of seven compounds were less than 0.05% and 0.75%, respectively. The intra- and inter-day precision was in the range of 1.81-3.80% and 3.21-4.30%, respectively. When applied to analysis of several infant foods it showed good applicability. CONCLUSION The developed method has been proven to be simple, inexpensive, selective, sensitive, accurate and reliable for analysis of some acidic micronutrients in infant foodstuffs. Furthermore, this developed method also has powerful potential in the analysis of many other complementary foodstuffs. © 2015 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Zhi-Zi-Hou-Po decoction (ZZHPD) is one of the famous antidepressant Chinese formulas and is composed of Magnolia officinalis cortex (HP), Gardenia jasminoides Ellis (ZZ) and Citrus aurantium L. (ZS). Magnolol (MN) and honokiol (HN) from HP are the major active ingredients responsible for the therapeutic effects of ZZHPD. The aim of this study is to compare the pharmacokinetics and rat brain distribution of MN and HN after oral administration of HP extract and its compatibility with other herbal medicines in ZZHPD by HPLC-FLD. Compared with the HP group, Tmax (time to reach peak drug concentration in plasma) and AUC(0- τ) significantly increased in the ZZHPD and HP-ZZ groups. There was little change in the HP-ZS group in comparison with the HP group, which indicated that ZZ promotes absorption extent and defers the absorption rate of MN. The different compatibility of ZZHPD had a different degree of impact on the concentration of MN and HN in brain. The concentration of MN significantly increased in the HP-ZZ group while it decreased in the HP-ZS group compared with the HP group, which explained the concentration of compounds being slightly greater in the ZZHPD group than in the HP group. HP mixed with other medicines resulted in a decrease in HN concentration in the brain, particularly HP compatible with ZS. The results could be helpful for revealing the compatibility mechanism and providing clinical medication guidance for ZZHPD. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Characterization of 15 polycyclic aromatic hydrocarbons (PAHs) in extra virgin, virgin, second centrifugation, lampante, refined, crude olive pomace, and refined olive pomace oils was carried out in 24 different types of olive oils and seven different types of pomace oils produced in Turkey and Spain. The extraction method was followed by liquid-liquid extraction, a solid phase clean up using C18 and Florisil cartridges, and evaporation. Then the evaporated residue dissolved in tetrahydrofuran/methanol 50:50 v/v, was analyzed by reversed phase high-performance liquid chromatography with fluorescence detector using two excitations (280, 256 nm) and emission (410, 446 nm) wavelenghts channels. PAHs content of crude and refined olive pomace oils were found higher than in the other oils. In the samples analyzed, the highest concentrations of PAHs corresponded to benzo[ ghi]perylene, naphthalene, pyrene, acenaphthene, benzo[ k]fluoranthene, and phenanthrene. [ABSTRACT FROM AUTHOR]

ABSTRACT 22-[ N(−7-Nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-23,24-bisnor-5-cholen-3 β-ol (NBD-cholesterol), a fluorescent cholesterol analog, was an extragenous cholesterol tracer used to study cholesterol absorption and metabolism in cultured cells. In order to measure free intracellular cholesterol and its esters, a precise and sensitive method employing high-performance liquid chromatography/fluorescence detection (HPLC-FLD) was developed for the first time. Method validation showed a limit of detection at 30 ng/mL. The calibration curve was linear within the range of 0.0625-10.0 µg/mL ( r2 = 0.999). Accuracy and precision were highlighted by good recovery and low variations. Apart from NBD-cholesteryl oleate, two additional cellular metabolites of NBD-cholesterol, probably an isomer and an oxidation product, were determined in the lipid extracts of Caco-2 human colon adenocarcinoma cells according to mass spectrometry. In AC29 mouse malignant mesothelioma cells overexpressing acyl-CoA:cholesterol acyltransferase-1 (ACAT1) or ACAT2, only the oxidized metabolite was detected. Using the newly developed method, YIC-C8-434, a known ACAT inhibitor, was shown to inhibit ACAT activity in Caco-2 cells, as well as in AC29/ACAT1 or AC29/ACAT2 cells. In conclusion, the sensitive and specific HPLC-FLD method is a powerful tool for simultaneous quantification of intracellular NBD-cholesterol and its oleoyl-ester. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background Mycotoxins, which may contaminate many foods and medicinal plants, are poisonous to humans. A high-performance liquid chromatography with fluorescence detection ( HPLC-FLD) method was successfully developed for analysing the contamination levels of zearalenone ( ZON) and its metabolite α-zearalenol ( α- ZOL) in 100 widely consumed foods and medicinal plants in China. Samples were extracted with methanol-water (80:20, v/v), and cleaned up by using an immunoaffinity column. Results The limits of detection of this developed method for ZON and α- ZOL were 4 µg kg−1 and 2.5 µg kg−1, respectively. Recoveries for the samples spiked with three levels (30, 60 and 300 µg kg−1 for ZON and α- ZOL) ranged from 85.8% to 96.1% with relative standard deviation ( RSD) of 2.6-7.1% for ZON, and from 89.9% to 98.7% with RSD of 1.9-9.2% for α- ZOL. Twelve (12%) of these tested samples were contaminated with ZON at levels ranging from 5.3 to 295.8 µg kg−1. The most contaminated samples were Semen coicis, four of them in a concentration level exceeding 60 µg kg−1 'maximum level' (range 68.9-119.6 µg kg−1). Positive samples were further confirmed by liquid chromatography-tandem mass spectrometry. Conclusion The results suggest that it is necessary to control ZON contamination in medicinal plants, especially Semen coicis. This is a successful study on the analysis of ZON and α- ZOL in medicinal plants in China by HPLC-FLD. Immunoaffinity clean-up and HPLC-FLD proved to have broad applicability in the field of simultaneously detecting ZON and α- ZOL in foods and medicinal plants and other complicated matrices.© 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

ABSTRACT A 96-well microplate-based HPLC endpoint assay is described for the determination of NADPH-cytochrome P450 reductase (CPR) activity. Novel sampling of NADPH into microplates was optimized. Separation was performed on a Zorbax Eclipse XDB-C18 analytical 4.6 × 150 mm, 5 µm column. To validate the method, recombinant human NADPH-P450 reductase and microsomes with cytochrome P450 CYP1A1 were used. The mobile phase consisted of 80% acetonitrile and 20% water at a flow-rate of 0.8 mL/min. The CPR activity was quantified using NADPH fluorescence at λEx = 340 nm and λEm = 450 nm. Enzymatic activity was directly proportional to the decrease in NADPH fluorescence. This analytical process enables a highly sensitive endpoint determination for reductase activity in vitro and monitoring of the consumption of NADPH in enzymatic reactions. The method avoids the use of substrates and of organic solvents that may affect CPR and cytochrome P450 activity. In the reaction, molecular oxygen served as a proton source. The method can substitute spectrophotometric detection methods for its accuracy, high reproducibility (~100%) and sensitivity. The lower limit of detection, shown using the Agilent 1200 aparatus, is in the 250 nmol range. In addition, using this method it is possible to set up reactions in a high-throughput format. Copyright © 2011 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Free fatty acids (FFA) are basic and indispensable components of medicinal plants. Many researches indicate that the efficacy of medicinal plant requires the presence of FFA. In the present study, ultrasonic-assisted extraction of FFA from Swertia species was optimized by response surface methodology (RSM), ensuring the highest FFA recoveries. A novel pre-column fluorescence labelling method using 2-(5-benzoacridine)ethyl- p-toluenesulfonate (BAETS) as a labelling reagent has been developed for highly sensitive and selective analysis of FFA by HPLC with fluorescent detection (FLD) and online mass spectrometry identification. RSM was also employed to optimize the fluorescence labelling of FFA. HPLC separation of 17 FFA derivatives was carried out on a reversed-phase Hypersil BDS C column (4.6 × 200 mm, 5 μm, Agilent Co.) with a gradient elution. The detection limits and quantifications were as low as 0.60 and 1.22 ng mL, respectively. FFA analysis from nine Swertia species was performed by the newly developed method, and the FFA composition of these Swertia samples was first reported. [ABSTRACT FROM AUTHOR]

The lipid components of three Cameroonian seed oils, ke tchock ( Aframomum arundinaceum), njangsa ( Ricinodendron heudelotii) and calabash nutmeg ( Monodora myristica), have been investigated. Gas chromatography (GC)-mass spectrometry (MS) fatty acid (FA) analysis showed M. myristica seed oil to be dominated by linoleic (49.29%) and oleic (37.17%) acids; R. heudelotii was mainly linoleic (58.73%), followed by stearic (15.00%) and oleic (14.21%) acids; A. arundinaceum was predominantly oleic (65.76%) and palmitic (20.36%) acids. Electrospray ionization (ESI)-Fourier transform ion cyclotron resonance (FTICR)-MS analysis showed seven major triacylglycerol (TAG) classes for M. myristica, with C54:5, C54:4 and C54:6 dominating. R. heudelotii had eight major TAG classes with C54:8, C54:7 and C54:6 being most abundant. A. arundinaceum also had eight major TAG classes with C52:2, C54:3 and C50:2 dominating. C nuclear magnetic resonance (NMR) analysis of the TAGs showed that both sn-1,3 and sn-2 positions were predominantly occupied by linoleoyl and oleoyl chains. High-performance liquid chromatography (HPLC) fluorescence detector (FLD) analysis showed that M. myristica contained only α- and β-tocopherols (195.40 and 73.95 µg/g, respectively), R. heudelotii contained mainly γ-tocopherol (289.40 µg/g), and A. arundinaceum had mainly γ- and β-tocopherols (236.78 and 124.93 µg/g, respectively). GC-MS analysis of the unsaponifiable matter showed that β-sitosterol was the most abundant phytosterol in all three seed oils. The absolute amounts of 4-desmethylsterols were 196.15, 608.71 and 362.15 µg/g for M. myristica, R. heudelotii and A. arundinaceum seed oils, respectively. These compositional and structural studies provide justification for the use of all three seed oils in food products. [ABSTRACT FROM AUTHOR]

Lake Dianchi is in Yunnan Province in southwestern China. In recent years, significant cyanobacterial blooms have occurred in this lake nearly every year because of eutrophication. Monitoring data for the past 5 years acquired by our research group showed that phytoplankton composition alternated between species of Microcystis sp. during warm seasons and those of Aphanizomenon sp. during cool seasons. In March 2003, when phytoplankton composition was highly dominated by Aphanizomenon sp., samples were taken from the lake for toxin detection and immediate strain isolation. A mouse bioassay with extracts from the lyophilized field material showed obvious intoxication from paralytic shellfish poisons (PSPs), and all mice died within 30 min. Further analysis of both field and isolated algal strain Aphanizomenon DC-1 by the postcolumn HPLC-FLD method confirmed its PSP-producing ability. The analogues found in the extracts from the field material were neoSTX, dcSTX, and dcGTX3, with contents of 2.279, 1.135, and 0.547 ng/mg DW, respectively. Under laboratory culture condition, toxin content in the Aphanizomenon strain DC-1 varied greatly during different growth phases, with two peaks: in the early-exponential and late-stationary growth phases. When the culture grew at a relatively high rate during the mid- to late-exponential growth phase, toxin content declined gradually. Moreover, the types of toxin in the DC-1 strain varied greatly during a single culture cycle. The HPLC results showed that dcSTX was the only toxin isomer detected throughout the culture period, and its level remained stable. On the other hand, dcGTX2 and GTX4 were the major toxins during the early-exponential and stationary phases, respectively. This article presents the first data on the identification and detection of paralytic shellfish toxins from cyanobacteria in Lake Dianchi. As far as we know, this is also the first report of this type of toxin in inland water bodies in China. Our study indicates the threat associated with PSP toxins in Lake Dianchi and suggests that necessary measures and programs for control are urgently needed to prevent the spread of toxic cyanobacterial blooms. [ABSTRACT FROM AUTHOR]

Tocopherols and tocotrienols have been extensively studied owing to their anticancer potential, especially against breast cancer. Therefore, the aim of this study was to quantitatively determine tocochromanols in human breast adipose tissue with the use of HPLC–FLD. The sample preparation procedure included homogenization and solvent extraction with isopropanol–ethanol–0.1% formic acid mixture prior to solid‐phase extraction. After implementation of central composite design, satisfactory separation of all eight target compounds was achieved within 10.5 min. Chromatographic runs were carried out with the use of a naphthylethyl chromatographic column with methanol–water mixture (89:11, v/v) as the mobile phase. Fluorescence detection of tocochromanols was performed with excitation and emission wavelengths 298 and 330 nm, respectively. The method was validated in terms of linearity, carryover, recovery, precision, accuracy and stability. Extraction yield was also determined for accurate evaluation of vitamin E content in human breast adipose tissue samples. Finally, concentrations of particular tocochromanols compounds were assessed in human breast adipose tissue samples obtained from 99 patients, including women with breast cancer, healthy volunteers and deceased women who had died as a result of accidents. The raw data was transformed according to the newly developed equation for accurate estimation of the concentrations of tocochromanols in breast adipose tissue samples. Results obtained in the study indicated that the proposed analytical assay could be useful in breast cancer research. [ABSTRACT FROM AUTHOR]

The determination of amino acids and monoamine with actions like neurotransmitters or modulators has become increasingly important for studying the relationship between the dysfunction of neurotransmitters and the pathogenesis of diabetic encephalopathy. Here, a high‐performance liquid chromatography with fluorescence detection method was developed to simultaneously determine nine monoamines and amino acids including three excitatory neurotransmitters (aspartate, glutamate, and serotonin), four inhibitory neurotransmitters (glycine, γ‐aminobutyric acid, taurine, dopamine), a precursor of 5‐HT (tryptophan) and methionine using homoserine as the internal standard. The separation was performed on a BDS column with methanol‐buffer solution of 35 mmol/L sodium acetate and 5 mmol/L citric acid (pH 6.0) using a simple gradient elution. Several parameters including specificity, precision, and recovery were validated after optimization of the analytical conditions. The developed method was successfully applied to determine the cortex and the hippocampus samples from Sprague–Dawley rats. Our results showed that various neurotransmitters involved in diabetes mellitus may tend to be differentially modulated and present a different alteration tendency at different time course, which might be associated with the duration of diabetes mellitus. [ABSTRACT FROM AUTHOR]