Cu@Pd core-shell nanostructures for highly sensitive and selective amperometric analysis of histamine.

We demonstrate a facile and rapid methodology for preparation of Cu@Pd core-shell nanostructures on a cost-effective pencil graphite substrate. Galvanic replacement reaction was carried out for palladium modification on template electrodeposited copper nanostructures on pencil graphite substrate. The nanostructures are shown to be very stable with excellent electrocatalytic activities. Under optimised conditions, they could be used for histamine sensing at a very low oxidation potential of +0.55V vs. Ag/AgCl. The low oxidation potential enabled sensitive and selective analysis of histamine using chronoamperometry without any interference from oxygen evolution reactions. We have demonstrated that the sensor shows excellent selectivity towards histamine even in the presence of many of the common interfering biogenic amines. The sensor exhibited a sensitivity of 0.082 µ A/µ M/cm 2 with a limit of detection as low as 3.2 ± 0.1nM. The oxidation potential and limit of detection obtained using this sensor are much superior to the results reported so far in the literature. Practical feasibility of the developed sensor was manifested by histamine analysis in canned tuna fish samples, where the chronoamperometric estimation was also validated by conventional HPLC analysis.

Isolation and identification of allergens and biogenic amines of Prosopis juliflora genotypes

Background: Prosopis, or mesquite (Prosopis juliflora (Sw.) DC.), was introduced in Saudi Arabia several decades ago and is heavily used in street, roadside, and park plantations. It shows great adaptation to the prevailing climatic conditions such as high temperature, severe drought, and salinity and spreads naturally in many parts of the Kingdom. This research was conducted to isolate allergen proteins and biogenic amines from the pollen grains of P. juliflora genotypes in Saudi Arabia from two regions, namely Al-Qassim and Eastern regions. Results: The results showed that 18 different allergen proteins were detected in P. juliflora genotypes, with molecular weight ranging from 14 to 97 kDa. Moreover, P. juliflora genotypes from the two studied regions contained eight biogenic amines, namely histamine, tyramine, tryptamine, ß-phenylethylamine, butricine, codapherine, spermidine, and spermine. All genotypes from the Al-Qassim region were found to contain all eight amines, while in the Eastern region, histamine was absent in three genotypes, spermine was absent in six genotypes, and spermidine was absent in three genotypes. Genotypes B23, E20, and E21 had the lowest biogenic amine quantity. Conclusions: All identified proteins from mesquite trees from both regions (Eastern and Al-Qassim) cause allergies in patients who are sensitive to pollen grains. Bioamines, except histamine and tyramine, were recorded at varying concentrations in different genotypes.

Determination of Nonvolatile Amines in Foods by Improved Dansyl Derivatization Reaction.

An analytical method for the determination of nonvolatile amines (putrescine, cadaverine, histamine, tyramine, and spermidine) in foods was developed, using an improved dansyl derivatization technique. The five amines were extracted from food with 1% trichloroacetic acid. Three milliliter of extract was applied to a polymer-based strong cation exchange resin mini-column, which was washed with 5 mL of water, and eluted with 5 mL of 1 mol/L potassium carbonate solution. The eluate was dansylated, then 5 mL of toluene was added with shaking. The toluene layer was evaporated. The residue was taken up in 1 mL of acetonitrile and shaken with 1 mL of 5% proline in 1 mol/L potassium carbonate solution. The upper acetonitrile layer was collected, filtered, and subjected to HPLC. The limits of quantitation for putrescine and cadaverine in the samples were both 0.2 µg/g; those of spermidine, tyramine, and histamine were 0.8, 2.0, and 5.0 µg/g, respectively. The average recoveries of the five amines from nine foods exceeded 80%.

Portable amperometric immunosensor for histamine detection using Prussian blue-chitosan-gold nanoparticle nanocomposite films.

Histamine (HA) is a biogenic amine that can accumulate to high concentration levels in food as a result of microbial activity and can cause toxic effects in consumers. In this work, a portable electrochemical immunosensor capable of detecting HA with high sensitivity and selectivity was developed. Prussian blue-chitosan-gold nanoparticle (PB-CS-AuNP) nanocomposite films with excellent biocompatibility were synthesized and characterized by scanning electron microscopy and energy dispersive X-ray analysis. The PB-CS-AuNP were coated onto a screen-printed electrode by one-step electrodeposition and used to conjugate the HA ovalbumin conjugate (HA-Ag). HA was determined by a competition between the coating HA-Ag and the HRP labeled HA antibody (HRP-HA-Ab). After careful optimization of assay conditions and Box-Behnken analysis, the developed immunosensor showed a linear range from 0.01 to 100µg/mL for HA in fish samples. The average recoveries from spiked samples ranged from 97.25% to 105%. The biosensor also showed good specificity, reproducibility, and stability, indicating its potential application in monitoring HA in a simple and low cost manner.

Detection of Histamine in Fish and Fishery Products in Osaka Prefecture (Fiscal 2015 Report).

Histamine food poisoning is caused by ingestion of spoiled fish containing high levels of histamine. This paper reports cases in which histamine was detected in Osaka prefecture in fiscal year 2015 in a survey of fish and fishery products on the market and the food poisoning. A suspected case of histamine food poisoning was also evaluated to investigate the cause and minimize further problems. Histamine in food was separated on SPE cartridge columns, and analyzed after derivatization with fluorescamine by means of HPLC-FL. Histamine was detected in some fishery products on the market and in food that had caused poisoning. The samples in which histamine was detected were semi-dried whole round herring (Urumeiwashi-maruboshi), mackerel (Saba) and sardine dumpling (Iwashi-tsumire). These foods were the main causes of histamine food poisoning according to the report of the Ministry of Health, Labour and Welfare, Government of Japan.

Amperometric Biosensor Based on Diamine Oxidase/Platinum Nanoparticles/Graphene/Chitosan Modified Screen-Printed Carbon Electrode for Histamine Detection.

This work describes the development and optimization studies of a novel biosensor employed in the detection and quantification of histamine in freshwater fish samples. The proposed biosensor is based on a modified carbon screen-printed electrode with diamineoxidase, graphene and platinum nanoparticles, which detects the hydrogen peroxide formed by the chemical process biocatalysed by the enzyme diamine oxidase and immobilized onto the nanostructurated surface of the receptor element. The amperometric measurements with the biosensor have been implemented in buffer solution of pH 7.4, applying an optimal low potential of +0.4 V. The novel biosensor shows high sensitivity (0.0631 µA·µM), low detection limit (2.54 × 10(-8) M) and a broad linear domain from 0.1 to 300 µM. The applicability in natural complex samples and the analytical parameters of this enzyme sensor have been performed in the quantification of histamine in freshwater fish. An excellent correlation among results achieved with the developed biosensor and results found with the standard method for all freshwater fish samples has been achieved.

Antihistamine from Tragia involucrata L. leaves.

BACKGROUND: Synthetic antihistamine drugs cause various adverse effects to overcome these problems with natural phytomedicine or phytoconstituents. METHODS: Tragia involucrata leaves were extracted with soxhlet apparatus and fractionated with column chromatography the homogenized fractions were monitored with thin layer chromatography (TLC) and characterized by using UV-visible, FT-IR, 1H NMR, 13C NMR and MS spectral studies. Isolated compounds were screened their antihistamine activity on ileum preparation, bronchoconstriction and triple response on histamine-induced guinea pig. RESULTS: Antihistamine 5-hydroxy-1-methylpiperidin-2-one has been isolated and characterized from the leaves of Tragia involucrata L. A promising muscle relaxant, bronchorelaxant and anti-allergic effect of 5-hydroxy-1-methylpiperidin-2-one was observed in histamine-induced guinea pig and found to be 55.54±2.78% protection at the dose level of 12.5 mg/kg in bronchoconstriction effect and 49.05±2.45% protection in triple response. These findings were confirmed by in silico molecular docking also against histamine H1 receptor compared with chlorpheniramine maleate and mepyramine. This shows that the 5-hydroxy-1-methylpiperidine-2-one possess good inhibitory effect on histamine-induced guinea pig. The muscle relaxant, bronchodilating and anti-allergic potency of 5-hydroxy-1-methylpiperidin-2-one has been discussed in context with its probable profile as an anti-asthmatic agent from T. involucrata L. leaves. CONCLUSIONS: We can conclude that isolated 5-hydroxy-1-methylpiperidin-2-one from T. involucrata L. has potent antihistamine agent on histamine-induced guinea pig.

An easy-to-use excimer fluorescence derivatization reagent, 2-chloro-4-methoxy-6-(4-(pyren-4-yl)butoxy)-1,3,5-triazine, for use in the highly sensitive and selective liquid chromatography analysis of histamine in Japanese soy sauces.

In this study, a novel pre-column excimer fluorescence derivatization reagent, 2-chloro-4-methoxy-6-(4-(pyren-4-yl)butoxy)-1,3,5-triazine (CMPT), was developed for polyamines, specifically histamine. By CMPT derivatization, the polyamines, histamine and tyramine were converted to polypyrene derivatives, and emitted intra-molecular excimer fluorescence at 475nm. This could clearly be distinguished from the normal fluorescence emitted from reagent blanks at 375 nm. Unlike conventional excimer fluorescence derivatization reagents, CMPT is chemically stable and its reactivity sustained over at least 36 days even in solution state. We successfully applied this reagent to the sensitive and selective analysis of histamine in different kinds of Japanese commercial soy sauces. The detection and quantification limits of histamine were 15 and 50 µg L(-1), respectively, equating to 1.35 pmol and 4.5 pmol for a 6 µL injection. This sensitivity helped the direct analysis of soy sauce samples only treated by one-step liquid-liquid extraction without concentration. The histamine levels of commercial soy sauce samples (koikuchi, usukuchi and saishikomi) investigated were 1.24-768.5 mg L(-1).

Rational design and chromatographic evaluation of histamine imprinted polymers optimised for solid-phase extraction of wine samples.

This article reports on the computational design, development and application of a molecularly imprinted polymer (MIP) with specific affinity towards histamine. Computational modelling was used to screen a monomer library in order to select the monomers able to form the strongest complex with the target analyte. These were subsequently used for MIP synthesis by radical polymerisation initiated by UV. MIPs were then evaluated by liquid chromatography and solid phase extraction (SPE) and best MIP behaviour was observed when itaconic acid was used as functional monomer. Finally, after optimisation of the polymer composition, MIPs were used as adsorbents for SPE and clean-up of histamine in wine samples. The proposed histamine extraction method with the MIP-SPE cartridge was found to be reproducible (<5% RSD) and accurate (93-99% recovery) and provided clear wine extracts. The described methodology is simple and fast and is suitable for the selective histamine extraction and its subsequent quantification by HPLC-DAD from complex matrices such as wine samples.

Dual-templates molecularly imprinted monolithic columns for the evaluation of serotonin and histamine in CEC.

To extend the application of molecularly imprinted polymers, the dual-templates molecularly imprinted monolithic columns were developed in a capillary format. Two templates serotonin and histamine were simultaneously imprinted using two different functional monomers such as methacrylic acid (MAA) and methylenesuccinic acid (MSA) in a mixture of ethylene glycol dimethacrylate (EDMA) as a cross-linker and AIBN as polymerization initiator dissolved in DMF as porogen. The resulting molecular imprinted polymers (MIPs) were characterized based on their performance in the CEC separation of two imprinted templates. The optimization parameters such as pH, ACN composition, and concentration of the eluent were varied to achieve best resolution and efficiency for CEC separation of templates with each MIP column. It was found that the MIP monolith column fabricated using MSA offered better resolution and separation efficiency compared to column fabricated with MAA. This work utilized the dual-templates imprinting approach successfully and broadens the scope of multi-templates imprinting capabilities in capillary format in CEC application.

Dibromotyrosine and histamine derivatives from the tropical marine sponge Aplysina sp.

Two new compounds, 3-amino-7,8-dihydroimidazo-[1,5-c]-pyrimidin-5(6H)-one (1) and ethyl 3-(2-amino-1H-imidazol-4-yl)propylcarbamate (2), along with the previously known 7,8-dihydroimidazo-[1,5-c]-pyrimidin-5(6H)-one (3), aeroplysinin-1 (4), dibromoverongiaquinol (5), bisoxazolidinone derivative (6), aerophobins-1 (7) and -2 (8), purealidins J (9) and L, have been isolated from Aplysina sp. from the South China Sea. The structures were elucidated on the basis of 1H, 13C NMR, MS and IR analyses. The histamine-derived alkaloids 1-3 may be unknown bioconversion products of purealidin J (9), aerophobin-2 (8) and aerophobin-1 (7), respectively, when 7-9 are cleaved at C-8-C-9 in reactions of activated chemical defense in Aplysina sponge.

Selective histamine piezoelectric chemosensor using a recognition film of the molecularly imprinted polymer of bis(bithiophene) derivatives.

A histamine piezoelectric (acoustic) sensor using a molecularly imprinted polymer (MIP) film has been devised and tested. The sensor comprises an electrodeposited MIP film as the recognition element and a 10 MHz AT-cut shear-thickness-mode bulk-acoustic-wave quartz crystal resonator with Pt film electrodes as the signal transducer. Preparation of the sensing film involved two consecutive electrochemical polymerizations, performed under cyclic voltammetric conditions, with the use of a supporting electrolyte of 0.1 M tetra-n-butylammonium perchlorate in acetonitrile. First, a poly(bithiophene) barrier film was deposited by electropolymerization on the Pt/quartz resonator to prevent histamine electro-oxidation and avoid possible contamination of the Pt electrode surface. Next, the histamine-templated MIP film was deposited by electropolymerization on top of this barrier film. For that purpose, two functional monomers of bis(bithiophene) derivatives, i.e., one bearing the 18-crown-6 and the other dioxoborinane substituent, were copolymerized in the presence of the histamine template. The consecutive growth of both these overlaid films was monitored with an electrochemical quartz crystal microbalance (EQCM). Subsequently, the histamine was extracted from MIP with 0.01 M NaOH for 12 h. The UV-vis and X-ray photoelectron spectroscopic measurements confirmed the completeness of the removal of the histamine template from the MIP film. The analytical performance of the chemosensor was assessed under flow injection analysis (FIA) conditions using the carrier 0.5 M HEPES buffer (pH = 7.5) solution and the piezoelectric microgravimetry detection at QCM. The negative peaks of resonant frequency linearly decreased with the increase of the histamine concentration in the range 10-100 mM for 150 microL/min flow rate, and 100 microL volume of the injected sample. The sensitivity of the chemosensor (0.33 Hz/mM) was more than twice as that of the chemosensor without the poly(bithiophene) barrier film (0.15 Hz/mM). The chemosensor performance was superior for selective histamine recognition if the poly(bithiophene) barrier film thickness exceeded 200 nm. The chemosensor discriminated histamine from functionally or structurally similar compounds, such as dopamine, tryptamine, and imidazole. Stability constants of the affinity complexes of MIP and analyte or the interfering agent were determined from kinetic studies. For the MIP-histamine complex, the stability constant thus evaluated was equal to 57.0 M(-1) being much higher than those for the MIP-tryptamine and MIP-dopamine complexes determined to be 10.7, and 6.4 M(-1), respectively. The concentration limit of detection was as low as 5 nM histamine if the carrier solution flow rate was as low as 35 microL/min and the injection sample volume as large as 1 mL.

Separation assay of histamine and its metabolites in biological specimens.

This review summarizes the determination methods for histamine and the metabolites in biological specimens by separation techniques, such as gas chromatography, liquid chromatography and capillary electrophoresis. The typical applications using these methods are also described in this review together with the characteristics of the methods.

Brominated derivatives from the Chinese sponge Pseudoceratina sp.

Chemical examination of the marine sponge Pseudoceratina sp. resulted in the isolation and characterization of two new dibromotyrosine-derived metabolites (1-2), and a new histamine-derived alkaloid (3), along with eight known dibromotyrosine based products. Their structures were elucidated on the basis of IR, 1D and 2D NMR, and MS spectral data analyses.

Occurrence of biogenic amines and polyamines in spinach and changes during storage under refrigeration.

Biogenic amines and polyamines were studied in 18 market samples of spinach. Histamine and spermidine were detected in relatively high amounts in all samples within the ranges of 9.5-69.7 and 15.6-53.0 mg/kg, respectively. Other biologically active amines were either detected at low levels or not found at all. Changes in amine content during storage at 6 degrees C were studied. The content of most of the amines remained constant during storage, with the exception of spermidine and histamine. Spermidine showed a clear decreasing trend, whereas histamine significantly increased in all trials, but decreased at the end of the storage in two of the trials. Trials showing a decrease in histamine content also showed the highest spermidine decrease and recorded the highest pH values. Microbial loads throughout storage were also followed, with Pseudomonadaceae and Enterobacteriaceae being the predominant bacterial groups. Trials with higher microbial loads in initial samples also showed the highest histamine content in these samples. Potential explanations for both the formation and the degradation of histamine during storage are discussed.

Selective analysis of histamine in food by means of solid-phase extraction cleanup and chromatographic separation.

A simple, practical technique is presented for the selective determination and measurement of histamine (HA) levels in fermented food. The method involved a solid-phase extraction cleanup using a Sep-Pak Plus C-18 cartridge and ion-paired reversed-phase high-performance liquid chromatographic (IP-RP-HPLC) separation, followed by detection of HA at its UV absorbance wavelength of 220nm. After evaporating a methanolic extract from the food sample, the resulting residue was reconstituted with 0.2M phosphate buffer (pH 3.0), and subsequently passed through the cartridge. The aliquot of the solution which came out of the cartridge was chromatographed in IP-RP mode on a C-18 column, as the stationary phase, and with a solution of 0.2M phosphate buffer (pH 3.0)-acetonitrile-water (1:24:166, v/v) containing 2mM sodium 1-octane sulfonic acid, as the mobile phase. When this method was applied to a mixture of HA, Cadaverine (Cad), Putrescine (Put), Serotonin (5HT), and Tyramine (Tyr), only HA was detected at 16.4min of retention time. The method was fully validated and validation parameters were: linearity range 2-1000ppm; correlation coefficient >0.991; mean recovery >99.5%; limit of quantification 2ppm and limit of detection 0.5ppm. The method was next applied to 12 brands of Miso (fermented soybean paste), 9 brands of Sake (rice wine), and 5 brands of Shouyu (Japanese soy sauce) to verify its ability to detect the presence of HA in a variety of fermented foods. The method proved to be both rapid and accurate and is therefore recommended for use in HA pollution surveys and in the routine practice of food-quality control.

PCR detection of foodborne bacteria producing the biogenic amines histamine, tyramine, putrescine, and cadaverine.

This study describes an easy PCR method for the detection of foodborne bacteria that potentially produce histamine, tyramine, putrescine, and cadaverine. Synthetic oligonucleotide pairs for the specific detection of the gene coding for each group of bacterial histidine, tyrosine, ornithine, or lysine decarboxylases were designed. Under the conditions used in this study, the assay yielded fragments of 372 and 531 bp from histidine decarboxylase-encoding genes, a 825-bp fragment from tyrosine decarboxylases, fragments of 624 and 1,440 bp from ornithine decarboxylases, and 1,098- and 1,185-bp fragments from lysine decarboxylases. This is the first PCR method for detection of cadaverine-producing bacteria. The method was successfully applied to several biogenic amine-producing bacterial strains.

Alternatives for coupling sequential injection systems to commercial capillary electrophoresis-mass spectrometry equipment.

On-line coupling of an automated flow system with a commercially available capillary electrophoresis (CE) system with an electrospray interface (ESI) for mass spectroscopic (MS) detection is described. The peculiarities of CE-ESI-MS interfaces, in which a high electrical field must be applied to the capillary end where the sample is provided by the flow system, introduce significant difficulties for the appropriate work of the entire arrangement. Experimental strategies are proposed for achieving stable conditions for on-line sample pre-treatment, conditioning of the separation capillary, sample injection, as the proper separation. The versatility and robustness of the proposed arrangement is discussed, taken as example the separation of a variety of amines. Connection of the CE system's pressure to the automated flow system enables hydrodynamic introduction of sample with high precision. The developed hyphenated system is of practical relevance as it opens an avenue for the simplification and automation of the whole analytical process required when using powerful CE-ESI-MS equipments.

The ameliorative effect of dates (Phoenix dactylifera L.) on ethanol-induced gastric ulcer in rats.

The present work aimed at testing, in a rat model of ethanol-induced gastric ulceration, a local folk medicinal claim that dates are beneficial in gastric ulcers in humans. Aqueous and ethanolic undialyzed and dialyzed extracts from date fruit and pits were given orally to rats at a dose of 4 ml/kg for 14 consecutive days. On the last day of treatment, rats were fasted for 24 h, and were then given ethanol, 80% (1 ml/rat) by gastric intubation to induce gastric ulcer. Rats were killed after 1 h of ethanol exposure, and the incidence and severity of the ulceration were estimated, as well as the concentrations of gastrin in plasma, and histamine and mucus in the gastric mucosa. A single group of rats that were fasted for 24 h, was administered orally with lansoprazole (30 mg/kg), and was given 80% ethanol as above, 8 h thereafter, served as a positive control. The results indicated that the aqueous and ethanolic extracts of the date fruit and, to a lesser extent, date pits, were effective in ameliorating the severity of gastric ulceration and mitigating the ethanol-induced increase in histamine and gastrin concentrations, and the decrease in mucin gastric levels. The ethanolic undialyzed extract was more effective than the rest of the other extracts used. It is postulated that the basis of the gastroprotective action of date extracts may be multi-factorial, and may include an anti-oxidant action.

Photobacterium phosphoreum caused a histamine fish poisoning incident.

An incident of histamine fish poisoning (HFP) occurred due to the consumption of iwashi maruboshi (dried sardine) in Osaka, Japan in March 2002. A histamine-producing bacterial strain, YS4-7, was isolated from iwashi maruboshi that contained 1700 mg of histamine per kilogram. This strain was identified as Photobacterium phosphoreum by biochemical examinations and partial sequencing of 16S rDNA. P. phosphoreum YS4-7 showed greater capability as a histamine producer at 4 and 12 degrees C than Morganella morganii JCM 1672. Strain YS4-7 produced 546 mg of histamine per kilogram in a sardine homogenate stored for 12 h at 20 degrees C. M. morganii, Raoultella planticola and Hafnia alvei have been isolated from fish implicated in HFP incidents, whereas this is the first report of P. phosphoreum being the causative bacterium in a sporadic case of histamine food poisoning.