Quantitation of Vaporized γ-Aminobutyric Acid in Cigarette Smoke Extract From e-Cigarettes by the Combination of HPLC-Fluorescence Detection and Derivatization With DBD-F.

Gamma-aminobutyric acid (GABA), which has attracted much attention as a bioactive ingredient, is used in functional foods. Recently, electronic cigarette (e-cigarette) products for inhaling vaporized GABA have become commercially available. In this study, we developed a high-performance liquid chromatography-fluorescence method for detecting GABA derivatized with 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F) in cigarette smoke extract (CSE).

Bactericidal Efficacy of So-Called Sanitizers in Japan.

Commercially available so-called sanitizers in Japan are often touted as having remarkable "sanitizing (jokin)" effect, "virus-removal" capabilities, and "99.99%" removal rate of microbes and pathogens. In this study, we investigated the bactericidal efficacy of these so-called sanitizers for environmental surfaces against Enterococcus faecalis and Pseudomonas aeruginosa.

4-Iodobenzonitrile as a fluorogenic derivatization reagent for chromatographic analysis of L-p-boronophenylalanine in whole blood samples using Suzuki coupling reaction.

Background: L-p-Boronophehylalanine (BPA) is used in boron neutron capture therapy (BNCT), which is a novel selective cancer radiotherapy technique. It is important to measure BPA levels in human blood for effective radiotherapy; a prompt gamma-ray spectrometer, ICP-AES, and ICP-MS have been used for this purpose. However, these methods require sophisticated and expensive apparatuses as well as experienced analysts.

LC-MS/MS analysis of components in smoke from e-cigarettes that use guarana extract as the caffeine source.

Currently, e-cigarette products to inhale caffeine (Caf) are commercially available and widely used. Guarana extract (GE) is used as the caffeine source in some e-cigarette products. In this study, an LC-MS/MS analysis of components in the smoke from e-cigarettes with GE was performed.

A Turn-On Quinazolinone-Based Fluorescence Probe for Selective Detection of Carbon Monoxide.

Carbon monoxide (CO) is a toxic, hazardous gas that has a colorless and odorless nature. On the other hand, CO possesses some physiological roles as a signaling molecule that regulates neurotransmitters in addition to its hazardous effects. Because of the dual nature of CO, there is a need to develop a sensitive, selective, and rapid method for its detection.

Analysis of vaporized caffeine in smoke from e-cigarettes using liquid chromatography-tandem mass spectrometry and clarification of minor components.

Purpose: Electronic cigarettes (e-cigarettes) are used widely, and e-cigarettes containing caffeine (Caf) have recently become commercially available. However, no risk evaluation of these Caf-containing products has been performed to date. Such an evaluation requires a sensitive analytical method for quantifying Caf in smoke from e-cigarettes.

Extremely Simple and Rapid HPLC Analysis of Tocilizumab in Human Serum with Selective Precipitation Using Alkylamine.

An assay using HPLC with fluorescence (FL) detection method for monitoring native FL of tocilizumab (TCZ) in human serum combined with extremely simple and rapid pretreatment without any antigen-antibody reaction was developed. Good separation of TCZ was achieved within 13 min on a Presto FF-C18 column (100 × 4.6 mm i.

Selective fluorescence labeling of myristicin using Mizoroki-Heck coupling reaction. Application to nutmeg powder, oil, and human plasma samples.

Myristicin [5-allyl-1‑methoxy-2,3-(methylenedioxy)benzene] is the major constituent of the seasoning nutmeg oil and powder. Sometimes myristicin is abused via its ingestion at high doses to cause hallucination. In these high doses, myristicin could cause severe adverse health effects, including convulsion, delirium, and palpitation.

HPLC Fluorescence Method for Eugenols in Basil Products Derivatized with DIBI.

Eugenols (Eugs) such as eugenol (Eug), methyleugenol (MeEug), and linalool (Lin) in basil product are the main bioactive components of basil products and have a terminal double-bond. A sensitive HPLC-fluorescence method for Eugs derivatized with 4-(4,5-diphenyl-1H-imidazol-2-yl)iodobenzene (DIBI) was developed. Good separation of DIB-Eugs was achieved within 20 min on an Atlantis T3 column (50 × 2.

Safety evaluation of recycling process used to produce recycled pulp for adult paper diapers.

Eight contaminants were used to perform a surrogate contamination test to evaluate safety of the process for producing recycled pulp for adult paper diapers. We performed a safety evaluation of the recycling process for producing recycled pulp following the European Food Safety Authority safety assessment for polyethylene terephthalate (PET) bottles using recycled PET. We also compared the first tier safety limit established on the basis of TTC (C) in the pulp that contained recycled pulp with residual contaminant concentrations (C).

Stereodivergent Synthesis of Bispyrrolidinoindoline Alkaloidal Scaffolds and Generation of a Lead Candidate with Stereospecific Antiproliferative Activity.

The fungal secondary metabolites (+)-WIN 64821 and (-)-ditryptophenaline are biosynthesized through condensation of l-tryptophan and l-phenylalanine, followed by reductive dimerization with generation of stereochemical variations. Inspired by the stereodivergent biogenetic process, we designed and synthesized a collection of bispyrrolidinoindoline diketopiperazine alkaloids and their analogues with systematic diversification of the stereochemistry of the privileged structural motif of the fungal alkaloids. Not only the stereochemical modifications of (+)-WIN 64821 at the 3-/3'-, 11-/11'-, and 15-/15'-positions, but also ring cleavage of the diketopiperazine moieties, allowed the generation of a lead compound exhibiting potent growth inhibitory activity (IC =3.

Quantification of three triterpenic acids in dried rosemary using HPLC-fluorescence detection and 4-(4,5-diphenyl-1H-imidazole-2-yl)benzoyl chloride derivatization.

Functional triterpenic acids such as ursolic acid (UA), oleanolic acid (OA) and betulinic acid (BA) are representative ingredients in rosemary that may have health benefits. UA, OA and BA in rosemary extracts were derivatized with 4-(4,5-diphenyl-1H-imidazole-2-yl)benzoyl chloride (DIB-Cl) and detected using HPLC-fluorescence (FL). Dried rosemary (50 mg) was ground, added to 3 ml of ethanol, sonicated for 40 min, then the sample solution was added to a mixture of 1% trimethylamine and 1 mM DIB-Cl in acetonitrile.

Evaluation of the targeted delivery of 5-fluorouracil and ascorbic acid into the brain with ultrasound-responsive nanobubbles.

Recently, ultrasound-induced drug delivery into the brain using bubble formulations has been developed. After the brain delivery, however, the information on pharmacokinetics of hydrophilic drugs in the brain is lacking. In this study, to clarify the time-course pharmacokinetics of hydrophilic drugs, we used a brain microdialysis method.

Proposal of a flow scheme for the chemical-form-based quantitative analysis of chlorine compounds in pulp for sanitary products and verification of safety.

To determine the amounts and chemical forms of chlorine compounds in elemental chlorine-free (ECF) bleached pulp for sanitary products, a chemical-form-based quantitative analysis flow scheme was created. The scheme involves quantitative determination of compounds eluted in elution tests assuming dermal exposure. The results indicated that most of the chlorine compounds in pulp used for sanitary products were insoluble organically bound chlorine and water-soluble chlorides consisting of chloride ions.

Luminol Chemiluminescence Profile of O/W Emulsions during Thermal Oxidation.

The luminol chemiluminescence (CL) profile of an oil-in-water (O/W) emulsion during thermal oxidation (60°C) was assessed using the luminol-K[Fe(CN)] assay, in which the oxidation species produced by the autoxidation of an O/W emulsion generated CL emission. Increased CL intensity was observed for O/W emulsions prepared using either linseed or corn oil, which was increased by the addition of Fe to the O/W emulsion. The relationship between the CL profile and results obtained by conventional approaches, such as the peroxide value (PV) and thiobarbituric acid (TBA) methods, were compared.

Validation of an LC-MS/MS Method for the Determination of Propofol, Midazolam, and Carbamazepine in Rat Plasma: Application to Monitor Their Concentrations Following Co-administration.

Propofol (PRO) is a hypnotic used to induce and maintain general anesthesia. A risk of drug-drug interactions exists in cases of clinical co-administration of PRO and midazolam (MDZ) or carbamazepine (CBZ). Therefore a sensitive and rapid assay is needed to monitor these drugs.

Quantitative and antioxidative behavior of Trolox in rats' blood and brain by HPLC-UV and SMFIA-CL methods.

Trolox, a water-soluble vitamin E analogue has been used as a positive control in Trolox equivalent antioxidant capacity and oxygen radical antioxidant capacity assays due to its high antioxidative effect. In this study, the ex vivo antioxidative effects of Trolox and its concentration in blood and brain microdialysates from rat after administration were evaluated by newly established semi-microflow injection analysis, chemiluminescence detection and HPLC-UV. In the administration test, the antioxidative effect of Trolox in blood and brain microdialysates after a single administration of 200 mg/kg of Trolox to rats could be monitored.

Investigation of the amount of transdermal exposure of newborn babies to phthalates in paper diapers and certification of the safety of paper diapers.

A risk assessment study of seven phthalates in paper diapers for newborn babies produced in Japan was performed. The diapers were purchased and the contents of the seven phthalates were determined and estimated amounts of exposure were calculated based on the eluted rate into artificial medium of urine or sweat, average weight of infants, and frequency of use. Di-2-ethylhexyl phthalate and di-n-butyl phthalate were detected in the topsheets and determined to be 0.

Risk assessment study of dioxins in sanitary napkins produced in Japan.

A risk assessment study of dioxins in sanitary napkins produced in Japan was performed. The daily estimated exposure volume to dioxins was compared with the tolerable daily intake (TDI). The concentrations of dioxins such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) in seven sanitary napkins were measured using gas chromatography and mass spectroscopy analytical methods.

Fluorescence derivatization method for sensitive chromatographic determination of zidovudine based on the Huisgen reaction.

A novel pre-column fluorescence derivatization method for chromatographic analysis of azide compounds was developed based on the Huisgen reaction, which is a specific cycloaddition reaction between an alkyne and an azide. We designed and synthesized a fluorescent alkyne, 2-(4-ethynylphenyl)-4,5-diphenyl-1H-imidazole (DIB-ET) as a reagent. DIB-ET has a lophine skeleton carrying an alkyne acting as fluorophore and reactive center, respectively.

Simultaneous determination of propofol and remifentanil in rat plasma by liquid chromatography-tandem mass spectrometry: application to preclinical pharmacokinetic drug-drug interaction analysis.

Propofol (Pro) is an ultra-short-acting hypnotic agent used for general anesthesia that has no analgesic properties. Remifentanil (Rem) is an ultra-short-acting opioid administered concomitantly as an analgesic with Pro. To evaluate the pharmacokinetic interactions between Pro and Rem, we developed and validated a method combining high-performance liquid chromatography with tandem mass spectrometry for simultaneous determination of Pro and Rem.

Quantitation of sulfur-containing amino acids, homocysteine, methionine and cysteine in dried blood spot from newborn baby by HPLC-fluorescence detection.

Sulfur-containing amino acids (SAAs), homocysteine (Hcy), methionine (Met) and cysteine (Cys) in blood are related to homocystinuria, an inborn error of metabolism. In this study, an assay method with HPLC-fluorescence detection to quantify the SAAs in a dried blood spot was established and applied to samples from newborn babies (n=200). Sample pretreatment involving reduction, derivatization with 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole, and liquid-liquid extraction with ethyl acetate gave the separation of the derivatives with retention times within 12 min.

Chromatographic determination of low-molecular mass unsaturated aliphatic aldehydes with peroxyoxalate chemiluminescence detection after fluorescence labeling with 4-(N,N-dimethylaminosulfonyl)-7-hydrazino-2,1,3-benzoxadiazole.

A highly sensitive, selective and reproducible chromatographic method is described for determination of low-molecular mass unsaturated aliphatic aldehydes in human serum. The method combines fluorescent labeling using 4-(N,N-Dimethylaminosulfonyl)-7-hydrazino-2,1,3-benzoxadiazole with peroxyoxalate chemiluminescence. The derivatives were separated on a reversed-phase column C8 isocratically using a mixture of acetonitrile and 90mM imidazole-HNO3 buffer (pH 6.

In vitro screening of Fe2+-chelating effect by a Fenton's reaction-luminol chemiluminescence system.

In vitro screening of a Fe(2+) -chelating effect using a Fenton's reaction-luminol chemiluminescence (CL) system is described. The luminescence between the reactive oxygen species generated by the Fenton's reaction and luminol was decreased on capturing Fe(2+) using a chelator. The proposed method can prevent the consumption of expensive seed compounds (drug discovery candidates) owing to the high sensitivity of CL detection.