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1.
Shokuhin Eiseigaku Zasshi ; 60(4): 96-107, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31474657

RESUMO

LC/Tribrid Orbitrap was developed to determine phosphodiesterase-5 (PDE-5) inhibitors and their analogs as adulterants in dietary supplements. High-resolution MS/MS and MS3 spectra of PDE-5 inhibitors and their analogs were obtained by LC/Tribrid Orbitrap using both higher-energy collisional dissociation and collision-induced dissociation. We investigated dietary supplements that claim to enhance men's sexual performance, and detected PDE-5 inhibitors and their analogs. We also estimated the structures of the PDE-5 inhibitor analogs and the impurities of PDE-5 inhibitors and their analogs in the dietary supplements.


Assuntos
Suplementos Nutricionais/análise , Inibidores da Fosfodiesterase 5/análise , Espectrometria de Massas em Tandem , Cromatografia Líquida , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5
2.
J Pharm Biomed Anal ; 148: 136-141, 2018 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-29017110

RESUMO

Two analogs of sildenafil (compounds 1 and 2) were detected in three powder products acquired from online drug markets during an LC-UV-MS analysis of psychotropic drugs. Their structures were established by high-resolution mass spectrometry and NMR spectroscopy. Compound 1 was identified as 5-(5-(3,5-dimethylpiperazine-1-carbonothioyl)-2-ethoxyphenyl)-1-methyl-3-propyl-1H-pyrazolo[4,3-d]pyrimidine-7(6H)-thione and named dimethyldithiodenafil. Compound 2 was identified as 5-(5-(3,5-dimethylpiperazine-1-carbonothioyl)-2-ethoxyphenyl)-1-methyl-3-propyl-1H-pyrazolo[4,3-d]pyrimidin-7(6H)-one and named dimethylthiocarbodenafil. Compound 1 was subjected to the phosphodiesterase assay (IC50=0.20nM). The three powder products were found to contain 12-19mg of dimethyldithiodenafil and 1.4-3.9mg of dimethylthiocarbodenafil per tube.


Assuntos
Inibidores de Fosfodiesterase/química , Citrato de Sildenafila/química , Cromatografia Líquida/métodos , Espectroscopia de Ressonância Magnética/instrumentação , Espectrometria de Massas/métodos , Pós/química , Psicotrópicos/química , Pirimidinas/química
3.
Chirality ; 28(3): 204-8, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26769592

RESUMO

A direct chiral liquid chromatography-circular dichroism (LC-CD) method was developed for the simple and rapid identification of N-octylnortadalafil [(6R, 12aR)-6-(1,3-benzodioxol-5-yl)-2-octyl-2,3,6,7,12,12a-hexahydropyrazino[1',2':1,6]pyrido[3,4-b]indole-1,4-dione; RR-OTDF] and its stereoisomers in dietary supplements. Samples were extracted with methanol. Compounds were then separated by chiral LC-CD using Chiralcel OD-RH (4.6 × 150 mm, 5 µm) with 5 mM ammonium formate (pH 3)/0.1% formic acid in acetonitrile (95:5, v/v) mixture solution (mobile phase A) and 0.1% formic acid in acetonitrile (mobile phase B). The isocratic elution used was mobile phase A / mobile phase B (3:7, v/v) at a flow rate of 1 ml/min. The column temperature was held at 30°C. RR-OTDF and its stereoisomers were separated within 20 min with the resolution factors being over 2.0. Using this method, RR-OTDF and (6R, 12aS)-6-(1,3-benzodioxol-5-yl)-2-octyl-2,3,6,7,12,12a-hexahydropyrazino[1',2':1,6]pyrido[3,4-b]indole-1,4-dione were detected in a dietary supplement.


Assuntos
Carbolinas/química , Cromatografia Líquida , Dicroísmo Circular , Suplementos Nutricionais , Indicadores e Reagentes/química , Estereoisomerismo
4.
J AOAC Int ; 95(4): 1048-52, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22970570

RESUMO

A sildenafil-related compound was detected in a dietary supplement marketed as an aphrodisiac. The compound was detected during analysis of the dietary supplement using LC-UV and LC/electrospray ionization-MS. The structure of the compound was established using high resolution MS, NMR spectrometry, and X-ray crystal structure analysis. The compound was identified as 5-(5-((3,5-dimethylpiperazin-1-yl)sulfonyl)-2-ethoxyphenyl)-l-methyl-7-((1-methyl-4-nitro-1H-imidazol-5-yl)thio)-3-propyl-1H-pyrazolo[4,3-d] pyrimidine. Based on this structure, the compound was named nitroprodenafil. The dietary supplement was found to contain 90 mg nitroprodenafil/capsule. This article describes the structural characterization of a new sildenafil-related compound. The compound was detected during analysis of a dietary supplement using LC-UV and LC/electrospray ionization (ESI)-MS. The structure was established using high resolution MS (HRMS), NMR spectrometry, and X-ray crystal structure analysis. The structures of methisosildenafil, thiomethisosildenafil, and this new analog, named nitroprodenafil (21), are shown in Figure 1. In the Demizu et al. report, the compound is named mutaprodenafil instead ofnitroprodenafil. Considering the naming right, the authors of this paper think the use of mutaprodenafil is appropriate as the compound name, although nitroprodenafil is used.


Assuntos
Cromatografia Líquida/métodos , Suplementos Nutricionais/análise , Espectrometria de Massas/métodos , Piperazinas/análise , Sulfonas/análise , Cápsulas , Técnicas de Química Analítica/métodos , Cristalografia por Raios X/métodos , Contaminação de Medicamentos , Espectroscopia de Ressonância Magnética/métodos , Modelos Químicos , Piperazinas/química , Purinas/análise , Purinas/química , Reprodutibilidade dos Testes , Citrato de Sildenafila , Espectrometria de Massas por Ionização por Electrospray/métodos , Sulfonas/química , Raios Ultravioleta
5.
Shokuhin Eiseigaku Zasshi ; 52(1): 51-8, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21383535

RESUMO

A liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed to determine the residues of dimetridazole (DMZ), metronidazole (MNZ) and ronidazole (RNZ) in salmon and honey. These compounds were extracted with ethyl acetate from samples and cleaned up using a silica solid phase extraction (SPE) cartridge. These compounds were determined by reversed-phase LC using a C18 column with distilled water-methanol as the mobile phase, and MS detection in the positive mode by applying selected reaction monitoring (SRM). DMZ-d(3), MNZ-(13)C(2),(15)N(2) and RNZ-d(3) were used as internal standards. The method was validated in salmon and honey spiked with these compounds at 0.4-2 µg/kg, and average recoveries were in the range of 91.2-107.0%. Repeatability was 1.7-17.1% and intermediate precision was less than 20%. The detection limits of DMZ, MNZ and RNZ in salmon and honey were 0.05-0.2 µg/kg. The method was applied to 3 salmon and 20 honey samples. The concentrations of these compounds in all samples were lower than the detection limits established by the Ministry of Health, Labour and Welfare in Japan.


Assuntos
Antiprotozoários/análise , Cromatografia Líquida/métodos , Dimetridazol/análise , Mel/análise , Metronidazol/análise , Ronidazole/análise , Salmão/metabolismo , Animais , Resíduos de Drogas/análise , Espectrometria de Massas em Tandem
6.
J AOAC Int ; 94(6): 1770-7, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22320083

RESUMO

An analog of aildenafil, which is a potent and highly selective inhibitor of phosphodiesterase 5, was found in a dietary supplement marketed for enhancement of sexual function. The compound was isolated by silica gel column chromatography, and its structure was identified by means of 13C-NMR spectrometry, 1H-NMR spectrometry, high-resolution MS, and X-ray structure determination. The compound was identified to be sulfoaildenafil (other names: thioaildenafil, dimethyl sildenafil thione, and thiomethisosildenafil). Sulfoaildenafil is very similar to the compound thiohomosildenafil. As it is difficult to distinguish between them by LC-photodiode array detector analysis, ultra-performance LC (UPLC)/MS, ion trap LC/MS/MS (LC/IT-MS/MS), and GC/MS were performed. The mass spectra of thiohomosildenafil by UPLC/MS and LC/IT-MS/MS showed mass fragments of m/z 58, 72, and 355, and the mass spectrum by GC/MS showed mass fragments of m/z 56, 72, and 420. Some of these fragments had low intensities, but they were useful for distinguishing between the two compounds. The relationship between aildenafil (other names: dimethylsildenafil and methisosildenafil) and homosildenafil is similar to that between sulfoaildenafil and thiohomosildenafil. Therefore, these compounds were also examined.


Assuntos
Suplementos Nutricionais/análise , Piperazinas/análise , Sulfonas/análise , Cromatografia Líquida/métodos , Nucleotídeo Cíclico Fosfodiesterase do Tipo 5/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Espectroscopia de Ressonância Magnética/métodos , Estrutura Molecular , Inibidores da Fosfodiesterase 5/análise , Espectrometria de Massas em Tandem/métodos
7.
J AOAC Int ; 93(4): 1340-6, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20922970

RESUMO

LC/MS/MS was developed to determine the residues of bithionol (BTN), bromofen (BMF), nitroxynil (NTX), oxyclozanide (OCZ), and tribromsalan (TBS) in milk. Samples were extracted with ethyl acetate and cleaned up by liquid-liquid separation with acetonitrile and n-hexane. The compounds were determined by RP-LC using a C18 column with 0.1% formic acid-methanol. Mass spectral acquisition was performed in the negative mode by applying selected-reaction monitoring. The method was validated in milk spiked with these compounds at 5-600 microg/kg; average recoveries were in the range 83.8-97.1%, with RSD values of 1.4-8.0%. The interassay RSDs were less than 11%. The LODs of these compounds in milk were 0.1 microg/kg. The method was applied to 24 raw milk samples. The concentration of these compounds in all samples was lower than the Japanese maximum residue limits. The method is rapid, sensitive, and specific for monitoring residues of BTN, BMF, NTX, OCZ, and TBS in milk.


Assuntos
Antiplatelmínticos/análise , Bitionol/análise , Cromatografia Líquida/métodos , Leite/química , Nitroxinila/análise , Oxiclozanida/análise , Salicilanilidas/análise , Espectrometria de Massas em Tandem/métodos , Animais , Bovinos , Limite de Detecção
8.
Shokuhin Eiseigaku Zasshi ; 49(1): 37-44, 2008 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-18344657

RESUMO

A rapid and precise determination residues of 4 tetracyclines (TCs) (oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC) and doxycycline (DOXY)) in meat was developed by employing three analyses; a microbiological screening, HPLC and LC/MS/MS. TCs were extracted with pH 4.0 McIlvaine buffer containing 0.01 mol/L EDTA from a meat sample, and then purified using a mixed mode, reversed-phase and cation-exchange cartridge. The mean recoveries (n=5) of 0.2 microg/g OTC, TC and CTC, 0.05 microg/g DOXY spiked in meat samples were 76.6-99.0% (C.V. 1.6-5.4%). In 13 meat samples in which the microbiological screening indicated the presence of TCs, CTC (9 samples) and DOXY (4 samples) were identified with HPLC and LC/MS/MS.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Carne/análise , Espectrometria de Massas em Tandem/métodos , Tetraciclinas/análise , Animais , Técnicas Bacteriológicas , Bovinos , Galinhas , Clortetraciclina/análise , Doxiciclina/análise , Oxitetraciclina/análise , Suínos
9.
Shokuhin Eiseigaku Zasshi ; 44(5): 246-52, 2003 Oct.
Artigo em Japonês | MEDLINE | ID: mdl-14733139

RESUMO

A simple and rapid liquid chromatographic method was developed for the simultaneous determination of twelve benzimidazole anthelmintics in livestock foods using reversed-phase high-performance liquid chromatography with photodiode array detection (PDA). A sample was homogenized with acetonitrile and n-hexane, and centrifuged. The acetonitrile phase was isolated and evaporated. The residue was dissolved in 0.1 mol/L carbonate buffer solution (pH = 9.1), sonicated, and then subjected to clean-up on a Bond Elut LRC-C18 cartridge. The benzimidazole compounds were separated isocratically on a Capcell Pak C18 UG 120 (5 microns, 150 x 4.6 mm i.d.) column and detected by PDA at 295 and 313 nm. Mixtures of acetonitrile and 0.05 mol/L ammonium acetate in mixing ratios of (20:80) and (40:60) were used as the mobile phase, and the flow-rate was 1.0 mL/min at 40 degrees C. The mean recoveries (n = 3) from 0.1-0.5 microgram/g added samples were 72.6-97.2% with coefficients of variation of 0.3-8.5%. The detection limits were 0.01-0.05 microgram/g.


Assuntos
Anti-Helmínticos/análise , Benzimidazóis/análise , Cromatografia Líquida de Alta Pressão/métodos , Ovos/análise , Carne/análise , Leite/química , Animais , Bovinos , Galinhas , Suínos
10.
Shokuhin Eiseigaku Zasshi ; 43(1): 6-9, 2002 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-11998321

RESUMO

A method is described for the determination of the anthelmintic levamisole in muscle, liver, kidney and fat of cattle, swine and poultry using high performance liquid chromatography with photodiode array detection. Levamisole was extracted from an alkaline sample with ethyl acetate and back-extracted with 0.1 mol/L hydrochloric acid. The extract was applied to an SCX solid-phase extraction column. The column was washed with water and methanol. Levamisole was eluted with a solution of ammonia in methanol. The eluate was evaporated to dryness and the residue was dissolved in the mobile phase and injected into the HPLC system. Mean recoveries from 0.01-0.10 microgram/g fortified muscle, liver, kidney and fat samples ranged from 78.3 to 99.8%. The detection limit for the assay was 0.005 microgram/g.


Assuntos
Antinematódeos/análise , Cromatografia Líquida de Alta Pressão/métodos , Levamisol/análise , Carne/análise , Animais , Bovinos , Galinhas , Suínos
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