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1.
Anal Bioanal Chem ; 405(13): 4443-50, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22825675

RESUMO

A sildenafil analogue was detected in a functional coffee sample labelled to have male sexual performance enhancement effects. This analogue was isolated and purified by flash chromatography and preparative high-performance liquid chromatography. Its structure was elucidated using high-resolution mass spectrometry; electrospray ionization-tandem mass spectrometry; and nuclear magnetic resonance spectroscopy, ultraviolet spectroscopy, and infrared spectroscopy. Compared with sildenafil, instead of an N-methylpiperazinyl moiety, ring opening of the piperazine ring with the loss of a carbon atom resulted in a substituted benzenesulfonamide. The chemical name of this analogue is N-[2-(dimethylamino)ethyl]-4-ethoxy-3-(1-methyl-7-oxo-3-propyl-6,7-dihydro-1H-pyrazolo[4,3-d]pyrimidin-5-yl)benzenesulfonamide. It is named descarbonsildenafil because it has one less carbon atom when compared with sildenafil.


Assuntos
Café/química , Piperazinas/química , Extratos Vegetais/química , Sulfonamidas/química , Sulfonas/química , Vasodilatadores/química , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas/métodos , Estrutura Molecular , Piperazinas/isolamento & purificação , Purinas/química , Purinas/isolamento & purificação , Citrato de Sildenafila , Sulfonamidas/isolamento & purificação , Sulfonas/isolamento & purificação , Vasodilatadores/isolamento & purificação
2.
J Pharm Biomed Anal ; 48(4): 1070-5, 2008 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-18829198

RESUMO

A PDE-5 inhibitor was detected and isolated from a health supplement claimed to be a preparation of fresh oyster extracts and be able to promote and support healthy sexual function and endurance, etc. The structure of this PDE-5 inhibitor was elucidated using LC-UV, LC-TOF-MS, MS-MS, IR spectroscopy, and 2D NMR. It was characterized as 8-(2-(4-(hydroxymethyl)piperidin-1-yl)benzylamino)-3-ethyl-1H-imidazo[4,5-g]quinazoline-2(3H)-thione, a compound reported to be a PDE-5 inhibitor.


Assuntos
Suplementos Nutricionais/análise , Contaminação de Medicamentos , Disfunção Erétil/dietoterapia , Imidazóis/química , Inibidores de Fosfodiesterase/química , Quinazolinas/química , Cápsulas , Cromatografia Líquida/métodos , Humanos , Imidazóis/isolamento & purificação , Espectroscopia de Ressonância Magnética/métodos , Masculino , Espectrometria de Massas/métodos , Estrutura Molecular , Inibidores de Fosfodiesterase/isolamento & purificação , Quinazolinas/isolamento & purificação , Espectrofotometria Ultravioleta/métodos
3.
J Pharm Biomed Anal ; 115: 169-73, 2015 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-26210743

RESUMO

In this study, an LC-MS/MS EPI method was developed for simultaneous determination of 32 toxic natural substances in herbal products. The analytes include aconite alkaloids, lobelia alkaloids, solanaceous alkaloids, digitalis steroid glycosides, strychnine, tetrahydropalmatine etc. They werecommonly used in herbal products. The target analytes were extracted from the samples using theQuEChERS method and analysed using AB SCIEX QTRAP 5500 coupled with Agilent HPLC 1260. Thecolumn used was biphenyl reversed phase analytical column. Mobile phase A and B were deionizedwater and methanol respectively, both containing 5mM ammonium formate and 0.1% formic acid. TheMRM-IDA-EPI method enabled quantification and confirmation of the analytes in a single run. The EPIwas used for the qualitative analysis while the MRM was used for the quantitative analysis. Limits ofdetection were determined to be below 10µg/kg for the majority of the analytes. The recoveries forthose commonly detected natural substances were in the acceptable range of 70-120%.


Assuntos
Suplementos Nutricionais/análise , Contaminação de Medicamentos , Medicamentos de Ervas Chinesas , Substâncias Perigosas/análise , Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/análise , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/toxicidade , Limite de Detecção , Reprodutibilidade dos Testes , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodos
4.
J Pharm Biomed Anal ; 50(5): 724-8, 2009 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-19574010
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