ABSTRACT
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%.
Subject(s)
Dietary Supplements/analysis , Drug Contamination , Drugs, Chinese Herbal , Hazardous Substances/analysis , Chromatography, High Pressure Liquid/methods , Drugs, Chinese Herbal/analysis , Drugs, Chinese Herbal/chemistry , Drugs, Chinese Herbal/toxicity , Limit of Detection , Reproducibility of Results , Spectrometry, Mass, Electrospray Ionization/methods , Tandem Mass Spectrometry/methodsABSTRACT
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.
Subject(s)
Coffee/chemistry , Piperazines/chemistry , Plant Extracts/chemistry , Sulfonamides/chemistry , Sulfones/chemistry , Vasodilator Agents/chemistry , Chromatography, High Pressure Liquid , Mass Spectrometry/methods , Molecular Structure , Piperazines/isolation & purification , Purines/chemistry , Purines/isolation & purification , Sildenafil Citrate , Sulfonamides/isolation & purification , Sulfones/isolation & purification , Vasodilator Agents/isolation & purificationABSTRACT
A health supplement used for sexual performance enhancement was sent to Health Sciences Authority of Singapore for testing. An unknown compound was detected and isolated and its structure was elucidated using NMR, high-resolution MS, ESI-MS/MS, UV and IR. The compound, dapoxetine, is reported to be a selective serotonin reuptake inhibitor under investigation for the treatment of premature ejaculation.
Subject(s)
Benzylamines/chemistry , Benzylamines/isolation & purification , Chemistry, Pharmaceutical/methods , Erectile Dysfunction/drug therapy , Naphthalenes/chemistry , Naphthalenes/isolation & purification , Selective Serotonin Reuptake Inhibitors/chemistry , Selective Serotonin Reuptake Inhibitors/isolation & purification , Sexual Dysfunction, Physiological/drug therapy , Benzylamines/analysis , Dietary Supplements , Drug Contamination , Humans , Magnetic Resonance Spectroscopy/methods , Male , Mass Spectrometry/methods , Naphthalenes/analysis , Selective Serotonin Reuptake Inhibitors/analysis , Spectrometry, Mass, Electrospray Ionization/methods , Spectrophotometry, Infrared/methods , Spectrophotometry, Ultraviolet/methods , Tandem Mass Spectrometry/methods , TemperatureABSTRACT
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.
