Rapid screening and structural elucidation of a novel sibutramine analogue in a weight loss supplement: 11-Desisobutyl-11-benzylsibutramine

• Published in: Journal of pharmaceutical and biomedical analysis Vol. 83; pp. 122 - 128
• Main Authors: Mans, Daniel J., Gucinski, Ashley C., Dunn, Jamie D., Gryniewicz-Ruzicka, Connie M., Mecker-Pogue, Laura C., Kao, Jeff L.-F., Ge, Xia
• Format: Journal Article
• Language: English
• Published: England Elsevier B.V 01-09-2013
• Subjects: Chromatography, Liquid - methods; Cyclobutanes - chemistry; Dietary supplement; Dietary Supplements; Food and Drug Administration; imports; Ion mobility spectrometry; liquid chromatography; Magnetic Resonance Spectroscopy - methods; Mass spectrometry; Nuclear magnetic resonance; nuclear magnetic resonance spectroscopy; screening; Sibutramine; tandem mass spectrometry; Tandem Mass Spectrometry - methods; weight loss; Weight Loss - drug effects; United States; Dietary supplement; Ion mobility spectrometry; Sibutramine; Nuclear magnetic resonance; Mass spectrometry
• ISSN: 0731-7085; 1873-264X
• DOI: 10.1016/j.jpba.2013.02.031

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► A novel analogue of sibutramine was detected in weight loss supplements. ► Nuclear magnetic resonance and tandem mass spectrometry led to ID. ► Ion mobility spectrometry served as a rapid screening method for detection.
A novel analogue of sibutramine, 11-desisobutyl-11-benzylsibutramine, has been discovered. During routine ion mobility spectrometry (IMS) screening of a weight loss supplement collected at an US FDA import operation facility an unknown peak was observed. Further analysis of the supplement by liquid chromatography-mass spectrometry (LC–MS) and high resolution mass spectrometry revealed an unknown peak with a relative retention time of 1.04 with respect to sibutramine and a predicted formula of C20H24NCl. In order to elucidate the analogue's structure, it was isolated from the supplement and characterized by tandem mass spectrometry and nuclear magnetic resonance (NMR), which revealed the analogue possessed a benzyl moiety at the 11 position in place of the isobutyl group associated with sibutramine.