Identification and quantitation of two new naphthoylindole drugs-of-abuse, (1-(5-hydroxypentyl)-1H-indol-3-yl)(naphthalen-1-yl)methanone (AM-2202) and (1-(4-pentenyl)-1H-indol-3-yl)(naphthalen-1-yl)methanone, with other synthetic cannabinoids in unregulated "herbal" products circulated in the Tokyo area

During our continual surveillance of unregulated drugs in May-June 2011, we found two new compounds as adulterants in herbal products obtained at shops in the Tokyo area. These compounds were identified by liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry, accurate mass spectrometry, and nuclear magnetic resonance spectroscopy. The first compound identified was a naphthoylindole (1-(5-hydroxypentyl)-1H-indol-3-yl)(naphthalen-1-yl)methanone (AM-2202, 1), which is a side-chain hydroxyl analogue of JWH-018. The second compound was (1-(4-pentenyl)-1H-indol-3-yl)(naphthalen-1-yl)methanone (2), which is side-chain double bond analogue of JWH-018. This is the first report to identify 1 and 2 in a commercial "herbal" product to our knowledge. For quantitation of the above compounds 1 and 2, and chemical analysis for previously reported compounds (AM-2201, 3; JWH-203, 4; JWH-019, 7; JWH-210, 8; mitragynine, 9), each product was extracted with methanol under ultrasonication to prepare solutions for analysis by liquid chromatography with ultraviolet detection. For the sake of identifying JWH-203 (4) and its positional isomers [JWH-203-3-chloroisomer (5) and 4-chloroisomer (6)] correctly, simultaneous liquid chromatography analysis on fluorocarbon-bonded silica gel column was performed. And a case report of commercially available products containing synthetic cannabinoids 7 and 8, and a natural occurring alkaloid 9, was also shown. Each of 6 commercially circulated products contained compounds 1-4 and 7-9; the amounts of the compounds ranged from 4.1 to 222 mg per pack.