Conjugation of the Dark Quencher QSY 7 to Various Synthetic Cannabinoids for Use in Fluorescence-Based Detection Platforms

Abstract : We have been able to synthesize and characterize several synthetic cannabinoid-dark quencher (DQ) conjugates for the use in fluorescence-based cannabinoid detection platforms. The carboxylic acid reactive QSY 7 amine was reacted with the carboxylated metabolites of JWH 018 and JWH 073 via a simple peptide conjugation reaction with the catalyst O-benzotriazole-N,N,N',N'-tetramethyl-uronium-hexafluoro-phosphate to yield 3 new DQ conjugates. Thin layer chromatography and liquid chromatography coupled mass spectrometry show full conversion of the synthetic cannabinoid starting material to product with observed and expected masses of 1,097 g/mol for JWH 018 pentanoic acid QSY 7 amine and 1,081.4 g/mol for JWH 073 butanoic acid-QSY 7 amine. These characterized conjugates are now ready for cannabinoid-receptor-based binding assays.