Direct analysis of Salvia divinorum leaves for salvinorin A by thin layer chromatography and desorption electrospray ionization multi-stage tandem mass spectrometry.

Salvinorin A (SA), the psychoactive compound in Salvia divinorum, can be detected directly from intact leaves using desorption electrospray ionization (DESI) mass spectrometry without sample preparation. The method identifies SA through several ions in positive ion mode, confirmed by exact mass measurements and multi-stage tandem mass spectrometry. Direct leaf analysis also reveals other salvinorins, including salvinorin B, C, D/E, and divinatorin B. Combining thin layer chromatography with DESI-MS provides a simple approach for analyzing natural products and screening illicit substances in intact plant material.

Study at a glance

Abstract

Salvia divinorum is widely cultivated in the US, Mexico, Central and South America and Europe and is consumed for its ability to produce hallucinogenic effects similar to those of other scheduled hallucinogenic drugs, such as LSD. Salvinorin A (SA), a kappa opiod receptor agonist and psychoactive constituent, is found primarily in the leaves and to a lesser extent in the stems of the plant. Herein, the analysis of intact S. divinorum leaves for SA and of acetone extracts separated using thin layer chromatography (TLC) is demonstrated using desorption electrospray ionization (DESI) mass spectrometry. The detection of SA using DESI in the positive ion mode is characterized by several ions associated with the compound - [M+H](+), [M+NH(4)](+), [M+Na](+), [2M+NH(4)](+), and [2M+Na](+). Confirmation of the identity of these ions is provided through exact mass measurements using a time-of-flight (ToF) mass spectrometer. The presence of SA in the leaves was confirmed by multi-stage tandem mass spectrometry (MS(n)) of the [M+H](+) ion using a linear ion trap mass spectrometer. Direct analysis of the leaves revealed several species of salvinorin in addition to SA as confirmed by MS(n), including salvinorin B, C, D/E, and divinatorin B. Further, the results from DESI imaging of a TLC separation of a commercial leaf extract and an acetone extract of S. divinorum leaves were in concordance with the TLC/DESI-MS results of an authentic salvinorin A standard. The present study provides an example of both the direct analysis of intact plant materials for screening illicit substances and the coupling of TLC and DESI-MS as a simple method for the examination of natural products.