Stable Isotope Ratio Analysis for Authentication of Natural Antioxidant Cannabidiol (CBD) from Cannabis sativa

Cannabidiol (CBD) is a non-psychoactive cannabinoid of Cannabis sativa that exhibits several beneficial pharmacological effects, including anti-inflammatory and antioxidant properties. The molecule can be obtained via extraction from the plant or through a biosynthetic route. The two products have both advantages and disadvantages, thus necessitating the development of methods capable of distinguishing between the two products. In this study, for the first time, the analysis of the stable isotope ratios of oxygen and hydrogen demonstrated high efficiency in the discrimination of CBD of a totally natural origin from that obtained through chemical synthesis. Considering a probability level of 95%, it was possible to identify threshold values for δ²H and δ¹⁸O of the totally natural CBD of -215‱ and +23.4‱, respectively. Higher values may indicate a non-entirely natural origin of CBD (i.e., a biosynthetic molecule).