Isolation and identification of a novel bisacodyl analogue, bisacodyl dicycloproyl carboxylate, as a potential illegal additive in a dried plum product advertised for weight loss.

In the process of a routine illegal adulterant inspection of food products sold online, a suspicious compound was detected in a dried plum food product, which claimed to have a natural weight loss effect. After mass spectrometric analysis the similarity between MS/MS peaks of this compound and that of bisacodyl, it was hypothesized to be a bisacodyl derivative. The chemical structure of the unknown compound was characterized by ultra-HPLC with quadrupole time-of-flight tandem mass spectrometry (UHPLC/Q-TOF MS), HPLC-diode array detection (HPLC-DAD) and nuclear magnetic resonance (NMR) methods. Based on these results, it was confirmed that the unknown compound had the substitution of two acetyl groups in bisacodyl by two cyclopropanecarbonyl groups, respectively. This distinctive compound has been termed as bisacodyl dicycloproyl carboxylate. The new compound has not been reported yet, and therefore the detection of bisacodyl analogue should be included in routine inspection of diet foods and health products.