Analysis of dencichine in Panax notoginseng by gas chromatography-mass spectrometry with ethyl chloroformate derivatization

Dencichine (β-N-oxalyl-l-α,β-diaminopropionic acid) is a haemostatic agent present in well-known traditional Chinese medicinal herbs such as Panax notoginseng, as well as other Panax species. It is also a reported neurotoxic agent found in Lathyrus sativus (grass pea seed) and cycad seeds. A method was developed for quantitative determination of the non-protein amino acid, dencichine, in plant samples of P. notoginseng and the adventitious roots directly from the explants of P. notoginseng after derivatization with ethyl chloroformate (ECF) by gas chromatography-mass spectrometry (GC-MS). l-2-chlorophenylalanine was used as an internal standard. Calibration curves were linear (r² = 0.9988, n = 6) in the range of 10-800 μg/ml for dencichine. Limit of detection and quantification for dencichine were 0.5 μg/ml and 2 μg/ml, respectively. This rapid and specific method may be applied to the quantification of dencichine in complex medicinal plants and their products.