Analytical Method Development of Volatile Flavor Compounds for Cynanchum wilfordii and Cynanchum auriculatum by HSS-GCxGC-TOFMS
Background : Cynanchum wilfordii and Cynanchum auriculatum belong to the Asclepiadaceae family and appear morphologically similar. In order to discriminate them, it is needed to find the presence of sap and the leaf shapes: C. auriculatum has a blade ovate leaf comparing to C. wilfordii. However, in the herbal medicine market, they have been handled as cut and dried roots. Due to their similar morphology, it is limited to distinguish the roots of C. wilfordii and C. auriculatum. Recently in Korea, it has been a critical issue to misuse these two roots in the herbal market and food industry. Thus, it is required to establish a robust tool for the discrimination and quality control of them. Methods and Results : To separation and characterization of flavor compounds, C. wilfordii and C. auriculatum samples were analyzed by head space solid phase micro extraction (HSS) fiber coupled with gas chromatography-mass spectrometry using Rtx-5MS (30 m x 0.25 mm x 0.25 μm) column. As a result, We have identified compounds of a few hundred in aliphatic aldehydes and aliphatic alcohols, alkenes and acids, aromatic compounds, aromatic compounds containing nitrogen & sulfur, etc,. In particular, The aliphatic and aromatic compounds had been clearly separated on the second dimensional direction by using two-dimensional GC. Conclusion : The volatile flavor compounds of C. wilfordii and C. auriculatum could easily analyzed without pre-treatment with improved resolution and sensitivity using HSS-GCxGC-TOFMS. We have identified compounds of a few hundred in C. wilfordii and C. auriculatum sample. And It was more accurately qualitative confirmed with separation of GCxGC and TSD. We have confirmed the PCA and PLS-DA Plot that was classified depending on C. wilfordii and C. auriculatum through multivariate statistical analysis of the identified flavor compounds.