Identification and charaterization of key chemical constituents in processed Gastrodia elata using UHPLC-MS/MS and chemometric methods

Authors: YE, XIDE - Jiangxi University Of Traditional Chinese Medicine; WANG, YAN-HONG - University Of Mississippi; ZHAO, JIANPING - University Of Mississippi; WANG, MEI - University Of Mississippi; AVULA, BHARATHI - University Of Mississippi; PENG, QIAOZHEN - University Of Mississippi; OUYANG, HUI - Jiangxi University Of Traditional Chinese Medicine; LINGYUN, ZHONG - Jiangxi University Of Traditional Chinese Medicine; ZHANG, JINLIAN - Jiangxi University Of Traditional Chinese Medicine; KHAN, IKHLAS - University Of Mississippi

Submitted to: Journal of Analytical Methods in Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/17/2019
Publication Date: 10/23/2019
Citation: Ye, X., Wang, Y., Zhao, J., Wang, M., Avula, B., Peng, Q., Ouyang, H., Lingyun, Z., Zhang, J., Khan, I.A. 2019. Identification and charaterization of key chemical constituents in processed Gastrodia elata using UHPLC-MS/MS and chemometric methods. Journal of Analytical Methods in Chemistry. https://doi.org/10.1155/2019/4396201.
DOI: https://doi.org/10.1155/2019/4396201

Interpretive Summary: The dry tuber of Gastrodia elata (G. elata), also known as Tianma, is one of the most important traditional Chinese herbal medicines. It has been used for the prevention and treatment of neuralgic and nervous diseases such as headaches, migraine, dizziness, etc. in the traditional Chinese medicine (TCM). G. elata contains a variety of components such as phenolic glucoside gastrodin, gastrodigenin (p-hydroxybenzylalcohol) and parishins as secondary metabolites. G. elata has to be processed before clinical application according to Chinese pharmacopeia. “Jianchang Bang” proposes a way that is to mix steamed and sliced G. elata with ginger juice, then dried at room temperature. The processing method has been believed as an especial traditional processing means for its local clinical application by the theory of “toxicity reducing and efficacy enhancing”. Although the processed product of G. elata with ginger has shown good efficacy in practical way, there is a limitation for its clinical application owe to without any scientific evidences. Therefore, finding out the difference of chemical composition in G. elata proposed by “Jiangchang Bang” method before and after processing is the key to reveal the concoction mechanism for providing clinical application. In order to understand the chemical composition of G. elata processed with ginger juice, an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) combined with multivariate statistical analysis method was developed. The method facilitated the elucidation of characteristic fragmentation pathways of targeted and nontargeted constituents with different ionization modes and then confirmed their molecular structures using MS/MS fragmentation pattern. It is the first time by using the UHPLC-MS/MS and chemometric methods for the identification of G. elata processed with ginger using “Jianchang Bang” method. Three new perishin type compounds were identified according to their retention time, accurate mass, and fragmentation patterns.

Technical Abstract: Gastrodia elata Blume is a saprophytic perennial herb that belongs to the Orchidaceae family. G. elata is often recommended to be processed when used in traditional Chinese medicine (TCM). In the current study, a traditional processing method, known as “Jianchang Bang”, was applied. Steamed and dried G. elata was processed with ginger juice for up to 5 days (GEP5D). An ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) combined with chemometric method was developed for the analysis of processed G. elata along with the raw material as well as steamed and dried (S&D) G. elata. Principal component analysis (PCA) revealed three clusters belonging to raw material, S&D and GEP5D samples. As a result, the primary marker compounds responsible for distinguishing different group of samples were identified with the aid of Time of Flight Mass Spectrometry (TOF MS) and MS/MS analyses. From PCA and Orthogonal Partial Least Squares Discriminate Analysis (OPLSDA) results, key chemical components for processed G. elata are identified. The discussion of structural characterization of marker compounds is also present. The results demonstrated that S&D G. elata processed with ginger juice influenced chemical components of G. elata. Compared the raw material of G. elata with GEP5D, three new perishin type compounds were identified according to their retention time, accurate mass, and fragmentation patterns. The chromatographic peak areas for marker compounds including S-(gastrodin)-glutathione, S-(4-hydroxybenzylamine)-glutathione, and perishin type compounds changed significantly. The structures for these marker compounds were further characterized by MS/MS. This result indicated that by applying the “Jianchang Bang” method, changes in chemical composition in G. elata’s contents was observed. The study also demonstrated that chemometric analysis is helpful to understand the processing mechanism and will provide a scientific support for the clinical application of G. elata.