Comparative study and quality evaluation regarding morphology characters, volatile constituents and triglycerides in seeds of five species used in traditional Chinese medicine

Authors: WEI, NA - Hainan University; Wang, Mei; ADAMS, SEBASTIAN - University Of Mississippi; YU, PING - Nanchang University; AVULA, BHARATHI - University Of Mississippi; WANG, YAN-HONG - University Of Mississippi; PAN, KUN - Hainan University; WANG, YONG - Hainan University; KHAN, IKHLAS - University Of Mississippi

Submitted to: Journal of Pharmaceutical and Biomedical Analysis
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/24/2020
Publication Date: 11/27/2020
Citation: Wei, N., Wang, M., Adams, S.J., Yu, P., Avula, B., Wang, Y., Pan, K., Wang, Y., Khan, I.A. 2020. Comparative study and quality evaluation regarding morphology characters, volatile constituents and triglycerides in seeds of five species used in traditional Chinese medicine. Journal of Pharmaceutical and Biomedical Analysis. 194. Article e113801. https://doi.org/10.1016/j.jpba.2020.113801.
DOI: https://doi.org/10.1016/j.jpba.2020.113801

Interpretive Summary: Five well-known plant species, viz. Alpinia oxyphylla, Alpinia katsumadai, Amomum villosum, Amomum villosum var. xanthioides, and Amomum longiligulare have been used in traditional Chinese medicine (TCM) for centuries. Each species is purportedly endowed with different medicinal properties. In addition to the medicinal use, their seeds have been used in China as health-care foods and dietary supplements. Of these species, A. oxyphylla and A. villosum are well renowned as two of the “four famous southern medicines” in China. Despite the popularity and commercial significance, the identification of the seeds from each species is very difficult due to the similarity of the external morphology structures. Many cases have been reported, which illustrates the confusion, mislabeling, and adulteration of these five species. The submitted manuscript involves an in-depth chemical investigation of these plant species. External morphology characters were studied. Volatile marker compounds from each species were identified using a SPME GC/Q-ToF method. A rapid, cost-effective, and environmentally friendly SFC/MS method was developed for the characterization and quantification of triglycerides in the seeds of the five studied TCM species. To our knowledge, this is the first comprehensive study utilizing the morphology, volatile constituents, and triglycerides for quality evaluation purpose of these five well-known TCM species.

Technical Abstract: Volatile compounds (VCs) and triglycerides (TGs) are the primary groups of constituents in the fruits of five well-known species used in traditional Chinese medicine, viz. Alpinia oxyphylla Miq. (AO), Alpinia katsumadai Hayata (AK), Amomum villosum Lour. (FAL), Amomum villosum Lour. var. xanthioides T. L. Wu et Senjen (FALX) and Amomum longiligulare T. L. Wu (FALO). The fruits of these species are morphologically similar and commonly used in both foods and traditional Chinese medicine (TCM). Each species is purportedly endowed with different medicinal properties. Efficient and environmentally friendly methods are desirable for the quality control of these species. The current study attempted to establish both comprehensive profiles and quality standards for the five TCM species. External morphology characters were provided to distinguish 18 fruit samples belonging to the five species which were collected from different geographical origins of China. The VCs of each sample were analyzed by SPME GC/Q-ToF. The identification of marker compounds from each species allowed for the differentiation of the fruits from the five plants. Characterization and quantification of 21 TGs was achieved using SFC/MS with an analysis time of less than 15 minutes. The complex TGs were unambiguously identified using the MS detection with the correct attribution of the acyl group to the sn-2 position. Moreover, the quantification of TGs was improved by using reference standards whenever possible or a single standard to determine multicomponent strategy. The validity of the proposed SFC/MS method was assessed by analyzing fatty acids from the hydrolysis and transesterification products of the same sample set using GC/MS. The quantification results from both TGs and fatty acids were consistent and were further substantiated by chemometric analysis. To our knowledge, this is the first comprehensive study utilizing the morphology, VCs, and TGs for quality evaluation purpose of these five well-known TCM species.