Chemical profiling and characterization of phenolic acids, flavonoids, terpene glycosides from Vangueria agrestis using ultra-high-performance liquid chromatography/ion mobility quadrupole time-of-flight mass spectrometry and

Authors: AVULA, BHARATHI - University Of Mississippi; BAE, JI-YEONG - University Of Mississippi; WANG, YAN-HONG - University Of Mississippi; WANG, MEI - University Of Mississippi; OSMAN, AHMED - University Of Mississippi; SMITH, KERRI - Waters Corporation; YUK, JIMMY - Waters Corporation; ALI, ZULFIQAR - University Of Mississippi; PLUMB, ROBERT - Waters Corporation; ISAAC, GIORGIS - Waters Corporation; KHAN, IKHLAS - University Of Mississippi

Submitted to: Biomedical Chromatography
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/31/2020
Publication Date: 4/6/2020
Citation: Avula, B., Bae, J., Wang, Y., Wang, M., Osman, A.G., Smith, K., Yuk, J., Ali, Z., Plumb, R., Isaac, G., Khan, I.A. 2020. Chemical profiling and characterization of phenolic acids, flavonoids, terpene glycosides from Vangueria agrestis using ultra-high-performance liquid chromatography/ion mobility quadrupole time-of-flight mass spectrometry and metabolomics approach. Biomedical Chromatography. https://doi.org/10.1002/bmc.4840.
DOI: https://doi.org/10.1002/bmc.4840

Interpretive Summary: In the traditional medicine of Africa, Vangueria agrestis of family Rubiaceae is used for the treatment of fever, kidney pain, and antimalarial activity. Little chemistry has been done on the plant and the present study was undertaken to establish the chemical profiling of constituents from root and aerial parts of V. agrestis using Ultra-High-Performance Liquid Chromatography/Ion Mobility Quadrupole Time of Flight Mass Spectrometry (UHPLC-Ion Mobility-QToF-MS) for screening and identifying the compounds. A total of sixty-five compounds including fourteen phenolic acids, sixteen flavonoids, twenty-two monoterpene glycosides, four iridoids, nine triterpene saponins were investigated from the methanolic extracts of root and aerial parts of V. agrestis. The method is applied to quality control of plant samples and dietary supplements claiming to contain V. agrestis. Finally, a chemometric approach with multivariate statistics such as principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used to profile the three different plant parts and to find the potential chemical markers that differentiate among these parts of V. agrestis samples.

Technical Abstract: Vangueria agrestis is a shrub indigenous to tropical Africa, belonging to family Rubiaceae and traditionally is used as a decoction for treatment of fever, pain and malaria. Little chemistry is known about V. agrestis plant and the current study was undertaken to investigate the chemical constituents, confirm the structures of most of the identified compounds on the basis of using precursor exact mass and fragment ion information. In this current work, the chemical profiling and structural characteristics of chemical constituents from methanolic extracts of dried aerial and roots of V. agrestis and dietary supplements were analyzed using Ultra-High-Performance Liquid Chromatography/Ion Mobility Quadrupole Time of Flight Mass Spectrometry (UHPLC-Ion Mobility-QToF-MS) coupled with UNIFI, a software platform that processes raw data files, and multivariate analysis in both negative and positive ion modes. A non-targeted analysis was carried out to profile the chemical constituents of crude extracts of V. agrestis and sixty-five compounds including reference compounds were identified. Phenolic acids, flavonoids, monoterpene and triterpene glycosides were identified. The fragments of flavonoids, monoterpene and triterpene glycosides revealed the characteristic cleavage of glycosidic linkages, and the fragmentation pattern provided structural information about the sugars. All targeted and non-targeted compounds identified can be used as chemical markers to determine the presence or absence of V. agrestis in dietary supplements. This analytical method also provides an alternative and fast method for quality assessment of dietary supplements. A chemometrics analytical tool for visualizing the differences between root and aerial parts of plant samples and dietary supplements quality was also developed.