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ARS Home » Southeast Area » Oxford, Mississippi » Natural Products Utilization Research » Research » Publications at this Location » Publication #327944
Research Project: Discovery and Development of Natural Products for Pharmaceutical and Agrochemical Applications II

Location: Natural Products Utilization Research

Title: Tandem Mass Spectrometry for Structural Identification of Sesquiterpene alkaloids from the stems of dendrobium nobile using LC-QToF3

Author
item WANG, YON-HONG - University Of Mississippi
item AVULA, BHARATHI - University Of Mississippi
item ABE, NAOHITO - University Of Mississippi
item WEI, FENG - National Institutes For Food And Drug Control
item WANG, MEI - University Of Mississippi
item MA, SHUANG-CHENG - National Institutes For Food And Drug Control
item ALI, ZULFIQAR - University Of Mississippi
item ELSOHLY, MAHMOUD - University Of Mississippi
item KHAN, IKHLAS - University Of Mississippi

Submitted to: Planta Medica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/4/2016
Publication Date: 4/7/2016
Citation: Wang, Y., Avula, B., Abe, N., Wei, F., Wang, M., Ma, S., Ali, Z., Elsohly, M.A., Khan, I.A. 2016. Tandem Mass Spectrometry for Structural Identification of Sesquiterpene alkaloids from the stems of dendrobium nobile using LC-QToF3. Planta Medica. 82(7):662-70.

Interpretive Summary: Dendrobium nobile has gained attention in pre-workout products since alkaloids from this plant were claimed to enhance physical or athletic performance. Structures of alkaloids were characterized on the basis of accurate mass spectra from QTOF mass analyzer in MS and MS-MS tandem modes. Nine alkaloids were separated within 12 minutes using a C18 column. The fragmentation pathways of two sub-group compounds (dendrobine and nobilonine) were illustrated. A method was developed can identify the alkaloid markers of this plant absorption, and it is suitable as a quality control method for various Dendrobium samples and commercial products. Alkaloids were identified from D. nobile that were not detected from 13 other Dendrobium species and the 7 dietary supplements that claimed to contain either dendrobine alkaloids or D. nobile plant or both constituents.

Technical Abstract: Dendrobium nobile is one of the fundamental herbs in traditional Chinese medicine (TCM). Sesquiterpene alkaloids are the main active components in this plant. Due to weak ultraviolet absorption and low content in D. nobile, these sesquiterpene alkaloids have not been extensively studied using chromatographic methods. Herein, tandem mass spectrometry combined with LC separation provides a tool for identification and characterization of alkaloids from D. nobile. A total of 9 sesquiterpene alkaloids were characterized by UHPLC-MS/MS. These alkaloids can be classified into two sub-groups that are represented by dendrobine and nobilonine. Tandem mass spectrometric studies revealed the fragmentation pathways of these two sub-groups alkaloids that were used for the identification and characterization of other alkaloids in D. nobile. Characterization of these alkaloids using accurate mass and diagnostic fragments provided a reliable methodology for the analysis of D. nobile by UHPLC­ MS/MS. The limit of detection (LOD) was defined as the signal-to-noise ratio equal to 3:1. LODs of dendrobine and nobilonine were less than 30 ng/mL. The developed method was applied for the analysis of various Dendrobium species and related dietary supplements. Alkaloids were identified from D. nobile, but not detected from commercial samples including 13 other Dendrobium species and the 7 dietary supplements.