Systematic Characterization of Triterpenoids in Ganoderma lucidum by UHPLC-Q/TOF MS

Background: Ganoderma lucidum, which is widely used as “Ganoderma” in China or other Asian countries (Japan, Korea, etc), exerts an important role in tonifying qi and calming the mind in clinical applications. Triterpenoids are the main active components in Ganoderma lucidum, with significant biological activities of hepatoprotective, anticancer, and anti-tumor, etc. However, the current analysis of triterpenoids in Ganoderma lucidum by mass spectrometry is limited, restricting its quality control and elucidation of its functional basis. Objective: This work aimed to systematically characterize the triterpenoids in Ganoderma lucidum. Methods: The Ganoderma lucidum powder was extracted by 50% ethanol/water and separated by Waters ACQUITY UPLC HSS T3 column (2.1 mm×100 mm, 1.8 μm). The data was obtained by Waters G2-Q-TOF mass spectrometry equipped with an electrospray ionization ion (ESI) source, and the MS data under positive and negative modes was acquired and analyzed. Results: A total of 43 triterpenoids were identified or tentatively characterized from the extracts of Ganoderma lucidum, including 32 known compounds and 11 potential new compounds. Among them, five triterpenoids were unambiguously identified by comparison with reference standards, including ganoderic acid A(28), ganoderic acid D(36), ganoderenic acid D(34), ganoderic acid F(43), and ganoderic acid G(16). The profiled triterpenoids could be divided into eight types according to the substituents at the C3, C7 and C15 positions of the parent structure. The mass fragmentation rules of Ganoderma lucidum triterpenoids were summarized. Under the positive ion mode, Ganoderma lucidum triterpenoids easily lost CH3 at the C10 position and H2O at C3, C7, and C15 positions, and the side chain bond at the C22(23) position was easily split. Under the negative ion mode, the split of the C and D rings was the characteristic feature. Conclusion: The mass fragmentation behaviors of Ganoderma lucidum triterpenoids under positive ion mode were summarized and emphasized, and reliable scientific data and methods for systematic characterization of Ganoderma lucidum triterpenoids were also supplied.