PhD Scientific Days 2021

PH_I_L: Pharmaceutical Sciences I. Lectures

NMR-based Structural Identification of the Bioactive Metabolites Found in Two Hungarian Poroid Fungi

Text of the abstract

Introduction: Mushrooms are appreciated not only as a nutritional food but also as a valuable tool in traditional medicine, due to their structurally diverse metabolic products. The chemical constituents of the fungi are much less characterized than those of plants and this is even more pronounced for the inedible poroid fungi. According to the literature, mycochemical components of poroid fungi cover a wide range of structurally related antioxidant phenolics, cytotoxic ceramides and triterpenes.
Aims: Our aim was to identify the isolated metabolites of two, previously unexamined Hungarian fungi Inonotus nidus-pici (INP) and Buglossoporus quercinus (BGS) by NMR spectroscopy.
Methods: The structures of the metabolites found in the methanolic extract was determined by NMR spectroscopy. Conventional 1D and 2D NMR techniques were used, to map each spin systems, to identify ring anellations and relative configurations.
Results
Three triterpenes were identified in the extract of INP: lanosterol, ergost-6,8,22-trien-3β-ol and ergosterol peroxide. A rare ceramide (citropremide) and a phenolic component, 3,4-dihydroxybenzalacetone was also found. The bioactivity screening indicated their cytotoxicity in the micromolar range, while antioxidant and antibacterial activity was observed in the case of the phenolic compound. To date, polyporenic acid A and its various esters (malonate-, monomethyl malonate- and 3-hydroxy-3-methylglutarate) were identified in the extract of BGS. Moreover, a new 29-hydroxy lanostane-type triterpene was described for the first time.
Conclusion: Five compounds were characterized in the extract of INP, including ergostane and lanostane triterpenes, a ceramide, and a phenolic component. In the case of our ongoing mycochemical profiling of BGS, five 24-methylene lanostane triterpenoids were identified including a new natural product. Our results provide the basis of the mycochemical and pharmacological study of other species in the genus Inonotus and Buglossoporus, which have not been researched so far.
Funding: PREPARED WITH THE PROFESSIONAL SUPPORT OF THE DOCTORAL STUDENT SCHOLARSHIP PROGRAM OF THE CO-OPERATIVE DOCTORAL PROGRAM OF THE MINISTRY OF INNOVATION AND TECHNOLOGY FINANCED FROM THE NATIONAL RESEARCH, DEVELOPMENT AND INNOVATION FUND (KDP-2020/1007075).

University and Doctoral School

Semmelweis University, Doctoral School of Pharmaceutical Sciences