Characterisation of indole alkaloids and phenolic acids from wild mushroom Tropicoporus linteus and its chemical profiles compared with other Sanghuang mushrooms

Abstract

Two new indole alkaloids, 1-methylindole-7-methoxy-3-carboxaldehyde (2) and 7-methoxyindole-3-carboxaldehyde (4), together with 7-methoxyindole-3-carboxylic acid methyl ester (1) and 1-methylindole-3-carbaldehyde (3) were isolated from the fruiting bodies of wild Sanghuang mushroom Tropicoporus linteus (TL663). TLC, ¹H-NMR and LC-MS chemical profiles of this mushroom compared with other three genera of wild Sanghuang mushroom extracts were investigated. The TLC, ¹H-NMR and LC-MS profiles of TL663 and Sanghuangporus sanghuang (SS664) were similar and significantly different from other mushrooms. These two samples indicated the same TLC chromatograms by showing prominent bands of 1 − 4 when observed under UV 254 nm and having sharp aldehyde proton signals of 3-carboxaldehyde indole type in ¹H-NMR spectra. From LC-MS analyses, peaks of isolated compounds 1 − 4 and indole-3-carboxaldehyde (5) in TL663 extract and peaks of protocatechuic acid (6), caffeic aldehyde (7), caffeic acid (8) and 3,4-dihydroxybenzalacetone (9) phenolic acids in TL663 fraction were identified.

Graphical Abstract

Keywords:

• Tropicoporus linteus
• Sanghuang mushroom
• indole alkaloid
• phenolic acid
• wild mushroom
• chemical profile

Acknowledgement

This research project was financially supported by Mahasarakham University (grant year 2021). PS and CK acknowledge the Faculty of Sciences, Mahasarakham University (MSU), and Center of Excellence for Innovation in Chemistry (PERCH-CIC).

Author contributions

P. Seephonkai and C. Kaewtong shared corresponding authorship.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

Mahasarakham University 10.13039/501100007288.