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.
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.