Derivatives of sesquiterpenes, 2-furaldehyde, phenols, and alkaloids isolated from Taraxacum mongolicum.

Four new compounds (1-4), together with 23 known compounds (5-27), were isolated from the whole plant of Taraxacum mongolicum. Among them, one racemic mixture (4) was separated with a chiral HPLC column. Their structures were identified by spectroscopic evidence and mass spectrometry. The absolute configurations of compounds 1, 3, and 4 were determined via comparison of their calculated and experimental electronic circular dichroism (ECD) spectra. Compound 3 showed an inhibitory effect against aldose reductase with a 59.1% inhibition. Two known compounds (13 and 27) showed α-glucosidase inhibition of 51.5% and 56.0%, respectively.