Abstract
Two novel enantiomers named (R)-ulodione A (1a) and (S)-ulodione A (1b) possessing a new 5/6–5 spiro skeleton and a related metabolite ulodione B (2) were isolated from the endolichenic fungus Ulospora bilgramii. Enantiomeric separation was achieved by HPLC on a chiral column. The structures and absolute configurations of ulodione A were elucidated by means of 1D and 2D NMR spectra, high-resolution electrospray ionization mass spectrometry (HRESIMS), X-ray diffraction (XRD), and electronic circular dichroism (ECD). The possible biosynthetic pathway for ulodione A was also postulated. Compounds 1a and 1b showed butyrylcholinesterase (BuChE) inhibitory activities, with IC50 values of 9.0 ± 0.1 and 9.3 ± 0.2 μM, respectively.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
