Abstract
Herpecaudin (3), a xanthine oxidase inhibitor with an unprecedented scaffold, was discovered from
Herpetospermum caudigerum seeds. The structure was determined by spectroscopic and X-ray single crystallographic
methods. A possible biogenetic pathway leading to herpecaudin is proposed, starting
from congeners 23,24-dihydrocucurbitacin E (1) and endecaphyllacin B (2), and involving retro-aldol cleavage as a key step. All three compounds proved to
be active and represent new scaffolds of non-purine analogue xanthine oxidase inhibitors.
Key words
Herpetospermum caudigerum
- Cucurbitaceae - Herpecaudin - xanthine oxidase inhibitor - retro-aldol reaction
- cucurbitane-type terpenoid