ChemInform Abstract: HORMINONE, TAXOQUINONE, AND OTHER ROYLEANONES OBTAINED FROM TWO ABYSSINIAN PLECTRANTHUS SPECIES (LABIATAE)

Diterpenoids with a novel 6/5-5 spiro tricyclic skeleton from Orthosiphon wulfenioides and their NLRP3 inflammasome inhibitory activity

“…Based on their structural features, 1-3 could plausibly be derived from a common precursor, royleanone, which was reported from two Abyssinian Plectranthus species. 33 Firstly, the allyl oxidation 34 and epoxidation 35 reactions could occur at C-7 and C-8/C-9 of royleanone, respectively. After epoxidation, intermediate a could undergo the Meinwald rearrangement to form the spiro ring intermediates b1 and b2 at the C-8 and C-9 positions, respectively, 36 as depicted in Scheme 1.…”