Tetranorsesquiterpenoids and Santalane-Type Sesquiterpenoids from Illicium lanceolatum and Their Antimicrobial Activity against the Oral Pathogen Porphyromonas gingivalis.

The methanol extract of the leaves of Illicium lanceolatum, indigenous to Fujian Province, People's Republic of China, was found to exhibit antimicrobial activity against the periodontal pathogen Porphyromonas gingivalis, and a bioassay-guided fractionation led to the isolation of two new compounds, 1 and 2, along with two known santalane-type sesquiterpenoids, 3 and 4. The structures of lanceolactone A (1) and lanceolactone B (2) were elucidated by analyzing their 2D NMR spectroscopic data. Compounds 1 and 2 were assigned as new tetranorsesquiterpenoids with a spiroacetal ring and tricyclic structure, respectively. Compound 3 (α-santal-11-en-10-one) showed potent antimicrobial activity against the oral pathogen P. gingivalis.