Sesquiterpenes from the roots of Illicium oligandrum.

Two new sesquiterpenes, oligandrin (1) and oligandric acid (2), together with three analogues, tashironin A (3), tashironin (4), and oplodiol (5), were isolated from the roots ofIllicium oligandrum. The structures of new compounds were determined based on 1D and 2D NMR experiments and X-ray diffraction. Compound1represents a presumed biosynthetic precursor ofseco-prezizaane sesquiterpenes which consists of a novel 6/6/5 tricarbocyclic skeleton. Compound2is the first example of chamipinene-type sesquiterpene possessing a 6/4/6 tricyclic system from the genusIllicium. Compounds1–5were evaluatedin vitrofor their activity against coxsackie virus B3 (CVB3), influenza virus A/Hanfang/359/95 (H3N2), and influenza virus A/FM/1/47 (H1N1). Compound1showed selective antiviral activity against CVB3 with IC50value of 11.11 μM. [ABSTRACT FROM PUBLISHER]