Résumé
Objective To investigate he diterpenoids from he roots of Illicium majus(Radix Illcii Maji) and their antiviral activity against the Coxsackie B virus. Methods The compounds were isolated by column chromatography over silica gel, octadecylsi-ane chemically bonded silica gel(ODS), and Sephadex HL-20 coupled with preparative HPLC. Their stuctures were elucidated by spectroscopic analysis and the in situ dimolybdenum circular dichroism(CD) method, and their antiviral activities against the Coxsackie B3 virus were evaluated by cytopathic effect(CPE) method. Results Twelve diterpenoids were isolated from the roots of Illicium ma-jus, which were identified as 4-epi-dehydroabietic acid(l), 8,11,13,15-abietatraen-19-oic acid(2), jiadifenoic acids B(3), C(4), G(5) and 1(6), majusanic acids B(7) and D(8), lambertic acid(9), angustanoic acids F(10) and G(ll), and 13-hydroxy-8,11, 13-podocarpatrien-19-oic acid(12). These diterpenoids displayed antiviral activity against the Coxsackie B3 virus, with IC50 values of 3. 3-66. 7 μmol/ml. Conclusion The antiviral activity and cytotoxicity of the diterpenoids relate o he substituent species and position. Compounds 3-6 and 9 were obtained from his plant for the first time.