Two New Furanoeremophilanes from Senecio santelisis

From an Argentine collection of Senecio santelisis PHIL., the new furanoeremophilanoids, (10 beta H)6 beta-acetoxy-1 alpha-hydroxyfuranoeremophilan-9-one (1) and (10 beta H)-1 alpha-hydroxy-6 beta-(propanoyloxy)furanoeremophilan-9-one (2), together with the known (10 beta H)-6 beta-acetoxy-1 alpha-hydroxyfuranoeremophilan9-one (3), (10 beta H)-1 alpha,6 beta-diacetoxyfuranoeremophilan-9-one (4), and (10 alpha H)-1 alpha-hydroxy-6 beta-(propanoyloxy)furanoeremophilan-9-one (5) were isolated. Their structures and relative configurations were established on the basis of spectroscopic analysis. CHCl3 Extract and pure compounds were evaluated for their antifungal activity. Compound 5 exhibited remarkable mycelial growth inhibition against B. cinerea with an IC50 value of 21.4 mu g/ml.