The chemical constituents from the active fractions ofEleutherine bulbosawith their antimicrobial activity

Six compounds including three new polyketide ones named eleubosas A-C (1-3)were isolated from the active frations ofEleutherine bulbosa. Their structures were elucidated by extensive spectroscopic methods, including NMR, MS and IR spectroscopic analyses data. All the isolates were evaluated against three pathogenic bacteria,Staphylococcus aureus,Escherichia coli, andPseudomonas aeruginosa, and the results showed that compounds1and2displayed moderate inhibitory activities againstE. coliwith MIC values both 12.5 mu g/mL, which are consistent with the clinical applications and need further studies.