New Butenolides and Cyclopentenones from Saline Soil-Derived Fungus <i>Aspergillus Sclerotiorum</i>

Abstract

Three new γ-hydroxyl butenolides (1−3), a pair of new enantiomeric spiro-butenolides (4a and 4b), a pair of enantiomeric cyclopentenones (5a new and 5b new natural), and six known compounds (6−11), were isolated from Aspergillus sclerotiorum. Their structures were established by spectroscopic data and electronic circular dichroism (ECD) spectra. Two pairs of enantiomers [(+)/(−)-6c and (+)/(−)-6d] obtained from the reaction of 6 with acetyl chloride (AcCl) confirmed that 6 was a mixture of two pairs of enantiomers. In addition, the X-ray data confirmed that 7 was also a racemate. The new metabolites (1−5) were evaluated for their inhibitory activity against cancer and non-cancer cell lines. As a result, compound 1 exhibited moderate cytotoxicity to HL60 and A549 with IC50 values of 6.5 and 8.9 µM, respectively, and weak potency to HL-7702 with IC50 values of 17.6 µM. Furthermore, compounds 1−9 were screened for their antimicrobial activity using the micro-broth dilution method. MIC values of 200 μg/mL were obtained for compounds 2 and 3 towards Staphylococcus aureus and Escherichia coli, while compound 8 exhibited a MIC of 50 μ/mL towards Candida albicans.

Keywords

• <i>Aspergillus sclerotiorum</i>
• γ-hydroxyl butenolides
• cyclopentenones
• enantiomer
• cytotoxicity
• antimicrobial activity