Abstract
Bioassay guided fractionation of the ethanolic extract of
Asphodelus microcarpus
Salzm. et Viv. (Xanthorrhoeaceae or Asphodelaceae) resulted in isolation of five compounds identified as asphodosides A-E (
1
–
5
). Compounds
2
–
4
showed activity against methicillin resistant
Staphylococcus aureus
(MRSA) with IC
50
values of 1.62, 7.0 and 9.0 μg/mL, respectively. They also exhibited activity against
Staphylococcus aureus
(non-MRSA) with IC
50
values of 1.0, 3.4 and 2.2 μg/mL, respectively. The structure elucidation of isolated metabolites was carried out using spectroscopic data (1D and 2D NMR), optical rotation and both experimental and calculated electronic circular dichroism (ECD).