The ethanolic extract of Aloe barbadensis Miller leaf skin showed inhibitory activity against
phosphodiesterase-4D (PDE4D), which is a therapeutic target of inflammatory disease.
Subsequent bioassay-guided fractionation led to the isolation of two new anthrones, 6′-Oacetyl-
aloin B (9) and 6′-O-acetyl-aloin A (11), one new chromone, aloeresin K (8), together with
thirteen known compounds.