Caerulines A and B, Flavonol Diacylglycosides from Persea caerulea .

Two undescribed 4'- O -methylkaempferol-[3″,4″-di- p -coumaroyl]-α-l-rhamnopyranosides, caerulines A and B ( 1-2 ), along with three known 4'- O -methylkaempferol diacylrhamnosides isomers ( 3-5 ) were isolated from an ethanol extract of the leaves of Persea caerulea , a native plant growing on the Colombian Caribbean coast. The chemical structures of 1 and 2 were elucidated by spectroscopic methods. The effect of compounds 1-5 against four pathogenic microorganisms [i.e., methicillin-resistant Staphylococcus aureus (MRSA), Acinetobacter baumannii , Candida albicans, and Aspergillus fumigatus ] was tested in vitro . The compounds exhibited no activity against these pathogens except MRSA (MIC 12-48 μg/mL). Caeruline B ( 2 ) was found to be the most active compound with a modest anti-MRSA activity (MIC = 12 μg/mL).