New Phenanthrene Derivatives and a Flavonoid Glycoside Dihexanoate From Malpighia glabra

Five previously undescribed compounds, including four rare phenanthrene derivatives, designated as malglabins A–D ( 1 – 4 ), and an unusual flavonoid glycoside dihexanoate, named kaempferol 3‐ O ‐(3′′,4′′‐di‐ O ‐caproyl)‐ α ‐L‐rhamnopyranoside ( 5 ), along with 12 known compounds, were isolated from the leaves and twigs of Malpighia glabra . Their structures (Figure 1) were elucidated through comprehensive spectroscopic analysis (high‐resolution electrospray ionization mass spectrometry and one‐/two‐dimensional nuclear magnetic resonance) complemented by chemical derivatization study and electronic circular dichroism calculations. In biological evaluations, compounds 3 and 4 exhibited weak cytotoxicity against A549 human lung adenocarcinoma cells (IC 50 = 34.71 ± 0.48 and 30.66 ± 0.67 µM, respectively), while none of the tested compounds demonstrated anti‐inflammatory activity in lipopolysaccharide‐stimulated RAW264.7 macrophages at concentrations up to 50 µM.