Viridaphin A1 glucoside, a green pigment possessing cytotoxic and antibacterial activity from the aphid Megoura crassicauda.

A green pigment, viridaphin A1 glucoside (1), was isolated from the green aphid Megoura crassicauda. One- and two-dimensional NMR spectrometric analyses of 1 and its aglycone established the structure as an octacyclic compound. Viridaphin A1 glucoside exhibited cytotoxicity against HL-60 human tumor cells with an IC50 of 23 µM and antibacterial activity against Bacillus subtilis NBRC 3134 with a minimum inhibitory concentration of 10.0 µg/mL. These results suggested that aphid pigments may protect aphids from invasive species, including viruses and bacteria.