Frondosins, five new sesquiterpene hydroquinone derivatives with novel skeletons from the sponge Dysidea frondosa: Inhibitors of interleukin-8 receptors

Abstract

Abstract Bioassay-guided fractionation of the EtOAc extract of the sponge Dysidea frondosa collected in Pohnpei yielded five sesquiterpenes, frondosins A - E ( 1–5 ). The structures and relative stereochemistry of the frondosins were established by interpretation of spectral data. Frondosins A - E ( 1–5 ), which possess novel carbon skeletons, were found to be inhibitors of interleukin-8 receptors and protein kinase C in the low micromolar range.