Calyceramides A–C: neuraminidase inhibitory sulfated ceramides from the marine sponge Discodermia calyx

Three new sulfated ceramides, calyceramides A–C (1–3) were isolated as inhibitors of neuraminidase from the marine sponge Discodermia calyx. Their structures were determined by spectroscopic and chemical methods. The ceramides inhibited neuraminidase with IC50 values of 0.2–0.8 μg mL−1.