Isolation and prepurification of active compounds in venom from Pelagia noctiluca (Scyphozoa: Pelagiidae) from the Caribbean Sea

Abstract

Crude extract from Pelagia noctiluca was purified using liquid chromatography. The isolated fractions were tested in sea crabs (Ocypode quadrata) and neurotoxic activity was observed. The protein content of the crude extract, quantified by the Bradford method, was 0.25 mg mL^–1. Polyacrylamide gel electrophoresis was used to determine the apparent molecular weight of the different fractions of the crude extract, and several bands were identified: 34, 48, and between 90 and 200 kDa. Haemolytic activity in human blood type A+ was 100% with 1.1 µg mL^–1 and 50% with 0.98 µg mL^–1 of crude extract. The crude extract was observed under a microscope and three types of nematocysts were found: heterotrichous microbasic eurytele, heterotrichous isorhiza, and holotrichous isorhiza.