triterpene glycosides 1-O-alkylglyceryl ether 3D culture Asteroidea Bohadschia argus Chemistry Holothuria (Theelothuria) spinifera Holothuroidea NMR spectra Psolus chitonoides Pteraster marsippus Research & information: general Thyonidium kurilensis anticoagulant activity biological activity bêche-de-mer ceramides cerebrosides chitonoidosides cytotoxic activity diacylglycerol ether disulfated steroids fucan sulfates fucosylated chondroitinsulfates gangliosides hemolytic kurilosides lipids mass spectrometry