Ethers and thioethers of monosaccharides have been synthesised which show potent toxicity to mouse (LD50 > or = 4 g.kg-1 O.W. and 0.2 to 1.5 g.kg-1 I.P.W.). A study of calcium antagonist activity for the full series of compounds indicated that the activity was similar for both O- and S- ethers and maximum activities were observed for monoacetoneglucose ethers possessing carbon chain close to 8 carbons.

We have studied the effect of non-ionic tensioactive derivative, 3-O-alkyl 1,2,-O-isopropylidene alpha-D-glucofuranose (OR3MAG), on calcium transients and intramembrane charge movement from dissociated intercostal muscle of mice foetuses. The variation of intracellular calcium concentration was measured using the fluorescent Ca2+ indicator Fura-2, and intramembrane charge movement was recorded with the patch clamp technique. OR3MAG (30 mu M-600 mu M) added to the bath irreversibly inhibited the calcium transient evoked by electrical stimulation. Furthermore, OR3MAG immobilized intramembrane charge movement triggered by membrane depolarization in a dose-dependent manner. We suggest that OR3MAG reduces intramembrane charge movement required for signal transduction between the sarcolemma and the sarcoplasmic reticulum, thereby inhibiting the excitation-calcium release mechanism.