Potent, specific and reversible inhibitor of Golgi BFA resistance factor 1 (GBF1), an ArfGEF, that decreases Arf1 activation in vivo. Arrests secretion of soluble and membrane-associated proteins at the endoplasmic reticulum-Golgi intermediate compartment. Causes disassembly and dispersal of the Golgi and trans-Golgi network. Purity 98%. MW (observed): 284.3