New Na+,K(+)-ATPase inhibitors, sarcochromenol sulfates A [1], B [2], and C [3] and sarcohydroquinone sulfates A [4], B [5], and C [6], have been isolated from the sponge Sarcotragus spinulosus. Four of them (1, 4-6) and all six corresponding acetates 1a-6a have been isolated, and their structures have been established by spectral methods and chemical transformations.