The present invention relates to diuretic pharmaceutical compositions and methods and in particular to certain derivatives of the formula I wherein R1, R2, R3, R5, R6 and R7 are independently X3R where R is selected from the group consisting of H, halo; optionally substituted saccharide, aliphatic, cycloalkyl, heterocycloalkyl, aryl and heteroaryl; —P(O)(ORa)(ORb) and —NRaRb, where Ra and Rb are independently H, optionally substituted aliphatic, cycloalkyl, heterocycloalkyl, aryl or heteroaryl; X1, X2 and X3 are independently —C(O)O—, —OC(O)—, —C(O)NH—, —NHC(O)—, —OC(O)NH—, —NHC(O)O—, —OS(O)y—, —S(O)y—, —O—, —NHC(O)—, —NHC(O)O—, —S(O)2NH—, a bond or absent; where y is an integer from 0 to 3; and R4 and R8 are independently H, (═O); hydroxy; or optionally substituted saccharide, aliphatic, cycloalkyl, heterocycloalkyl, aryl or heteroaryl; or —P(O)(ORa)(ORb) or —NRaRb, where Ra and Rb are independently H, or optionally substituted aliphatic, cycloalkyl or heterocycloalkyl, aryl or heteroaryl; or a prodrug or pharmaceutically acceptable salt thereof; and a pharmaceutically acceptable carrier.