| 主权项 |
1. A compound of formula (I) or a pharmaceutically acceptable salt thereof, wherein A1 is selected from the group consisting of halogen, trifluoromethyl, and —OR1; A2 is selected from the group consisting of halogen, trifluoromethyl, and —OR2; X1 is selected from the group consisting of alkyl, —O—, —N(H)—, —S—, —S(═O)—, and —C(═O)—; A3 is selected from the group consisting of alkyl, aryl, cycloalkyl, cycloalkylalkyl, heterocycle, and heteroaryl; A4 is selected from the group consisting of hydrogen, halogen, alkyl, cyano, trifluoromethyl, aryl-heteroaryl wherein the aryl is substituted or unsubstituted, and —OR3; R1, R2 and R3 are each independently selected from the group consisting of hydrogen, alkyl, —SO3Rx1, —PO3Ry1Rz1, —C(═O)Ra, and -R4-G1; Rx1, Ry1 and Rz1, at each occurrence, are independently selected from the group consisting of hydrogen and a pharmaceutically acceptable cation; Ra is alkyl or —OH; R4, at each occurrence, is independently selected from the group consisting of a substituent comprising 1 to 10 carbon atoms, a substituent comprising 1 to 10 carbon atoms and optionally containing at least one nitrogen atom, a substituent comprising 1 to 10 carbon atoms and optionally containing at least one C═O group, and a substituent comprising 1 to 10 carbon atoms and optionally containing at least one nitrogen and/or at least one C═O group; and G1, at each occurrence, is independently selected from the group consisting of hydrogen and —ONO2; wherein at least one of R1, R2 and R3 is -R4-G1, and wherein at least one occurrence of G1 is —ONO2. |
