Compositions and methods for inhibiting ribosome inactivating proteins

A method of treating or ameliorating toxicity caused by a ribosome inactivating protein (RIP) in a subject, the method comprising administering to the subject a therapeutically effective amount of a compound of Formula (I), or a salt, solvate, stereoisomer, geometric isomer, or tautomer thereof:

• wherein:
• R1 is optionally substituted aryl,
• wherein each optional substituent comprises at least one substituent selected from the group consisting of C1-C6 alkyl, C1-C6 cycloalkyl, C1-C6 alkoxy, halogen, hydroxyl, NRa2, C(O)—C1-C6 alkyl, CN, CF3, NO2, and C(O)-aryl,
• wherein two adjacent optional C1-C6 alkyl or C1-C6 alkoxy substituents may optionally combine to form a 5 or 6-membered fused ring;
• R2 is selected from the group consisting of
• each occurrence of Ra is independently selected from the group consisting of H, C1-C6 alkyl, C1-C6 alkoxy, benzyl, and aryl;
• Rb is selected from the group consisting of H, C1-C6 alkyl, C1-C6 alkoxy, benzyl, aryl, hydroxyl, and C1-C6 hydroxyalkyl;
• X1 is selected from the group consisting of S and O;
• and
• X2 is CH, N, or C, wherein if X2 is C, the optionally substituted aryl in R1 combines with X2 to form a 5, 6, or 7-membered fused ring.