Abstract: Disclosed is a method of inhibiting hepatitis B infection by administering a therapeutically effective amount of a compound having the formula (Formula 1): ##STR1## wherein R1 is selected from the group consisting of H, lower alkanoyl, lower arylalkylacyl, arylacyl, and C-1-linked saccharide, and R2 is separately selected from the group consisting of H, lower alkyl, lower arylalkyl, aryl, and C-1-linked saccharide. The compounds may also be used to treat other conditions, such as inflammatory bowel disease, autoimmune diseases, transplant rejection, septic shock, and for protection against irradiation damage. Novel celastrol derivatives are also disclosed.