UbcH5c-IN-1 (compound 6d) is a potent and selective small-molecule inhibitor of Ubiquitin-conjugating enzyme UbcH5c, with a Kd of 283 nM for E2 UbcH5c-IN-1 by covalent binding with Cys85. A promising lead compound for the development of new antirheumatoid arthritis (RA) agent. UbcH5c-IN-1 (compound 6d) (5 and 20 mg/kg, p.o., daily, 10-20 days) treatment in Freund's adjuvant (CFA)-induced adjuvant arthritis (AA) rat model results in appreciable decreases in the arthritis index score and hind paw swelling rate compared with those of the vehicle-treated AA model control group.|| Animal Model:|Freund's adjuvant (CFA)-induced adjuvant arthritis (AA) rat model.|Dosage:|5 and 20 mg/kg|Administration:|Oral administration daily between day 10-20 postimmunization.|Result:|Resulted in appreciable decreases in the arthritis index score and hind paw swelling rate compared with those of the vehicle-treated AA model control group.