A tanshinone IIA derivative with immunomodulatory activity; reduces CSE-induced secretion of IL-6 and IL-8 and prevents CSE-induced decreases in CFTR levels in 16HBE cells; reduces lung function decline, mucus production, bronchial collagen deposition, and airspace enlargement in a mouse model of CS-induced COPD at 5 mg/kg; reduces myocardial necrosis and production of TNF-α and IL-6 in a mouse model of CLP-induced sepsis at 15 mg/kg; reduces the number of peripheral CD4+ and CD8+ T cells and prolongs allogeneic skin graft survival in a rat transplantation model.