recently been discovered as a Toll-like Receptor 4 (TLR4) antagonist. However, the TLR4 antagonistic activity of DHA is modest and it exhibits cellular toxicity. In this work, the structure-activityrelationship (SAR) of DHA as TLR4 antagonist was explored. Since destroying the sesquiterpene endoperoxide scaffold substantially compromised the TLR4 antagonistic activity and molecular dynamics analysis