ABSTRACT
<p><b>AIM</b>To study the inhibition of oxygen consumption by annonaceous acetogenins (ACG) and their structure-activity relationship (SAR).</p><p><b>METHODS</b>The inhibition of oxygen consumption in chicken liver cell respiration by different structural ACG was studied by using oxygen electrode technique.</p><p><b>RESULTS</b>Six ACG showed potent inhibitory effects like rotenone which was a classical inhibitor of mitochondrial complex I, and was more potent than complex IV inhibitor KCN. The IC50 values of six ACG for inhibiting oxygen consumption suggested that bistetrahydrofuran (THF) ACG was 7-11 times more active than non-THF ACG, and A1-type ACG was more potent than A2-type ACG.</p><p><b>CONCLUSION</b>The terminal gamma-lactone was crucial for the inhibition of oxygen consumption. The distance between THF and gamma-lactone, the hydroxyl groups in the alkyl chain, were the important factors of SAR, but the 4-OH group possibly played some negative role in the exhibit of potent activity.</p>