LIPIDS OF COMMON HOUSE CRICKET ACHETA DOMESTICUS L .3. STEROLS

Sterols constitute 1.95% of the total extractable lipids of Acheta domesticus L., of which 18% are esterified. The free sterols consist of cholestane-3β-ol (0.5%), Δ5-cholestene-3β-ol (83.5%), Δ7-cholestene-3β-ol (2.3%) Δ5,7-cholestadiene-3β-ol (3%), Δ5,22-cholestadiene-3β-ol (4%), Δ5,7,22-cholestatriene-3β-ol (0.2%), campestane-3β-ol (0.03%), Δ5-campestene-3β-ol (1.0%), Δ7-campestene-3β-ol (trace), Δ5,7-campestadiene-3β-ol (0.2%), stigmastane-3β-ol (0.09%), Δ5-stigmastene-3β-ol (2.1%), Δ7-stigmastene-3β-ol (0.04%), Δ5,7-stigmastadiene-3β-ol (0.4%), Δ5,22-stigmastadiene-3βol (0.1%). The same sterols are present in the esterified sterol fraction. Δ7-Sterols and Δ5,7-sterols are present in significantly larger amounts in the esterified fraction than in the free sterol fraction. By a comparison with the sterols of the cricket food, it is clear that A. domesticus is capable of removing methyl and ethyl groups from C-24 of sterols of the campestane and stigmastane type. The ability to introduce a Δ7 double bond into saturated and Δ5-sterols is indicated, and it is suggested that Δ7-sterols of the C27, C28, and C29 sterol series may be intermediates in the conversion of Δ5-sterols to Δ5,7-sterols. © 1968 American Oil Chemists' Society.