Anatomical distribution of sterols in oysters ( Crassostrea gigas )

Oysters ( Crassostrea gigas ) contain at least 8 predominant sterols as determined by gas liquid chromatography and a modified Liebermann‐Burchard reaction. These sterols and the average amount found in mg/100 are: C 26 ‐sterol (22‐ trans ‐24‐norcholesta‐5, 22‐diene‐3β‐ol), 19.1; 22‐dehydrocholesterol, 15.1; cholesterol, 46.8; brassicasterol, 27.2; Δ 5,7 ‐sterols (i.e., 7‐dehydrocholesterol) 22.5; 24‐methylenecholesterol 29.1; 24‐ethylcholesta‐5,22‐diene‐3β‐ol, 1.2; and 24‐ethylcholesta‐5‐en‐3β‐ol, 12.7. The distribution of these sterols appears uniform (r 2 =0.938) between 5 major organs of the oyster. The percent body mass vs percent total sterols in these 5 organs are: mantle 44.1–41.4; visceral mass 30.3–36.7; gills 13.2–11.7; adductor muscle 8.3–3.7; and labial palps 4.2–6.5. The possible sources of these sterols are discussed.