Predicting the positional distribution of docosahexaenoic and docosapentaenoic acids in aquatic animal triglycerides

The positional distribution of 22∶6 and 22∶5 in aquatic animal triglycerides can be predicted by simple proportionality equations of the typey=kx. The mole % 22∶6 at the 1, 2, or 3 position (y) is obtained by multiplying the proportionality constant for that position (k ₁,k ₂, ork ₃) times the mole % 22∶6 in the total triglycerides (x). For fish and invertebrate triglycerides,k ₁=0.28,k ₂=2.06, andk ₃=0.66. For marine mammal blubber triglycerides,k ₁=0.94,k ₂=0.22, andk ₃=1.84. The same equations apply to both 22∶6 and 22∶5.