Triacylglycerols characteristic of porpoise acoustic tissues: molecular structures of diisovaleroylglycerides.

More than two-thirds of the triacylglycerols from the acoustic tissues of the porpoise (Tursiops gilli) consist of 2 moles of isovaleric acid for every 1 mole of long-chain acids. Cranial blubber, which has no distinct acoustic function, does not contain these unusual glycerides. The presence of large amounts of diisovaleroylisopentadecanoylglycerol suggests that this structure may be particularly important in sound transmission through lipid-protein matrices.