About the structure and biological function of CL Structure. Cardiolipins (Ptd2Gro, or CL) belong to the group of diphosphatidylglycerols within the phospholipids. Their structure consists of two diacylglycerophosphates linked to each other via a third glycerol backbone. In total, cardiolipins contain four ester-linked fatty acids. They can be of variable length, hydroxylated, and contain double … Continue reading Cardiolipin