There is provided an isoprenoid according to the general formula (I) wherein R1 and R2 are independently selected from H and alkyl; and R3, R4, R5 and R6 are independently selected from groups of the general formula (II) and (III) wherein R7 and R8 each represent a group of general formula CO—R9, in which each R9 is independently selected from H, OH, alkyl and alkoxy groups, or R7 and/or R8 present in R3 and R4 and/or in R5 and R6 combine to form a group of the general formula (IV) wherein R10 is selected from OH and alkoxy; or salts thereof. The isoprenoids are of particular use in the preparation of liposomes, for use in the delivery of pharmaceutically active components to a subject human or animal.