Lipid-selective antioxidants and their preparation and use

A compound of the formula I

• (A).sub.a (L)(X).sub.a, (I)
• in which
• a and a' independently of one another are 1 or 2,
• A is an antioxidative component selected from the group consisting of
• A.sub.2 --an alkyl-substituted mono-, di- or triphenol radical ##STR63## in which m is 1 or 2,
• n is 1 or 2, and
• m+n is 3 or 4,
• R.sup.1 is the same or different and is an alkyl radical or an alkoxy radical and the total number of carbon atoms of the alkyl and alkoxy radicals is a maximum of 8,
• A.sub.3 --a reductone radical ##STR64## in which R.sup.2 is H or a lower alkyl radical and
• R.sup.3 is H, COOR.sup.4 or CH.sub.2 OR.sup.4
• in which
• R.sup.4 is H or a lower alkyl radical,
• A.sub.4 --a 1,2-dithiacycloalkyl or 1,2-dithiacycloalkenyl radical having 2-6carbon atoms in the ring or the dithiol form of these radicals which has been reduced by hydrogenation, and
• A.sub.5 --an ascorbic acid radical or derivative thereof ##STR65## in which E is O, S or NR.sup.9
• R.sup.5 is H, EH, EQ or Q
• R.sup.6 is H, EH, EQ--(L--X.sub.1) or Q--(L--X.sub.1)
• R.sup.7 is H, EH, EQ, Q or one of the radicals defined above as A.sub.2 or A.sub.3
• R.sup.8 is H, EH, Q--(L--X.sub.1) or --PO(OR.sup.9).sub.2,
• R.sup.9 is a lower alkyl radical or Q,
• and only one or two of the radicals R.sup.5 -R.sup.9 are identical to Q or contain Q,
• L is a bridging member as defined below and
• X.sub.1 is a lipophilic component as defined below;
• L is a bridging member composed of one or more of the building blocks of the following formulae ##STR66## in which R.sup.10, R.sup.11 and R.sup.12 are H, a lower alkyl radical or Q, or in which
• R.sup.11 is --CO.sub.a R.sup.10 wherein a is 1 or 2,
• and 2 radicals selected from the group consisting of --O--, --S-- and --NR.sup.10 -- are separated from one another by at least one carbon or phosphorus atom;
• and
• X is a lipophilic component selected from the group consisting of
• X.sub.1 --a cholane derivative radical, of the following formula ##STR67## in which R.sup.13 is sec. C.sub.4 H.sub.9, R.sup.11 as defined in L or Q,
• E is O, S, NR.sup.10 as defined in L, .alpha.,.beta.-OH, H or .alpha.,.beta.-Q, H and a double bond can be present in the 4,5- or 5,6- or 7,8-position, and
• X.sub.2 --an alkyl or cycloalkyl radical or a fatty acid derivative radical having up to 24 carbon atoms and Q in all the above formulae represents a free valency (covalent single bond).