Patent ID: 6989434

Claim:
A lipophilic polyamino acid of the formula: and salts thereof, where: Z 1 and Z 2 , independently of one another, are both amino acids selected from the group consisting of ornithine, lysine, arginine and histidine; n is an integer ranging from 1 to about 2,000; A 1 and A 2 , independently of one another, are selected from the group consisting of the groups X 1 –X 4 as follows: X 1 is a straight-chain alkyl, alkenyl, or alkynyl group having from 2 to about 22 carbon atoms wherein one or more non-neighboring —CH 2 — groups can be replaced with an O or S atom; X 2 is a branched alkyl, alkenyl, or alkynyl group having from 2 to about 22 carbon atoms wherein one or more non-neighboring —CH 2 — groups can be replaced with an O or S atom; X 3 is a straight-chain or branched alkyl group substituted with one or two OH, SH, NH 2 or amine groups within about 3 carbon atoms of the bond between X 3 and Z; X 4 is a substituted straight-chain or branched alkyl, alkenyl or alkynyl group having from 2 to about 22 carbon atoms wherein the substituent is an aromatic, alicyclic, heterocyclic or polycyclic ring and wherein one or more of the non-neighboring —CH 2 — groups of said alkyl, alkenyl or alkynyl group can be substituted with an O or S atom; and the termini of the polyamino acid are an NH 2 and a OH.