Patent ID: 7365221

Claim:
A compound of Formula I: or a pharmaceutically acceptable salt thereof, wherein: R 1 is one of: (i) —C(O)CH 2 CR′R″(CH 2 ) b COOH, (ii) —C(O)(CH 2 ) d CR′R″(CH 2 ) b COOR 5 , or (iii) —C(O)CH 2 O(CH 2 ) a COOH wherein when R 1 is (i), R′ and R″ are each C 1 -C 4 alkyl, or R′ and R″ are taken together to form a di-, tri-, tetra-, penta-, hexa-, or heptamethylene linkage, and when R 1 is (ii), R′ and R″ are each C 1 -C 4 alkyl, or R′ is hydrogen and R″ is C 1 -C 4 alkyl, or R′ and R″ are taken together to form a di-, tri-, tetra-, penta-, hexa-, or heptamethylene linkage; R 5 is C 1 -C 6 alkyl or C 1 -C 6 carboxyalkyl, a is from zero to twelve, b is from zero to twelve, d is from zero to twelve; R 2 is hydrogen, halogen, hydroxyl or —OR 3 ; R 3 is C 2 -C 20 substituted or unsubstituted carboxyacyl; and R 4 is hydrogen or C(C 6 H 5 ) 3 ; wherein the dashed line represents an optional double bond between C20 and C29.