Patent ID: 7662976

Claim:
A compound having the structure I: where X 1 is OH or OR 1 , and X 2 and X 3 are independently OH, OR 1 or H, with the proviso that at least one of X 1 , X 2 and X 3 is OR 1 , and at least one of X 2 and X 3 is H; and OR 1 is O—(C═O)-Z, where Z is selected from the group consisting of: —OR 2 , —O—Y—(C═O)—OR 3 , —O—Y—NR 4 R 5 , —NR 4 R 5 , —NR 3 —Y—(C═O)—OR 3 , and —NR 3 —Y—N 4 N 5 ; wherein Y is a divalent alkyl, alkenyl or alkynyl group having up to six carbon atoms; R 2 is selected from alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, hydroxyalkyl, alkoxyalkyl, aryloxyalkyl, and acyloxyalkyl; each R 3 is independently selected from hydrogen and R 2 ; and R 4 and R 5 are independently selected from hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl, aryl, aralkyl, hydroxyalkyl, alkoxyalkyl, aryloxyalkyl, and acyloxyalkyl, or R 4 and R 5 taken together form a 5- to 7-member heterocyclic ring whose ring atoms are selected from the group consisting of carbon, nitrogen, oxygen and sulfur, wherein said ring atoms include at most 3 heteroatoms.