Patent ID: 8541458

Claim:
A compound having the structure wherein bond αis present or absent; R 1 and R 2 is each independently H, O − O or OR 9 , where R 9 , is H, alkyl, alkenyl, alkynyl or aryl, or H 1 and R 2 , together are ═O; R 3 is OH R 4 is R 5 and R 6 is each independently H, OH, or R 5 and R 6 taken together are ═O; and R 7 and R 8 is each independently H, F, Cl, Br, SO 2 Ph, CO 2 CH 3 , or SR 13 , where R 13 is H, aryl or a alkyl, alkenyl or alkynyl, or a salt or enantiomer of the compound.