Patent ID: 8796249

Claim:
A compound of formula A: or a salt or solvate thereof, wherein: R 1 is hydrogen, hydroxy, substituted or unsubstituted alkyl, or halogen; R 2 is hydrogen or α-hydroxy; R 4 is substituted or unsubstituted alkyl or halogen; R 5 is hydrogen; R 6 is hydrogen; R 7 is hydrogen, substituted or unsubstituted alkyl, or hydroxy; R 11 is hydroxyl, OSO 3 H, OSO 3 − , OCOCH 3 , OPO 3 H, OPO 3 2− or hydrogen; R 12 is hydroxyl, OSO 3 H, OSO 3 − , OCOCH 3 , OPO 3 H, OPO 3 2− or hydrogen, or taken together R 11 and R 12 form a carbonyl; m is 0, 1, or 2; n is 0 or 1; o is 0 or 1; and p is 1, wherein m+n+o=3.