Patent ID: 8685936

Claim:
A compound of the formula (I) and pharmaceutically acceptable salts thereof, wherein R 1 is H, Cl or F; R 2 is H or alkyl; m is 1 or 2; n is 1, 2, 3, 4 or 5; and each R 3 is independently H, â€”C(O)alkyl, â€”C(O)CH 2 CH 2 C(O)OH, R 4 , â€”C(O)NR 5 R 6 , â€”P(O)(OR 7 ) 2 or glucosyl, provided that at least one R 3 is not H, wherein R 4 is a natural or unnatural amino acid linked through the carboxyl moiety as an ester, R 5 is H or alkyl, R 6 is H or alkyl, and each R 7 is independently H or alkyl.