Patent ID: 8039668

Claim:
A compound having structure A, or a pharmaceutically acceptable salt thereof: wherein: each R is independently C(O)NHX; and X is (C 1 -C 6 )alkyl, substituted (C 1 -C 6 )alkyl, (C 3 -C 8 )cycloalkyl, substituted (C 3 -C 8 )cycloalkyl, aryl, substituted aryl, (C 1 -C 6 )alkylaryl, substituted (C 1 -C 6 )alkylaryl, wherein each X substituent is independently substituted or unsubstituted (C 1 -C 6 )alkyl, trifluoromethyl, halogen, substituted or unsubstituted phenyl or phenoxy.