Patent ID: 7700644

Claim:
A compound of the general formula (I): wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 are independently hydrogen, hydroxy, OR 9 , OC(O)H, OC(O)R 9 , OSi(R 10 ) 3 , C(O)R 11 , CO 2 R 12 , alkyl, haloalkyl, cycloalkyl, aryl, arylalkyl, thiol, alkylthio, amino, alkylamino, dialkylamino, nitro, cyano or halo, R 9 is alkyl, haloalkyl, aryl, arylalkyl or alkylaryl, R 10 is independently hydrogen, alkyl or aryl, R 11 is hydrogen alkyl, aryl, arylalkyl or an amino acid, R 12 is hydrogen, alkyl, haloalkyl, aryl or arylalkyl, and X is O, which compounds may be optionally substituted or a pharmaceutically acceptable salt thereof.