Indazole compounds

1. A compound of formula (I):

wherein

each  independently is a double bond;

each of X 1 , X 4 , X 5 , X 6 , X 7 , X 8 , and X 9 , independently, is C, and each of X 2 and X 3 , independently, is N;

each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 , independently, is H, C 1 -C 10 alkyl, or COOR a , in which R a is H or C 1 -C 10 alkyl; and

R 2 is C 4 , C 7 , or C 8 cycloalkyl.

2. The compound of claim 1 , wherein R 1 is H a .

3. The compound of claim 1 , wherein the compound is