TLC ( ethyl acetate / n - hexane = 1 : 1 ) Rf = 0 . 34 , mp : 275 - 277 ℃, HPLC purity : 97 . 9 %; ESI LC / MS : m / z calcd for C 24 H 18 NO 2 [ MH ] + 352 . 13 ; found 352 . 30 . 1 H NMR ( 250 MHz , DMSO - d 6 ) δ 9 . 83 ( br , 2 H , indenopyridine 6 - OH , 4 - phenyl 4 - OH ) , 8 . 24 ( d , J = 8 . 5 Hz , 2 H , 2 - phenyl H - 2 , H - 6 ) , 7 . 82 ( s , 1 H , indenopyridine H - 3 ) , 7 . 74 ( d , J = 8 . 6 Hz , 2 H , 4 - phenyl H - 2 , H - 6 ) , 7 . 55 ( d , J = 7 . 4 Hz , 1 H , indenopyridine H - 9 ) , 7 . 54 - 7 . 40 ( m , 3 H , 2 - phenyl H - 3 , H - 4 , H - 5 ) , 7 . 31 ( t , J = 7 . 6 7 Hz , indenopyridine H - 8 ) , 6 . 95 ( d , J = 8 . 6 Hz , 2 H , 4 - phenyl H - 3 , H - 5 ) , 6 . 89 ( d , J = 7 . 9 Hz , 1 H , indenopyridine H - 7 ) , 3 . 95 ( s , 2 H , indenopyridine H - 5 ) . 13 C NMR ( 62 . 5 MHz , DMSO - d 6 ) δ 160 . 76 , 158 . 30 , 155 . 75 , 154 . 10 , 145 . 99 , 142 . 39 , 139 . 32 , 132 . 43 , 130 . 04 , 129 . 99 , 128 . 88 ( 2 C ) , 128 . 78 ( 2 C ) , 128 . 63 ( 2 C ) , 126 . 93 ( 2 C ) , 117 . 07 , 115 . 81 ( 2 C ) , 115 . 52 , 111 . 90 , 31 . 93 .