TLC ( ethyl acetate / n - hexane = 1 : 2 ) Rf = 0 . 29 , mp : 256 - 258 ℃, HPLC purity : 99 . 3 %; ESI LC / MS : m / z calcd for C 24 H 18 NO [ MH ] + 336 . 14 ; found 336 . 35 . 1 H NMR ( 250 MHz , DMSO - d 6 ) δ 9 . 80 ( s , 1 H , indenopyridine 7 - OH ) , 8 . 24 ( d , J = 8 . 12 Hz , 2 H , 2 - phenyl H - 2 , H - 6 ) , 7 . 88 ( d , J = 8 . 4 Hz , 1 H , indenopyridine H - 9 ) , 7 . 84 ( d , J = 8 . 0 Hz , 2 H , 4 - phenyl H - 2 , H - 6 ) , 7 . 76 ( s , 1 H , indenopyridine H - 3 ) , 7 . 58 - 7 . 40 ( m , 6 H , 4 - phenyl H - 3 , H - 4 , H - 5 , 2 - phenyl H - 3 , H - 4 , H - 5 ) , 7 . 03 ( s , 1 H , indenopyridine H - 6 ) , 6 . 90 ( d , J = 8 . 27 Hz , 1 H , indenopyridine H - 8 ) , 4 . 01 ( s , 2 H , indenopyridine H - 5 ) . 13 C NMR ( 62 . 5 MHz , DMSO - d 6 ) δ 161 . 03 , 159 . 06 , 155 . 68 , 146 . 86 , 145 . 56 , 139 . 38 , 138 . 41 , 132 . 27 , 131 . 91 , 129 . 10 ( 3 C ) , 128 . 99 , 128 . 90 ( 3 C ) , 128 . 63 ( 2 C ) , 126 . 99 , 121 . 92 , 116 . 33 , 115 . 09 , 112 . 27 , 34 . 14 .