TLC ( ethyl acetate / n - hexane = 1 : 3 ) Rf = 0 . 29 , mp : 202 - 204 ℃, HPLC purity : 98 . 5 %; ESI LC / MS : m / z calcd for C 24 H 18 NO [ MH ] + 336 . 14 ; found 336 . 31 . 1 H NMR ( 250 MHz , DMSO - d 6 ) δ 9 . 54 ( s , 1 H , indenopyridine 8 - OH ) , 8 . 25 ( d , J = 7 . 27 Hz , 2 H , 2 - phenyl H - 2 , H - 6 ) , 7 . 86 - 7 . 84 ( m , 3 H , 4 - phenyl H - 2 , H - 6 , indenopyridine H - 30 , 7 . 59 - 7 . 42 ( m , 8 H , indenopyridine H - 9 , 4 - phenyl H - 3 , H - 4 , H - 5 , 2 - phenyl H - 3 , H - 4 , H - 5 , indenopyridine H - 6 ) , 6 . 88 ( dd , J = 8 . 1 , 2 . 27 Hz , 1 H , indenopyridine H - 7 ) , 3 . 99 ( s , 2 H , indenopyridine H - 5 ) . 13 C NMR ( 62 . 5 MHz , DMSO - d 6 ) δ 160 . 66 , 157 . 15 , 155 . 89 , 146 . 01 , 141 . 83 , 139 . 22 , 138 . 19 , 134 . 96 , 134 . 12 , 129 . 03 ( 3 C ) , 128 . 89 ( 3 C ) , 128 . 61 ( 2 C ) , 126 . 99 ( 2 C ) , 126 . 23 , 117 . 60 , 116 . 93 , 106 . 83 , 33 . 45 .