1 H NMR ( 400 MHz , DMSO - d 6 ) δ ppm 0 . 92 - 1 . 28 ( m , 17 H ) , 1 . 97 ( s , 2 H ) , 4 . 04 - 4 . 16 ( m , 1 H ) , 4 . 20 - 4 . 51 ( m , 3 H ) , 4 . 71 - 4 . 93 ( m , 2 H ) , 5 . 82 ( br s , 1 H ) , 5 . 95 - 6 . 14 ( m , 2 H ) , 7 . 11 - 7 . 28 ( m , 3 H ) , 7 . 31 - 7 . 43 ( m , 2 H ) , 7 . 75 - 8 . 21 ( m , 1 H )