Homonuclear 2D 1H,1H COSY and 1H,1H TOCSY experiments showed connectivity of this proton to one and two other protons, respectively (Fig. In the event you beloved this information as well as you would like to acquire more details about china n-acetylneuraminic acid powder i implore you to stop by our internet site. S2). Signal 2, at 2.73 ppm, corresponds then to a proton neighboring a carbonyl on one side and at least two other protons on the other side with chemical shifts in the 3-4 ppm region.