Table 5.

FT-IR Spectral Assignments For Samples Of Synthetic Saliva And Human Saliva

Artificial Saliva	Human Saliva	Assignment	Components Of Saliva And Reference
Wavenumbers (cm−1)	Wavenumbers (cm−1)
515	517	Out of plane C=O bending	Amide VI52
696	–	OCN bending	Amide IV52
772	–	Out of plane NH bending	Amide V52
1054	1055	Stretching vibrations C-OH and stretching vibrations in carbohydrate structure of C-C	Sugar moieties of glycosylated proteins, including α-amylase53,54
-	1238	C-N stretching	Amide III52,54–57
1285	-	C-N stretching	Amide III52,54–57
1317	-	CH2 vibration of α-anomer	Carbohydrates58
-	1393	CH3 symmetric bending and C=O stretch of COO−	Proteins and lipids59–61
-	1535	N-H bending	Proteins (Amide II)54–56
1595	-	N-H bending	Proteins (Amide II)52,54–56
-	1633	C=O stretching	Proteins (Amide I)54–58
1689	-	C=O stretching	Proteins (Amide I)52,54–58
-	2052	Thiocyanate (SCN−) anions	Product of detoxication of CN− acquired with food54,62,63
2879	2872	Symmetric vibration of C-H	Lipids, proteins54,64
2916	2918	Asymmetric vibration of C-H	Lipids, proteins54,64
-	3275	Asymmetric stretching of N-H and vibrations of O-H	Proteins, Amide A54–56
3377	-	Stretching vibrations of O-H and asymmetric stretching of N-H	Proteins, Amide A58,64

Abbreviations: FT-IR, Fourier Transform Infrared Spectroscopy; C, carbon; O, oxygen; N, nitrogen; H, hydrogen; cm, centimetre.