Wavenumber (cm−1)

Functional Group Assignments

2957

CH3asym stretching (mainly lipids)

2922

CH2asym stretching (mainly lipids)

2873

CH3sym stretching (mainly proteins)

2852

CH2sym stretching (mainly lipids)

1710, 1733

C=O carbonyl stretching of saturated aliphatic esters

1630

Amide I (protein C=O stretch)

1555

Amide II (C-N, N-H stretching) mainly proteins

1415

O-H bending, polysaccarides

1377

Symmetric bending of aliphatic CH3, triterpene compounds (CH2=CH-CH3)

1250

Pectic substances

1235

Amide III (C-N, N-H stretching) mainly proteins

1145

Cellulose (b-glucan),

triterpene compounds (C-O)

1101

Antisym in-phase, pectic substances

1073

Rhamnogalactorunan, b-galactan

1064

C-O stretching , polysaccharides (glucomannan)

1035

OH and C-OH stretching in sugars, polysaccharides (arabinan)