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. 2022 Mar 31;20(4):246. doi: 10.3390/md20040246

Table 2.

FT-IR characteristic peaks and assignments. Letters (A to V) refer to bands shown on Figure 5.

Wavenumber (cm−1) Assignment Reference Ps Ec Em To Nc Cj Co Rb Bs Rs Cr
A 3200–3400 OH stretching [30] 3309 3305 3306 3350 3358 3290 3301 3329 3318 3340 3303
B 2950–2960 CH3 stretching [30] nd nd nd nd nd nd nd nd 2954 2954 2953
C 2920–2930 CH2 stretching [30] 2923 2927 2927 2928 2924 2923 2923 2925 2923 2925 2924
D 2870–2880 CH3 stretching [30] nd nd nd nd nd nd 2873 2873 2871 2875 2875
E 2845–2855 CH2 stretching [30] 2855 nd nd nd 2845 2852 2852 2848 2854 2854 2854
F 1725–1740 O-Ac [38] 1730 nd 1725 1726 1730 1726 nd nd nd nd nd
G 1630–1660 C=O [47] 1640 1640 1638 1650 1641 1638 1648 1641 1638 1633 1639
H 1585–1605 COO− stretching [32,33,34] 1599 1596 1597 1605 1605 1599 nd nd nd nd nd
I 1525–1540 amide II (proteins) [30] 1536 1536 1537 1535 1536 1536 1542 1531 1535 1536 1535
J 1455–1470 CH3 bending [30] 1460 1461 1461 1458 1461 1461 1459 nd nd nd 1460
K 1400–1420 COO− stretching [31,32,33] 1414 1414 1414 1413 1415 1413 1412 1409 1413 1414 1414
L 1340–1350 CH bending [30] 1352 1354 1355 1355 1358 1353 1346 1353 1354 1353 1348
M 1245–1255 S=O [36,37] 1242 1246 1251 1245 1247 1247 1252 1252 1255 1257 1257
N 1240–1250 O-Ac [9]
O 1215–1225 S=O [35] 1211 nd nd 1213 1216 nd 1221 1221 1217 1217 1215
P 1135–1145 C-O-C [31] 1143 1145 1143 1138 1144 1146 1149 1152 1144 1143 1142
Q 1165–1075 C-OH [31] 1068 1076 1074 1075 1068 1080 1075 1072 1075 1068 1071
R 1020–1030 C-C [31] 1031 1030 1031 1025 1020 1036 1025 1023 1030 1025 1020
S 980–985 C-H [30] 980 975 977 977 979 980 985 nd 975 nd nd
T 925–935 C-O-C (AnGal) [45] nd nd nd 923 nd nd 933 932 934 nd nd
U 890–900 β linkage [46] 897 894 894 nd 898 895 nd 891 nd nd nd
V 840–850 α linkage [46] nd nd nd 845 nd nd 850 847 843 851 852

nd: peak can’t be detected and assigned. It can be present but masked by another closed peak. Ps: Porphyridium sordidum, Ec: Erythrolobus coxiae, Em: Erythrolobus madagascarensis, To: Timspurckia oligopyrenoides, Nc: Neorhodella cyanea, Cj: Corynoplastis japonica, Co: Chroodactylum ornatum, Rb: Rhodaphanes brevistipitata, Bs: Bangiopsis subsimplex, Rs: Rhodospora sordida, Cr: Chroothece richteriana.