Table 3 Absorption peak frequency data from FTIR spectrum of the chloroform leaf extract of Vernonia amygdalina
S/no. | Absorption frequency (cm−1)* | Chemical bond (s)** | Ref [45] | Putative class of compounds |
|---|---|---|---|---|
1 | 3442.93 | O–H, broad; non-phenolic, SV | 3300–3700 | Alcohols in steroids, sugars (glucosides) |
2 | 3009.50 | sp2 C‒H, Vinylic; epoxy ring, SV |  | Alkene, epoxy |
3 | 2918.81 | sp3 C–H, SV | 2700–3000 | CH2, Methylene grp |
4 | 2849.78 | sp3 C–H, SV | 2700–3000 | CH2, Methylene grp |
5 | 1731.30 | C = O; unsaturated ester, SV | 1715–1730 | Carbonyl |
6 | 1712.43 | C = O; conjugated ester, SV |  | Carbonyl |
7 | 1649.50 | C = C; unconjugated; weak | 1640–1680 | Alkene |
8 | 1619.20 | C = C; conjugated | 1620–1670 | Alkene |
9 | 1492.00 | C–H, deformation, BV |  |  |
10 | 1453.75 | C–H, deformation; BV |  | CH2 |
11 | 1161.80 | C–O; ester, lactone, SV |  |  |
12 | 1046.70 | C–O; alcohol, SV | 1000–1050 | 1050–1150 |