Table 3.
The results of partial least squares (PLS) analysis on the wavenumbers, functional group, and vibration mode contribute to the antioxidant and α-glucosidase inhibitory activities.
| In Vitro Assay | Peak Code | Wavenumber (cm−1) | Functional Group | Vibration Mode |
|---|---|---|---|---|
| Antioxidant activity | A | 3606.638 | O–H | Stretching |
| B | 2945.009 | C–H | Stretching | |
| C | 2370.352 | O=C=O, N–H | Stretching | |
| D | 2345.2 | O=C=O | Stretching | |
| E | 1681.812 | C=O | Stretching | |
| F | 1527.517 | C=C (aromatic) | Stretching | |
| G | 1471.584 | O–H | Bending | |
| H | 1417.582 | –C–H (CH3) | Bending | |
| I | 1384.795 | C–O | Bending | |
| J | 1267.145 | C–O (OH, COOH) | Bending | |
| K | 1162.996 | C–C | Bending | |
| L | 1108.993 | C–O | Stretching (aliphatic of ether) | |
| M | 1083.92 | C–O | Stretching (secondary alcohol) | |
| N | 933.483 | –C–H (alkene) | Bending (trans disubtituen) | |
| O | 875.622 | –C–H (aromatic) | Bending | |
| P | 821.619 | –C–H (aromatic) | Bending (trisubtituen) | |
| Q | 784.974 | C–Cl | Bending | |
| R | 669.253 | C–X (halogen) | Halogen and aromatic disubtituen | |
| α-glucosidase inhibitory activity | A | 3170.755 | O–H | Stretching |
| B | 2916.169 | C–H | Stretching | |
| C | 2869.881 | C–H | Stretching | |
| D | 2842.879 | C–H | Stretching | |
| E | 2352.994 | O=C=O | Stretching | |
| F | 2318.277 | N–H, O–H, S–H | Streching | |
| G | 1737.744 | C=O | Stretching | |
| H | 1616.237 | N–H (NH2) | Bending | |
| C=C (alkene) | Stretching | |||
| I | 1591.164 | C=C (aromatic) | Streching | |
| J | 1496.658 | C=N, N=O | Bending | |
| C=C (alkene) | Stretching | |||
| K | 1448.441 | –C–H (–CH3) | Bending | |
| L | 1251.715 | C–O | Stretching | |
| M | 1220.857 | C–O | Stretching | |
| N | 1024.131 | C–N | Stretching | |
| O | 975.914 | C–H | Bending | |
| P | 914.196 | C–N | Bending | |
| Q | 811.976 | C–H | Bending | |
| R | 775.437 | C–Cl | Stretching | |
| S | 665.396 | C–X (halogen) | Halogen and aromatic disubtituen |