Table 1.
Overview of the substances studied
| ||
|---|---|---|
| Substance | R1 | R2 |
| I | CH2CH3 | N(CH3)2 |
| II | CH3 | N(CH2CH3)2 |
| III | CH3 | NHCH(CH3)2 |
| IV | CH2CH3 | NHCH(CH3)2 |
| V | CH3 | NHCH2CH(CH3)2 |
| VI | CH3 | NHC(CH3)3 |
| VII | CH3 |
|
| VIII | CH2CH3 |
|
| IX | CH3 |
|
| X | CH2CH3 |
|
| XI | CH3 |
|
| XII | CH2CH3 |
|
| XIII | CH3 |
|
| XIV | CH3 |
|
| XV | CH2CH3 |
|
Scheme 1.
Synthesis of the target compounds (R1/R2 see Table 1)
Table 2.
Antioxidant activities of the compounds investigated
| Substance | R1 | R2 | Inhibition DPPH[%]±SD | Inhibition ABTS[%]±SD |
|---|---|---|---|---|
| I | CH2CH3 | N(CH3)2 | 4.0±0.9 | 99.1±1.0 |
| IV | CH2CH3 | NHCH(CH3)2 | 6.2±1.2 | 33.5±1.1 |
| VII | CH3 | pyrrolidin-1-yl | 4.1±0.9 | 94.1±0.8 |
| IX | CH3 | piperidino | 5.1±0.7 | 92.7±1.1 |
| X | CH2CH3 | piperidino | 4.5±1.1 | 90.8±1.0 |
| XI | CH3 | morpholino | 3.8±0.5 | 85.9±3.9 |
| XII | CH2CH3 | morpholino | 3.5±0.4 | 84.3±2.3 |
| XIV | CH3 | N-methylpiperazin-1-yl | 3.6±0.5 | 98.7±0.6 |
| XV | CH2CH3 | N-methylpiperazin-1-yl | 2.9±1.5 | 99.1±0.2 |
| X | CH2CH3 | azepan-1-yl | 3.8±0.6 | 98.7±0.8 |
| 4-OHaceto | – | n | 0.94±0.01 | |
| EACh | – | 4.3±2.5 | 8.2±0.4 |
Table 3.
Conformational analysis of [3-aminomethyl-4-(hydroxy)phenyl)methylketones
| Compound | Heat of formation ΔHform(1) * [kJ.mol−1] | Heat of formation ΔHform(2) ** [kJ.mol−1] | Length of the hydrogen bond [nm] NH...O | Length of the hydrogen bond [nm] OH...N | Angle [°] | Energy [kJ.mol−1] |
|---|---|---|---|---|---|---|
| II | −272.33 | −259.62 | 0.247 | 132.56 | 12.71 | |
| V | −332.48 −331.22 | −312.75 −312.75 | 0.237 | 0.236 | 120.17 128.56 | 19.73 18.47 |
| VI | −301.63 −294.44 | −280.14 −280.14 | 0.229 | 0.244 | 123.07 134.70 | 21.49 14.30 |
| VII | −249.25 | −238.01 | 0.243 | 131.00 | 11.24 | |
| IX | −295.64 | −285.08 | 0.255 | 132.35 | 10.82 | |
| XI | −305.64 | −295.53 | 0.238 | 134.91 | 10.11 | |
| XIII | −203.65 | −191.28 | 0.246 | 131.63 | 12.37 | |
| XIV | −385.94 | −409.93 | 0.250 | 131.20 | 10.03 |