Antioxidant activity of novel phenolic compounds bearing basic substituents—synthesis and insights from molecular modeling

Compound	*Heat of formation ΔH_form(1) [kJ.mol⁻¹]**	Heat of formation ΔH_form(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

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

Language: English

Submitted on: Mar 6, 2026

Accepted on: May 15, 2026

Published on: Jul 6, 2026

In partnership with: Paradigm Publishing Services

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© 2026 Ružena Čižmáriková, Jindra Valentová, Mája Polakovičová, Ladislav Habala, published by Comenius University in Bratislava, Faculty of Pharmacy
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

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