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Oxoberberine: a promising natural antioxidant in physiological environments

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journal contribution
posted on 04.05.2022, 06:22 by Cam Nam Pham, Quang Trung Nguyen, Thi Hoa Nguyen, Ngoc Bich Huynh, Duc Manh Tran, Tuan Quang Duong, Adam MechlerAdam Mechler, Quan Van VoQuan Van Vo
Oxoberberine (OB, 2,10-dihydroxy-3,9-dimethoxy-8-oxo-protoberberine, artathomsonine), which was isolated from Artabotrys thomsonii, was shown to exhibit potent antioxidant activity in vitro, however that is the only reported evidence of the radical scavenging activity of this compound thus far. In the present study, thermodynamic and kinetic calculations were used to determine the free radical scavenging activity of OB against a range of biologically important species, under physiological conditions. In the first part the activity is calculated against the HOO˙ radical that is both biologically important and a reference radical for comparison. It was found that OB has high antiradical capacity against HOO˙ in both lipid medium and water at physiological pH with k overall = 1.33 × 105 and 1.73 × 106 M-1 s-1, respectively. The formal hydrogen transfer mechanism defined the activity in nonpolar environments, whereas in the aqueous solution the single electron transfer competes with the hydrogen transfer pathway. The results showed that, in lipid medium, the HOO˙ trapping capability of OB is better than typical antioxidants such as Trolox, BHT, resveratrol and ascorbic acid. Similarly, the activity of OB in water at pH 7.4 is roughly 19 and 7 times faster than those of Trolox and BHT, respectively, but slightly lower than the activities of resveratrol or ascorbic acid. In the second part, it was found that OB also exhibits high activity against other typical free radicals such as CH3O˙, CH3OO˙, CCl3OO˙, NO2, SO4˙-, DPPH and ABTS˙+ with k f ranging from 2.03 × 105 to 5.74 × 107 M-1 s-1. Hence, it is concluded that OB is a promising radical scavenger in the physiological environment.

Funding

The research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 104.06-2020.17 (P. C. N).

History

Publication Date

01/01/2022

Journal

RSC Advances: an international journal to further the chemical sciences

Volume

12

Issue

16

Pagination

6p. (p. 9738-9743)

Publisher

Royal Society of Chemistry

ISSN

2046-2069

Rights Statement

© 2022 The Author(s). Published by the Royal Society of Chemistry. This article is licensed under a Creative Commons Attribution 3.0 Unported (CC BY 3.0). You are free do Share (copy and redistribute the material in any medium or format) and adapt (remix, transform, and build upon the material for any purpose, even commercially). The licensor cannot revoke these freedoms as long as you follow the license terms.