Screening for antiradical efficiency of 21 semi-synthetic derivatives of quercetin in a DPPH assay

Abstract

The group of 21 novel semi-synthetic derivatives of quercetin was screened for the antiradical efficiency in a DPPH assay. The initial fast absorbance decrease of DPPH, corresponding to the transfer of the most labile H atoms, was followed by a much slower absorbance decline representing the residual antiradical activity of the antioxidant degradation products. Initial velocity of DPPH decolorization determined for the first 75-s interval was used as a marker of the antiradical activity. Application of the kinetic parameter allowed good discrimination between the polyphenolic compounds studied. The most efficient chloronaphthoquinone derivative (compound Ia) was characterized by antiradical activity higher than that of quercetin and comparable with that of trolox. Under the experimental conditions used, one molecule of Ia was found to quench 2.6±0.1 DPPH radicals.

2-Chloro-1,4-naphthoquinone derivative of quercetin as an inhibitor of aldose reductase and anti-inflammatory agent

“…Recently, antioxidant activity of 1 was proved in a DPPH test in vitro 14 . Based on the initial velocity of DPPH decolorization, the antiradical activity of 1 was found higher than that of quercetin and comparable with that of trolox.…”

“…As part of our ongoing interest in developing new aldose reductase inhibitors, we recently reported the synthesis of 21 novel derivatives of quercetin and the results of their screening for inhibition of aldose reductase and antioxidant activity action 13,14 . Among the novel compounds studied, the most promising results were obtained for the 2-chloro-1,4-naphthoquinone derivative of quercetin (compound 1, Figure 1).…”

“…Recently 21 novel semi-synthetic derivatives of quercetin have been synthesized and screened for inhibition of ALR2 and for antioxidant action 13,14 . Among the compounds studied, 2-chloro-1,4-naphthoquinone derivative (compound 1, Figure 1) exhibited the highest biological activities.…”

Chemical Profiling and Assessment of Antineurodegenerative and Antioxidant Properties of Veronica teucrium L. and Veronica jacquinii Baumg.

“…They exert antioxidant effects by various mechanisms (radical scavenging, hydrogen donating, singlet oxygen quenching and metal iron chelating). The biological activity of quercetin derivatives strongly depends on the nature and position of the substituents . Some quercetin derivatives present in V. jacquinii showed higher anti‐DPPH activity compared to ascorbic acid and quercetin ( IC 50 = 21.6 and 27.5 m m for isoquercetin and hyperoside, respectively, and 27.8 and 32.2 m m for ascorbic acid and quercetin, respectively) .…”

Protection or cytotoxicity mediated by a novel quinonoid-polyphenol compound?

“…1) was synthesized and studied (Stefek et al 2012;Veverka et al 2013;Milackova et al 2013). The compound CHNQ showed profound antioxidant properties in a chemical model of DPPH test with an efficacy similar to the reference antioxidant trolox .…”