From catechol‐tocopherol to catechol‐hydroquinone polyphenolic antioxidant hybrids

Abstract

Multidefence antioxidants represent a valuable solution for the protection against oxidative stress. From the planned synthesis of a catechol‐tocopherol hybrid, we isolated a catechol‐hydroquinone hybrid through a BBr3‐mediated benzochromene‐fluoren‐1‐ol transposition. The compound prepared showed a remarkable chain‐breaking antioxidant in the catechol portion, while the very sensitive hydroquinone moiety revealed to be an efficient generator of hydroperoxyl radicals.

A composite carbon-based solid acid-supported palladium catalyst (Pd/C-SO3H) for hydrogenolysis of plant-derived polymeric proanthocyanidins

“…Both PPC and OPC showed better DPPHc scavenging ability than BHT because the ortho- phenolic hydroxyl groups of the proanthocyanidin B ring act as hydrogen donors, which can accept free radicals and form stable intramolecular hydrogen bonds, semi-steroidal free radicals or o-benzoquinones, thus blocking the free radical chain reaction. 42 Aer depolymerization of PPC by Pd/C-SO 3 H to produce OPC, the antioxidant capacity is greatly enhanced, and OPC can be used as a novel chain-breaking antioxidant.…”

Development of a formulation for light stabilizers to protect dyed cotton knitted fabrics against light

“…Resorcinol at certain concentrations can demonstrate antioxidant activity associated with the formation of hydroxyquinone according to the scheme shown in Fig. 9 [41,42].…”

“…The antioxidant properties of diphenols are associated with the presence of movable hydrogen atoms in hydroxyl groups in their structure, which easily release it when interacting with free radicals. In this case, phenols act as the reducers of free radicals, turning into less-active phenoxy radicals [42,43].…”

Chain Breaking Antioxidant Activity of Heavy (S, Se, Te) Chalcogens Substituted Polyphenols

“…Actually, the multi-defence antioxidant activity of hybrid derivatives is particularly appealing since the synergism between structurally different antioxidants is a mandatory requisite, at a biological level, for transforming high oxidant radical species into safe unreactive derivatives through a cascade of red-ox quenching processes [52,53,54,55,56,57,58,59].…”