98-29-3Relevant articles and documents
Indirect inactivation of tyrosinase in its action on 4-tert-butylphenol
Mu?oz-Mu?oz, Jose Luis,García-Molina, María Del Mar,García-Molina, Francisco,Varon, Ramón,García-Ruiz, Pedro Antonio,Rodríguez-López, Jose Neptuno,García-Cánovas, Francisco
, p. 344 - 352 (2014)
Under anaerobic conditions, the o-diphenol 4-tert-butylcatechol (TBC) irreversibly inactivates met and deoxytyrosinase enzymatic forms of tyrosinase. However, the monophenol 4-tert-butylphenol (TBF) protects the enzyme from this inactivation. Under aerobic conditions, the enzyme suffers suicide inactivation when it acts on TBC. We suggest that TBF does not directly cause the suicide inactivation of the enzyme in the hydroxylase activity, but that the o-diphenol, which is necessary for the system to reach the steady state, is responsible for the process. Therefore, monophenols do not induce the suicide inactivation of tyrosinase in its hydroxylase activity, and there is a great difference between the monophenols that give rise to unstable o-quinones such as L-tyrosine, which rapidly accumulate L-dopa in the medium and those like TBF, after oxidation, give rise to a very stable o-quinone.
Ortho-Hydroxylation of 4-tert-butylphenol by nonheme iron(III) complexes as a functional model reaction for tyrosine hydroxylase
Funabiki, Takuzo,Yokomizo, Tomomasa,Suzuki, Shinko,Yoshida, Satohiro
, p. 151 - 152 (1997)
Hydroxylation of 4-tert-butylphenol to 4-tert-butylcatechol is performed by a catecholatoiron(III) complex-hydroquinone-O2 system which mimicks the roles of Fe2+ and Fe3+ in tyrosine hydroxylase; the ortho-hydroxylation of phenols by iron-oxygen active species is suggested.
Direct Synthesis of Hydroquinones from Quinones through Sequential and Continuous-Flow Hydrogenation-Derivatization Using Heterogeneous Au–Pt Nanoparticles as Catalysts
Miyamura, Hiroyuki,Tobita, Fumiya,Suzuki, Aya,Kobayashi, Shū
supporting information, p. 9220 - 9224 (2019/06/13)
Pt–Au bimetallic nanoparticle catalysts immobilized on dimethyl polysilane (Pt–Au/(DMPSi-Al2O3)) have been developed for selective hydrogenation of quinones to hydroquinones. High reactivity, selectivity, and robustness of the catalysts were confirmed under continuous-flow conditions. Various direct derivatizations of quinones, such as methylation, acetylation, trifluoromethanesulfonylation, methacrylation, and benzoylation were successfully performed under sequential and continuous-flow conditions to afford the desired products in good to excellent yields. Especially, air-sensitive hydroquinones, such as anthrahydroquinones and naphthohydroquinones, could be successfully generated and derivatized under closed sequential and continuous-flow conditions without decomposition.
Catalytic conversion of 4-tert-butylphenol in hydrogen peroxide solutions in the presence of titanium oxide compounds and titanosilicates
Talipova,Kharrasov,Veklov,Badikova,Kutepov
, p. 395 - 402 (2017/07/05)
The catalytic conversion of 4-tert-butylphenol (TBP) in hydrogen peroxide solutions in the presence of titanium oxide samples with different phase compositions and crystalline and amorphous titanosilicate samples has been studied. It has been shown that microporous crystalline titanosilicate TS-1 exhibits low activity in the TBP conversion owing to steric restrictions to the diffusion of the substrate molecules to catalytically active sites. The samples of titanium oxide compounds and mesoporous titanosilicates exhibit similar activity, while the selectivity of the latter for 4-tert-butylcatechol (TBC) is higher. The effect of the mesoporous titanosilicate concentration in the reaction mixture and the test temperature and duration on the TBP conversion and the TBC selectivity has been determined.