ライフサイエンスコーパス: phenoxyl

1 ological activity of 2-chloro-3-(substituted phenoxyl)-1, 4-naphthoquinones and 2,3-bis(substituted p

2 ion can transfer an electron and a proton to phenoxyl and nitroxyl radicals, indicating that e(-) and

3 f selected vibrational levels of the various phenoxyl and thiophenoxyl coproducts, providing uniquely

4 n resulted in the formation of surface-bound phenoxyl- and semiquinoine-type radicals with characteri

5 g a nitrogen radical moiety Fe(III)-N. and a phenoxyl anion.

6 ctive cofragments (imidazolyl, pyrrolyl, and phenoxyl) are formed in very limited subsets of their av

7 2))) and reduced salen (2(R(1),R(2))) Cu(II)-phenoxyl complexes with a combination of -(t)Bu, -S(i)Pr

8 roject along the subunit helix axis, and one phenoxyl engages in hydrogen-bonding interaction that ha

9 en atom abstraction by the tyrosine-cysteine phenoxyl free radical ligand to form the product aldehyd

10 activation barrier for the beta-scission of phenoxyl from 1-phenyl-2-phenoxyethanol-1-yl (V): log(k

11 rent hydrogen-bonding states of the tyrosine phenoxyl group in proteins.

12 were used to find the rotation angle of the phenoxyl group.

13 he non-hydrogen-bonded state of the tyrosine phenoxyl group.

14 with the aromatic ring, which stabilizes the phenoxyl hole by ca. 8 kcal mol(-1) (1 kcal = 4.18 kJ; 3

15 nvolve hydrogen atom transfer to the tyrosyl phenoxyl in a radical redox mechanism for catalysis.

16 signature of a modified (cysteinyl-tyrosine) phenoxyl in the vibrational spectra of the active comple

17 computational studies indicate that the key phenoxyl intermediate serves as an open-shell electron-w

18 s suggest that oxygen activation via a Cu(I) phenoxyl ligand-to-metal charge transfer complex is high

19 of specific donor and acceptor roles of the phenoxyl OH group.

20 to polarization of the pi-charge toward the phenoxyl-OH as well as the resonating character of its H

21 d donor, I2/I1 = 0.30, and when the tyrosine phenoxyl oxygen is a strong hydrogen-bond acceptor, I2/I

22 signed to the proton originally ortho to the phenoxyl oxygen.

23 d a stacked transition state geometry of the phenoxyl-phenol self-exchange reaction.

24 reduction potential difference ( E(red)) of phenoxyl/phenol and anilinyl/aniline couples.

25 The vibronic couplings for the phenoxyl/phenol and the benzyl/toluene self-exchange rea

26 Electrochemical studies show that the phenoxyl/phenol couple of the model system is chemically

27 eling is electronically nonadiabatic for the phenoxyl/phenol reaction and electronically adiabatic fo

28 Previous studies designated the phenoxyl/phenol reaction as proton-coupled electron tran

29 For the phenoxyl/phenol system, the electrons are unable to rear

30 The preference for phenoxyl/phenol to occur by PCET while methoxyl/methanol

31 ty on the oxygens selectively stabilizes the phenoxyl/phenol TS by providing a larger binding energy

32 In contrast, the SOMO at the phenoxyl/phenol TS is a pi symmetry orbital within each

33 oxygens in the PCET transition structure for phenoxyl/phenol, as compared to the PCET hilltop for met

34 [1(SR2)](+) are class II mixed-valent Cu(II)-phenoxyl-phenolate species that exhibit intervalence cha

35 on mode nu(16a), such that when the tyrosine phenoxyl proton is a strong hydrogen-bond donor, I2/I1 =

36 radical, 2,6-di-(t)butyl-4-(4'-nitrophenyl) phenoxyl radical ((t)Bu2NPArO(*)) is described.

37 Phenoxyl radical (C(6)H(5)O) was prepared photochemicall

38 d II with the obligate generation of the DCF phenoxyl radical (DCF(.)).

39 Subsequently, AOH(*) reduces the phenoxyl radical (kET = 5.5 x 10(9) M(-1) s(-1)), formin

40 The phenoxyl radical 1 was generated in high yields by flash

41 Similarly, the phenoxyl radical 2,4,6-tBu3C6H2O* and excess TEMPO* each

42 h in competition with beta-scission to yield phenoxyl radical and acetophenone.

43 elding a 2-substituted (cyano- or isocyano-) phenoxyl radical and an H-atom, (ii) recombination of th

44 lable and crystallographically characterized phenoxyl radical and is the only example in which the pa

45 ltered in the presence of a highly oxidizing phenoxyl radical and O(2).

46 lving a sigma lone pair on the oxygen of the phenoxyl radical and the O-H bond of phenol.

47 The anisotropic coupling tensors of the phenoxyl radical are resolved in the photoinduced D-band

48 nisms involving the evolution of the primary phenoxyl radical ArO are proposed to rationalise these e

49 aq)) diffusing into the bulk and leaving the phenoxyl radical at the surface.

50 hypothesis that HRP can be inactivated by a phenoxyl radical attack.

51 contrast, when ascorbic acid reduced the DCF phenoxyl radical back to its parent molecule, it formed

52 lving the reduction of the resorufin-derived phenoxyl radical by the drugs' hydroquinone moiety back

53 Reduction of the phenoxyl radical by the quencher radical was examined as

54 Photocatalytic generation of phenoxyl radical cations also enabled a nucleophilic aro

55 ens up strategies for the stabilization of a phenoxyl radical cofactor, with its full oxidizing capab

56 = CF(3), tBu) and a localized Cr(V) nitride phenoxyl radical for the more electron-donating NMe(2) s

57 essions were determined for beta-scission of phenoxyl radical from 1-phenyl-2-phenoxyethanol-1-yl, Ph

58 as increase of the quinoid character of the phenoxyl radical in polar media.

59 -tyrosine cross-link to the stability of the phenoxyl radical in the enzyme, while highlighting the i

60 ectrochemical oxidations in each case is the phenoxyl radical in which the phenolic proton has transf

61 AT, a second molar equiv of 2 couples to the phenoxyl radical initially formed, giving a Cu(II)-OO-(A

62 by phenolic toxins following metabolism into phenoxyl radical intermediates.

63 lectron oxidation of etoposide by MPO to its phenoxyl radical is important for converting this antica

64 uces Fe(IV) horizontal lineO, Cu(II)-OH, and phenoxyl radical moieties, analogous to the chemistry ca

65 This complex, containing an unusual iron(II)-phenoxyl radical motif, represents an elusive example of

66 The results indicate that phenoxyl radical of 2,2,5,7,8-pentamethyl-6-hydroxychrom

67 NADPH quenched directly the EPR signal of phenoxyl radical of a phenolic antitumor drug, etoposide

68 OR catalyzed quenching of EPR signal of the phenoxyl radical of a vitamin E homolog, 2,2,5,7,8-penta

69 approximately 500 nm, which we assign to the phenoxyl radical of compound 1.

70 Previous studies demonstrated that the phenoxyl radical of etoposide can be produced by action

71 by EPR spectroscopy and equilibrated with a phenoxyl radical of known stability in order to determin

72 tes lead to generation of kinetically stable phenoxyl radical of the incarcerated 4-hydroxy-diphenyla

73 ), for (i) benzyl radical plus toluene, (ii) phenoxyl radical plus phenol, and (iii) methoxyl radical

74 troxide and thiyl radicals generated through phenoxyl radical recycling by peroxidase.

75 tion of halophenols, wherein generation of a phenoxyl radical via formal homolysis of the aryl O-H bo

76 d, detected significant perturbations of the phenoxyl radical vibrational bands.

77 LYP/cc-pVTZ) led to a detailed assignment of phenoxyl radical vibrations.

78 scheme that involves coupling of a liberated phenoxyl radical with a ligated 2-naphthoxyl radical.

79 utyl phenol is oxidized to the corresponding phenoxyl radical with a second-order rate constant of 0.

80 tributed to the coupling between a liberated phenoxyl radical with an iron-ligated phenolic coupling

81 adical scavenging and/or by MPO results in a phenoxyl radical with low reactivity toward lipids, its

82 )), i.e., the first 1H(+)/1e(-) (catechol--> phenoxyl radical) and the second 1H(+)/1e(-) (phenoxyl r

83 Birch) reduction/protonation/reoxidation (by phenoxyl radical)/deprotonation cycle.

84 This results in the generation of bis(phenoxyl radical)bis(mu-OH)dicopper(II) intermediates, s

85 full characterization of the 4-(nitrophenyl)phenoxyl radical, 2,6-di-(t)butyl-4-(4'-nitrophenyl) phe

86 e of the dimer, the first for a para-coupled phenoxyl radical, revealed a bond length of 1.6055(23) A

87 lic moiety with reactive radicals yields its phenoxyl radical, whose reactivity may determine the pro

88 henoxyl radical) and the second 1H(+)/1e(-) (phenoxyl radical--> quinone) free radical scavenging mec

89 e consistent with the initial formation of a phenoxyl radical-spectroscopic studies indicated that th

90 TBP to give [Cu(II)2(UN-O(-))(OH)](2+) and a phenoxyl radical.

91 ic cleavage of the alcohol OH group from the phenoxyl radical.

92 tion increases the midpoint potential of the phenoxyl radical/phenol couple so that proton translocat

93 We hypothesize that etoposide phenoxyl radicals (etoposide-O(.)) formed from etoposide

94 s, and luminescence quenching data implicate phenoxyl radicals and Bronsted acid-activated oligo(phen

95 emarkably augmented EPR-detectable etoposide phenoxyl radicals and enhanced etoposide-induced topoiso

96 nce of H2O2 and GSH caused the generation of phenoxyl radicals and GS* radicals, of which only the la

97 dium azide, suggesting the potential role of phenoxyl radicals and/or their derivatives.

98 Phenoxyl radicals are intermediates of one-electron oxid

99 Phenoxyl radicals are readily reduced by thiols, ascorba

100 neration of reactive intermediates, possibly phenoxyl radicals but not H2O2, is responsible for the E

101 mpartments from which APEX2-generated biotin-phenoxyl radicals cannot escape.

102 chromane, a hindered phenolic compound whose phenoxyl radicals do not oxidize endogenous thiols, effe

103 nce for MPO-dependent formation of etoposide phenoxyl radicals in growth factor-mobilized CD34(+) cel

104 lic compounds resulting in the generation of phenoxyl radicals may be an important contributor to the

105 MPO-catalyzed production of etoposide phenoxyl radicals observed directly in HL-60 cells by el

106 Phenoxyl radicals of etoposide did not inactivate the OR

107 radicals with higher redox potential, e.g., phenoxyl radicals of etoposide, oxidize NADPH directly.

108 Phenoxyl radicals of phenol can also inactivate OR likel

109 d with DTNB was protected from inhibition by phenoxyl radicals of phenol.

110 R was inhibited irreversibly when exposed to phenoxyl radicals of phenol.

111 ence for the combination of hydroperoxyl and phenoxyl radicals over H-atom transfer between them.

112 tin-phenol substrate, APEX2 generates biotin-phenoxyl radicals that covalently tag proximal endogenou

113 nd protonated products and the corresponding phenoxyl radicals to form.

114 noxyl radicals, (b) the ability of etoposide phenoxyl radicals to oxidize GSH and protein thiols (aft

115 ar redox reaction of the cyclohexadienyl and phenoxyl radicals to yield a carbocation/phenoxide pair,

116 adish peroxidase (HRP) can be inactivated by phenoxyl radicals upon reaction with H(2)O(2)/phenol, we

117 Phenoxyl radicals with higher redox potential, e.g., phe

118 This report describes reactions of phenoxyl radicals with human NADPH-cytochrome P-450 oxid

119 (GSH) to eliminate EPR-detectable etoposide phenoxyl radicals, (b) the ability of etoposide phenoxyl

120 e-electron oxidation products of phenol, its phenoxyl radicals, is involved in the oxidative effects.

121 y phenols that yield comparatively transient phenoxyl radicals, leading to cross-coupling between the

122 This value is higher than related isolated phenoxyl radicals, making this a useful reagent for hydr

123 ein-derived (tyrosyl) radicals and etoposide phenoxyl radicals, respectively, we established that car

124 rO-C bond homolysis to give para-substituted phenoxyl radicals, which can be observed directly in las

125 lectron transfer (PCET) with phenols to form phenoxyl radicals, with dihydroanthracene to form anthra

126 on of OR with NADP+ prior to the exposure to phenoxyl radicals.

127 rmed on dimerization of two tyrosine-derived phenoxyl radicals.

128 nation of the rotational conformation of the phenoxyl ring in a radical with unprecedented accuracy (

129 chlorine (Cl) substituents are added to the phenoxyl ring.

130 with little spin density perturbation in the phenoxyl ring.

131 lations to impulsively excited low-frequency phenoxyl-ring motions, which optimize the geometry of th

132 However, the phenoxyl side-chain of Tyr183, which is part of the cons

133 ing sulfanyl substituents into copper-bonded phenoxyls significantly alters their optical and redox p

134 age g value (gav = 2.0055) characteristic of phenoxyl tau-radicals arising from a minority apoenzyme

135 hydrogen atom transfers (HAT) to 2 equiv of phenoxyl that are generated transiently at the anode.

136 Thus, for the non-hydrogen-bonded phenoxyl, the lower-wavenumber member of the Fermi doubl

137 A phenoxyl-type radical, with g-value between 2.0029 and 2

138 st lifetimes, 25 and 23 h, were observed for phenoxyl-type radicals on 0.5% CuO and chlorophenoxyl-ty