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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

32 [1(SR2)](+) are class II mixed-valent Cu(II)-phenoxyl-phenolate species that exhibit intervalence cha

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

54 by phenolic toxins following metabolism into phenoxyl radical intermediates.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

83 Phenoxyl radicals are intermediates of one-electron oxid

84 Phenoxyl radicals are readily reduced by thiols, ascorba

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

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

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

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

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

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

91 Phenoxyl radicals of etoposide did not inactivate the OR

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

93 Phenoxyl radicals of phenol can also inactivate OR likel

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

111 with little spin density perturbation in the phenoxyl ring.

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

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

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

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

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

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

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