ライフサイエンスコーパス: zwitterion

1 nation of a mono-nido-carboranyl imidazolium zwitterion.

2 he reaction mixture to capture the resulting zwitterion.

3 ansfer occurs at indole C4 in the tryptophan zwitterion.

4 equilibrium constant for the formation of a zwitterion.

5 odimethane is the preferred pathway from the zwitterion.

6 best described as a H2C=O(delta+)-O(delta-) zwitterion.

7 e riboside moiety is recognized as a neutral zwitterion.

8 PT to carbon atom of the naphthalene giving zwitterion.

9 approximately 50% in the presence of excess zwitterion.

10 he distortion of the COO- chromophore in the zwitterions.

11 aration of the monodiazeniumdiolated amidine zwitterions.

12 allenging due to the short lifetime of these zwitterions.

13 lar nucleophilic addition generates bent 1,3-zwitterions.

14 ed to a reporter was used to identify active zwitterions.

15 , characterization, and application of novel zwitterions.

16 The cationic nitrogen of zwitterion 1 is located symmetrically with respect to it

17 y 2-guanidiniocarbonyl pyrrole 5-carboxylate zwitterion (1) (previously reported by us to dimerize to

18 with PPh3 proceeds to give two regioisomeric zwitterions, 1-(Ph3P)C14H7O2B(C6F5)2 (7a) and 3-(Ph3P)C1

19 as shown that the phosphonium hydrido borate zwitterion 10 is formed exergonically in solution but te

20 same intermediate could also be regarded as zwitterion 14', which then undergoes an initial hydride

21 -assisted PT to naphthalene position 4 in 5, zwitterion 17 is formed, which cyclizes to stable naphth

22 onding fluoroborate/ or cyanoborate/ammonium zwitterions 1F, 1CN, 2F, and 2CN.

23 sual charge-separated pyridinium barbiturate zwitterion 2 from 1,3-dimethylbarbituric acid and 2-pyri

24 Reaction of 1 with P(t-Bu)3 affords the zwitterion 3-(t-Bu)3PC14H7O2B(C6F5)2 (5) in addition to

25 MeOH and benzoic acid to perepoxide (2) and zwitterion (3) intermediates.

26 ture to yield the phosphonium/hydrido borate zwitterion 5.

27 ither as the sigma,pi-biradicals 8 or as the zwitterions 8', for subsequent synthetic elaborations.

28 t to capture the carbocationic center in the zwitterion 8e' furnished the 5H-pyrido[4,3-b]indole 32 i

29 The (3-oxo-2-butenyl)triphenylphosphonium zwitterion, a commonly known nucleophile, is identified

30 s observed for spinach PSII, suggesting that zwitterions act specifically by binding to the extrinsic

31 This catecholic zwitterion adheres to diverse surfaces and self-assemble

32 The uniquely reactive nature of the selected zwitterions allows their in situ modification and afford

33 he mutant EH(2).P complex contains the imine zwitterion and exhibits a charge-transfer band, a featur

34 with a second molecule of BF3 stabilizes the zwitterion and suppresses the fluorine migration, thus p

35 cular hydrogen bond between the intermediate zwitterion and the enone was found to be the key interac

36 was found that the loss of CO(2) from these zwitterions and from oxygen-protonated OMP is retarded b

37 sigmatropic steps, and (3) azolium methanide zwitterions and ketenimines as key intermediates.

38 Eight 2:1 cocrystals of amino acid zwitterions and Li(+) salts were crystallized from hot w

39 rimental evidence for chain extension of the zwitterions and reinitiation by the N-heterocyclic carbe

40 pha-carbon of the Schiff base stabilizes the zwitterions and shifts the equilibrium in favor of the o

41 ommon: electronic effects that stabilize the zwitterions and steric effects that inhibit their cycliz

42 hat a striking similarity exists between the zwitterions and the respective precursor parent anion.

43 ra of nine isomeric pyridinium dicarboxylate zwitterions and three nonzwitterionic methoxycarbonylpyr

44 ls demonstrate a singlet ground state of the zwitterion, and its calculated geometry and magnetic pro

45 including salts, polypeptides, small organic zwitterions, and surfactants.

46 ylketenes in acetonitrile forming observable zwitterions, and these undergo amine catalyzed dealkylat

47 The anion and zwitterion are the only protonation forms of HIMA whose

48 These versatile functional zwitterions are converted easily to polymer prodrugs, hy

49 Zwitterions are critically important in many biological

50 Zwitterions are dipolar molecules that typically are hig

51 Polymer zwitterions are generally regarded as hydrophilic and re

52 f the 3'-OH group, indicating formation of a zwitterion at the transition state.

53 cteristics of 33 amphoteric drugs (about 64% zwitterions at physiological pH) were studied using the

54 ce a set of multicoordinating imidazole- and zwitterion-based ligands suited for surface functionaliz

55 1) s(-1) for carbon deprotonation of proline zwitterion by hydroxide ion at 25 degrees C.

56 oxidation sequence or to hydrazine sulfamate zwitterions by an unusual N-amination.

57 These molecules are stable zwitterions by virtue of the meta positions occupied by

58 of small molecules with large dipoles, like zwitterions, can be controlled by applied potential.

59 Because of the zwitterion character of the common buffer constituents,

60 ble to GBCAs, we have designed and developed zwitterion-coated exceedingly small superparamagnetic ir

61 tion of the first titanium(IV) phosphinidene zwitterion complex ((tBu)nacnac)Ti=P[Trip]{CH3B(C6F5)(3)

62 hange occurs exclusively at C5 in the cis-W3 zwitterion, consistent with the presence of the chi(2) =

63 idene with BF3 in rare gas matrices yields a zwitterion consisting of a cyclopentadienyl cation beari

64 ophoresis has been used to determine whether zwitterions contribute to the ionic strength of a soluti

65 icted a 3'-endo conformation for the ribosyl zwitterion, corresponding to a H1'-C1'-C2'-H2' torsional

66 However, a stable zwitterion could be obtained using Onsager's reaction-fi

67 Three conjugated polymer zwitterions (CPZs), containing thiophene-, diketopyrrolo

68 d be captured either as biradicals and/or as zwitterions depending on the nature of the substituent a

69 e identification of pharmacologically active zwitterions designed to be retained in the liver.

70 Hence, zwitterions do not contribute to the ionic strength of a

71 The polar liquid zwitterion does not affect the viability and activity of

72 reducing the charge on the nucleic acid in a zwitterion effect as well as through additional noncoval

73 arborane anion through methylation to form a zwitterion enabled facile chemical reduction of the comp

74 The zwitterions exhibit reactivity different from the corres

75 As a result, the zwitterion exists in a nitrogen-oxygen ion pair configur

76 This zwitterion favors nucleophilic character in solution, wh

77 ing of the pseudoequilibrated formation of a zwitterion followed by a rate controlling amine assisted

78 ifferently charged species: neutral but in a zwitterion form for malten and monopositive with an inte

79 n of the benzylic OH (as hydroxide ion) gave zwitterions (formal m-quinone methides).

80 resent in norbornene is inadequate to induce zwitterion formation analogous to that observed with don

81 esult from transfer of the substrate proline zwitterion from the polar solvent water to a nonpolar en

82 zoxan produced monodiazeniumdiolated amidine zwitterions from which NO release was observed for up to

83 )-ZW, (as a multicoordinating anchor) with a zwitterion group for water compatibility.

84 Thus, protoadamantyl zwitterion has a less nonclassical character than the co

85 ,3-dipolar cycloaddition reactions, in which zwitterions have been detected or proposed, have two fac

86 The catecholic zwitterion holds particular promise as an adhesive for n

87 line methyl ester and pK(a) = 29 for proline zwitterion in water and of the second-order rate constan

88 -11) s(-1) for deprotonation of free proline zwitterion in water at pH 8 and k(cat) = 2600 s(-1) for

89 the mechanism of racemization of an alanine zwitterion in water is altered from an essentially conce

90 s tailored receptors for cations, anions, or zwitterions in organic or aqueous media.

91 ure of sulfonium- and ammonium-based polymer zwitterions in water, adhesive droplets are prepared by

92 298 K and ultimately give the corresponding zwitterions in which [BAr(F)4](-) coordinates and NBA is

93 urface potential measurements indicates that zwitterion insertion leads to the formation of a spontan

94 Describing organic cation and zwitterion interaction with dissolved natural organic ma

95 high proton-affinity sites of humic acid and zwitterion interaction with high proton-affinity sites.

96 This suggests that the formation of a zwitterion intermediate in the enzyme-catalyzed transfor

97 oton transfer results in formation of an ion-zwitterion intermediate with a greater dissociation thre

98 (1) Trapping the charged zwitterion intermediate with added nucleophiles allows a

99 A stepwise mechanism involving short-lived zwitterion intermediates is established.

100 on of the carboxylate moiety, converting the zwitterions into typical cationic amphiphiles.

101 x 10(-4) cm(2) V(-1) s(-1) while the twisted zwitterion is a high resistivity insulator.

102 In addition, we demonstrate that this zwitterion is a powerful phospha-Staudinger reagent and

103 The resulting zwitterion is a stable [9]annulene with strong aromatici

104 The zwitterion is highly labile and by visible or IR irradia

105 y (basicity) of the anionic subunit in these zwitterions is comparable to that of the respective pare

106 ion of charge between the monopoles in these zwitterions is demonstrated by moderately large nonzero

107 a wider breadth of applications for polymer zwitterions is hindered by their inherent lack of functi

108 The aggregation of these highly polar zwitterions is investigated using several experimental t

109 We show that the binding of zwitterions is nondenaturing, is highly reversible, and

110 nd-assisted pi-pi-interaction of the dimeric zwitterions is suggested to promote this aggregation mod

111 2)-inactive PSII show that the inhibition by zwitterions is the result of a specific decrease in the

112 The remaining one, involving the zwitterion, is shown to be consistent with experimental

113 has been found that the ring closure of the zwitterion leading to the formation of sultines was kine

114 for the initially formed sigma,pi-biradicals/zwitterions, leading to the 5,6-dihydrobenzo[c][1,8]naph

115 A series of highly efficient, modular zwitterion-mediated transformations have been developed

116 walls in addition to the originally proposed zwitterion model.

117 More importantly, by the use of zwitterion moieties as the hydrophilic block, this polym

118 the QD surface and a controllable number of zwitterion moieties for water solubilization.

119 poic acid (LA) groups chemically linked to a zwitterion moiety.

120 Ar-B] or initial proton transfer to give the zwitterions [(-)OAr-BH(+)].

121 3-Nitrophenylboronic acid recognizes zwitterions of amino acids in DMSO, and its UV absorptio

122 late groups, and a number of cyclic analogs, zwitterions of similar size such as trans-(aminomethyl)c

123 ace through a reaction mechanism involving a zwitterion or a BF3 addition compound (formed by fluorid

124 Since 2-azatyrosine is in the zwitterion or phenolate ion form at all the pH values ex

125 not affect sequestration of fast-dissipating zwitterions or negatively charged pharmaceuticals.

126 complex fluorescence decay of the tryptophan zwitterion originates in ground-state heterogeneity with

127 metal chelation by the phosphate because the zwitterion pair is charge neutral.

128 pproximately 3.5) (W)(S)pHs showing that the zwitterion (+Phe-Ala-) is less strongly adsorbed than th

129 lpha-amino carbon of the glycylglycylglycine zwitterion (pK(a) = 25.1) is similar to that for deproto

130 sarcosine oxidase (MSOX) binds the L-proline zwitterion (pKa = 10.6).

131 rface to the ground state generates a planar zwitterion prior to formation of a Favorskii cyclopropan

132 pha-keto carboxylates and thiazolium-derived zwitterions produces reactive carbonyl anions in a buffe

133 intramolecularly either as biradicals or as zwitterions, producing 2(1H)-quinolinone 19, 2(1H)-pyrid

134 -8 undergo solvent-assisted PT giving QM6 or zwitterion QM8 that react with nucleophiles delivering a

135 demonstrated to show the scalability of the zwitterion reaction.

136 nder the effect of anhydrous GaCl3 using 1,2-zwitterion reactivity was elaborated.

137 the kinetic criteria under which the active zwitterions remain in solution; these simulations were s

138 of the negatively charged chain ends of the zwitterions, resulting in quasi-living polymerization be

139 xes have charge-solvated binding modes, with zwitterion (salt bridge) forms being much less stable.

140 ive zwitterion stability, but even then, the zwitterion (salt bridge, SB) form is not the most stable

141 ge transport studies, thin films of the flat zwitterion show semiconducting properties, with a hole m

142 ding to the results, the formation of adduct zwitterion species is a preliminary step required for al

143 DI) backbones, were synthesized with pendant zwitterions, specifically sulfobetaine groups.

144 ion to a metal ion can increase the relative zwitterion stability, but even then, the zwitterion (sal

145 re, a case is described in which the polymer zwitterion structure is tailored to decrease water solub

146 zation was observed using the trehalose- and zwitterion- substituted polyesters.

147 thiadiazole monomers were copolymerized with zwitterion-substituted dibromothiophene, DPP, and NDI mo

148 of cyanobacterial PSII is inhibited by small zwitterions, such as glycine betaine and beta-alanine.

149 o have a limited permeability to Na+ and the zwitterion taurine.

150 we found that the QDs photoligated with this zwitterion-terminated bis(lipoic) acid exhibit great col

151 for plant cell walls based on a polar liquid zwitterion that dissolves cellulose, the most recalcitra

152 blem since in the solid state it exists as a zwitterion that is unstable in vacuo and therefore canno

153 e are therefore proposing that, analogous to zwitterion, the generic name "Zwitterhormon" (German spe

154 somerization of a pyrrolin-2-ylium-3-aminide zwitterion, the primary product of 1,4-diazahexatriene 1

155 bon of glycylglycine and glycylglycylglycine zwitterions, the internal alpha-amino carbon of the glyc

156 solution-phase amino acids normally exist as zwitterions, this is not the case under gas-phase condit

157 deprotonation/reprotonation of the resulting zwitterion to give a rearranged hexahydroindolinone on f

158 deprotonation/reprotonation of the resulting zwitterion to give a rearranged hexahydroindolinone.

159 g followed by deprotonation of the resulting zwitterion to give the rearranged ketone.

160 Aggregation of dimers of these zwitterions to higher supramolecular structures was achi

161 aethylammonium chloride (TEA(+)Cl(-)) or the zwitterion tricine(+/-).

162 ing of relatively large, organic cations and zwitterions (viz., the antibiotics clarithromycin and te

163 The fluorescence decay of the cis-W3 zwitterion was biexponential with lifetimes of 3.1 and 0

164 of TPT, and the permeability of the lactone zwitterion was comparable to that of the neutral form of

165 A zwitterion was the first intermediate detected, and it c

166 Oral delivery of the poorly permeable zwitterions was achieved by prodrugs susceptible to clea

167 , whereas direct N-C(alpha) bond cleavage in zwitterions was disfavored.

168 evidence for the intermediacy of radicals or zwitterions was found.

169 ricyclic 1,3- and 1,5-hydrogen shifts in the zwitterions were also calculated.

170 Conjugated polymeric zwitterions, when utilized as interlayer materials in bu

171 tonation at the NH of these salts leads to a zwitterion which, in the 4-pyridyl system, also exists a

172 CO2 and/or epoxide to produce inner salts or zwitterions which behave in a manner similar to that of

173 derivatives with ArI(OAc)2 gave aryliodonium zwitterions, which were sufficiently stable for chromato

174 s a closed shell, antiaromatic 16pi-electron zwitterion with a small HOMO-LUMO gap.

175 Zwitterions with a balanced charge and minimized dipole

176 the crystal, the d(TpA)* molecules exist as zwitterions with a protonated amidine fragment of the ei

177 Quinuclidine rapidly forms long-lived zwitterions with arylketenes, providing a model for cata

178 borderline between singlet biradicaloids and zwitterions with diminished reactivity compared to known

179 The reactions of these zwitterions with nucleophiles provided facile access to

180 DFT calculations suggest that the molecular zwitterions within these structures are all significantl