Theoretical study of water-assisted hydrolytic deamination mechanism of adenine

Zheng, Hongyan; Meng, Fancui

doi:10.1007/s11224-009-9495-z

Cited by 19 publications

(19 citation statements)

References 16 publications

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“…1. A negative activation barrier for hypoxanthine production in the closing system of four water molecules around adenine has been predicted theoretically [12,13]. While the aim of the present MPI and EII experiments on hypoxanthine is to elucidate adenine-water reactivity, the molecule is also interesting as a universal nucleobase that binds without discrimination to natural bases.…”

Section: Introductionmentioning

confidence: 84%

“…The most abundant gas-phase tautomers (amine-N9H adenine [19] and keto-N1H/N9H hypoxanthine [20]) are shown on the right. is hypoxanthine (C 5 H 4 N 4 O) with mass 136 a.u., equal to protonated adenine or an adenine isotopomer containing one 13 C. The most abundant gas-phase tautomers of adenine (amine-N9H [19]) and hypoxanthine (keto-N1H/N9H [20]) are shown schematically in Fig. 1.…”

Section: Introductionmentioning

confidence: 99%

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Multi-photon and electron impact ionisation studies of reactivity in adenine–water clusters

Barc¹,

Ryszka²,

Poully³

et al. 2014

International Journal of Mass Spectrometry

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Keywords:Adenine Cluster Dissociative ionisation Hypoxanthine Multi-photon ionisation Electron impact ionisation a b s t r a c t Multi-photon ionisation (MPI) and electron impact ionisation (EII) mass spectrometry experiments have been carried out to probe unimolecular and intermolecular reactivities in hydrated adenine clusters. The effects of clustering with water on fragment ion production from adenine have been studied for the first time. While the observation of NH 4 + fragments indicated the dissociation of protonated adenine, the dominant hydration effects were enhanced C 4 H 4 N 4 + production and the suppression of dissociative ionisation pathways with high activation energies. These observations can be attributed to energy removal from the excited adenine radical cation via cluster dissociation. Comparisons of MPI and EII measurements provided the first experimental evidence supporting hypoxanthine formation in adenine-water clusters via theoretically predicted barrierless deamination reactions in closed shell complexes.

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Section: Introductionmentioning

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Multi-photon and electron impact ionisation studies of reactivity in adenine–water clusters

Barc¹,

Ryszka²,

Poully³

et al. 2014

International Journal of Mass Spectrometry

View full text Add to dashboard Cite

show abstract

“…From the abovementioned we can see that in this deamination reaction, the rate-determining step is the nucleophilic attack step to form the tetrahedral intermediate just like the deamination of cytosine under basic condition [19], which is different from the water-assisted hydrolytic deamination of adenine [17]. In the latter, the second step to release ammonia molecule is the ratedetermining step.…”

Section: Ring Opening and Formation Of Int2mentioning

confidence: 95%

“…The outcomes of non-assisted [14,15] and water-assisted [16][17][18] base deamination show that water assistance decreases the energy barrier obviously. However, the introduction of the third water molecule does not affect the reaction mechanism and it only acts as a medium [17].…”

Section: Ring Opening and Formation Of Int2mentioning

confidence: 99%

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A new photoproduct of 5-methylcytosine and adenine: a theoretical study

Meng

Wang

2011

Struct Chem

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Both the cycloaddition mechanism of 5-methylcytosine with adenine and the deamination mechanism of the cycloaddition product have been studied using density functional theory method. The results suggest that the cycloaddition reaction could occur more easily through photochemical reaction pathway than through thermal reaction pathway. The obtained four-member ring structure could be easily transformed to an eight-member ring structure through bond cleavage of C 5 -C 6 (the energy barrier is \2 kcal/mol). Then hydrolytic deamination reaction takes place with water assistance. The hydroxyl group of one water molecule attacks the C 4 0 atom and the hydrogen atom of another water molecule attacks N 3 0 atom to form a tetrahedral intermediate. Subsequently, the hydrogen atom of hydroxyl group transfers to N 8 0 to produce ammonia, and the amino group of the former 5-methylcytosine changes to carboxyl oxygen. Our calculations explain the phenomena that 5-methylcytosine and adenine could obtain the same photoproduct as thymine and adenine from theoretical aspects.

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Hydrothermal Reaction Kinetics and Pathways of Phenylalanine Alone and in Binary Mixtures

2012

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We examined the behavior of phenylalanine in high-temperature water (HTW) at 220, 250, 280, and 350 °C. Under these conditions, the major product is phenylethylamine. The minor products include styrene and phenylethanol (1-phenylethanol and 2-phenylethanol), which appear at higher temperatures and longer batch holding times. Phenylethylamine forms via decarboxylation of phenylalanine, styrene forms via deamination of phenylethylamine, and phenylethanol forms via hydration of styrene. We quantified the molar yields of each product at the four temperatures, and the carbon recovery was between 80-100 % for most cases. Phenylalanine disappearance follows first-order kinetics with an activation energy of 144 ± 14 kJ mol⁻¹ and a pre-exponential factor of 10(12.4 ± 1.4) min⁻¹. A kinetics model based on the proposed pathways was consistent with the experimental data. Effects of five different salts (NaCl, NaNO₃, Na₂ SO₄, KCl, K₂ HPO₄) and boric acid (H₃BO₃) on phenylalanine behavior at 250 °C have also been elucidated. These additives increase phenylalanine conversion, but decrease the yield of phenylethylamine presumably by promoting formation of high molecular weight compounds. Lastly, binary mixtures of phenylalanine and ethyl oleate have been studied at 350 °C and three different molar concentration ratios. The presence of phenylalanine enhances the conversion of ethyl oleate and molar yields of fatty acid. Higher concentration of ethyl oleate leads to increased deamination of phenylethylamine and hydration of styrene. Amides are also formed due to the interaction of oleic acid/ethyl oleate and phenylethylamine/ammonia and lead to a decrease in the fatty acid yields. Taken collectively, these results provide new insights into the reactions of algae during its hydrothermal liquefaction to produce crude bio-oil.

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Theoretical study of water-assisted hydrolytic deamination mechanism of adenine

Cited by 19 publications

References 16 publications

Multi-photon and electron impact ionisation studies of reactivity in adenine–water clusters

Multi-photon and electron impact ionisation studies of reactivity in adenine–water clusters

A new photoproduct of 5-methylcytosine and adenine: a theoretical study

Hydrothermal Reaction Kinetics and Pathways of Phenylalanine Alone and in Binary Mixtures

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