Pathways to Glycine and Other Amino Acids in Ultraviolet-irradiated Astrophysical Ices Determined via Quantum Chemical Modeling
Pathways to Glycine and Other Amino Acids in Ultraviolet-irradiated Astrophysical Ices Determined via Quantum Chemical Modeling
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通过量子化学模型确定紫外线照射的天体物理冰中甘氨酸和其他氨基酸的途径
DOI：
10.1086/341227
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
D. Woon
中科院分区：
文献类型：
--
作者：
D. Woon
最近的一项实验研究报告说，甘氨酸和其他氨基酸形成时，低温水冰含有少量的CH 3 OH，NH 3，和HCN进行紫外线（UV）照射。采用量子化学计算来评估各种途径的可行性，形成甘氨酸，丙氨酸，丝氨酸在稀水冰含有CH 3 OH和HCN。在沉积和UV照射在15 K，然后加热到室温的实验处理条件下，氨基酸可以通过重组自由基产生的水和甲醇，随后氢化HCN。研究表明，同位素取代实验将确定CH 3OH作为辐射实验中观察到的氨基酸的COOH羧酸基团中的C原子的来源，CO+OH反应起着重要的作用。甘氨酸中剩余的C和N原子被预测为经由顺序氢化产生CH 2NH2而源自HCN。丙氨酸和丝氨酸的形成途径也进行了讨论。
A recent experimental study reported that glycine and other amino acids were formed when cryogenic H2O ice containing small amounts of CH3OH, NH3, and HCN was subjected to ultraviolet (UV) irradiation. Quantum chemical calculations were employed to evaluate the viability of various pathways to the formation of glycine, alanine, and serine in dilute H2O ice containing CH3OH and HCN. Under the experimental processing conditions of deposition and UV irradiation at 15 K followed by heating to room temperature, amino acids can form by recombining radicals produced by dehydrogenating H2O and CH3OH and subsequently hydrogenating HCN. The study indicates that isotopic substitution experiments would identify CH3OH as the source of the C atom in the COOH carboxylic acid group of the amino acids observed in the irradiation experiments, with the CO+OH reaction playing an important role. The remaining C and N atoms in glycine are predicted to originate from HCN via sequential hydrogenation to yield CH2NH2. Formation pathways for alanine and serine are also discussed.