Chiral recognition between tryptophan (Trp) and carbohydrates such as D-glucose (D-Glc), methyl-α-D-glucoside (D-glucoside), D-maltose, and D-cellobiose in cold gas-phase cluster ions was investigated as a model for chemical evolution in interstellar molecular clouds using a tandem mass spectrometer containing a cold ion trap. The photodissociation mass spectra of cold gas-phase clusters that contained Na+, Trp enantiomers, and D-maltose showed that Na+(D-Glc) was formed via the glycosidic bond cleavage of D-maltose from photoexcited homochiral Na+(D-Trp)(D-maltose), while the dissociation did not occur in heterochiral Na+(L-Trp)(D-maltose). The enantiomer-selective dissociation was also observed in the case of D-cellobiose. The enantiomer-selective glycosidic bond cleavage of disaccharides suggested that photoexcited D-Trp could prevent chemical evolution of sugar chains from D-enantiomer of carbohydrates in molecular clouds. The spectra of gas-phase clusters that contained Na+, Trp enantiomers, and D-Glc indicated that enantiomer-selective protonation of L-Trp from D-Glc could induce enantiomeric excess via collision-activated dissociation of the protonated L-Trp. In the case of protonated clusters, photoexcited H+(L-Trp) dissociated via Cα-Cβ bond cleavage in the presence of D-Glc or D-glucoside, where the excited states of H+(L-Trp) contributed to the enantiomer-selective reaction in the clusters. These enantiomer selectivities in cold gas-phase clusters indicated that chirality of a molecule induced enantiomeric excess of other molecules via enantiomer-selective reactions in molecular clouds.

中文翻译：

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通过光解离探测的冷气相色氨酸和色氨酸中的手性识别。

研究了色氨酸（Trp）与碳水化合物在冷气相簇离子中的手性识别，这些碳水化合物包括D-葡萄糖（D-Glc），甲基-α-D-葡萄糖苷（D-葡萄糖苷），D-麦芽糖和D-纤维二糖使用包含冷离子阱的串联质谱仪作为星际分子云中化学演化的模型。含有Na +，Trp对映异构体和D-麦芽糖的冷气相团簇的光解质谱表明，Na +（D-Glc）是通过D-麦芽糖从光激发的同质手性Na +（D-Trp）中糖苷键裂解而形成的（ D-麦芽糖），而在异手性Na +（L-Trp）（D-麦芽糖）中未发生解离。在D-纤维二糖的情况下也观察到对映体选择性解离。对二糖的对映异构体选择性糖苷键裂解表明，光激发的D-Trp可以阻止分子云中碳水化合物D-对映异构体糖链的化学演化。包含Na +，Trp对映异构体和D-Glc的气相团簇的光谱表明，L-Trp从D-Glc的对映体选择性质子化可通过质子化L-Trp的碰撞活化解离诱导对映体过量。在质子化簇的情况下，在存在D-Glc或D-葡萄糖苷的情况下，光激发的H +（L-Trp）通过Cα-Cβ键裂解解离，其中H +（L-Trp）的激发态有助于对映体选择性集群中的反应。