The degradation of glycine (Gly), proline (Pro), and tryptophan (Trp) was studied under simulated Mars conditions during UV-driven production of oxychlorines and compared under Mars ambient and humid conditions, as films, and with addition of sodium chloride (NaCl), sodium chlorate (NaClO₃), and sodium perchlorate (NaClO₄) salts. It was shown that glycine sustained no significant destruction in either of the non-salt samples under Mars ambient or humid conditions. However, its degradation increased in the presence of any of the three salts and under both conditions though more under humid conditions. Proline degradation followed the order No Salt > NaCl > NaClO₃ > NaClO₄ under Mars ambient conditions but the reverse order under Mars humid conditions. A mechanism is proposed to explain how water and silica participate in these degradation reactions and how it is strongly influenced by the identity of the salt and its ability to promote deliquescence. No difference was observed for tryptophan between Mars ambient and humid conditions, or for the different salts, suggesting its degradation mechanism is different compared to glycine and proline. The results reported here will help to better understand the survival of amino acids in the presence of oxychlorines and UV on Mars and thus provide new insights for the detection of organic compounds on future Mars missions.

中文翻译：

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在氯化物和氧氯盐存在下通过紫外线照射在火星上降解氨基酸

甘氨酸 (Gly)、脯氨酸 (Pro) 和色氨酸 (Trp) 的降解在紫外线驱动的氧氯生产过程中在模拟火星条件下进行研究，并在火星环境和潮湿条件下作为薄膜进行比较，并添加氯化钠（ NaCl)、氯酸钠 (NaClO ₃ ) 和高氯酸钠 (NaClO ₄ ) 盐。结果表明，在火星环境或潮湿条件下，甘氨酸在任一非盐样品中均未受到显着破坏。然而，在三种盐中的任何一种存在下和在两种条件下，其降解增加，但在潮湿条件下降解更多。脯氨酸降解顺序为 No Salt > NaCl > NaClO ₃ > NaClO ₄在火星环境条件下，但在火星潮湿条件下顺序相反。提出了一种机制来解释水和二氧化硅如何参与这些降解反应，以及它如何受到盐的特性及其促进潮解的能力的强烈影响。没有观察到火星环境和潮湿条件之间或不同盐类中色氨酸的差异，这表明与甘氨酸和脯氨酸相比，其降解机制不同。这里报告的结果将有助于更好地了解氨基酸在火星上存在氧氯和紫外线的情况下的存活情况，从而为未来火星任务中有机化合物的检测提供新的见解。