The heating above 400 °C of serine, cysteine, selenocysteine and threonine leads to a complete decomposition of the amino acids and to the formation in low yields of alanine for the three formers and of 2-aminobutyric acid for the latter. At higher temperature, this amino acid is observed only when sublimable α-alkyl-α-amino acids are present, and with an enantiomeric excess dependent on several parameters. Enantiopure or enantioenriched Ser, Cys, Sel or Thr is not able to transmit its enantiomeric excess to the amino acid formed during its decomposition. The presence during the sublimation-decomposition of enantioenriched valine or isoleucine leads to the enantioenrichment of all sublimable amino acids independently of the presence of many decomposition products coming from the unstable derivative. All these studies give information on a potentially prebiotic key-reaction of abiotic transformations between α-amino acids and their evolution to homochirality.

中文翻译：

---

恶劣条件下蛋白质氨基酸之间不对称性的转移。


丝氨酸、半胱氨酸、硒代半胱氨酸和苏氨酸加热到400°C以上会导致氨基酸完全分解，并以低产率形成前三种丙氨酸和后一种2-氨基丁酸。在较高温度下，仅当存在可升华的 α-烷基-α-氨基酸时才能观察到该氨基酸，并且对映体过量取决于几个参数。对映体纯或对映体富集的 Ser、Cys、Sel 或 Thr 不能将其对映体过量传递给其分解过程中形成的氨基酸。对映体富集的缬氨酸或异亮氨酸在升华分解过程中的存在导致所有可升华氨基酸的对映体富集，而与来自不稳定衍生物的许多分解产物的存在无关。所有这些研究都提供了有关 α-氨基酸之间非生物转化及其向纯手性进化的潜在前生物关键反应的信息。