In the terrestrial dipolar magnetic field, magnetic circular dichroism (MCD) of UV sunlight by paramagnetic O 2 in an Archean atmosphere (mostly CO 2 and N 2 ) results in circular polarization anisotropy (~ 10 −10 ). This is used to calculate enantiomeric excess (EE~10 −13 ) of glyceraldehyde (3-carbon sugar) with a model that includes racemic production and asymmetric photolysis of its enantiomers. The sign and magnitude of enantiomeric excess (EE) vary with the Earth’s latitude. Unlike random noise fluctuation in spontaneous mirror symmetry breaking (SMSB) models, the sign of EE is deterministic and constant over large areas of prebiotic Earth. The magnitude is several orders greater than the mean amplitude of stochastically fluctuating EE. MCD could provide the initial EE for growth of homochirality by asymmetric autocatalysis.

中文翻译：

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太古代大气中的磁圆二色性和生物分子的不对称光解：益生元糖的对映体过量

在陆地偶极磁场中，太古宙大气（主要是CO 2 和N 2 ）中的顺磁性O 2 对UV太阳光的磁圆二色性（MCD）导致圆极化各向异性（~ 10 -10 ）。这用于计算甘油醛（3-碳糖）的对映体过量（EE~10 -13 ），其模型包括其对映体的外消旋产生和不对称光解。对映体过量 (EE) 的符号和大小随地球纬度而变化。与自发镜像对称破缺 (SMSB) 模型中的随机噪声波动不同，EE 的符号在前生命地球的大面积区域内是确定性和恒定的。幅度比随机波动 EE 的平均幅度大几个数量级。MCD 可以通过不对称自催化为纯手性的生长提供初始 EE。