Sharma A
Department of Physics, Alabama A&M University, Huntsville, AL, 35762, USA.
J Biol Phys. 2020 Sep;46(3):283-295. doi: 10.1007/s10867-020-09552-7. Epub 2020 Jul 2.
In the terrestrial dipolar magnetic field, magnetic circular dichroism (MCD) of UV sunlight by paramagnetic O in an Archean atmosphere (mostly CO and N) results in circular polarization anisotropy (~ 10). This is used to calculate enantiomeric excess (EE~10) 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.
在地球偶极磁场中，太古宙大气（主要是一氧化碳和氮气）中的顺磁性氧对紫外线阳光的磁圆二色性（MCD）导致圆偏振各向异性（约为10）。利用一个包含外消旋产物及其对映体不对称光解的模型，此结果被用于计算甘油醛（三碳糖）的对映体过量（EE约为10）。对映体过量（EE）的符号和大小随地球纬度而变化。与自发镜像对称性破缺（SMSB）模型中的随机噪声波动不同，EE的符号是确定性的，并且在益生元地球的大片区域内保持不变。其大小比随机波动的EE的平均幅度大几个数量级。MCD可以通过不对称自催化为同手性的增长提供初始EE。
