Life on Earth uses a common set of l-amino acids (l-aa) to construct proteins and d-nucleosides (d-Nu) to form nucleic acids, which serve as the carrier of genetic information. Herein, we reveal the intrinsic mechanism of chiral selection of l-aa and d-Nu from the perspective of chemical origin of life. This work employed 15N-labeled l-aa and performed one-pot synthesis of nucleotide amidate of amino acid (N-aa-NMP) using equal amounts of l-15N-aa and d-14N-aa with d-/l-Nu in the aqueous solution of trimetaphosphate, generating l-15N-aa-NMP and d-14N-aa-NMP, respectively. The 31P-NMR data indicated that l-aa was preferentially selected during the formation of N-aa-NMP in the presence of d-Nu. Surprisingly, d-aa was preferred over l-aa in the presence of l-Nu. Further analysis revealed that l-15N-aa-d-NMP vs. d-14N-aa-l-NMP and d-14N-aa-d-NMP vs. l-15N-aa-l-NMP were mirror isomers of each other, respectively. These data suggest that there could be a set of chiral systems opposite to that on Earth, which infers there might be a world of life that is a mirror image of the Earth.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |