[vixen99]

You can make these things in a lab. However Phind said "In summary, while scientists have proposed various models for how biological homochirality may have emerged, there is currently no known example of mixed protein chirality occurring in nature. Biological molecules appear to exhibit almost exclusive homochirality at the molecular level."

[ethbr1]

It makes sense, I guess. Why would something natural want to interact with both chiralities of a target? Usually there's a reason for one... and the other is unrelated.