The stereoisomer D-phenylalanine (DPA) can be made by traditional natural and organic synthesis, either as only one enantiomer or to be a component of your racemic combination. It doesn't take part in protein biosynthesis even though it is present in proteins in tiny quantities - specially aged proteins and foods https://bromantane80111.vigilwiki.com/6514193/detailed_notes_on_quetiapine_fumarate