Llantionina

Llantionina is a term encountered in some Spanish-language texts to denote lanthionine, a non-proteinogenic amino acid that forms part of certain natural products known as lantibiotics. In English-language literature, the compound is widely known as lanthionine.

Lantibiotics are ribosomally synthesized and post-translationally modified peptides produced by Gram-positive bacteria; lanthionine residues create thioether bridges that stabilize the macrocyclic structure and contribute to antimicrobial activity. Llantionina thus refers to the thioether-linked amino acid residues within these peptides.

Biosynthesis involves dehydration of serine or threonine to dehydroalanine or dehydrobutyrine, followed by a Michael-type addition of cysteine thiol to form the lanthionine linkage. Both the cross-links and ring structures are essential for the biological function of lantibiotics such as nisin, epidermin, and subtilin.

In research, lanthionine is used in studies of peptide maturation, structure–activity relationships, and in the synthesis of modified peptides. The term llantionina appears mainly in non-English literature as a variant spelling; cross-referencing with lanthionine clarifies usage.