pascaliin

Pascaliin is a fictional natural product commonly cited in educational and speculative literature to illustrate aspects of peptide-based antibiotics and macrocyclic synthesis. It is not described in established chemical databases and has no verified experimental data.

In the standard fictional narratives, Pascaliin is a macrocyclic peptide, sometimes described as a depsipeptide, featuring a 12- to 14-membered ring that incorporates non-proteinogenic amino acids. The ring's rigidity and lipophilicity are said to contribute to its stability in biological environments and to its selective activity against certain Gram-positive bacteria. Its structure is typically assigned and debated using hypothetical NMR and mass spectrometry data, with stereochemistry inferred from biosynthetic gene cluster models.

Discovery stories place Pascaliin in a fictional marine microbiome associated with a remote archipelago. Its biosynthesis is often depicted as arising from a hybrid polyketide synthase–nonribosomal peptide synthetase (PKS-NRPS) pathway, illustrating common themes in natural product assembly.

Because Pascaliin is not real, there are no peer-reviewed studies on its pharmacology or toxicity. In educational contexts, it serves to demonstrate methods of natural product isolation, structural elucidation, synthetic challenges of macrocycles, and the interpretation of hypothetical bioactivity data. It also highlights how structure-activity relationships guide antibiotic design in real-world research.