4-Hydroxyhygric acid is a unique non-protein imino acid (a proline analogue) isolated from the leaves of five species of the tropical leguminous tree Copaifera. It serves as a key chemical defense metabolite for the plant. Studies have demonstrated that it functions as a potent inhibitor of larval development in the seed-feeding bruchid beetle Callosobruchus maculatus and exhibits significant feeding deterrence against the leaf-feeding lepidopteran Spodoptera littoralis. By modulating insect growth and behavior, it acts as a natural biopesticide within the tropical forest ecosystem.

18:0-18:2 PE is a lipid used in drug delivery, primarily composed of unsaturated fatty acids. 18:0-18:2 PE is considered a key precursor of important odors (IOs) in Eriocheir sinensis.

Propanedial is one of the final products of lipid peroxidation and is frequently utilized to assess lipid peroxidation reactions.