Metabolit

Metabolit is the term used in several languages for what in English is called a metabolite: a small molecule produced or consumed during metabolism. Metabolites serve as substrates, intermediates, products, and cofactors in metabolic pathways. They can be intracellular or present in extracellular fluids and can originate from endogenous processes or from the environment, such as nutrients and xenobiotics.

Primary metabolites are compounds essential for growth and maintenance, including amino acids, nucleotides, simple sugars, organic acids, and coenzymes. Secondary metabolites are not essential for growth but play roles in interactions with the environment, such as defense or signaling. Examples include antibiotics like penicillin, plant alkaloids, caffeine, terpenoids, and polyketides produced by microbes and plants.

Analytical approaches in metabolomics study metabolites comprehensively or selectively. Techniques such as mass spectrometry and nuclear magnetic resonance spectroscopy enable identification and quantification of metabolites in cells, tissues, or biofluids. Metabolomic data support insights into physiology, disease states, drug effects, and plant or microbial ecology.

The term metabolite is central to biochemistry, physiology, pharmacology, and systems biology. Understanding the metabolome—the full complement of metabolites in a system—helps link gene function, enzyme activity, and phenotype, aiding biomarker discovery and the development of therapeutics and agrochemicals.