Acylkarnitin

Acylkarnitin, more commonly spelled acylcarnitine, refers to a family of molecules derived from carnitine that carry acyl groups across cell membranes, particularly into mitochondria for β‑oxidation. Each acylcarnitine consists of a carnitine core linked via an ester bond to a fatty acyl chain of varying length and saturation. The normal physiological role of acylcarnitines is to transport long‑chain fatty acids from the cytosol into the mitochondrial matrix, where they are metabolized to generate ATP. In this process, carnitine acetyltransferase and carnitine palmitoyltransferases shuttle the acyl moiety in a reversible manner, making the carnitine cycle essential for efficient energy production.

The concentration and pattern of acylcarnitines in plasma, urine, or tissues have become valuable metabolic biomarkers. Elevated levels of specific acylcarnitines can indicate defects in mitochondrial fatty‑acid oxidation, fatty‑acid synthesis disorders, or other metabolic conditions such as carnitine palmitoyltransferase II deficiency. Newborn screening programs routinely measure a panel of acylcarnitines to detect inborn errors of metabolism early. In research, detailed acylcarnitine profiling, often using liquid chromatography–mass spectrometry, helps elucidate metabolic fluxes, drug effects, or nutritional status.

Acylkarnitin or acylcarnitine metabolism is thus a central node linking diet, energy homeostasis, and disease. Ongoing investigations into the regulation of the carnitine system continue to refine our understanding of metabolic flexibility and its therapeutic manipulation.