Acylrest

Acylrest is a term encountered in various fields of chemistry and biochemistry to refer to the acyl portion of an acyl-containing molecule that remains after a transformation that removes or replaces another substituent. The exact meaning can vary with context, and the term is not standardized across all disciplines.

In organic chemistry, acyl groups are typically written as R-CO-. The acylrest, in this sense, denotes the acyl fragment that stays attached to a larger molecule or framework after a reaction such as cleavage, substitution, or acyl transfer. It highlights the portion that contributes the carbonyl-containing fragment to the product, as opposed to the leaving group or non-acyl portions of the starting material.

In biochemistry and lipid science, acylrest often refers to fatty acyl chains that are bound to a glycerol backbone or other core structures in lipids. Examples include palmitoyl or oleoyl groups in triglycerides and phospholipids. Here the term emphasizes the identity and role of the acyl chains separate from the backbone or headgroup of the lipid molecule.

In analytical contexts such as mass spectrometry, acylrest fragments can appear as part of fragmentation patterns, aiding the identification of fatty acids or acyl chain compositions within complex lipids or esters. Because the usage of acylrest is context-dependent, readers should consult the specific source or glossary where the term appears to determine its precise meaning in that work.