L-Cyclopentylglycine is a naturally occurring amino acid analogue in which the side chain is a cyclopentyl group attached to the glycine backbone, giving the molecule a substituted glycine (α-amino acid) structure with a cycloalkyl hydrophobic character. It contains a free α-amino group and a free α-carboxyl group and is specified as the L stereoisomer, with the side chain lacking additional heteroatom functionality beyond the cyclopentyl ring. L-Cyclopentylglycine is used in peptide synthesis and structure-activity studies as a hydrophobic, sterically constrained amino acid building block whose cyclopentyl side chain can be incorporated into peptides to probe conformational and interaction effects.
CAT No: CP21501
L-Cyclopentylglycine is an L-configured amino acid in which the glycine backbone is substituted at the alpha position with a cyclopentyl group, producing a chiral amino acid intermediate suited to stereochemically controlled synthesis. The molecule contains a primary amino functionality and a carboxylic acid (or, depending on the supplied form, an amino-acid salt/derivative), enabling standard peptide-coupling chemistry and acid-base controlled handling. The cyclopentyl side chain provides a hydrophobic, conformationally constrained substituent that can influence backbone torsion preferences and binding-site interactions in peptide and peptidomimetic contexts. The combination of a reactive amino group and a carboxyl group also makes L-Cyclopentylglycine a practical precursor for protected amino acid derivatives and downstream functional group transformations used in fine chemical and biochemical research workflows.
1. Peptide Synthesis
L-Cyclopentylglycine is applied in peptide synthesis as an L-amino acid building block for incorporating a cyclopentylglycine residue into peptide chains via amide bond formation. The amino and carboxyl functionalities support coupling strategies compatible with common N-protection and C-activation approaches, while the hydrophobic cyclopentyl side chain can modulate local structure, solubility, and membrane partitioning trends in peptide analogs. Protected amino acid derivatives of L-Cyclopentylglycine can be used to control chemoselectivity during sequential fragment assembly and to enable selective deprotection at defined stages. Downstream peptide products can serve as research-grade substrates for biochemical assays, as reference standards for analytical characterization, and as scaffold components in peptidomimetic libraries.
2. Peptidomimetics And SAR Studies
L-Cyclopentylglycine is used in peptidomimetic construction and structure-activity relationship studies where a constrained, lipophilic side chain is incorporated to tune conformational behavior and binding interactions. The cyclopentyl group attached to the glycine-derived position can act as a sterically defined substituent that influences side-chain packing and may alter hydrogen-bonding patterns around neighboring residues. L-Cyclopentylglycine can be derivatized into appropriately protected forms for incorporation into analog series, supporting systematic modification of hydrophobic character while maintaining the stereochemical integrity of the L-center. Resulting analogs can be generated for SAR mapping, fragment comparison, and molecular design efforts that rely on consistent amino acid stereochemistry and reproducible coupling outcomes.
3. Chiral Building Block Chemistry
L-Cyclopentylglycine is employed as a chiral amino acid intermediate for stereoselective synthesis of cyclopentyl-containing derivatives used in synthetic organic chemistry. The L-configuration provides a defined stereochemical handle for downstream transformations, including conversion to N-protected amino acids, ester derivatives, or activated acid forms that participate in controlled coupling or derivatization sequences. The carboxyl functionality can be used to access C-terminal modifications, while the amino functionality enables selective functional group interconversions after protection. Downstream products can include labeled or functionalized amino acid derivatives, chiral intermediates for medicinal chemistry programs, and process-relevant feedstocks for producing cyclopentylglycine-containing fine chemicals.
4. Chemical Biology Substrates
L-Cyclopentylglycine is used in chemical biology research to generate peptide-based substrates and probes that report on enzyme recognition and processing. The amino acid residue can be incorporated into short peptide motifs where the cyclopentyl side chain contributes hydrophobic contacts and can influence substrate orientation within enzyme active sites. The presence of a reactive amino acid motif allows conversion into protected intermediates for selective labeling, enabling subsequent attachment of tags, linkers, or reporter groups through amide formation or side-chain functionalization strategies. Generated substrate analogs can support mechanistic studies, comparative enzymology experiments, and analytical method development for monitoring peptide cleavage or binding interactions.
5. Pharmaceutical Intermediate Preparation
L-Cyclopentylglycine is applied in pharmaceutical intermediate preparation as a stereochemically defined building block for producing cyclopentylglycine-containing fragments used in medicinal chemistry synthesis. The amino acid functional set supports conversion to protected amino acid derivatives and activated carboxyl intermediates that can enter multi-step routes for assembling drug-like molecules or peptidic pharmacophores. The hydrophobic cyclopentyl substituent can be leveraged to adjust physicochemical properties such as lipophilicity and conformational preferences in intermediate scaffolds. Downstream manufacturing-oriented use includes preparation of consistent, stereochemically controlled intermediates for peptide-like structures and other nitrogen-containing heteroamide motifs that require reliable amino acid coupling compatibility.
6. Analytical Standards to Characterization
L-Cyclopentylglycine is suitable for analytical research and characterization workflows requiring defined amino acid standards and reference materials. The compound's well-defined L-stereochemistry and cyclopentyl side chain enable unambiguous identification and quantification in amino acid profiling, peptide hydrolysate analysis, and method validation for chromatography and mass spectrometry. Derivatization to protected or derivatized forms can be applied to improve detectability or chromatographic behavior while preserving the stereochemical signature of the L-center. Downstream utility includes use as a calibration component for peptide synthesis monitoring, as a structural reference for confirming incorporation of cyclopentylglycine residues, and as a building block for preparing analytical derivatives used in biochemical research.
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