Fmoc-beta-(3-benzothienyl)-Ala-OH

Fmoc-beta-(3-benzothienyl)-Ala-OH is an Fmoc-protected β-substituted alanine bearing a 3-benzothienyl aromatic side chain, combining a chiral amino acid stereocenter with a thioether-containing heteroaromatic ring. The molecule contains an Fmoc carbamate on the α-amino group and a free carboxylic acid at the α-position, enabling controlled peptide coupling while maintaining orthogonality to the heteroaromatic functionality. The benzothiophene-like motif contributes increased π-surface area and sulfur/heteroatom electronic character, which can influence nucleophilicity, oxidative stability, and noncovalent binding in peptide analogs. The β-substitution pattern relative to alanine can affect conformational preferences and side-chain presentation, making the compound a chiral intermediate suited for peptide building block preparation and downstream structure refinement.

1. Peptide Synthesis

Fmoc-beta-(3-benzothienyl)-Ala-OH is used in solid-phase peptide synthesis and solution-phase peptide coupling as an Fmoc-protected amino acid with a free carboxylic acid for amide bond formation. The Fmoc carbamate supports standard deprotection strategies to generate a reactive α-amine while preserving the benzothienyl heteroaromatic side chain under typical coupling conditions. The β-(3-benzothienyl) substitution can modulate local backbone geometry and side-chain projection, supporting the construction of peptides where aromatic and sulfur-containing interactions are required for molecular recognition. The resulting peptide products can be carried forward into SAR studies, binding assays, and peptide analog libraries that probe how β-substitution and aromatic heterocycles alter structure-function relationships.

2. Peptidomimetics And SAR Studies

Fmoc-beta-(3-benzothienyl)-Ala-OH is applied in peptidomimetic design where β-substituted alanine scaffolds introduce steric and electronic features beyond canonical α-substitution patterns. The chiral center and the β-benzothienyl group provide a defined stereochemical handle for generating analog series that can be compared across structure-activity relationship studies. The heteroaromatic sulfur and fused ring system can participate in hydrophobic contacts, π-stacking, and polarizability-driven interactions, while the carboxylic acid enables conversion into amide-linked motifs or protected derivatives for iterative scaffold assembly. The compound can therefore serve as a controlled building block for generating peptide-like structures that incorporate benzothienyl pharmacophore elements in a synthetically consistent manner.

3. Side-Chain Functionalization

Fmoc-beta-(3-benzothienyl)-Ala-OH is suitable for amino acid derivatization and side-chain functionalization workflows that start from a protected, stereodefined backbone. The benzothienyl substituent contains heteroatom-rich aromatic character that can be leveraged for subsequent electrophilic substitution, cross-coupling, or selective oxidation-state tuning depending on the downstream target. The Fmoc group allows orthogonal manipulation of the α-amine during intermediate preparation, while the free carboxylic acid can be activated for formation of amides, esters, or linkers used in conjugation chemistry. The resulting functionalized amino acid derivatives can be incorporated into larger constructs such as labeled peptides, affinity probes, or modular fragments for chemical biology and materials-oriented molecular assembly.

4. Chemical Biology Probes

Fmoc-beta-(3-benzothienyl)-Ala-OH is employed in chemical biology research to build peptide-based probes that incorporate a heteroaromatic, sulfur-containing motif for controlled binding and detection. The Fmoc-protected amino acid format supports reproducible incorporation into peptide sequences, enabling systematic variation of the β-benzothienyl residue position and stereochemistry. The heteroaromatic ring can serve as a recognition element that may enhance membrane affinity, stabilize hydrophobic contacts, or provide a distinct spectroscopic or chromatographic signature for analytical tracking. Downstream peptide probe constructs can be used in binding characterization, competitive displacement experiments, and mechanistic studies where amino acid side-chain identity and stereochemical placement govern molecular recognition.

5. Pharmaceutical Manufacturing Intermediates

Fmoc-beta-(3-benzothienyl)-Ala-OH can be integrated into pharmaceutical intermediate preparation and process chemistry for the manufacture of Fmoc-protected peptide building blocks and peptide-derived intermediates. The presence of an Fmoc-protected α-amino group and a free carboxylic acid supports scalable peptide coupling strategies and conversion into activated forms suitable for controlled amide formation in manufacturing flows. The benzothienyl heteroaromatic functionality provides a defined structural motif for generating drug-like peptide fragments or peptidomimetic intermediates that require consistent stereochemistry and robust handling during synthesis. The compound's protected amino acid architecture aligns with common industrial synthetic planning for downstream assembly into larger peptide or peptidomimetic products used in specialty chemical production.

6. Analytical Research Standards

Fmoc-beta-(3-benzothienyl)-Ala-OH is suitable for analytical research as a chiral amino acid reference and as a defined precursor for generating peptide standards. The Fmoc moiety and the benzothienyl side chain create characteristic mass spectrometric and chromatographic features that can support method development for peptide quantification, identity confirmation, and impurity profiling. The free carboxylic acid enables conversion into derivatives that match expected analytical forms, such as amide-linked fragments or labeled analogs, improving comparability across analytical workflows. Incorporation into short peptide sequences can further provide robust internal standards for monitoring coupling outcomes and stereochemical integrity during amino acid derivative synthesis and peptide construction.

1. The effect of sex on immune responses to a homocitrullinated peptide in the DR4-transgenic mouse model of Rheumatoid Arthritis

2. Uncarboxylated osteocalcin decreases insulin-stimulated glucose uptake without affecting insulin signaling and regulators of mitochondrial biogenesis in myotubes

3. Investigating Potential Interactions Between Neurohypophyseal Peptides, their Drug Analogs, and Coagulation Factor VIII

4. Immune responses to homocitrulline-and citrulline-containing peptides in rheumatoid arthritis

5. Immune responses to peptides containing homocitrulline or citrulline in the DR4-transgenic mouse model of rheumatoid arthritis