fmoc-sta-oh - Reagent grade

Cat. No.: F483671

GRADE & PURITY Reagent Grade

Storage

Room temperature

Specifications

Specifiche e purezza

Reagent grade

Condizioni di conservazione di stoccaggio

Room temperature

Grado

Reagent Grade

Application Protocols

No assay protocols (e.g., WB, IHC, IF, FC) apply to this small-molecule building block. For synthetic use, follow your laboratory’s SPPS or solution-phase coupling protocols. A general outline for SPPS cycles is provided under Reaction Conditions and Synthetic Utility; adapt equivalents and timings to your instrument and resin system.

Biological Roles

This product is a synthetic building block and is not intended for biological use in organisms. However, the embedded “statine” motif has recognized roles in chemical biology when incorporated into peptides (literature context):

• Statine is a β-hydroxy-α-amino acid analogue that can mimic the tetrahedral intermediate formed during peptide bond hydrolysis by aspartic proteases (literature). When inserted at scissile positions in peptide substrates, it can confer resistance to cleavage and modulate binding.
• Peptidomimetics containing statine have been instrumental as mechanistic probes for protease active sites, aiding in elucidating substrate specificity and transition-state stabilization without making therapeutic claims.
• The Fmoc group itself is purely a synthetic protecting group, facilitating iterative assembly; it has no biological role.

Important use note (item-specific):

• Research Use Only: as stated, this product is for research use only, not for diagnostic, therapeutic, or in vivo applications.

Practical implication for researchers:

• Incorporation of statine into short peptides enables biophysical studies (e.g., binding assays, structural studies via NMR or crystallography) of enzyme–substrate analogues, provided that the final purified constructs meet appropriate purity and characterization standards.

Buffer Applications

This item is a solid peptide building block and is not typically used to prepare laboratory buffer systems. It lacks intrinsic buffering capacity in the physiological pH range when used alone.

• For workflows involving this reagent (e.g., SPPS), buffers are generally not employed; instead, organic solvent systems (DMF, NMP, DCM) with bases (e.g., DIPEA, piperidine) are used.
• If aqueous work-up is required after solution-phase synthesis, standard buffers (e.g., phosphate, acetate) may be used for peptide handling, but these pertain to the final peptide product rather than this starting material.

Green Alternatives

In peptide synthesis, environmental impact is dominated by solvent and coupling reagent choice rather than the amino-acid building block itself. For Fmoc–Sta–OH workflows, consider the following greener substitutions (literature/industry guidance):

Comparison (general):

• DMF/NMP (traditional) vs NBP/PC/Cyrene (greener):

  • Solvation/swelling: DMF/NMP excellent; NBP/PC good for many resins; Cyrene promising but viscosity is higher.
  • Toxicity/regulatory: DMF/NMP under stricter controls; NBP and PC have improved profiles; Cyrene is bio-derived.
  • Practical note: Verify solubility of Fmoc–Sta–OH in alternatives and adjust temperature/sonication.

• DCM (traditional) vs EtOAc/2-MeTHF/CPME (greener):

  • For washes and co-solvent roles, EtOAc or 2-MeTHF reduce halogenated waste; CPME offers low peroxide formation and hydrophobicity.

• Coupling reagents:

  • Prefer DIC + Oxyma Pure over benzotriazole-based reagents to avoid explosive sensitizers (HOBt/HOAt) and reduce hazard potential.
  • Investigate ethyl cyano(hydroxyimino)acetate (Oxyma)-mediated protocols with reduced reagent excess to minimize E-factor.

Process considerations:

• Room-temperature or mild-temperature couplings to cut energy use.
• High-loading resins and optimized equivalents to reduce solvent volume per mmol.
• Flow-peptide synthesis or microwave-assisted protocols can improve atom economy and reduce cycle time; validate statine stability under your conditions first.

All substitutions require verification of performance and product quality by analytical HPLC/LC–MS.

Pharmaceutical Uses

This product is not an approved excipient and is provided strictly for research and development. It serves as a synthetic intermediate for assembling peptides/peptidomimetics that may be evaluated during drug discovery campaigns.

• Role in development chemistry (general):

  • Enables structure–activity relationship (SAR) studies by embedding a statine unit that modulates peptide backbone geometry and protease susceptibility (literature).
  • Facilitates preparation of lead-like peptidomimetics for in vitro screening and biophysical characterization.

• Pharmacopeial status: Not specified for this item; refer to CoA/Spec Sheet. There is no claim of compliance with USP/EP/JP.

• Manufacturing considerations (preclinical research):

  • Selection of protecting group strategy (Fmoc/tBu) is compatible with most parallel synthesis platforms.
  • Process analytical technology (PAT) such as in-line UV or at-line HPLC can be used to monitor coupling completeness and deprotection efficiency.

No therapeutic or clinical claims are made or implied. Any use beyond laboratory research requires appropriate validation and regulatory assessment.

Physical Properties

Item-specific physicochemical specifications are not provided in the product data. For authoritative values used for QC/release, consult the CoA/Spec Sheet.

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
• Melting point, boiling point, density, refractive index: Not specified for this item; refer to CoA/Spec Sheet.
• Solubility (general/literature guidance for Fmoc–amino acid derivatives):
  • Good solubility in DMF, NMP, DMSO; variable in DCM/CH2Cl2 and THF depending on stereochemistry and purity.
  • Poor aqueous solubility at neutral pH due to the hydrophobic Fmoc group; carboxylate solubility can be increased with mild base (e.g., DIPEA) in organic media.
• pKa/logP: Not specified for this item; refer to CoA/Spec Sheet.

Handling traits (general):

• Many Fmoc–amino acid derivatives are microcrystalline solids that are stable at ambient conditions when dry. The presence of a free β-hydroxyl can modestly increase polarity and hydrogen bonding, impacting solubility and crystallinity (literature).
• Hygroscopicity can vary; store tightly closed to avoid moisture uptake that can affect accurate weighing and coupling stoichiometry.

Note: Do not treat literature guidance as product specifications; verify with the item’s CoA/SDS for precise parameters.

Quality and Grades

• Grade/Purity: Reagent Grade (item-specific). Reagent Grade indicates suitability for general laboratory synthesis and research workflows. It typically emphasizes chemical identity and reasonable impurity control for synthetic utility, but may not meet low-UV or trace-metal specifications associated with chromatographic or semiconductor grades.

What Reagent Grade means in practice (general):

• Suitable for solid-phase peptide synthesis (SPPS), fragment coupling, and solution-phase assembly when routine analytical controls (NMR/LC–MS/HPLC) are available in-house.
• UV background is not specifically minimized (unlike HPLC grade solvents/reagents). If optical monitoring is critical (e.g., UV cleavage monitoring), verify via CoA.
• Trace water/metal/peroxide specifications: Not specified for this item; refer to CoA/Spec Sheet.

Implications for peptide chemistry:

• Fmoc materials are often qualified by HPLC purity and residual solvent content; exact cutoffs are product-specific. For highest-fidelity SPPS (e.g., long sequences), users may re-evaluate by analytical HPLC and Kaiser/Chloranil tests to benchmark coupling performance.

Stabilizers/additives:

• None stated for this item. If present in other catalog variants (e.g., added bases or anti-caking agents), these would be disclosed on the CoA/Spec Sheet.

Recommendation:

• For mission-critical assemblies (e.g., lead candidate libraries), consider running a small-scale test coupling to confirm performance under your platform conditions.

Reaction and Applications

Fmoc–Sta–OH is a specialized building block for constructing peptides and peptidomimetics that incorporate the statine motif, a β-hydroxy-α-amino acid analogue used to mimic transition states in aspartic protease substrates (literature). Key applications and practices include:

• Solid-phase peptide synthesis (SPPS):

  • Incorporated at defined sequence positions using standard Fmoc/tBu strategy.
  • Activated with HATU/HBTU/TBTU or DIC/EDC + Oxyma/HOAt; bases such as DIPEA/ collidine.
  • The β-hydroxyl may be left free or protected (varies by route); if free, minimize O-acylation (depsipeptide formation) using Oxyma-based additives, low temperature, and controlled base.

• Solution-phase coupling:

  • Carbodiimide or uronium activation with in situ ester formation followed by amine capture; careful control of stoichiometry and temperature reduces racemization/epimerization at the statine center (literature).

• Post-assembly transformations:

  • Fmoc removal with secondary amines (e.g., piperidine, piperazine, or DBU mixtures) to continue chain elongation.
  • Final global side-chain deprotection and cleavage conditions depend on the protecting groups used for the rest of the sequence; the Fmoc group is absent by this stage.

• Analytical characterization:

  • Monitor couplings by test cleavages and LC–MS/HPLC.
  • For sequences rich in hydrophobic content (Fmoc + statine), stronger eluents or gradients may be required to achieve baseline separation.

Note: Stereochemical integrity is critical to bio-relevant function; minimize base exposure time and avoid elevated temperatures during activation/coupling.

Reaction Conditions

General literature guidance for peptide assembly with Fmoc–amino acid derivatives; adjust to your platform and verify with small-scale tests.

• Fmoc deprotection:

  • 20% piperidine in DMF, 1–2 × 5–10 min at rt; alternatives: 5% piperazine in NMP/EtOH or low-DBU cocktails to reduce base strength. Monitor for potential base sensitivity of neighboring residues.

• Coupling (on-resin):

  • Typical systems: HATU/HBTU/TBTU (3–4 equiv) with DIPEA (6–8 equiv) in DMF or NMP, rt, 5–30 min for fast cycles; extend to 60–120 min for hindered sites. Alternatively, DIC (3–5 equiv) + Oxyma (3–5 equiv), rt to 40 °C, 30–120 min.
  • To suppress O-acylation at the β–OH: use Oxyma, minimize pre-activation time (<1–2 min), and keep temperature at rt; perform double coupling if necessary.

• Solution-phase amidation:

  • EDC or DIC + Oxyma in DMF/THF or DMF/DCM with DIPEA, 0–25 °C, 1–12 h. Quench and purify by flash chromatography or preparative HPLC.

• Expected outcomes (literature):

  • High coupling conversions (>95%) are typical under optimized conditions; sequences with adjacent hindered residues may require recoupling.

• Workup and analysis:

  • Wash resins thoroughly to remove uronium/guanidinium byproducts. For solution couplings, aqueous bicarbonate washes remove excess base and urea byproducts.
  • Verify by test cleavage and LC–MS; inspect for depsipeptide side-products when the β–OH is unprotected.

Safety and Handling

Hazard classification details are not supplied in the product data for this item. Always consult the SDS for authoritative information.

• GHS Classification, Signal Word, H-Statements, Pictograms: Not specified for this item; refer to SDS.

General laboratory safety considerations for Fmoc–amino acid derivatives (literature/practice):

• Likely to be combustible organic solids; avoid dust formation and ignition sources.
• May cause skin/eye irritation or respiratory irritation as dust. Use appropriate PPE: lab coat, safety glasses, nitrile gloves.
• Work in a fume hood to avoid inhalation of dust and to manage amine bases and coupling reagents typically co-used (e.g., DIPEA, HATU/HBTU/DIC/Oxyma).
• Incompatibilities: Strong oxidizers; strong acids/bases may lead to degradation (e.g., carbamate cleavage under strong base, esterification/transcarbamoylation under harsh acid).
• First aid (overview; defer to SDS):
  • Skin/eye contact: Rinse with water for several minutes; remove contaminated clothing; seek medical attention if irritation persists.
  • Inhalation: Move to fresh air; seek medical advice if symptoms occur.
  • Ingestion: Rinse mouth; do not induce vomiting; seek medical attention.
• Waste: Collect residues and contaminated materials as organic solid waste; coupling byproducts (e.g., uronium/guanidinium salts) should be segregated per institutional SOPs.

Note: Fmoc deprotection uses bases (e.g., piperidine), which are hazardous; manage separately per their SDS.

Solvent Selection

As a solid Fmoc-protected amino acid analogue, Fmoc–Sta–OH is dissolved for coupling or analytical work rather than used as a bulk solvent.

Solubility/miscibility profile (general/literature for Fmoc–AAs):

• Preferred peptide solvents: DMF, NMP, and DMSO (excellent solvating power; compatible with uronium/phosphonium and carbodiimide couplings).
• Secondary solvents: DCM/CH2Cl2 and THF can be used as co-solvents to modulate viscosity or solubility; pure DCM may be insufficient depending on stereochemistry and salt form.
• Poor in alcohols and water at neutral pH; mild base (e.g., DIPEA) can aid dissolution in polar aprotic media.

When to choose what:

• Routine SPPS: DMF remains the benchmark for swelling polystyrene resins and dissolving Fmoc–AAs and coupling additives.
• Green-leaning workflows: NBP (N-butylpyrrolidone) or PC (propylene carbonate), and Cyrene have emerged as DMF/NMP alternatives; solubility of Fmoc–Sta–OH should be confirmed empirically.
• For solution-phase couplings to hindered amines, mixtures of DMF/DCM or DMF/THF can balance solubility and reactivity.

Practical tips:

• Warm gently (ambient to ~30 °C) and sonicate to speed dissolution; avoid strong heating that can promote premature side reactions.
• Filter solutions (0.2 µm PTFE) to remove particulates before automated dispensing.
• Maintain anhydrous conditions when high coupling efficiency is required; dry solvents and use molecular sieves as needed.

Storage and Reconstitution

• Storage conditions (item-specific): Room temperature per product data. Store in a tightly closed container in a dry, well-ventilated place. Protect from prolonged exposure to light and ambient moisture.
• Shipped in: Not specified for this item; refer to CoA/Spec Sheet.

Good practice (general):

• Upon receipt, keep container tightly sealed. If frequent access is expected, consider aliquoting under dry conditions to minimize moisture uptake.
• Desiccant use is recommended in storage cabinets, especially in humid environments.
• Before critical couplings, if moisture sensitivity is suspected, dry the solid under vacuum (ambient–30 °C) for several hours.

Reconstitution/dissolution (for use):

• Dissolve the required amount in anhydrous DMF or NMP; add DIPEA as needed to aid dissolution immediately before activation/coupling. Gentle warming and sonication can assist.
• Filter solutions (0.2 µm PTFE) prior to automated dosing.

Freeze–thaw guidance:

• Not typically applicable to solids. If stock solutions are prepared, store in airtight vials under inert gas at 2–8 °C or –20 °C as compatible with solvent, and avoid repeated freeze–thaw by aliquoting. Verify stability empirically before long-term storage of solutions.

Research Use Only: as noted in the product data.

Structure and Identity

This product is an Fmoc-protected statine building block commonly denoted as Fmoc-Sta-OH, used in peptide and peptidomimetic synthesis. It combines an N-terminal 9-fluorenylmethoxycarbonyl (Fmoc) protecting group with the nonproteinogenic amino acid “statine” (4-amino-3-hydroxy-6-methylheptanoic acid) motif.

• Molecular formula: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular weight: Not specified for this item; refer to CoA/Spec Sheet.
• SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• InChIKey: Not specified for this item; refer to CoA/Spec Sheet.
• CAS: Not specified for this item; refer to CoA/Spec Sheet.

Structural features (general/literature description):

• Contains an Fmoc carbamate linked to the α-amino functionality, providing base-labile protection for Fmoc/tBu-type SPPS workflows.
• The “Sta” backbone is a β-hydroxy-α-amino acid analogue with a side-chain methyl branch, furnishing a secondary alcohol adjacent to the amide-forming center; this is responsible for the classical statine transition-state-mimic behavior in aspartic protease inhibitor motifs (literature).
• Stereochemistry: Commercial Fmoc–Sta–OH is typically supplied as a defined stereochemistry (e.g., 3S,4S or related), but the absolute configuration for this specific item is Not specified; refer to CoA/Spec Sheet.
• 2D description: An Fmoc polycyclic aromatic system (fluorene) bearing a methoxycarbonyl linker to the amino nitrogen; the backbone bears a carboxylic acid terminus for coupling and a vicinal hydroxyl group on the β-carbon relative to the amide nitrogen (literature).

Synthetic Utility

Key functional elements and their consequences for synthesis (general/literature):

• Carboxylic acid terminus (–CO2H): Engages in amide bond formation to extend peptide chains; activated by uronium/phosphonium or carbodiimide systems. Use of Oxyma helps suppress racemization and O-acylation.
• Fmoc-protected amine (carbamate): Base-labile; cleanly removed under secondary amine conditions (e.g., 20% piperidine in DMF), revealing the free amine for subsequent couplings.
• β-Hydroxyl (secondary alcohol): Can undergo undesired O-acylation during activation, forming depsipeptides. Mitigation: lower temperature, shorter activation times, appropriate additives, and nucleophilic scavengers. Alternatively, route designs may employ temporary O-protection when necessary (literature practice varies).
• Stereocenters: The statine backbone bears multiple stereocenters; base and heat can promote epimerization. Minimize base exposure and avoid prolonged pre-activation.

Retrosynthetic value:

• Enables insertion of a hydroxyethylene-like isostere within peptide backbones, a common motif in protease transition-state analogues, thus broadening accessible chemical space for peptidomimetic libraries.

Analytics and QC:

• Verify coupling efficiency by on-resin tests (e.g., Kaiser, Chloranil for secondary amines where applicable) and by LC–MS after test cleavage.
• Chiral HPLC or Marfey’s analysis on cleaved fragments can confirm stereochemical fidelity if needed.

Target Specificity

Not applicable. This product is a small-molecule building block and does not have antigen/epitope or species reactivity attributes. No clone or isotype information applies.