Ile-His - ≥98% , CAS No.97284-12-3

CAS: 97284-12-3 Cat. No.: I978124 PubChem CID: 7019081

GRADE & PURITY ≥98%

Storage

Room temperature

Specifications

Specifications & Purity

≥98%

Storage

Room temperature

Purity

≥98%

Names and Identifiers

Canonical Smiles

CCC(C)C(C(=O)NC(CC1=CN=CN1)C(=O)O)N

IUPAC Name

(2S)-2-[[(2S,3S)-2-amino-3-methylpentanoyl]amino]-3-(1H-imidazol-5-yl)propanoic acid

InChIKey

QNBYCZTZNOVDMI-HGNGGELXSA-N

INCHI

1S/C12H20N4O3/c1-3-7(2)10(13)11(17)16-9(12(18)19)4-8-5-14-6-15-8/h5-7,9-10H,3-4,13H2,1-2H3,(H,14,15)(H,16,17)(H,18,19)/t7-,9-,10-/m0/s1

Isomeric SMILES

CC[C@H](C)[C@@H](C(=O)N[C@@H](CC1=CN=CN1)C(=O)O)N

PubChem CID

7019081

Taxonomic Classification

Taxonomy Tree

• Kingdom Organic compounds
  • Superclass Organic acids and derivatives
    • Class Carboxylic acids and derivatives
      • Subclass Amino acids, peptides, and analogues
        • Level5 Peptides
          • Level6 Dipeptides

• Kingdom: Organic compounds
• Superclass: Organic acids and derivatives
• Class: Carboxylic acids and derivatives
• Subclass: Amino acids, peptides, and analogues
• Intermediate Tree Nodes: Peptides
• Direct Parent: Dipeptides
• Alternative Parents: Histidine and derivatives Isoleucine and derivatives N-acyl-L-alpha-amino acids Alpha amino acid amides Imidazolyl carboxylic acids and derivatives N-acyl amines Heteroaromatic compounds Secondary carboxylic acid amides Amino acids Carboxylic acid salts Azacyclic compounds Carboxylic acids Monocarboxylic acids and derivatives Organic oxides Organic zwitterions Organic salts Carbonyl compounds Organopnictogen compounds Hydrocarbon derivatives Monoalkylamines
• Molecular Framework: Aromatic heteromonocyclic compounds
• Substituents: Alpha-dipeptide - Histidine or derivatives - Isoleucine or derivatives - N-acyl-alpha amino acid or derivatives - N-acyl-alpha-amino acid - N-acyl-l-alpha-amino acid - Alpha-amino acid amide - Alpha-amino acid or derivatives - Imidazolyl carboxylic acid derivative - N-acyl-amine - Fatty amide - Fatty acyl - Azole - Imidazole - Heteroaromatic compound - Carboxamide group - Secondary carboxylic acid amide - Amino acid or derivatives - Amino acid - Carboxylic acid salt - Azacycle - Carboxylic acid - Organoheterocyclic compound - Monocarboxylic acid or derivatives - Primary aliphatic amine - Organic zwitterion - Organic salt - Amine - Organic oxygen compound - Organic nitrogen compound - Hydrocarbon derivative - Carbonyl group - Organic oxide - Organopnictogen compound - Primary amine - Organooxygen compound - Organonitrogen compound - Aromatic heteromonocyclic compound
• Description: This compound belongs to the class of organic compounds known as dipeptides. These are organic compounds containing a sequence of exactly two alpha-amino acids joined by a peptide bond.
• External Descriptors: dipeptide

Data sources

1. Djoumbou Feunang Y, Eisner R, Knox C, Chepelev L, Hastings J, Owen G, Fahy E, Steinbeck C, Subramanian S, Bolton E, Greiner R, and Wishart DS. ClassyFire: Automated Chemical Classification With A Comprehensive, Computable Taxonomy. Journal of Cheminformatics, 2016, 8:61.

DOI: 10.1186/s13321-016-0174-y

Chemical and Physical Properties

• Molecular Weight: 268.310 g/mol
• XLogP3: -2.200
• Hydrogen Bond Donor Count: 4
• Hydrogen Bond Acceptor Count: 5
• Rotatable Bond Count: 7
• Exact Mass: 268.154 Da
• Monoisotopic Mass: 268.154 Da
• Topological Polar Surface Area: 121.000 Ų
• Heavy Atom Count: 19
• Formal Charge: 0
• Complexity: 324.000
• Isotope Atom Count: 0
• Defined Atom Stereocenter Count: 3
• Undefined Atom Stereocenter Count: 0
• Defined Bond Stereocenter Count: 0
• Undefined Bond Stereocenter Count: 0
• The total count of all stereochemical bonds: 0
• Covalently-Bonded Unit Count: 1

Application Protocols

No item-specific tested application protocols are provided for this dipeptide. General guidance:

• Preparation of stock solutions

  • Weigh the required amount quickly to minimize moisture uptake. Dissolve in water or dilute acid (e.g., 0.01–0.1 M HCl) to the desired concentration (commonly 1–100 mM for biochemical assays). Adjust pH if necessary.
  • For LC–MS standards, prepare 1–10 mM stocks in water or 50:50 water/acetonitrile with 0.1% formic acid; store aliquots frozen to minimize freeze–thaw.

• Filtration and sterilization

  • Pass solutions through 0.20–0.22 µm low-protein-binding filters before use in sensitive assays.

• Metal-binding assays

  • Use chelex-treated buffers; titrate metals at controlled pH (5.5–7.0) and monitor by UV, CD, ITC, or MS.

These are literature-based, general-use suggestions. For validated, application-specific parameters, consult primary methods and adapt to your system.

Biological Roles

• General biochemical context (literature; no clinical claims)

  • Dipeptides like Ile-His are relevant to nutrient absorption studies via proton-coupled oligopeptide transporters (PEPT1/PEPT2) and can serve as model substrates to probe transport kinetics, specificity, and pH dependence.
  • Histidine’s imidazole confers metal-binding and acid–base catalysis capabilities; Ile-His can weakly coordinate metal ions (e.g., Zn2+, Cu2+) via the imidazole nitrogen and terminal groups, aiding studies of metal–peptide interactions.
  • Charge state is pH dependent: at physiological pH, the peptide typically exists as a zwitterion; the imidazole side chain (pKa ~6.0–6.2) can modulate net charge and binding interactions around neutral pH.
  • Enzymatic turnover: dipeptidases and aminopeptidases can hydrolyze Ile-His; rates depend on sequence, pH, and enzyme source, making it useful as a kinetic probe.

• Spectroscopic implications

  • UV: imidazole-containing peptides show strong peptide-bond absorption ~214–220 nm and weak bands near 280 nm; CD spectroscopy can report on backbone conformation in various solvents.

• Practical notes for biological work

  • Prepare fresh aqueous solutions; filter sterilize if needed for cell-free assays.
  • Limit DMSO content in biological systems to ≤1–2% v/v to preserve assay integrity.
  • For metal-binding assays, use metal-free buffers (chelexed) to control background.

Buffer Applications

Ile-His is not a standard buffering reagent. However, the histidine side chain offers modest buffering capacity near pH ~6 due to the imidazole (literature pKa ~6.0–6.2).

• Practical guidance (general)

  • If used incidentally in formulations, do not rely on Ile-His as the primary buffer. Instead, select established buffers (e.g., phosphate pH 6–8, acetate pH 4–5.5, HEPES pH 6.8–8.2) and consider that Ile-His may contribute minor buffering near pH 6.
  • For precise pH control, use validated buffer components; treat Ile-His as a solute/ligand rather than a buffering agent.

• Recipes and buffer systems

  • Not typically applicable for this compound; choose a dedicated buffer appropriate to your assay and maintain ionic strength to support peptide solubility and stability.

Green Alternatives

This product is a small peptide building block, not a process solvent. “Green alternatives” therefore concern media and coupling choices rather than replacing the compound itself.

• Greener media for handling and analysis (literature/guidance)

  • Prefer water or aqueous buffers over organic solvents wherever feasible.
  • If an organic co-solvent is needed, ethanol is generally greener than acetonitrile or DMF for analytical dilutions (when compatible with the method).

• Peptide coupling considerations

  • Use water-compatible coupling systems (e.g., EDC·HCl with NHS or HOBt alternatives like OxymaPure) in mixed aqueous media when possible.
  • Minimize use of DMF/NMP; consider 2-MeTHF or CPME for workups where appropriate, though many peptide couplings still require polar aprotic solvents.

• Small comparison (general)

  • DMF/NMP: excellent solubilizers for coupling; regulatory and environmental concerns; difficult to remove from waste streams.
  • Aqueous buffer + water-compatible carbodiimide: reduced solvent burden; may require careful pH control and give slower reactions.

• Operational tips

  • Scale reactions judiciously to reduce solvent use.
  • Employ lyophilization rather than large-volume precipitations where practical.
  • Evaluate micellar catalysis or aqueous-organic emulsions for greener transformations if compatible with your protecting group strategy.

Pharmaceutical Uses

• Research Use Note: For research use only (from Product Data). No clinical or therapeutic claims.

• General formulation context (literature/guidance)

  • Small peptides like Ile-His may be used as model compounds in preformulation studies (solubility profiling, stability vs pH/ionic strength), device/material compatibility testing, or as analytical standards in peptide quantification methods.
  • Counterion/salt form affects hygroscopicity and solubility; confirm whether the material is supplied as a free acid/base or with a specific counterion on the CoA.
  • Excipiency: Not a recognized pharmacopeial excipient; any use would be exploratory in laboratory settings only.

• Quality considerations for formulation R&D

  • Confirm purity (HPLC), identity (MS), and water content (KF) prior to formulation.
  • Assess pH-dependent stability; avoid extended exposure to strong acid/base and elevated temperatures.
  • Evaluate adsorption to plastics or filters in low-concentration preparations; pre-rinse or use low-binding materials.

Physical Properties

• Item-specific specs (Product Data)

  • Appearance: Not specified for this item; refer to CoA/Spec Sheet.
  • Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.

• Literature/computed properties (for context; not product specifications)

  • Molecular weight (C12H20N4O3): ~268.32 g/mol
  • Acid–base behavior: typical dipeptide with one α-NH2 (pKa ~8–9, literature), one α-COOH (pKa ~2–3, literature), and histidine imidazole (pKa ~6.0–6.2, literature); overall is amphoteric and zwitterionic around neutral pH.
  • Solubility: dipeptides like Ile-His are generally water-soluble, with enhanced solubility in dilute aqueous acid (e.g., 0.1 M HCl) and reduced solubility in most nonpolar organic solvents; miscible with water, sparingly to poorly soluble in alcohols depending on ionization state (literature, general peptide behavior).
  • LogP/logD: strongly pH-dependent due to ionizable groups; neutral logP not typically reported; at neutral pH expect negative logD (literature peptide trend).
  • Optical rotation: depends on concentration, solvent, and stereochemistry (if L/L), typically nonzero for chiral dipeptides; specific value not established here.
  • Melting/decomposition: many small peptides decompose before melting; specific temperature not established for this compound.

• Refractive index, density, BP/MP: Not typically meaningful for solid peptides; no literature consensus values located here. Consult primary literature or CoA if required.

Quality & Grades

• Item-specific grade/purity: Not specified for this item; refer to CoA/Spec Sheet.

• How to interpret grades for peptide reagents (general guidance)

  • Research grade: suitable for most biochemical and synthetic workflows; typical assays include HPLC purity and MS identity. Low water and residual solvents are preferred but must be confirmed on the CoA.
  • Peptide purity reporting: commonly given as % area by analytical RP-HPLC and confirmed by MS/HRMS; counterions (e.g., acetate, trifluoroacetate) and residual salts are sometimes reported. For dipeptides, chiral purity (enantiomeric/diesteromeric) may also be specified.
  • Stabilizers: simple dipeptides usually ship without stabilizers; if present (e.g., TFA salt), note implications for pH and mass balance.

• What to check on receipt

  • Identity confirmation (MS), purity (% by HPLC), water content (Karl Fischer), residual solvents, counterion content, and specific rotation if stereochemistry is critical.
  • Salt form: free acid vs salt (e.g., acetate) affects solubility and pH—verify on CoA.

• UV profile for QC

  • Histidine’s imidazole absorbs in the UV (around 210–220 nm and weakly ~280 nm); if using HPLC-UV, choose wavelengths accordingly. Exact extinction coefficients are method-dependent; confirm experimentally.

Reaction & Applications

• Research-use context (from Product Data): For research use only.

• Typical applications for Ile-His (literature/general)

  • Biochemical studies: model system for peptide conformations, metal-binding via histidine imidazole, and proton-coupled transport studies due to dipeptide nature.
  • Enzymology: substrate/ligand for dipeptidases, peptidyl transporters (e.g., PEPT1/PEPT2 in model systems), and histidine-dependent enzymes.
  • Analytical standards: retention-time markers in peptide LC–MS method development or to benchmark imidazole-containing peptide behavior.
  • Coordination/organometallic studies: histidine’s imidazole can chelate transition metals; Ile-His can serve as a simple bidentate/monodentate ligand model in aqueous coordination chemistry.

• Practical notes

  • pH control: protonation of the imidazole near pH ~6 modulates charge and metal-binding; consider pH when designing binding assays.
  • Sample prep: dissolve in water or dilute acid; filter through 0.2 µm to remove particulates prior to HPLC/biophysical measurements.
  • Quantitation: UV at 214–220 nm is sensitive; imidazole gives weak absorption near 280 nm—optimize wavelength for your detector.
  • Stability: avoid extended exposure to pH >9 or <1 at elevated temperatures to limit hydrolysis.

• Not typically applicable

  • As a solvent/reagent for organic reactions in bulk synthesis—see “Synthetic Utility” instead for use as a building block.

Reaction Conditions

• General conditions for peptide couplings involving Ile-His (literature; guidance only)

  • Solvents: dry DMF or NMP are common for activation/condensation; DCM or 2-MeTHF used for extractions; water/buffer for final handling.
  • Coupling reagents: EDC·HCl (with Oxyma or NHS), DIC (with Oxyma), HATU/HBTU/TBTU with DIPEA or NMM as base. Typical molar ratios: 1.0 eq peptide acid, 1.1–1.5 eq coupling reagent, 1.1–2.0 eq base, 1.1–1.5 eq nucleophile.
  • Temperatures: 0–25 °C for activation; 20–40 °C for coupling. Many couplings proceed at RT within 0.5–4 h; monitor by LC–MS or analytical HPLC.
  • pH control (aqueous EDC): maintain pH 4.5–6.0 (MES/acetate buffers) to balance carboxyl activation and amine nucleophilicity while limiting hydrolysis.
  • Protecting groups: if histidine imidazole is unprotected, risk of N-acylation on imidazole increases under strong activation; using Trt-protection or milder reagents reduces side reactions.

• Purification and workup

  • Quench uronium/carbodiimide residues by aqueous workup; remove urea byproducts (e.g., from EDC) via extraction or precipitation.
  • Purify by RP-HPLC (C18) with water–acetonitrile gradients containing 0.1% formic acid or TFA (method-dependent). Collect fractions, lyophilize to obtain TFA or formate salts unless exchanged.

• Yields (indicative, literature)

  • Fragment couplings of dipeptides routinely afford 60–90% isolated yield under optimized conditions; actual results depend on sequence, protection, and purification losses.

Safety & Handling

• Item-specific safety data (from Product Data)

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

• General safety guidance for small peptides (literature/standard lab practice)

  • Expected hazard: Many unprotected dipeptides are of low acute toxicity and are often not classified as hazardous; however, always consult the product-specific SDS for authoritative information.
  • PPE: wear lab coat, safety glasses, and appropriate gloves (e.g., nitrile). Avoid generating dust or aerosols. Handle in a clean, dry environment.
  • Incompatibilities: strong oxidizers and strong acids/bases may degrade peptides (hydrolysis, racemization). Avoid prolonged exposure to elevated temperatures and moisture.
  • First aid (general): in case of inhalation, move to fresh air; for skin/eye contact, rinse with water. If ingested, rinse mouth with water. Seek medical attention if symptoms persist. Follow SDS.
  • Spill response: avoid dust formation; collect solid with minimal dust generation and dispose according to local regulations.
  • Waste: dispose as organic laboratory waste; peptides may be amenable to aqueous waste streams depending on local rules—follow institutional guidelines.

• Stability considerations

  • Peptide bonds are generally stable at neutral pH but hydrolyze under strong acid/base or high temperature.
  • The histidine imidazole can coordinate metals; minimize unintended metal contamination if chelation is a concern in assays.
  • Light sensitivity is typically low, but store per product guidance to prevent degradation.

Solvent Selection

• Polarity and miscibility (general peptide behavior)

  • Water: primary solvent; solubility improves with slight acidification (e.g., 0.01–0.1 M HCl) if needed.
  • Aqueous buffers: compatible across pH ~2–8, noting pH-dependent ionization (imidazole pKa ~6–6.2). Avoid strong base for prolonged periods to limit hydrolysis/racemization.
  • Alcohols (MeOH, EtOH): limited solubility unless water is present; co-solvent use can aid lyophilization and sample prep.
  • Aprotic solvents (DMSO, DMF): can dissolve at higher concentrations when water solubility is insufficient; dilute into aqueous media promptly to avoid prolonged exposure.

• Practical selection tips

  • For analytical HPLC: aqueous mobile phases with acetonitrile or methanol; add 0.1% formic acid for LC–MS.
  • For biochemical assays: prepare stock in water or buffer near neutral pH; adjust pH to ensure full dissolution without exceeding stability limits.
  • For solid-phase manipulations or coupling: use dry DMF/NMP during synthesis; isolate then exchange into aqueous systems for biological work.

• Comparison (literature-based, qualitative)

  • Water/buffer: best for bioassays; lowest toxicity.
  • DMSO: high solubilizing power; use minimal % in assays (≤1–2% v/v typically) to maintain biological compatibility.
  • DMF: excellent for coupling steps; not desirable in biological assays—remove by evaporation or precipitation.

Storage & Reconstitution

• Item-specific storage (from Product Data)

  • Storage Conditions: Room temperature.
  • Shipped In: Not specified for this item; refer to CoA/Spec Sheet.

• General best practices for peptides (guidance)

  • Solid material: keep tightly closed in a desiccator at ambient temperature as recommended; protect from prolonged exposure to humidity and light. If long-term storage is intended, many labs store peptides at 2–8 °C or −20 °C desiccated; follow your QA policy.
  • Reconstitution: dissolve in water or dilute acid (e.g., 0.01–0.1 M HCl). Adjust pH gradually if needed to reach complete dissolution. Avoid strong base.
  • Working solutions: prepare fresh when possible. For longer storage, aliquot and freeze (−20 °C) to avoid repeated freeze–thaw. Thaw on ice and mix gently to avoid foaming.
  • Container considerations: use low-binding plastics or glass for low-concentration solutions to minimize adsorption.

• Stability notes

  • Avoid extended exposure to temperatures >40 °C and to extreme pH to minimize hydrolysis or side reactions at the imidazole.
  • If the product is supplied as a specific salt or with counterions, solubility and pH upon dissolution will vary—verify on the CoA/Spec Sheet.

Structure & Identity

Ile-His is the dipeptide isoleucyl–histidine (N-terminus: Ile; C-terminus: His), a small peptidic building block featuring a branched aliphatic residue and an imidazole-containing aromatic residue.

• Item-specific identifiers (from Product Data)

  • SKU: I978124
  • Product Name: Ile-His
  • CAS: 97284-12-3
  • PubChem CID: 7019081
  • InChIKey: 301270 (as provided; format appears truncated)
  • SMILES: Not specified for this item; refer to CoA/Spec Sheet.

• Computed/literature structural information (for reference; not item-specific specs)

  • Common name: L-Isoleucyl-L-histidine (configuration often implied for “Ile-His” in peptide context; verify on CoA)
  • Functional groups: primary amine (N-terminus), amide (peptide bond), carboxylic acid (C-terminus), imidazole ring (histidine side chain), branched aliphatic side chain (isoleucine)
  • Molecular formula (dipeptide, unprotected termini): C12H20N4O3 (literature/computed)
  • Molecular weight: ~268.32 g/mol (literature/computed)
  • 2D description: N-terminal isoleucine (sec-butyl side chain) linked via a peptide bond to histidine; histidine bears a 1,3-imidazole on the β-methylene of the side chain; C-terminus is a free carboxylate/acid depending on pH; imidazole can be neutral or protonated near physiological pH.

• Notes

  • Stereochemistry (L/L) is typical but not guaranteed by the provided data; confirm configuration and protecting groups (if any) on the CoA/Spec Sheet.

Synthetic Utility

• Role as a building block

  • Ile-His provides an N-terminal isoleucine and a C-terminal histidine, enabling extension at either end to build larger peptides or peptidomimetics with an internal His residue adjacent to Ile.
  • The histidine imidazole offers a handle for metal coordination, cross-linking, or selective modification (e.g., metal-catalyzed labeling, diazonium chemistry on imidazole under controlled conditions).

• Transformations and strategies (literature/general)

  • Peptide elongation: couple C-terminus to amine-bearing fragments using carbodiimides (EDC/DIC) with additives (Oxyma, HOBt alternative) or uronium reagents (HATU/HBTU) in DMF/NMP; protect the N-terminus if selective C-terminal activation is required.
  • N-terminal acylation: introduce acyl, succinyl, or PEG groups to modulate properties; control pH and use appropriate coupling agents.
  • Side-chain considerations: histidine often protected as Trt or Boc during SPPS; deprotected sequences can be accessed convergently by fragment coupling where Ile-His is one fragment.
  • Conjugation chemistry: activate the C-terminus as an NHS ester for bioconjugation; or use click-compatible handles introduced via N-acylation.

• Analytical utility

  • Serves as a sequence-defined standard to validate LC–MS method performance for imidazole-containing peptides and assess retention mechanisms (ion-pairing vs gradient strength).

Target Specificity

Not applicable. This product is a small molecule/peptide building block, not an antibody or affinity reagent. No antigen/epitope, species reactivity, clone, or isotype data apply.

Frequently Asked Questions

What is the purity of this product?

This product is supplied at ≥98% purity (chemical assay). Lot-specific values are stated on the Certificate of Analysis.

How should this product be stored?

Store at room temperature.

What are the CAS number, molecular formula and molecular weight?

The CAS Number is 97284-12-3. InChIKey QNBYCZTZNOVDMI-HGNGGELXSA-N.

What documentation is provided?

Available product documentation, including Certificates of Analysis (COA), Safety Data Sheets (SDS), and specification sheets, is shown in the product document area. Document availability and access follow the current site policy.