Boc-Arg(NO)-OH , CAS No.3581950

CAS: 3581950 Cat. No.: B951523 Formula: C₁₁H₂₁N₅O₆ Molecular Weight: 319.310

Storage

Room temperature

Specifications

Storage

Room temperature

Names and Identifiers

Canonical Smiles

CC(C)(C)OC(=O)NC(CCCN=C(N)N[N+](=O)[O-])C(=O)O

IUPAC Name

5-[[amino(nitramido)methylidene]amino]-2-[(2-methylpropan-2-yl)oxycarbonylamino]pentanoic acid

InChIKey

OZSSOVRIEPAIMP-UHFFFAOYSA-N

INCHI

1S/C11H21N5O6/c1-11(2,3)22-10(19)14-7(8(17)18)5-4-6-13-9(12)15-16(20)21/h7H,4-6H2,1-3H3,(H,14,19)(H,17,18)(H3,12,13,15)

Molecular Weight

319.310

Taxonomic Classification

Taxonomy Tree

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

• Kingdom: Organic compounds
• Superclass: Organic acids and derivatives
• Class: Carboxylic acids and derivatives
• Subclass: Amino acids, peptides, and analogues
• Intermediate Tree Nodes: Amino acids and derivatives
• Direct Parent: Alpha amino acids and derivatives
• Alternative Parents: Nitro fatty acids Nitroguanidines Branched fatty acids Nitramines Carbamate esters Propargyl-type 1,3-dipolar organic compounds Monocarboxylic acids and derivatives Carboxylic acids Carboximidamides Organic zwitterions Organic salts Organic oxides Hydrocarbon derivatives Carbonyl compounds
• Molecular Framework: Aliphatic acyclic compounds
• Substituents: Alpha-amino acid or derivatives - Nitro fatty acid - Nitroguanidine - Branched fatty acid - Fatty acyl - Fatty acid - Nitramine - Carbamic acid ester - Guanidine - Organic nitro compound - Carboxylic acid - Monocarboxylic acid or derivatives - Organic 1,3-dipolar compound - Carboximidamide - Allyl-type 1,3-dipolar organic compound - Propargyl-type 1,3-dipolar organic compound - Organonitrogen compound - Organic salt - Hydrocarbon derivative - Organic nitrogen compound - Organooxygen compound - Organic oxygen compound - Carbonyl group - Organic zwitterion - Organic oxide - Aliphatic acyclic compound
• Description: This compound belongs to the class of organic compounds known as alpha amino acids and derivatives. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon), or a derivative thereof.
• External Descriptors: Not available

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: 319.310 g/mol
• XLogP3: 0.300
• Hydrogen Bond Donor Count: 4
• Hydrogen Bond Acceptor Count: 7
• Rotatable Bond Count: 9
• Exact Mass: 319.149 Da
• Monoisotopic Mass: 319.149 Da
• Topological Polar Surface Area: 172.000 Ų
• Heavy Atom Count: 22
• Formal Charge: 0
• Complexity: 439.000
• Isotope Atom Count: 0
• Defined Atom Stereocenter Count: 0
• Undefined Atom Stereocenter Count: 1
• 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 tested biological assay protocols are provided for this SKU. For synthetic use, a generic coupling protocol (literature-guidance) is provided for convenience:

Generic coupling (solution phase):

• To a dry DMF solution of the amine component (1.0 equiv) at 0–5 °C, add Boc-Arg(NO)-OH (1.1 equiv), Oxyma (1.1 equiv), and DIPEA (3 equiv). Stir 5–10 min, then add HATU (1.1 equiv). Allow to warm to 20–25 °C and stir 1–2 h.
• Monitor by LC-MS. Upon completion, dilute with EtOAc, wash with 0.5 M NaHCO3, water, and brine. Dry (Na2SO4), filter, concentrate, and purify by chromatography under conditions compatible with the N–NO group (neutralized silica or reverse-phase).

Note: This is general literature guidance only and not an item-specific validated protocol. Optimize stoichiometry, solvent, and temperature for your substrate and confirm stability of the nitroso group.

Biological Roles

Item-specific biological data: Not specified for this item; refer to primary literature and CoA if applicable.

General context (biochemistry/literature):

• Arginine is a proteinogenic amino acid with a guanidinium side chain that participates in electrostatic interactions, hydrogen bonding, and catalysis in enzymes. In proteins and peptides, arginine often mediates binding to phosphate-rich biomolecules (e.g., nucleic acids) via bidentate interactions.
• Nitrosation of guanidino nitrogens to form N-nitrosoguanidines significantly alters basicity, hydrogen-bonding capacity, and charge distribution, affecting peptide conformation and binding properties. Such modifications are studied as models for post-translational modifications and reactive nitrogen species chemistry.
• In chemical biology, N-nitrosated arginine derivatives are used as probes or standards to examine nitrosative stress pathways and to understand how side-chain modifications impact recognition by enzymes and binding partners (research use only, no clinical claims).

Use considerations:

• The presence of Boc (Nα protection) renders the derivative non-native; it is intended for synthetic incorporation rather than direct biochemical assays unless deprotected or otherwise adapted.
• Any biological evaluations should be designed with controls to deconvolute the effects of nitrosation vs. protection state.

Buffer Applications

This product is a protected amino acid building block and is not typically used to prepare laboratory buffers or maintain pH. If your workflow involves aqueous stages (e.g., workups or analytical HPLC):

• Choose buffers that do not contain strong acids capable of removing Boc or perturbing the N–NO group (avoid TFA in preparative aqueous phases unless intentional deprotection is desired).
• Volatile buffers such as ammonium formate/acetate at near-neutral pH can be compatible with LC-MS analysis of related compounds (general guidance).

Green Alternatives

While item-specific green metrics are not provided, greener process choices can be made when employing Boc-Arg(NO)-OH (general/literature guidance):

• Solvent substitution:
  • Replace DCM with 2-MeTHF or CPME for solution couplings and extractions when solubility permits.
  • Consider EtOAc or Me-THF in place of toluene/heptane for workups.
  • Water/EtOH co-solvent systems for crystallization when feasible.
• Reagent selection:
  • Prefer less hazardous coupling systems (e.g., DIC + Oxyma) over benzotriazole-based additives; minimize use of HOBt due to explosive hazard when dry.
  • Use recyclable bases (e.g., 2,6-lutidine) and minimize stoichiometric excess.
• Waste minimization:
  • Telescoping activation and coupling steps; in-process solvent recovery for DMF/EtOAc.

Comparison snapshot (literature):

• DCM vs 2-MeTHF: 2-MeTHF is biorenewable and lower toxicity; however, resin swelling and solubility of polar Boc-amino acids may be inferior—pilot a small-scale screen.
• DMF vs Cyrene/PolarClean: Emerging greener dipolar aprotics can work for some couplings; viscosity and base compatibility must be validated.

Caveats:

• The N–NO functionality can be sensitive; validate any solvent/reagent switch on small scale to confirm chemical stability and coupling efficiency.

Pharmaceutical Uses

No pharmacopeial listing or excipient role is specified for this item; refer to the CoA/Spec Sheet. This product is supplied strictly for research and laboratory use.

General/literature context:

• Boc-Arg(NO)-OH can serve as an intermediate in the synthesis of peptide leads and peptidomimetics where modulation of arginine basicity and H-bonding is desired.
• In process chemistry, protected amino acid intermediates are often used to assemble target sequences before global deprotection and purification steps. Specifications for residual solvents, optical purity, and impurity profiles are application-specific and must be defined by the user’s quality system.

Compliance note:

• Do not use in humans or for clinical diagnostics. Any translation toward GMP manufacturing would require independent qualification, specifications, and change control.

Physical Properties

Item-specific values:

• Appearance: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet.
• Other specs (mp, bp, density, UV cutoff, water/peroxide/metals): Not specified for this item; refer to CoA/Spec Sheet.

General/literature expectations for Boc-protected amino acids and N-nitrosated guanidines (for planning only):

• Physical state: usually off-white to pale solid for Boc-protected amino acid derivatives; hygroscopicity can vary.
• Solubility (literature): good in polar aprotic organic solvents (DMF, DMSO), moderate in dichloromethane/ethyl acetate/methanol; poor in alkanes and many nonpolar solvents. Water solubility reduced by Boc; ionization of the carboxyl may increase aqueous solubility at basic pH.
• pKa (literature trends): α-CO2H pKa ~2–3; guanidinium pKa is strongly perturbed by N-nitrosation (substantially less basic than native arginine). Exact values depend on regiochemistry and should be determined experimentally for this item.
• Stability (literature): Boc is acid-labile (e.g., TFA cleaves). N-nitrosoguanidines can be sensitive to strong acids, heat, and photolysis; avoid prolonged bright light and elevated temperatures.

Always confirm exact, item-specific values on the CoA/Spec Sheet.

Quality & Grades

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

Guidance on typical quality attributes for protected amino acid building blocks (general):

• Purity reporting: Often specified by HPLC area% and corroborated by NMR/HRMS. Low levels of starting amino acid, over-nitrosated species, or Boc-deprotected byproducts are common impurities to monitor.
• Residual solvents/metals: For solid-phase peptide synthesis (SPPS) and medicinal chemistry, limits may be set on residual solvents and catalytic metals; exact limits are item-specific and must be verified on the CoA.
• Optical purity: For L-derivatives, enantiomeric excess (ee) or specific rotation may be reported; confirm on CoA.
• Stabilizers: None are typical for Boc-protected amino acids; if any stabilizer or antioxidant is used for nitroso integrity, it will be declared on the Spec Sheet.

What the grade implies (general definitions):

• “Peptide/Protected amino acid grade”: emphasizes high chemical purity and low moisture for efficient coupling; low colored impurities for cleaner SPPS.
• “Analytical/AR grade”: suitable for general lab use; may not meet stringent SPPS needs.

Recommendation: Match your application (SPPS vs. solution-phase coupling vs. method development) to the certified specifications on the CoA for this SKU.

Reaction & Applications

Manufacturer Applications: Not specified beyond “For research use only.” The following expands typical uses for this scaffold (general/literature):

Primary application: building block for modified peptides and peptidomimetics where the arginine side chain is N-nitrosated.

• Peptide coupling: Condense Boc-Arg(NO)-OH with amines using EDC/HOBt, DIC/Oxyma, or uronium/phosphonium reagents (HATU, HBTU, PyBOP). Avoid excessive acid exposure that may compromise Boc or the N–NO moiety.
• Fragment ligation: Use in solution-phase fragment couplings to install N-nitrosoguanidine motifs site-selectively on arginine residues.
• Side-chain chemistry: The N–NO group can serve as a handle for subsequent transformations (e.g., controlled denitrosation or conversion to other N-functionalized guanidines) under mild conditions (literature), enabling late-stage diversification.
• Analytical method development: Reference standard for studying nitrosation chemistry in amino acid derivatives; useful in mechanistic NO-donor/inhibitor model systems (non-clinical, research only).

Practical tips (literature):

• Base selection: DIPEA, NMM, or collidine in DMF/DCM. Excess strong base can provoke side reactions at the N–NO.
• Additives: Oxyma Pure or HOAt-like substitutes can improve coupling while lowering racemization.
• Temperature: Typically 0–25 °C for activation/coupling. Elevated temperature can accelerate side reactions or nitroso loss.
• Monitoring: HPLC with UV at 214/230 nm and MS detection; N–NO chromophore may absorb in visible range depending on environment.

Reaction Conditions

Item-specific, validated conditions are not provided. The following are general, literature-informed guidelines for coupling Boc-Arg(NO)-OH:

Typical amide coupling (solution or on-resin):

• Solvent: DMF (anhydrous). Alternatives: DCM, NMP, or DMF/DCM blends depending on solubility and resin swelling.
• Base: DIPEA (2–5 equiv) or NMM (2–4 equiv). Minimize prolonged exposure to strong base.
• Activator: HATU or HBTU (1.0–1.2 equiv) with Oxyma additive to suppress side reactions; or DIC (1.1–1.3 equiv) + Oxyma (1.1–1.3 equiv).
• Temperature: 0–25 °C for activation; coupling commonly at 20–25 °C. Avoid heating unless validated.
• Time: 0.5–2 h typical; monitor by Kaiser or chloranil tests (on resin) and by LC-MS/HPLC (solution).

Workup/purification (general):

• Quench residual activators with dilute amine or wash sequences (on resin). For solution, aqueous bicarbonate/brine washes followed by silica or reverse-phase chromatography; protect N–NO from strong acid on silica (consider neutral or base-deactivated media).

Expected outcomes:

• High conversions achievable under mild conditions; yields depend on sequence context and resin choice. Validate on small scale.

Stability notes:

• Avoid strong acids (TFA) unless intentionally deprotecting Boc; assess effect on N–NO prior to scale-up. Limit light exposure during extended reactions.

Safety & Handling

Authoritative safety information must be taken from the SDS for this SKU.

Item-specific hazard data (from Product Data):

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

General safety considerations for Boc-protected, N-nitrosated guanidines (literature/prudent practice):

• Potential hazards: N-nitroso functionalities are of toxicological concern and can be carcinogenic in some cases. Handle with heightened caution, minimize dust and aerosols, and avoid skin contact.
• PPE: lab coat, nitrile gloves, safety glasses or goggles; use in a fume hood.
• Incompatibilities: Avoid strong acids (can promote deprotection and possible nitrosation/denitrosation chemistry), strong oxidizers, and reducing agents that can decompose N–NO groups. Avoid prolonged exposure to heat and light.
• First aid (general): in case of contact, rinse affected area with water for 15 minutes; if inhaled, move to fresh air; seek medical attention according to SDS guidance.
• Spill/cleanup: avoid dust formation; collect solids with suitable absorbent; dispose in compliance with institutional and regulatory requirements.
• Storage: See “Storage & Reconstitution” tab; follow SDS for segregation and container labeling.

Note: Do not infer GHS classification from these general remarks; consult the SDS for this specific SKU.

Solvent Selection

Item-specific solvent data: Not specified for this item; refer to CoA/Spec Sheet.

General/literature guidance for Boc-protected arginine derivatives bearing N–NO groups:

• Polarity and miscibility: Typically soluble in polar aprotic solvents such as DMF and DMSO. Often moderately soluble in dichloromethane (DCM), ethyl acetate, methanol, and acetonitrile; poorly soluble in alkanes and cycloalkanes.
• SPPS context: DMF remains the workhorse solvent for Fmoc-SPPS; for Boc-chemistry or fragment coupling, DCM or mixtures (DCM/DMF) are common for swelling polystyrene resins and dissolving protected amino acids.
• Aqueous workup: Boc reduces aqueous solubility; basification can increase solubility of the carboxylate. Avoid strong acid during dissolution to minimize unwanted transformations of the N–NO group.
• Drying and quality: Use anhydrous, amine-free solvents for coupling (especially with acid chlorides/anhydrides or uronium/phosphonium reagents). Dry DMF/CH2Cl2 and molecular sieves (3 Å or 4 Å) help minimize hydrolysis.

Comparison notes (literature):

• DMF vs DMSO: DMF usually preferred for couplings due to lower viscosity and better resin diffusion; DMSO useful for highly polar substrates.
• DCM vs EtOAc: DCM provides superior resin swelling; EtOAc is greener but may offer lower solubility for polar protected amino acids.
• ACN: good for LC-compatible processes and some solution couplings; check solubility case-by-case.

Storage & Reconstitution

Item-specific conditions (from Product Data):

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

General handling/storage guidance for Boc-Arg(NO)-OH (literature/prudent practice):

• Protect from light and moisture; store in a tightly closed, inert-atmosphere container if possible (e.g., argon-filled desiccator) to preserve the N–NO functionality.
• Avoid prolonged exposure to heat; room-temperature storage is acceptable per Product Data, but cooler, dry, and dark conditions further enhance stability for long-term storage.
• After opening: recap promptly, purge headspace with inert gas when feasible, and return to desiccator. Record open date for inventory control.

Reconstitution/dissolution:

• For stock solutions, use anhydrous DMF, DMSO, or DCM (as solubility permits). Filter through PTFE (0.2 μm) if particulates occur.
• For analytical solutions, prepare fresh to minimize potential slow decomposition of N–NO; store aliquots at 2–8 °C, protected from light, and use within a few days unless stability is verified.

Note: For any deviations (e.g., refrigerated shipping, special stabilizers), consult the lot-specific CoA/Spec Sheet and the SDS.

Structure & Identity

Brief description: Boc-Arg(NO)-OH is a protected, nitrosated arginine derivative designed for peptide and modified-peptide synthesis. It features an Nα-tert-butyloxycarbonyl (Boc) protecting group and an N-nitroso modification on the guanidino side chain of arginine.

Item-specific identifiers (from Product Data):

• CAS: 3581950 (as provided)
• CID: 3581950 (as provided)
• InChIKey: 271777 (as provided)
• SMILES: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular Formula: Not specified for this item; refer to CoA/Spec Sheet.
• Molecular Weight: Not specified for this item; refer to CoA/Spec Sheet.

Structural features (general/literature description):

• Core backbone: α-amino acid (arginine) with free carboxylic acid (−CO2H), α-amine protected as Boc (−NH–C(O)–O–tBu).
• Side chain: guanidino group (−NH–C(=NH)–NH2 in arginine) converted to an N-nitrosoguanidine motif (−N(NO)–C(=NH)–NH−) or closely related regioisomer depending on nitrosation site (literature).
• Stereochemistry: typically L-configuration at the α-carbon for peptide use (literature), unless otherwise specified on CoA.
• 2D description in words: a Boc-protected α-amine linked to a three-methylene side chain terminating in an N-nitrosated guanidinium; terminal carboxylate present as acid.

Notes:

• Exact regiochemistry of nitrosation (Nω vs Nε within guanidine) and stereochemistry should be confirmed on the product CoA/Spec Sheet for this specific SKU.

Synthetic Utility

Functional group set enabling synthesis (general/literature):

• Carboxylic acid (−CO2H): amenable to activation/coupling (acid chlorides, mixed anhydrides, active esters; uronium/phosphonium reagents) to form amide bonds with amines on resins or in solution.
• Nα-Boc protecting group: orthogonal to many side-chain protections; removable with TFA or HCl in anisole/scavengers. Its presence suppresses α-amine nucleophilicity during side-chain manipulations.
• N-nitrosoguanidine side chain: tunable handle—can be maintained to modulate properties, or converted/removed under controlled conditions (literature). Its electron-withdrawing character reduces basicity and can alter coupling rates and solubility.

Retrosynthetic value:

• Provides a convergent entry to nitroso-arginine motifs late in a sequence, avoiding harsh on-resin nitrosation.
• Facilitates SAR exploration by toggling side-chain electronics without altering backbone stereochemistry.

Named/typical transformations (literature):

• Carbodiimide couplings (DCC/DIC) with Oxyma/HOAt analogs to reduce racemization.
• Uronium/phosphonium methods (HATU, HBTU, PyBOP) for high-efficiency amide formation.
• Selective deprotection: Boc removal with TFA, followed by downstream guanidine-side chemistry as needed.

Note: Confirm compatibility of the N–NO group with chosen activators and bases; run micro-scale trials to balance efficiency and integrity.

Target Specificity

Not applicable. This product is a small-molecule building block and is not an antibody, enzyme, or affinity reagent. No target-binding specificity, isotype, or clone information applies.