Fmoc-OSu targets amino groups, transferring the Fmoc protecting group to amines. As a chemical reagent, its primary utility is in peptide synthesis, where it is used to protect the amino group of amino acids during peptide chain assembly. The Fmoc group is base-labile and can be removed under mild conditions, ensuring high purity in peptide assembly. It does not have a biological target.

Fmoc-OSu does not exhibit pharmacological activity in vitro. As a chemical reagent, it is used to introduce Fmoc protection rather than as a bioactive compound. In vitro studies using this compound focus on its chemical reactivity in peptide synthesis reactions. The reagent is considered the most efficient for the selective preparation of N-Fmoc derivatives of hydroxy-amino acids in high yield.

Fmoc-OSu is not a pharmacologically active compound and does not have defined in vivo activity as a drug. Its primary value is as a chemical reagent in synthetic chemistry, where it serves as a protecting group reagent for the preparation of peptides. It is not intended for in vivo administration in any therapeutic context.

In vitro assays for Fmoc-OSu focus on its chemical properties as a protecting group reagent. A standard protocol involves reacting the reagent with an amino acid in the presence of a base to form the Fmoc-protected amino acid. The reaction is typically carried out in an organic solvent such as DMF or DCM. The progress of the reaction and the purity of the product are monitored by HPLC or TLC.

In vitro cellular assays using Fmoc-OSu are not performed, as the compound is a chemical reagent used in organic synthesis rather than a bioactive molecule. Its use is confined to the laboratory, where it serves as a protecting group reagent for the preparation of peptides. It is not designed for cell culture studies.

In vivo animal studies with Fmoc-OSu are not conducted, as the compound is a chemical reagent rather than a pharmacologically active agent. Its use is confined to the laboratory, where it serves as a protecting group reagent for the preparation of peptides.

Fmoc-OSu is not a drug candidate, and pharmacokinetic data are not available. As a chemical reagent, it is designed for use in organic synthesis rather than systemic administration. Its use is confined to in vitro synthetic applications.

Fmoc-OSu is generally considered to have low toxicity, consistent with its use as a chemical reagent. The compound should be stored dry. Standard laboratory safety precautions, including the use of personal protective equipment, are recommended.

[1]. Formation of Fmoc-beta-alanine during Fmoc-protections with Fmoc-OSu. J Pept Sci. 2008 Jun;14(6):763-6.

[2]. Fmoc N-hydroxysuccinimide ester: A facile and multifunctional role in N-glycan analysis. Anal Chim Acta. 2020 Sep 22;1131:56-67.

Fmoc-OSu undergoes a Lossen rearrangement under basic conditions: ring-opening of the succinimide moiety followed by rearrangement to an isocyanate, which leads to H-β-Ala-OH and then Fmoc-β-Ala-OH after Fmoc-protection with an additional equivalent of Fmoc-OSu [1].
Fmoc-β-Ala-OH impurity was found during Fmoc-protection of H-α-Me-Val-OH (1.8% isolated), H-β-cyclopropyl-Ala-OH (9% in crude, reduced to 0.5% after two recrystallizations with yield drop from 99% to 43%), and H-tBu-Gly-OH (2% in crude, recrystallization cut yield from 89% to 56%) [1].
Using 1.0 eq or 0.9 eq Fmoc-OSu reduced Fmoc-β-Ala-OH formation to 0.2% or traces, respectively, compared to 6.0% with 1.25 eq in the Fmoc-protection of H-Asn(Trt)-OH [1].
Commercially available Fmoc-amino acid derivatives (Fmoc-Lys(Boc)-OH, Fmoc-Trp-OH, Fmoc-Ala-OH, Fmoc-Cys(Trt)-OH) were found to contain 0.1-0.5% Fmoc-β-Ala-OH [1].
In N-glycan analysis, Fmoc-OSu labeling combined with microwave-assisted PNGase F digestion (20 min) and reaction at 40 °C for 1 h at pH 8.5 with 150 mM Fmoc-OSu gave optimal derivatization efficiency [2].
Fluorescence intensity of Fmoc-OSu-labeled N-glycans was approximately 5 times higher than Fmoc-Cl labeled and 13 times higher than 2-AA labeled; also 1.5 times higher than AQC labeled [2].
The method showed good reproducibility (CVs below 3.11%, mean CV 1.44%) and linearity (R²=0.9998) for Man5GlcNAc2 [2].
Free reducing N-glycans can be recovered from Fmoc-labeled N-glycans by treatment with morpholine in DMF at 37 °C for 1 h, followed by diethyl ether extraction and centrifugation [2].
Applied to serum N-glycan analysis for lung squamous cell cancer: 10 chromatographic peaks showed significant changes (p<0.05); composite ROC AUC of 0.989 with 90.6% sensitivity and 100% specificity; PCA of peaks 3,6,8,20 distinguished cancer from healthy controls [2].
Recommendation: Replace Fmoc-OSu with Fmoc-Cl to avoid Fmoc-β-Ala-OH formation; if replacement is not possible, use equimolar amount of Fmoc-OSu [1].
Fmoc-OSu (N-(9-Fluorenylmethoxycarbonyloxy)succinimide, CAS 82911-69-1) is a reagent used for introducing the Fmoc protecting group onto amino acids in peptide synthesis. It is a crystalline reagent widely employed in solid-phase peptide synthesis (SPPS). It is intended for research use only.

C19H15NO5

337.3261

337.095

82911-69-1

134122

White to off-white solid powder

1.4±0.1 g/cm3

494.3±38.0 °C at 760 mmHg

150-153 °C(lit.)

252.7±26.8 °C

0.0±1.3 mmHg at 25°C

1.662

2.32

0

5

5

25

524

0

WMSUFWLPZLCIHP-UHFFFAOYSA-N

InChI=1S/C19H15NO5/c21-17-9-10-18(22)20(17)25-19(23)24-11-16-14-7-3-1-5-12(14)13-6-2-4-8-15(13)16/h1-8,16H,9-11H2

(2,5-dioxopyrrolidin-1-yl) 9H-fluoren-9-ylmethyl carbonate

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~100 mg/mL (~296.45 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (7.41 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (7.41 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (7.41 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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 (Please use freshly prepared in vivo formulations for optimal results.)