Cyclooctyne-O-NHS ester is a cleavable ADC bridge used for the synthesis of antibody active molecule conjugates (ADCs). Cyclooctyne-O-NHS ester is a reagent for click chemistry. It has Alkyne groups and could undergo CuAAc (copper-catalyzed azide-alkyne cycloaddition reaction) with compounds bearing Azide groups.

Physicochemical Properties

Molecular Formula	C14H17NO5
Molecular Weight	279.29
Exact Mass	279.11
CAS #	1425803-45-7
PubChem CID	118384301
Appearance	White to off-white solid powder
LogP	1.2
Hydrogen Bond Donor Count	0
Hydrogen Bond Acceptor Count	5
Rotatable Bond Count	5
Heavy Atom Count	20
Complexity	456
Defined Atom Stereocenter Count	0
SMILES	O=C(ON1C(CCC1=O)=O)COC2C#CCCCCC2
InChi Key	KSXCIPWSNSHGIM-UHFFFAOYSA-N
InChi Code	InChI=1S/C14H17NO5/c16-12-8-9-13(17)15(12)20-14(18)10-19-11-6-4-2-1-3-5-7-11/h11H,1-4,6,8-10H2
Chemical Name	(2,5-dioxopyrrolidin-1-yl) 2-cyclooct-2-yn-1-yloxyacetate
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

Targets	Cleavable Linker
ln Vitro	ADCs are made up of an antibody and an ADC cytotoxin that are joined together by an ADC linker.
References	[1]. Design and synthesis of tumor-targeting theranostic drug conjugates for SPECT and PET imaging studies. Bioorg Chem. 2018 Feb;76:458-467.

Solubility Data

Solubility (In Vitro)

DMSO : 100 mg/mL (358.05 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 6.25 mg/mL (22.38 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 62.5 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. Solubility in Formulation 2: ≥ 5 mg/mL (17.90 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 50.0 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. Solubility in Formulation 3: ≥ 5 mg/mL (17.90 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 50.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.5805 mL	17.9025 mL	35.8051 mL
	5 mM	0.7161 mL	3.5805 mL	7.1610 mL
	10 mM	0.3581 mL	1.7903 mL	3.5805 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.