FSY-OSO2F modified with the isotope 18F can be used as a tracer for subcutaneous tumor MCF-7. FSY-OSO2F is taken up by MCF-7 cells by regulating L-Tyr, ASC and ASC2 transporters. FSY-OSO2F can visualize glioma U78MG after labeling with 18F.

Physicochemical Properties

Molecular Formula	C9H10FNO5S
Molecular Weight	263.24280500412
Exact Mass	263.026
CAS #	1839622-49-9
PubChem CID	118561836
Appearance	Typically exists as solid at room temperature
LogP	-1
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	7
Rotatable Bond Count	5
Heavy Atom Count	17
Complexity	358
Defined Atom Stereocenter Count	1
SMILES	C(O)(=O)[C@H](CC1=CC=C(OS(F)(=O)=O)C=C1)N
InChi Key	IVWVAUUBEKCCJQ-QMMMGPOBSA-N
InChi Code	InChI=1S/C9H10FNO5S/c10-17(14,15)16-7-3-1-6(2-4-7)5-8(11)9(12)13/h1-4,8H,5,11H2,(H,12,13)/t8-/m0/s1
Chemical Name	(2S)-2-amino-3-(4-fluorosulfonyloxyphenyl)propanoic acid
Synonyms	FSY-OSO2F; 1839622-49-9; (S)-2-Amino-3-(4-((fluorosulfonyl)oxy)phenyl)propanoic acid; (2S)-2-amino-3-{4-[(fluorosulfonyl)oxy]phenyl}propanoic acid; (2S)-2-AMINO-3-(4-[(FLUOROSULFONYL)OXY]PHENYL)PROPANOIC ACID; orb2566212; SCHEMBL17318149;
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
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	Amino acid transporters (LAT1/ASCT2 substrate) [1]
ln Vitro	FSY-OSO2F exhibited time-dependent uptake in U87MG glioblastoma cells, reaching plateau at 60 min. Competitive inhibition assays with 2 mM leucine reduced uptake by 82%, confirming LAT1 transporter involvement [1]
ln Vivo	PET/CT imaging in U87MG xenograft mice showed rapid tumor uptake of FSY-OSO2F (peak SUV = 3.2 at 15 min post-injection). Tumor-to-muscle ratio reached 8.5 at 60 min, significantly higher than clinical tracer [18F]FET (ratio = 4.1, p<0.01) [1]
Cell Assay	Cellular uptake kinetics: U87MG cells seeded in 24-well plates (2×10⁵/well) incubated with FSY-OSO2F (37 kBq/well) at 37°C. Cells harvested at 2, 5, 15, 30, 60 min, washed with ice-cold PBS, lysed, and radioactivity measured by gamma counter. Results normalized to protein content [1] Transporter inhibition: Cells pre-treated with 2 mM leucine for 30 min before adding FSY-OSO2F. Uptake measured after 15 min incubation [1]
Animal Protocol	PET imaging: BALB/c nude mice with U87MG tumors (150-200 mm³) anesthetized and injected intravenously with FSY-OSO2F (5-7 MBq in 100 μL saline). Dynamic PET scans performed for 60 min. Biodistribution study conducted at 60 min post-injection (n=4) [1]
ADME/Pharmacokinetics	Blood clearance: Rapid elimination from blood with t₁/₂ = 12.3 ± 1.5 min (initial phase) and t₁/₂ = 98.7 ± 10.2 min (terminal phase) [1] Biodistribution (60 min post-IV): Tumor uptake: 4.32 ± 0.41 %ID/g Liver: 1.05 ± 0.12 %ID/g Kidney: 12.68 ± 1.53 %ID/g Muscle: 0.51 ± 0.07 %ID/g [1] Excretion: Primarily renal with 75.2 ± 6.3% injected dose excreted in urine within 60 min [1]
References	[1].Design of Novel 18F-Labeled Amino Acid Tracers Using Sulfur 18F-Fluoride Exchange Click Chemistry. ACS Med Chem Lett. 2024 Jan 25;15(2):294-301.
Additional Infomation	Blood clearance: Rapid elimination from blood with t₁/₂ = 12.3 ± 1.5 min (initial phase) and t₁/₂ = 98.7 ± 10.2 min (terminal phase) [1] Biodistribution (60 min post-IV): Tumor uptake: 4.32 ± 0.41 %ID/g Liver: 1.05 ± 0.12 %ID/g Kidney: 12.68 ± 1.53 %ID/g Muscle: 0.51 ± 0.07 %ID/g [1] Excretion: Primarily renal with 75.2 ± 6.3% injected dose excreted in urine within 60 min [1]

Solubility Data

Solubility (In Vitro)

Typically soluble in DMSO (e.g. 10 mM)

Solubility (In Vivo)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples. Injection Formulations (e.g. IP/IV/IM/SC) Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] *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. Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline) Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline) Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline) Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil) Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Oral Formulations Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). Oral Formulation 3: Dissolved in PEG400 Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose Oral Formulation 6: Mixing with food powders Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.7988 mL	18.9941 mL	37.9881 mL
	5 mM	0.7598 mL	3.7988 mL	7.5976 mL
	10 mM	0.3799 mL	1.8994 mL	3.7988 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.