4-Thouridine is a ribonucleoside analog extensively used in RNA analysis and (m)RNA labeling. 4-Thouridine inhibits rRNA synthesis and induces nucleolar stress response.

Physicochemical Properties

Molecular Formula	C9H12N2O5S
Molecular Weight	260.2670
Exact Mass	260.046
CAS #	13957-31-8
PubChem CID	3032615
Appearance	White to yellow solid powder
Density	1.7±0.1 g/cm3
Melting Point	139-140℃ (ethanol )
Index of Refraction	1.733
LogP	-0.21
Hydrogen Bond Donor Count	4
Hydrogen Bond Acceptor Count	6
Rotatable Bond Count	2
Heavy Atom Count	17
Complexity	374
Defined Atom Stereocenter Count	4
SMILES	C1=CN(C(=O)NC1=S)[C@H]2[C@@H]([C@@H]([C@H](O2)CO)O)O
InChi Key	ZLOIGESWDJYCTF-XVFCMESISA-N
InChi Code	InChI=1S/C9H12N2O5S/c12-3-4-6(13)7(14)8(16-4)11-2-1-5(17)10-9(11)15/h1-2,4,6-8,12-14H,3H2,(H,10,15,17)/t4-,6-,7-,8-/m1/s1
Chemical Name	1-[(2R,3R,4S,5R)-3,4-dihydroxy-5-(hydroxymethyl)oxolan-2-yl]-4-sulfanylidenepyrimidin-2-one
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

ln Vitro	4-Thiouridine (0–10 μM) labels and suppresses emerging rRNA without moderating rRNA synthesis in a substantial way [1]. 4-Thiouridine (≥50 μM) significantly suppresses the synthesis and processing of rRNA [1].
References	[1]. 4-thiouridine inhibits rRNA synthesis and causes a nucleolar stress response. RNA Biol. 2013 Oct;10(10):1623-30.
Additional Infomation	4-thiouridine is a thiouridine in which the oxygen replaced by sulfur is that at C-4. It has a role as an affinity label and an antimetabolite. It is a thiouridine and a nucleoside analogue. 4-Thiouridine has been reported in Streptomyces libani with data available. A photoactivable URIDINE analog that is used as an affinity label.

Solubility Data

Solubility (In Vitro)

H2O : ≥ 100 mg/mL (~384.22 mM) DMSO : ~100 mg/mL (~384.22 mM)

Solubility (In Vivo)

Solubility in Formulation 1: ≥ 2.5 mg/mL (9.61 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. Solubility in Formulation 2: ≥ 2.5 mg/mL (9.61 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.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	3.8422 mL	19.2108 mL	38.4216 mL
	5 mM	0.7684 mL	3.8422 mL	7.6843 mL
	10 mM	0.3842 mL	1.9211 mL	3.8422 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.