Absorption, Distribution and Excretion
Humans recover queuine from either ingested food or the gut flora. The proportion of queuine salvaged and absorbed from the normal turnover process of human microbiota has not yet been determined, but it may be significant given the number of microorganisms in the human gastrointestinal tract. Furthermore, it is believed that there may exist a dedicated transporter for queuine, considering various purines, purine-derivatives and base analogs are incapable of affecting queuine transport in competitive uptake experiments.
Data regarding the route of elimination of queuine is not readily available or accessible.
Data regarding the volume of distribution of queuine is not readily available or accessible.
Data regarding the clearance of queuine is not readily available or accessible.

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Metabolism / Metabolites
Data regarding the metabolism of queuine is not readily available or accessible.

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Biological Half-Life
Data regarding the half-life of queuine is not readily available or accessible.

Protein Binding
Data regarding the protein binding of queuine is not readily available or accessible.

Antunes S, Couto J, Ferrolho J, Sanches GS, Merino Charrez JO, De la Cruz Hernández N, Mazuz M, Villar M, Shkap V, de la Fuente J, Domingos A. Transcriptome and Proteome Response of Rhipicephalus annulatus Tick Vector to Babesia bigemina Infection. Front Physiol. 2019 Apr 2;10:318. doi: 10.3389/fphys.2019.00318. eCollection 2019. PubMed PMID: 31001128; PubMed Central PMCID: PMC6454348.

Queuine is a pyrrolopyrimidine. It has a role as an Escherichia coli metabolite. It is a conjugate base of a queuine(1+).
Queuine is a derivative of [7-Deazaguanine]. Bacteria possess the exclusive ability to synthesize queuine, which is then salvaged and passed on to plants and animals. Quantities of queuine have been found in tomatoes, wheat, coconut water, and milk from humans, cows, and goats. Humans salvage and recover queuine from either ingested food or the gut flora. All eukaryotic organisms, including humans, transform queuine to queuosine by placing it in the wobble position (anticodon) of several tRNAs including aspartic acid, asparagine, histidine, and tyrosine. Endogenously, it has been determined that queuine contributes to generating various important biochemicals like tyrosine, serotonin, dopamine, epinephrine, norepinephrine, nitric oxide, lipids, and others.
Queuine is a metabolite found in or produced by Escherichia coli (strain K12, MG1655).
Queuine has been reported in Euglena gracilis and Caenorhabditis elegans with data available.

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Drug Indication
Current and on-going research suggests queuine is a natural biochemical compound that can be found endogenously in the human body and plays an essential role in the generation of other critical bodily chemicals including tyrosine, serotonin, dopamine, epinephrine, norepinephrine, nitric oxide, lipids, and others. Such research subsequently proposes that if queuine could be utilized as a pharmaceutic, that it may be considered a so-called 'putative longevity vitamin' indicated for age-delaying and/or prolonged survival functionality (perhaps via maintaining the ongoing generation of the aforementioned bodily chemicals) for the human body.

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Mechanism of Action
Certain studies have shown that queuine-deficient mice became tyrosine deficient and expired within eighteen days of being withdrawn from a queuine containing diet. Considering tyrosine is generally a nonessential amino acid, it is presumed that the expiration of the mice was due to a resultant deficiency in the cofactor tetrahydrobiopterin (BH4) (which does contribute to the generation of tyrosine), the endogenous generation of which queuine is believed to contribute to. As a result, one of the potential mechanisms of action by which queuine may act as a vitamin for age-delaying and/or prolonged survival functionality speaks to the plausible essentiality of BH4 for partaking in activities like the hydroxylation of tryptophan to produce serotonin for numerous neurological functions like controlling executive function and playing a part in the pathophysiology of autism, attention-deficit/hyperactivity, bipolar, and schizophrenia disorders. Elsewhere, another study has also demonstrated that queuine and the use of a synthetic analog have been effective in eliciting full remission in a mouse model of multiple sclerosis, particularly via the importance of tRNA guanine transglycosylase (TGT) present in the animal model to utilize the queuine analog substrate. Essentially, animals deficient in TGT are incapable of using queuine or any synthetic analog of the biochemical to modify tRNA to produce queuosine for further related downstream pharmacodynamics and fail to respond to such therapy. Although the specific mechanism of action beyond these actions has not yet been formally elucidated, these actions suggest that some manner of modulation of protein translation may be the principal means via which this therapeutic effect is elicited. In human cells, queuine tRNA-ribosyltransferase (QTRT-1) interacts with queuine tRNA-ribosyltransferase subunit QTRTD1 to form an active queuine tRNA-ribosyltransferase. This enzyme exchanges queuine for the guanine at the wobble position of tRNAs with GU(N) anticodons (tRNA-Asp, -Asn, -His and -Tyr), thereby forming the hypermodified nucleoside queuosine.

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Pharmacodynamics
Studies have demonstrated that a deficiency in queuine in in-vitro human cells and in animals results in a decreased level of the cofactor tetrahydrobiopterin (BH4). Since BH4 is a necessary cofactor for the transformation of phenylalanine to tyrosine, of tryptophan to serotonin, of tyrosine to dopamine (dopamine, which itself is further converted into epinephrine and norepinephrine), of arginine to nitric oxide, and for the oxidation of alkyl glycerol lipids, it is proposed that queuine plays an important pharmacodynamic role in the generation and maintenance of these essential biochemical compounds.

C12H15N5O3

277.2792

277.117

72496-59-4

72496-59-4

135398670

White to off-white solid powder

-2.4

6

5

3

20

466

3

C1=C[C@@H]([C@@H]([C@H]1NCC2=CNC3=C2C(=O)NC(=N3)N)O)O

WYROLENTHWJFLR-ACLDMZEESA-N

InChI=1S/C12H15N5O3/c13-12-16-10-8(11(20)17-12)5(4-15-10)3-14-6-1-2-7(18)9(6)19/h1-2,4,6-7,9,14,18-19H,3H2,(H4,13,15,16,17,20)/t6-,7-,9+/m0/s1

2-amino-5-[[[(1S,4S,5R)-4,5-dihydroxycyclopent-2-en-1-yl]amino]methyl]-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-one

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)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

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.

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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).

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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)

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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).

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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

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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.

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