Size | Price | Stock | Qty |
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1mg |
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5mg |
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Other Sizes |
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Targets |
GABAA receptors (GABAARs); glycine receptors (GlyRs)
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ln Vitro |
Picrotin has an IC50 value of 13.1 μM and is sensitive to α2 GlyR[1].Picrotoxin, an antagonist of structurally-rated GABA(A) receptors (GABA(A)Rs) and glycine receptors (GlyRs), is an equimolar mixture of picrotoxinin (PTXININ) and picrotin (PTN). These compounds share a common structure except that PTN contains a slightly larger dimethylmethanol in place of the PTXININ isopropenyl group. Although the homomeric alpha1 GlyR is equally sensitive to both compounds, we show here that homomeric alpha2 and alpha3 GlyRs, like most GABA(A)Rs, are selectively inhibited by PTXININ. As conservative mutations to pore-lining 6' threonines equally affect the sensitivity of the alpha1 GlyR to both compounds, we conclude that PTXININ and PTN bind to 6' threonines by hydrogen bonding with exocyclic oxygens common to both molecules. In contrast, substitution of the 2' pore-lining glycine by serine selectively reduces PTN sensitivity, whereas the introduction of 2' alanines selectively increases PTXININ sensitivity. These results define the orientation of PTXININ and PTN binding in the alpha1 GlyR pore and allow us to conclude that the relatively reduced sensitivity of PTN at GABA(A)Rs and alpha2 and alpha3 GlyRs is due predominantly to its larger size and reduced ability to form hydrophobic interactions with 2' alanines.[1]
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Enzyme Assay |
Contrary to its effect on the gamma-aminobutyric acid type A and C receptors, picrotoxin antagonism of the alpha1 homomeric glycine receptors (GlyRs) has been shown to be non-use-dependent and nonselective between the picrotoxin components picrotoxinin and picrotin. Picrotoxin antagonism of the embryonic alpha2 homomeric GlyR is known to be use-dependent and reflects a channel-blocking mechanism, but the selectivity of picrotoxin antagonism of the embryonic alpha2 homomeric GlyRs between picrotoxinin and picrotin is unknown. Hence, we used the patch clamp recording technique in the outside-out configuration to investigate, at the single channel level, the mechanism of picrotin- and picrotoxinin-induced inhibition of currents, which were evoked by the activation of alpha2 homomeric GlyRs stably transfected into Chinese hamster ovary cells. Although both picrotoxinin and picrotin inhibited glycine-evoked outside-out currents, picrotin had a 30 times higher IC50 than picrotoxinin. Picrotin-evoked inhibition displayed voltage dependence, whereas picrotoxinin did not. Picrotoxinin and picrotin decreased the mean open time of the channel in a concentration-dependent manner, indicating that these picrotoxin components can bind to the receptor in its open state. When picrotin and glycine were co-applied, a large rebound current was observed at the end of the application. This rebound current was considerably smaller when picrotoxinin and glycine were co-applied. Both picrotin and picrotoxinin were unable to bind to the unbound conformation of the receptor, but both could be trapped at their binding site when the channel closed during glycine dissociation. Our data indicate that picrotoxinin and picrotin are not equivalent in blocking alpha2 homomeric GlyR.[2]
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Toxicity/Toxicokinetics |
mouse LD50 intraperitoneal 135 mg/kg Journal of Medicinal Chemistry., 11(729), 1968
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References | |
Additional Infomation |
Picrotin is an organic heteropentacyclic compound that is picrotoxinin in which the olefinic double bond has undergone addition of water to give the corresponding tertiary alcohol. It is the less toxic component of picrotoxin, lacking GABA activity. It has a role as a plant metabolite. It is an organic heteropentacyclic compound, an epoxide, a tertiary alcohol, a gamma-lactone, a diol and a picrotoxane sesquiterpenoid. It is functionally related to a picrotoxinin.
Picrotin has been reported in Dendrobium moniliforme and Anamirta cocculus with data available. See also: Picrotoxin (annotation moved to). |
Molecular Formula |
C15H18O7
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Molecular Weight |
310.29922
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Exact Mass |
310.105
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Elemental Analysis |
C, 58.06; H, 5.85; O, 36.09
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CAS # |
21416-53-5
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PubChem CID |
442291
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Appearance |
White to off-white solid powder
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Density |
1.59g/cm3
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Boiling Point |
595.8ºC at 760 mmHg
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Melting Point |
256-258ºC
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Flash Point |
228.9ºC
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Vapour Pressure |
1.12E-16mmHg at 25°C
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Index of Refraction |
1.637
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LogP |
-0.8
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Hydrogen Bond Donor Count |
2
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Hydrogen Bond Acceptor Count |
7
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Rotatable Bond Count |
1
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Heavy Atom Count |
22
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Complexity |
644
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Defined Atom Stereocenter Count |
8
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SMILES |
CC([C@@H]1[C@H]2OC(=O)[C@@H]1[C@@]1(C[C@H]3O[C@@]43C(O[C@H]2[C@]14C)=O)O)(C)O
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InChi Key |
RYEFFICCPKWYML-QCGISDTRSA-N
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InChi Code |
InChI=1S/C15H18O7/c1-12(2,18)6-7-10(16)20-8(6)9-13(3)14(7,19)4-5-15(13,22-5)11(17)21-9/h5-9,18-19H,4H2,1-3H3/t5-,6+,7-,8-,9-,13-,14-,15+/m1/s1
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Chemical Name |
(1R,3R,5S,8S,9R,12S,13R,14S)-1-hydroxy-14-(2-hydroxypropan-2-yl)-13-methyl-4,7,10-trioxapentacyclo[6.4.1.19,12.03,5.05,13]tetradecane-6,11-dione
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Synonyms |
Picrotin; NSC-129536; NSC 129536; picrotin; 21416-53-5; Picrotin (VAN); CHEBI:8205; U06Z6QD7N2; PICROTIN [MI]; DSSTox_CID_25605; DSSTox_RID_80998; NSC129536
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HS Tariff Code |
2934.99.03.00
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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)
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Solubility (In Vitro) |
DMSO : ~100 mg/mL (~322.27 mM)
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Solubility (In Vivo) |
Solubility in Formulation 1: ≥ 2.5 mg/mL (8.06 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 (8.06 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. View More
Solubility in Formulation 3: ≥ 2.5 mg/mL (8.06 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), suspension solution. |
Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
1 mM | 3.2227 mL | 16.1134 mL | 32.2269 mL | |
5 mM | 0.6445 mL | 3.2227 mL | 6.4454 mL | |
10 mM | 0.3223 mL | 1.6113 mL | 3.2227 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.
Calculation results
Working concentration: mg/mL;
Method for preparing DMSO stock solution: mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation::Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O,mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.