| Size | Price | |
|---|---|---|
| 250mg | ||
| Other Sizes |
| ln Vitro |
One indicator of abrin toxicity is L-(+)-Abrine. The molecule L-(+)-Abrine, which may be found in human urine and survives metabolic processes in considerable quantities, is a powerful indicator of abrine poisoning [1].
The MTOX enzyme catalyzes the conversion of L-abrine to L-tryptophan, producing hydrogen peroxide (H₂O₂) as a byproduct.[1] The colorimetric assay demonstrated a detection limit of 4 μM L-abrine using MTOX-mediated H₂O₂ generation followed by horseradish peroxidase (HRP)/tetramethylbenzidine (TMB) oxidation; this detection limit was achievable in both water and mock urine samples after background H₂O₂ removal.[1] The catalytic activity of MTOX toward L-abrine was shown to be highly selective compared to other structurally related compounds such as sarcosine .[1] |
|---|---|
| ln Vivo |
Lemon seeds contain the poisonous protein known as abrin. Jequirity seeds also contain L-(+)-Abrine (L-Abrine), which is a biomarker of abrin exposure. Twenty rats were used in an animal study to track the excretion and recovery of L-(+)-Abrine. The animals were given three different doses of L-(+)-Abrine, one high dose of L-tryptophan, or no exposure at all (control). The low L-(+)-Abrine dose matches the LD50 of intraperitoneally administered abrine in mice, assuming that the concentration ratio of abrine to L-(+)-abrine is 1:4 and the LD50 of abrine is 20 μg/kg. 0.63. To guarantee the detection and monitoring of target analytes throughout the experiment, medium and high dosages of L-(+)-Abrine (250 and 400 μg/kg) were included [2].
In a rat exposure study, L-abrine was administered intramuscularly at doses of approximately 50 μg/kg body weight, 250 μg/kg body weight, and 400 μg/kg body weight. Urine was collected prior to dosing and at 24 h and 48 h post-dosing. L-abrine was predominantly excreted in the first 24 h after exposure at all three dose levels. At 48 h, urinary L-abrine in rats exposed to the low and mid-level doses (50 and 250 μg/kg) were below the method limit of detection (0.09 ng/mL). Quantification was possible for the first 24 h at all dose levels, but beyond 24 h only the 400 μg/kg dose remained detectable. The total urinary recovery of L-abrine (mass excreted vs mass injected) was between 2.72% and 4.07%. [2] - A single large dose of L-tryptophan (20,000 μg/kg body weight) was administered intraperitoneally to four rats to determine if tryptophan is metabolized to L-abrine. No L-abrine was detected in the urine from these animals, indicating that tryptophan is not metabolized to L-abrine in rats and does not interfere with L-abrine determination. [2] |
| Enzyme Assay |
The enzyme N-methyltryptophan oxidase (MTOX) was used to generate H₂O₂ from L-abrine. In a typical assay, various concentrations of L-abrine were prepared in water or Tris buffer saline (pH 6). Free MTOX (5 μg) or MTOX immobilized on magnetic beads (120 μg of beads) was added and incubated at room temperature for 1 minute, 1 hour, or 18 hours. Then, tetramethylbenzidine (TMB) and horseradish peroxidase (HRP) were added. The blue color developed proportional to the amount of H₂O₂ produced. After 1 minute, the reaction was stopped by adding 1 M H₂SO₄, and the absorbance was recorded at 450 nm.[1]
For the immobilized MTOX bead system, the same procedure was followed, but the beads were separated with a magnet before transferring the liquid sample to H₂SO₄.[1] To detect L-abrine in mock urine, an initial background H₂O₂ removal step was introduced: mock urine containing L-abrine and variable H₂O₂ was incubated with phenol (final concentration 600 μM) and HRP for 1 hour at room temperature. Then TMB was added and incubated for another hour to allow any blue color to subside. Subsequently, MTOX (5 μg) was added to catalyze L-abrine and generate new H₂O₂, and the blue color intensity was measured at 450 nm using a microplate reader.[1] |
| Animal Protocol |
Twenty male Wistar rats (approximately 6-7 weeks old, weighing 175-200 g) were used. Animals were maintained in polycarbonate cages with water bottles or automatic watering system in approved facilities, and held in quarantine for 2 weeks prior to dosing. A total of 12 rats were dosed intramuscularly with L-abrine at three levels: four rats at approximately 50 μg/kg body weight, four at 250 μg/kg body weight, and four at 400 μg/kg body weight (the biomarker concentration was estimated assuming L-abrine is present in rosary peas at a concentration four times that of the toxin abrin; the expected abrin LD50 was 20 μg/kg). Four control rats were dosed with water (vehicle). Another four rats were dosed intraperitoneally with 20,000 μg/kg L-tryptophan to verify that endogenous L-tryptophan is not metabolized to L-abrine. Prior to dosing, body weight was measured and recorded. Urine was collected for approximately 24 h prior to dosing, and then at 24 h and 48 h after dosing. Urine samples were stored at -20°C. At 48 h after dosing, survivors were anesthetized with halothane. [2]
- The vehicle for all dosing experiments was water. No pain or distress was anticipated or observed in the treated rats because L-abrine has little toxicity. [2] |
| ADME/Pharmacokinetics |
L-abrine can survive metabolism in significant amounts, making it detectable in human urine.[1]
|
| Toxicity/Toxicokinetics |
L-abrine is described as an acute toxic alkaloid.[1]
|
| References | |
| Additional Infomation |
N(α)-Methyl-L-tryptophan is an N-methyl-L-α-amino acid, an N(α)-methyl derivative of L-tryptophan. It functions as a metabolite in Escherichia coli. It is both a derivative of L-tryptophan and an N-methyl-L-α-amino acid. It is a zwitterionic tautomer of N(α)-methyl-L-tryptophan. N-Methyltryptophan is a metabolite found in or produced by Escherichia coli (K12 strain, MG1655 strain). Abrine has also been reported in Daphnia solani, Aspergillus fumigatus, and other organisms with relevant data.
L-abrine (N-methyl L-tryptophan) is a chemical marker for abrin, a lethal toxin found in Abrus precatorius seeds (jequirty pea or rosary pea). Abrin is a class II ribosome-inactivating protein, homologous to ricin but more lethal. The human lethal dose of abrin is estimated at 0.1–1 μg/kg, compared to 5–10 μg/kg for ricin inhalation.[1] L-abrine constitutes about 1% of the dry weight of A. precatorius seeds, making it a useful marker for abrin poisoning.[1] The detection system described in this study is reusable (5–6 cycles with minimal sensitivity loss), portable, and colorimetric, requiring no expensive antibodies or equipment.[1] |
| Molecular Formula |
C12H14N2O2
|
|---|---|
| Molecular Weight |
218.2518
|
| Exact Mass |
218.105
|
| CAS # |
526-31-8
|
| PubChem CID |
160511
|
| Appearance |
Off-white to light yellow solid powder
|
| Density |
1.3±0.1 g/cm3
|
| Boiling Point |
439.1±35.0 °C at 760 mmHg
|
| Melting Point |
>300 °C (dec.)(lit.)
|
| Flash Point |
219.4±25.9 °C
|
| Vapour Pressure |
0.0±1.1 mmHg at 25°C
|
| Index of Refraction |
1.649
|
| LogP |
1.18
|
| Hydrogen Bond Donor Count |
3
|
| Hydrogen Bond Acceptor Count |
3
|
| Rotatable Bond Count |
4
|
| Heavy Atom Count |
16
|
| Complexity |
257
|
| Defined Atom Stereocenter Count |
1
|
| SMILES |
CN[C@@H](CC1=CNC2=CC=CC=C21)C(=O)O
|
| InChi Key |
CZCIKBSVHDNIDH-NSHDSACASA-N
|
| InChi Code |
InChI=1S/C12H14N2O2/c1-13-11(12(15)16)6-8-7-14-10-5-3-2-4-9(8)10/h2-5,7,11,13-14H,6H2,1H3,(H,15,16)/t11-/m0/s1
|
| Chemical Name |
(2S)-3-(1H-indol-3-yl)-2-(methylamino)propanoic acid
|
| 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)
|
| Solubility (In Vitro) |
H2O : ~1.85 mg/mL (~8.48 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
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *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). View More
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)] 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). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 4.5819 mL | 22.9095 mL | 45.8190 mL | |
| 5 mM | 0.9164 mL | 4.5819 mL | 9.1638 mL | |
| 10 mM | 0.4582 mL | 2.2910 mL | 4.5819 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.
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