Heme breakdown product
Bilirubin Conjugate disodium targets the bilirubin transport and metabolism pathways as a drug metabolite. Bilirubin, the parent compound, is a major end product of heme breakdown that is transported in plasma bound to albumin, taken up by hepatocytes, and conjugated with glucuronic acid for excretion in bile. The ditaurate derivative mimics endogenous bilirubin glucuronide conjugates and is used to study these transport and metabolic processes.

Bilirubin, a major end product of heme breakdown, is an important constituent of bile, responsible for its characteristic colour. Over recent decades, our understanding of bilirubin metabolism has expanded along with the processes of elimination of other endogenous and exogenous anionic substrates, mediated by the action of multiple transport systems at the sinusoidal and canalicular membrane of hepatocytes. Several inherited disorders characterised by impaired bilirubin conjugation (Crigler-Najjar syndrome type I and type II, Gilbert syndrome) or transport (Dubin-Johnson and Rotor syndrome) result in various degrees of hyperbilirubinemia of either the predominantly unconjugated or predominantly conjugated type. Moreover, disrupted regulation of hepatobiliary transport systems can explain jaundice in many acquired liver disorders. In this review, we discuss the recent data on liver bilirubin handling based on the discovery of the molecular basis of Rotor syndrome. The data show that a substantial fraction of bilirubin conjugates is primarily secreted by MRP3 at the sinusoidal membrane into the blood, from where they are subsequently reuptaken by sinusoidal membrane-bound organic anion transporting polypeptides OATP1B1 and OATP1B3. OATP1B proteins are also responsible for liver clearance of bilirubin conjugated in splanchnic organs, such as the intestine and kidney, and for a number of endogenous compounds, xenobiotics and drugs. Absence of one or both OATP1B proteins thus may have serious impact on toxicity of commonly used drugs cleared by this system such as statins, sartans, methotrexate or rifampicin. The liver-blood cycling of conjugated bilirubin is impaired in cholestatic and parenchymal liver diseases and this impairment most likely contributes to jaundice accompanying these disorders. [1]

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As a ditaurate derivative of bilirubin, Bilirubin Conjugate disodium exhibits biological activities similar to endogenous bilirubin conjugates. Bilirubin conjugates have been shown to exhibit antioxidant and antimutagenic effects and to play a role in gut barrier function. The compound is used as a standard for direct bilirubin measurement in diazo tests, where it behaves similarly to bilirubin glucuronides purified from human bile. It is also used to study bilirubin metabolism, transport, and excretion.

In vivo, bilirubin circulates in the plasma bound to albumin and is taken up by hepatocytes, where it is conjugated to one or two glucuronic acids in a reaction catalyzed by UDP-glucuronosyltransferase. Bilirubin Conjugate disodium, as a stable water-soluble ditaurate derivative, is used to mimic these endogenous conjugates for research purposes. It is found prevalent in a variety of disease states related to jaundice and hepatocellular dysfunction.

In vitro assays for Bilirubin Conjugate disodium typically involve its use as a standard in diazo tests for direct bilirubin measurement. The compound is dissolved in appropriate solvents and incubated with diazo reagents, and the formation of azobilirubin is measured spectrophotometrically. The compound can also be used in transport studies with hepatocyte cultures or membrane vesicles to assess bilirubin uptake and excretion. HPLC or LC-MS methods are used to quantify the compound in biological samples.

In vitro cellular assays for Bilirubin Conjugate disodium involve treating hepatocyte cultures or other cell lines with the compound to study bilirubin uptake, metabolism, and transport. Cells are incubated with the compound at concentrations ranging from 1 to 100 µM for various time periods. Cellular uptake and efflux are measured by HPLC or LC-MS. The compound's effects on cellular functions such as oxidative stress and apoptosis can also be assessed using standard assays.

In vivo animal studies for Bilirubin Conjugate disodium typically involve administration to rodents via intravenous or intraperitoneal injection to study bilirubin metabolism and excretion. Blood, bile, and tissue samples are collected at various time points and analyzed by HPLC or LC-MS to quantify the compound and its metabolites. The compound is used to model hyperbilirubinemia and to study the pharmacokinetics of bilirubin conjugates.

Doses and formulations are determined based on the specific study objectives.

Bilirubin Conjugate disodium has a molecular weight of 842.89 g/mol and formula C37H44N6Na2O10S2. It is a stable, water-soluble ditaurate derivative of bilirubin. Recommended storage is powder at -20°C for 3 years and in solvent at -80°C for 6 months or -20°C for 1 month. The compound appears as an orange to red solid powder with a LogP of 5.843. Detailed PK parameters would be similar to bilirubin conjugates, which are excreted in bile.

New insights in bilirubin metabolism and their clinical implications. World J Gastroenterol. 2013 Oct 14;19(38):6398-407.

Over the past few decades, the molecular basis of hyperbilirubinemia has been elucidated, and mutations affecting basolateral and apical membrane transporters responsible for the accumulation of bound or unconjugated bilirubin have been identified. [1]

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Bilirubin Conjugate disodium is intended for research use only and is not approved for human therapeutic applications. As a bilirubin derivative, it is generally considered to have low toxicity, but appropriate safety precautions should be taken when handling. The compound is used as a standard for direct bilirubin measurement and for studying bilirubin metabolism. Standard toxicity assessments would include acute toxicity and repeated-dose toxicity studies if required.

C37H44N6O10S2-2.2[NA+]

842.88906

842.236

68683-34-1

16414149

Orange to red solid powder

5.843

6

10

16

57

1880

0

C=CC\1=C(C(N/C1=C/C2=C(C(CCC([O-])=NCCS(=O)(O)=O)=C(N2)CC3=C(C(C)=C(N3)/C=C/4\C(C)=C(C(N4)=O)C=C)CCC([O-])=NCCS(=O)(O)=O)C)=O)C.[Na+].[Na+]

IQKDYMAMJBFOQJ-KPUSBRQXSA-L

InChI=1S/C37H46N6O10S2.2Na/c1-7-24-23(6)36(46)43-31(24)18-29-22(5)27(10-12-35(45)39-14-16-55(51,52)53)33(41-29)19-32-26(9-11-34(44)38-13-15-54(48,49)50)21(4)28(40-32)17-30-20(3)25(8-2)37(47)42-30;;/h7-8,17-18,40-41H,1-2,9-16,19H2,3-6H3,(H,38,44)(H,39,45)(H,42,47)(H,43,46)(H,48,49,50)(H,51,52,53);;/q;2*+1/p-2/b30-17+,31-18+;;

disodium;2-[3-[5-[(E)-(4-ethenyl-3-methyl-5-oxopyrrol-2-ylidene)methyl]-2-[[5-[(E)-(3-ethenyl-4-methyl-5-oxopyrrol-2-ylidene)methyl]-4-methyl-3-[3-oxo-3-(2-sulfonatoethylamino)propyl]-1H-pyrrol-2-yl]methyl]-4-methyl-1H-pyrrol-3-yl]propanoylamino]ethanesulfonate

68683-34-1; BILIRUBIN CONJUGATE; disodium;2-[3-[5-[(4-ethenyl-3-methyl-5-oxopyrrol-2-ylidene)methyl]-2-[[5-[(3-ethenyl-4-methyl-5-oxopyrrol-2-ylidene)methyl]-4-methyl-3-[3-oxo-3-(2-sulfonatoethylamino)propyl]-1H-pyrrol-2-yl]methyl]-4-methyl-1H-pyrrol-3-yl]propanoylamino]ethanesulfonate; Bilirubin Conjugate ditaurate disodium; Bilirubin Conjugate, Ditaurate, Disodium Salt; Bilirubin conjugate ditaurate disodium; Bilirubin conjugate; Disodium 2,2'-[(1,10,19,22,23,24-hexahydro-3,7,13,18-tetramethyl-1,19-d;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ~100 mg/mL (~118.64 mM)

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.)