635-65-4Relevant articles and documents
A method for preparing high-content bilirubin IX[alpha] from bilirubin IX[alpha] diester
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Paragraph 0028; 0041-0043; 0050-0055, (2019/04/10)
A method for preparing high-content bilirubin IX[alpha] from bilirubin IX[alpha] diester is disclosed, belonging to the field of bilirubin IX[alpha] preparation. The method includes following steps (aroute including firstly hydrolysis and then reduction): a step of adding dropwise a methanol solution of sodium hydroxide into an alcohol solution of bilirubin IX[alpha] diester, adding water, then performing hydrolysis, adjusting pH to 4-5 with a weak acid, performing rotary evaporation to remove a solvent, washing a product with water to remove inorganic salt, and performing vacuum drying to obtain bilirubin IX[alpha]; and a step of adding a free radical scavenger (stabilizer) into an alcohol solution of the bilirubin IX[alpha], adding a reductant that is borohydride, adding an acetone immediately after reduction is finished to decompose the excessive reductant, then adjusting pH to 4-5 with weak acid, performing rotary evaporation to remove a solvent, performing water washing, and performing purification with methanol and chloroform to obtain bilirubin IX[alpha] the purity of which is more than 97%. The method has characteristics of no need of chromatographic separation, mild reaction conditions, low cost, and convenient operation, and is suitable for industrial large-scale production.
Bilirubin photo-isomers: Regiospecific acyl glucuronidation in vivo
McDonagh, Antony F.
, p. 465 - 482 (2014/03/21)
(4Z,15Z)-Bilirubin-IXα, the end product of heme catabolism, requires uridine glucuronosyl transferase 1A1 (UGT1A1)-catalyzed glucuronidation for elimination in bile, where it appears as two isomeric monoglucuronides and a diglucuronide. When people are exposed to light, endogenous bilirubin is converted partly to photo-isomers that are produced in greater abundance during treatment of jaundiced babies with phototherapy. Little is known about the metabolism of the photo-isomers, other than that they appear not to require glucuronidation for elimination in bile. Studies have been hampered by their unavailability and instability, as well as confusion about the identity, structures, preparation, and purity of bilirubin photoproducts. This paper outlines methods for preparing photo-isomers of bilirubins in sufficient quantity and purity for metabolic studies in rats and reappraises the composition of some previous preparations. The studies show that (Z,E)-isomers of bilirubins and the structural isomer (Z)-lumirubin undergo glucuronidation in the rat, but unlike (4Z,15Z)-bilirubin, form only monoglucuronides. Moreover, glucuronidation is regiospecific for just one of the two propionic acid groups, the one attached to the isomerized half of the molecule. This unusual stereoselectivity appears to be dictated by intramolecular hydrogen bonding. Formation of hydroxylated bilirubins was not detected. During phototherapy, photo-isomers will compete with endogenous (4Z,15Z)-bilirubin for glucuronidation by nascent hepatic enzyme UGT1A1. Graphical abstract: [Figure not available: see fulltext.]
PRODUCTION OF RED BLOOD CELLS AND PLATELETS FROM STEM CELLS
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, (2014/03/24)
This disclosure provides methods of making a megakaryocyte-erythroid progenitor cell (MEP), comprising differentiating a stem cell into a MEP in culture in the presence of an aryl hydrocarbon receptor (AhR) agonist. In some embodiments the stem cell is a pluripotent stem cell. In some embodiments the MEP co-expresses CD41 and CD235. In some embodiments the number of MEPs produced in the culture increases exponentially. Methods of making a red blood cell (RBC) by culturing a MEP in the presence of an AhR agonist are also provided. Methods of making a megakaryocyte and/or a platelet, comprising culturing a MEP in the presence of an AhR modulator are also provided. In some embodiments the AhR modulator is an AhR antagonist. This disclosure also provides compositions comprising at least 1 million MEPs per ml and compositions in which at least 50% of the cells are MEPs.
The synthesis of [10-13C]bilirubin IXα
Sturrock,Bull,Kirsch
, p. 263 - 274 (2007/10/02)
The total synthesis of [10-13C]bilirubin IXα, the principal waste product of haem degradation, is described. Site specific labelling was accomplished by the Vilsmeier formylation of one of the dipyrrolic fragments using [1-13C]dimethylformamide. The penultimate dehydrohalogenation reaction was complicated by a competing elimination reaction which yielded a bridged biliverdin derivative. [10-13C]bilirubin IXα was prepared in an overall yield of 6% (from the step where 13C was introduced) with quantitative isotopic incorporation.
Facile preparation of symmetric bilirubins IIIα and XIIIα from IXα
Ma,Lightner
, p. 1005 - 1008 (2007/10/02)
Improved, simple precedures for synthesis and isolation of symmetrically substituted bilirubin-XIIIα and bilirubin-IIIα from the natural pigment, bilirubin-IXα, are described.
BILIRUBIN CHEMISTRY. I. A SIMPLE METHOD FOR PROTECTING THE EXO-VINYL GROUP
Monti, Diego,Speranza, Giovanna,Manitto, Paolo
, p. 361 - 366 (2007/10/02)
Regiospecific addition of thioacetic acid followed by RHg(+)-induced methanolysis and acid-catalysed methanol elimination proves to be an efficient method for protecting the exo-vinyl group of bilirubin.An analogous mercury(II)-activated displacement on bilirubin-thioacetic acid addition product was used to obtain the hydroxybilirubin 3b of potential biological interest.The synthesis of "mercury-bilirubin" is also reported.
