26019-74-9Relevant academic research and scientific papers
Synthesis of γ-Oxyprotoporphyrin IX and Pterobiline (Biliverdin IXγ)
Jackson, Anthony H.,Jenkins, Rhiannydd M.,Jones, D. Michael,Matlin, Stephen A.
, p. 763 - 764 (1981)
The γ-meso-hydroxy-derivative of protoporphyrin IX has been synthesised by condensation of a bis(formylpyrrolyl) ketone and a dipyrrolylmethane; the iron complex underwent oxidative ring-opening to give biliverdin IXγ (pterobiline), the blue-green butterfly pigment, thus providing a model for its biosynthesis.
Synthesis of a 10-oxo-bilirubin: Effects of the oxo group on conformation, transhepatic transport, and glucuronidation
Chen, Qingqi,Huggins, Michael T.,Lightner, David A.,Norona, Wilma,McDonagh, Antony F.
, p. 9253 - 9264 (2007/10/03)
Bilirubin, the yellow pigment of jaundice, is a linear tetrapyrrole with a methylene group at its center, C(10), a position of crucial importance to its conformation and metabolism. The presence of the central methylene group allows the bilirubin to fold into an intramolecularly hydrogen-bonded conformation. This paper describes the first synthesis of a bilirubin analogue with an oxo group at C(10). The change from CH2 to C=O, from sp3 to sp2, is designed to stress the molecule at its hinge and relax its conformation. Such compounds have been suggested as potential oxidative metabolites of bilirubin in vivo. 10-Oxo-mesobilirubin-XIIIα (1) is a red crystalline solid, unlike its parent, mesobilirubin-XIIIα, which is a bright yellow solid. It is surprisingly polar, relative to the parent, yet it does not exhibit a significantly larger bicarbonate/chloroform partition coefficient. Like the parent, 1 appears to adopt an intramolecularly hydrogen-bonded ridge-tile-like conformation. In normal rats, 1 is metabolized to acylglucuronides, which are secreted into bile, but a portion of the administered dose is secreted into bile intact. In mutant rats (Gunn rats) lacking bilirubin glucuronyl transferase, 1 was excreted efficiently in bile in unchanged form, unlike the parent with a methylene group at C(10). Thus, introduction of the oxygen function at C(10) has little effect on hepatic uptake but a dramatic effect on canalicular secretion into bile.
SYNTHESIS OF BILIVERDIN IXγ (PTEROBILIN)
Jackson, Anthony H.,Jenkins, Rhianydd M.,Jones, D. Michael,Matlin, Stephen A.
, p. 1849 - 1858 (2007/10/02)
Condensation of a bis(acetoxyethyl)pyrromethane dicarboxylic acid (11d) with a diformylpyrroketone (12b) afforded a bis(acetoxyethyl)-γ-meso-hydroxyporphyrin (13d) which was converted into the related bis(chloroethyl)-γ-benzoyloxyporphyrin (14f).The Zn complex of the latter was transformed by brief treatment with base, followed by chloromethylethyl ether into the zinc bis(chloroethyl)-γ-ethoxymethoxyporphyrin (20b).Dehydrochlorination with potassium t-butoxide in t-butanol, and acid catalysed demetallation and deprotection then afforded the somewhat unstable blue γ-oxyprotoporphyrin dimethyl ester (21).The Fe-complex of the latter readily underwent oxidative ring opening by aerial oxidation in pyridine, and after demetallation gave biliverdin IXγ (pterobilin) dimethyl ester (22).
