D A. Lightner

The secondary structure of bilirubin, with a ridge-tile shape and six intramolecular hydrogen bonds, is more stable than any other conformation and perhaps the most important determinant of its solubility...

(4Z)-8-(5-Carboxypentyl)-9-butyl-2,3-diethyl-dipyrrin-1-one (1), a new analogue of xanthobilirubic acid, (4Z)-8-(carboxyethyl)-2,7,9-dimethyl-3-ethyl-dipyrrin-1-one, was synthesized in four steps from the known 2,3-diethyl-dipyrrin-1-one. Whereas xanthobilirubic acid (which is a model for one-half of bilirubin, the...

The metabolism and biliary excretion of a stretched bilirubin analog with a p-xylyl group replacing the central CH2 hinge were investigated in normal rats, Gunn rats deficient in bilirubin conjugation,...

The bichromophoric pigment bilirubin acts as a molecular exciton in its UV-visible and circular dichroism (CD) spectroscopy. In both polar and nonpolar solvents, an optically active analog, (beta R,beta 'R)-dimethylmesobilirubin-XIII...

A symmetrical C(10)-thiabilirubin analogue, 8,12-bis(2-carboxyethyl)-2,3,17,18-tetraethyl-7,13-dimethyl-10-thia-(21H,23H,24H)-bilin-1,19-dione (1), was synthesized from 8-(2-carboxyethyl)-2,3-diethyl-7-methyl-10H-dipyrrin-1-one in one step by reaction with sulfur dichloride. The thia-rubin exhibited the expected IR, UV-vis, and NMR spectroscopic properties, which...

The isomers 3,3'-(1,2-ethynediyl)bis(2-pyridone), (I), and 6,6'-(1,2-ethynediyl)bis(2-pyridone), (II), were designed to form a hydrogen-bonded pair through alignment of their complementary cyclic lactam moieties. Instead, an equimolar mixture of (I) and (II)...

Bilirubin, the yellow-orange tetrapyrrole pigment of jaundice, is essentially insoluble in pure water, but is much more soluble in solutions of bile salts such as sodium taurocholate. The biophysical chemistry...

(4Z)-9-(5-Carboxypentyl)-2,3,7,8-tetramethyl-(10H)-dipyrrin- 1-one (1, semirubin), a new dipyrrinone model for one-half of bilirubin, the yellow-orange neurotoxic pigment of jaundice, was synthesized following Friedel-Crafts acylation of 2,3,7, 8-tetramethyl-(10H)-dipyrrin-1-one (5) with the half-ester...

The relative steric size of methyl, methoxy, and methylthio groups was determined from circular dichroism (CD) spectroscopy using a sensitive system based on the bilirubin model. In the cyclohexane model,...

Photoirradiation of solutions of natural (4Z,15Z)-bilirubin-IX alpha in chloroform with approximately 366 nm UV light leads rapidly to a new photoisomer that has been characterized by NMR spectroscopy and by...