What molecule am I?
Urobilin, also known as urochrome, is a tetrapyrroledicarboxylic acid that causes the yellow color in urine. The natural compound has the (–) stereochemical configuration.
In the 1930s, hepatologist Cecil James Watson at the University of Minnesota Hospitals (Minneapolis) published a pioneering series of articles on urobilin and its derivatives. In one (1935), he reported differences in properties among various urobilin analogues.
Watson also studied stercobilin (CAS Registry no. 34217-90-8), a similarly structured molecule that is responsible for the color of feces. The two are similar to bilirubin, the Molecule of the Week for March 27, 2017. All three are bile pigments formed in the liver and spleen as breakdown products from hemoglobin-derived porphyrins.
Urobilin is a key marker in urinalysis. For example, if a patient’s urine has a deep yellow color, it may indicate that the patient is dehydrated. If you’re a parent, and your child asks why urine is yellow, an entry in The Conversation will help you provide a suitable answer.
Urobilin hazard information*
| Hazard class** | Hazard statement |
|---|---|
Not a hazardous substance or mixture |
*No urobilin safety data sheet is available. Information is for the chemically similar urobilin hydrochloride.
**Globally Harmonized System of Classification and Labeling of Chemicals.
This molecule was suggested by a reader. We present almost all of the molecules suggested by our readers. If you have a molecule you would like us to consider, please send us a message. And thank you for your interest in Molecule of the Week! —Ed.
Urobilin fast facts
| CAS Reg. No. | 1856-98-0 |
| SciFinder nomenclature | 21H-Biline-8,12-dipropanoic acid, 3,18-diethyl-1,4,5,15,16,19,22,24-octahydro-2,7,13,17-tetramethyl-1,19-dioxo- |
| Empirical formula | C33H42N4O6 |
| Molar mass | 590.71 g/mol |
| Appearance | Yellow crystals |
| Melting point | 236 ºCa |
| Water solubility | Soluble |
Learn more about this molecule from CAS, the most authoritative and comprehensive source for chemical information.
Molecule of the Week needs your suggestions!
If your favorite molecule is not in our archive, please send us a message. The molecule can be notable for its current or historical importance or for any quirky reason. Thank you!
Stay Ahead of the Chemistry Curve
Learn how ACS can help you stay ahead in the world of chemistry.
