Molybdenum (chemical symbol Mo) is one of the essential trace elements. It complexes with a molecule called molybdopterin to form molybdenum cofactor, essential for the functioning of several important metabolic enzymes.
Molybdenum has the atomic number 42, with an atomic weight of 95.94 g/mol. It is a transition metal with a silvery-white coloration 2.
35 isotopes of molybdenum are known, of these 7 are stable and 28 unstable, i.e. radioactive. Although it is thought that there may be as many as 30 isotopes still to be discovered 4.
Diet, absorption, transport and storage
Molybdenum is essential for the normal functioning of four enzymes (molybdoenzymes) in humans:
- sulfite oxidase
- oxidation of sulfite to sulfate, the terminal reaction in the oxidation of S-containing amino acids
- xanthine oxidase
- catalyses hypoxanthine to xanthine, and xanthine to uric acid, important in the purine degradation pathway
- aldehyde oxidase
- key for hepatic drug metabolism
- mitochondrial amidoxime-reducing component (mARC)
- reduction of some N-hydroxylated substrates 1
True molybdenum deficiency is very rare, with a few isolated case reports, mainly in those on total parenteral nutrition 3.
Also see molybdenum cofactor deficiency (MCD).
No toxicity has been reported in humans from excessive intake of molybdenum 5.
- molybdenum metal is a key component of the anodes in some x-ray tubes, especially in mammography
- molybdenum generators are important as a source for Tc-99m
History and etymology
Molybdenum was discovered by Karl Scheele, a Swedish chemist, in 1778. He originally thought it was lead, thus the element was named for the Ancient Greek word molybdos, meaning "lead-like" 1.
- 1. Novotny JA, Peterson CA. Molybdenum. (2018) Advances in nutrition (Bethesda, Md.). 9 (3): 272-273. doi:10.1093/advances/nmx001 - Pubmed
- 2. William Alexander Newman Dorland. Dorland's Illustrated Medical Dictionary. (2018) ISBN: 9781416023647
- 3. Stehle P, Stoffel-Wagner B, Kuhn KS. Parenteral trace element provision: recent clinical research and practical conclusions. (2016) European journal of clinical nutrition. 70 (8): 886-93. doi:10.1038/ejcn.2016.53 - Pubmed
- 4. Parker AM and Thoennessen M. Discovery of Rubidium, Strontium, Molybdenum, and Rhodium Isotopes. (2012) Atom.Data Nucl.Data Tabl. 98 (2012) 812-831. DOI: 10.1016/j.adt.2012.06.001.
- 5. Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington (DC): National Academies Press (US); 2001. 11, Molybdenum. Available from: https://www.ncbi.nlm.nih.gov/books/NBK222301/
- 6. Durmaz MS, Özbakır B. Molybdenum cofactor deficiency: Neuroimaging findings. (2018) Radiology case reports. 13 (3): 592-595. doi:10.1016/j.radcr.2018.02.025 - Pubmed
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