Difference between revisions of "Ionophores in Society"

Revision as of 19:07, 24 July 2013

Ionophores are not only chemically interesting in their own right but have important medical and economic roles in our society.

A selection of ionophores for study in chemistry courses for pre-med, vet, pharmacy, pharmacology, biochemistry, and other science students is presented below.

The use of ionophore 'growth promoters' in the animal feedstock industry is also relevant to environmental chemistry concerns about their presence in manure and sewerage sludges used as fertiliser for human and animal crops.

The ion transport ability of these materials can be easily studied using tethered membrane technology.

Amphotericin B

Amphotericin B is an antibiotic used to treat serious fungal infections. It forms ion channels in the fungal cell membrane with the assistance of ergosterol which is a naturally occurring lipid in fungal membranes. As a medicine it is taken intravenously as a liposomal preparation.

While its affinity for ergosterol makes it target fungal cells, it can also interact, though to a lesser extent, with the cholesterol in mammalian cells. This limits its therapeutic dosage because of toxicity.

Amphotericin B is similar both in structure and in action to Nystatin.

http://www.drugs.com/pro/amphotericin-b.html

Beauvericin

Beauvericin

Beauvericin is closely related to the enniatins. It is a potentially toxic agent found in grain crops affected by fungus.

Occurrence of Beauvericin and Enniatins in Wheat Affected by Fusarium avenaceum Head Blight. A. Logrieco, A. Rizzo, R. Ferracane, and A. Ritieni, Applied Environmental Microbiology, 68, 82-85, 2002. doi: 10.1128/AEM.68.1.82-85.2002

Gramicidin A

Gramicidin

Gramicidin is used as a topical antibiotic. It is often regarded as the archetypal ion channel despite its unusual dimer arrangement in the cell membrane. It was also one of the first commercially available antibiotics.

Gramicidin is usually sold as a mixture of related linear polypeptides by Sigma-Aldrich and many other suppliers. The main component is Gramicidin A.

Gramicidin S is an unusual macrocyclic variant.

http://www.drugs.com/search.php?searchterm=Gramicidin

Enniatin Complex

Enniatin complex

Enniatins are produced by fungal species that commonly infect wheat and other grains. High levels are potentially toxic.

There have also been some reports of Enniantins having promise as antibiotics and anti-cancer drugs..

http://toxinology.nilu.no/Researchareas/Fungaltoxins/Factsheets/Enniatins/tabid/4536/Default.aspx

Lasalocid

Lasalocid

Lasalocid is commonly used as an antibiotic for control of coccidiosis, a protozoan parasite of poultry and livestock.

http://www.drugs.com/search.php?searchterm=Lasalocid

Maduramicin

Maduramicin

Maduramicin is used as an antibiotic for control of coccidiosis, a protozoan parasite of poultry and livestock.

http://www.drugs.com/search.php?searchterm=Maduramicin

Monensin A

Monensin A

Monensin is used in the livestock industry as a food supplement, where it can alter the gut flora (bacteria populations) of the animal so that animal growth rates are improved.

http://www.bioagrimix.com/haccp/html/ionophores.html

http://www.drugs.com/search.php?searchterm=Monensin

Narasin

Narasin

Narasin is a derivative of salinomycin, and has similar properties.

http://www.drugs.com/search.php?searchterm=narasin

Nystatin A1

Nystatin

Nystatin is an antifungal antibiotic often prescribed for the treatment of Candida infections. It forms ion channels in the fungal cell membrane with the assistance of ergosterol which is a naturally occurring lipid in fungal membranes. As a medicine Nystatin is taken orally or topically.

While its affinity for ergosterol makes it target fungal cells, it can also interact, though to a lesser extent, with the cholesterol in mammalian cells. This can limit its therapeutic dosage because of toxicity.

It is similar both in structure and in action to Amphotericin B.

http://www.drugs.com/search.php?searchterm=nystatin

Salinomycin

Salinomycin

Salinomycin is used in the livestock industry as a food supplement, where it can alter the gut flora (bacteria populations) of the animal so that animal growth rates are improved.

It is also being investigated as an anti-cancer agent.

http://www.bioagrimix.com/haccp/html/ionophores.html

http://www.merck-animal-health-usa.com/binaries/intp1069_SACOX_tcm96-86731.pdf

http://www.drugs.com/search.php?searchterm=salinomycin

Persistence of antibiotics such as macrolides, tiamulin and salinomycin in soil. Michael P. Schlüsener, Kai Bester, Environmental Pollution, 143, 565–571, 2006. doi: 10.1016/j.envpol.2005.10.049

Effects of the veterinary pharmaceutical salinomycin and its formulation on the plant Brassica rapa. V. Furtula, G. L. Stephenson, K. M. Olaveson, P. A. Chambers, Archives of Environmental Contamination and Toxicology, 63, 513-522, 2012. doi: 10.1007/s00244-012-9807-y

Valinomycin

Valinomycin

Valinomycin is historically one of the best known ionophores, especially for its 10⁵ fold selectivity for potassium over sodium ions. It is being investigated for use as an antibiotic.

It is used in the manufacture of potassium ion selective electrodes.