Zinc pyrithione
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| Names | |
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| IUPAC name
bis(2-pyridylthio)zinc 1,1'-dioxide
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| Other names
ZnP, pyrithione zinc, zinc OMADINE
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| Identifiers | |
3D model (JSmol)
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| ChEMBL | |
| ChemSpider | |
| ECHA InfoCard | 100.033.324 |
PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| C10H8N2O2S2Zn | |
| Molar mass | 317.70 g/mol |
| Appearance | colourless solid |
| Melting point | 240 °C (decomp.) [1] |
| Boiling point | decomp. |
| 8 ppm (pH 7) | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Zinc pyrithione is a coordination complex of zinc. This colourless solid is used as an antifungal and antibacterial agent. This coordination complex, which has many names, was first reported in the 1930s.[2]
Structure of the compound
The pyrithione ligands, which are formally monoanions, are chelated to Zn2+ via oxygen and sulfur centers. In the crystalline state, zinc pyrithione exists as a centrosymmetric dimer (see figure), where each zinc is bonded to two sulfur and three oxygen centers.[3] In solution, however, the dimers dissociate via scission of one Zn-O bond.
Pyrithione is the conjugate base derived from 2-mercaptopyridine-N-oxide (CAS# 1121-31-9), a derivative of pyridine-N-oxide.
Uses
Medical
Zinc pyrithione is best known for its use in treating dandruff and seborrhoeic dermatitis. It also has antibacterial properties and is effective against many pathogens from the streptococcus and staphylococcus class. Its other medical applications include treatments of psoriasis, eczema, ringworm, fungus, athletes foot, dry skin, atopic dermatitis, tinea, and vitiligo.
Zinc pyrithione is approved for over-the-counter topical use in the United States as a treatment for dandruff. It is the active ingredient in several anti-dandruff shampoos such as Head & Shoulders. However, in its industrial forms and strengths, it may be harmful by contact or ingestion.
In paint
Due to its low solubility in water (8 ppm at neutral pH), zinc pyrithione is suitable for use in outdoor paints and other products that provide protection against mildew and algae. It is an effective algaecide. It is chemically incompatible with paints relying on metal carboxylate curing agents. When used in latex paints with water containing high amount of iron, a sequestering agent that will preferentially bind the iron ions is needed. Its decomposition by ultraviolet light is slow, providing years of protection even against direct sunlight.
In sponges
Zinc pyrithione is also used as an antibacterial treatment for household sponges, most notably by the 3M Corporation.[4]
Mechanism of action
Its antifungal effect is proposed to derive from its ability to disrupt membrane transport by blocking the proton pump that energizes the transport mechanism.[5] A new study proposes that the mode of action of zinc pyrithione arises from iron starvation of the substrate.[6] Experiments have suggested that fungi are capable of inactivating pyrithione in low concentrations.[7]
Possible health concerns
 | This section may be confusing or unclear to readers. In particular, the title of "health concerns" and the mention of "DNA damage" are likely to be very alarming to average readers who come here wanting to know more about their dandruff shampoo. A clear, understandable explanation is needed. (September 2011) |
One recent study found that low doses of zinc pyrithione added to human cells grown in petri dishes can trigger a stress response, energy crisis, and DNA damage in these cells. It is unclear whether a similar effect occurs with normal human skin.[8][further explanation needed]
See also
- selenium disulfide, an active ingredient used in shampoos such as Selsun Blue.
- Ketoconazole, another antifungal agent used in shampoos.
References
- ^ Thieme Chemistry (Hrsg.): Römpp Online. Version 3.1. Georg Thieme Verlag, Stuttgart 2007.
- ^ "astate.edu". Archived from the original on 2007-06-21. Retrieved 2007-08-24.
- ^ Barnett, B. L.; Kretschmar, H. C.; Hartman, F. A. (1977). "Structural characterization of bis(N-oxopyridine-2-thionato)zinc(II)". Inorg. Chem. 16 (8): 1834–8. doi:10.1021/ic50174a002.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Notice of Filing a Pesticide Petition to Establish
- ^ Chandler CJ, Segel IH (1978). "Mechanism of the Antimicrobial Action of Pyrithione: Effects on Membrane Transport, ATP Levels, and Protein Synthesis". Antimicrob. Agents Chemother. 14 (1): 60–8. PMC 352405. PMID 28693.
- ^ J Biosci Bioeng. 2010 May;109(5):479-86. Epub 2009 Nov 22
- ^ Chandler CJ, Segel IH (1978). "Mechanism of the Antimicrobial Action of Pyrithione: Effects on Membrane Transport, ATP Levels, and Protein Synthesis". Antimicrob. Agents Chemother. 14 (1): 1. PMC 352405. PMID 28693.
At "low" pyrithione concentrations, transport inhibition plateaued at some finite value. This observation suggests that the fungi can detoxify low levels of the inhibitor.
{{cite journal}}: More than one of|pages=and|page=specified (help) - ^ Lamore SD, Cabello CM, Wondrak GT (2010). "The topical antimicrobial zinc pyrithione is a heat shock response inducer that causes DNA damage and PARP-dependent energy crisis in human skin cells". Cell Stress Chaperones. 15 (3): 309–22. doi:10.1007/s12192-009-0145-6. PMC 2866994. PMID 19809895.
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