:2,6-Pyridinedicarbothioic acid
{{Chembox
| Watchedfields = changed
| verifiedrevid = 438566750
| ImageFile = 2,6-Pyridinedicarbothioicacid.svg
| ImageSize =
| ImageAlt = Skeletal formula of 2,6-pyridinedicarbothioic acid
| ImageFile1 = 2,6-Pyridinedicarbothioic acid 3D ball.png
| ImageSize1 = 220
| ImageAlt1 = Ball-and-stick model of the 2,6-pyridinedicarbothioic acid molecule
| IUPACName = 2,6-Pyridinedicarbothioic acid
| PIN = Pyridine-2,6-bis(carbothioic S-acid)
| OtherNames = PDTC, dithiopyridinedicarbothioic acid
|Section1={{Chembox Identifiers
| CASNo_Ref = {{cascite|correct|CAS}}
| CASNo = 69945-42-2
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = KJ7K75Z4JS
| SMILES = C1=CC(=NC(=C1)C(=O)S)C(=O)S
| PubChem = 10214455
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 8389947
| SMILES1 = O=C(S)c1nc(C(=O)S)ccc1
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI=1S/C7H5NO2S2/c9-6(11)4-2-1-3-5(8-4)7(10)12/h1-3H,(H,9,11)(H,10,12)
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = SSRIAMRLMUFTNV-UHFFFAOYSA-N
}}
|Section2={{Chembox Properties
| C=7 | H=5 | O=2 | S=2
| Appearance =White crystalline solid
| Density = 1.415 g/cm3
| MeltingPtC = 97 to 99
| BoilingPtC = 404.4
| Solubility = 1000 g/L (5.02 mol/L)}}
|Section3={{Chembox Hazards
|MainHazards = acidic
|FlashPtC = 198.4}}
}}
2,6-Pyridinedicarbothioic acid (PDTC) is an organosulfur compound that is produced by some bacteria. It functions as a siderophore, a low molecular weight compound that scavenges iron. Siderophores solubilize compounds by forming strong complexes. PDTC is secreted by the soil bacteria Pseudomonas stutzeri and Pseudomonas putida.{{cite book |doi=10.1007/978-3-211-99661-4_1 |year=2010 |last=Budzikiewicz |first=Herbert |title=Fortschritte der Chemie organischer Naturstoffe / Progress in the Chemistry of Organic Natural Products, Vol. 92 |editor-first=A. Douglas |editor-last=Kinghorn |editor-first2=Heinz |editor-last2=Falk |editor-first3=Junichi |editor-last3=Kobayashi |volume=92 |trans-title=Progress in the Chemistry of Organic Natural Products |chapter=Microbial Siderophores |pages=1–75 |pmid=20198464 |isbn=978-3-211-99660-7}}
Synthesis and biosynthesis
PDTC can be synthesized in the laboratory by treating the diacid dichloride of pyridine-2,6-dicarboxylic with H2S in pyridine:
:{{chem2|NC5H3(COCl)2 + 2 H2S + 2 C5H5N → [C5H5NH+][HNC5H3(COS)2-] + [C5H5NH]Cl}}
This route produces the pyridinium salt of pyridinium-2,6-dicarbothioate. Treatment of this orange-colored salt with sulfuric acid gives colorless PDTC, which can then be extracted with dichloromethane.{{cite journal |doi=10.1080/03086648308080490 |title=Zur Struktur Eines 1:1-Adduktes von Pyridin-2,6-Dicarbothiosäure und Pyridin |date=1983 |last1=Hildebrand |first1=U. |last2=Ockels |first2=W. |last3=Lex |first3=J. |last4=Budzikiewicz |first4=H. |journal=Phosphorus and Sulfur and the Related Elements |volume=16 |issue=3 |pages=361–364 }}
The biosynthesis of PDTC remains unclear although some insights can be deduced from the genetics.{{cite journal | doi = 10.1186/1471-2148-2-8 | year = 2002 | last1 = Cortese | first1 = Marc S | last2 = Caplan | first2 = Allan B | last3 = Crawford | first3 = Ronald L | journal = BMC Evolutionary Biology | volume = 2 | pages = 8 | pmid = 11972321 | title = Structural, functional, and evolutionary analysis of moeZ, a gene encoding an enzyme required for the synthesis of the Pseudomonas metabolite, pyridine-2,6-bis(thiocarboxylic acid) | pmc = 115864 | doi-access = free }} It is suggested that Pseudomonas stutzeri may have acquired at least one of the genes by lateral transfer from mycobacteria.{{cite journal | doi = 10.1023/A:1015241925322 | year = 2002 | last1 = Cortese | first1 = Marc S. | last2 = Paszczynski | first2 = Andrzej | last3 = Lewis | first3 = Thomas A. | last4 = Sebat | first4 = Jonathan L. | last5 = Borek | first5 = Vladimir | last6 = Crawford | first6 = Ronald L. | journal = BioMetals | volume = 15 | issue = 2 | pages = 103–120 | pmid = 12046919 | title = Metal chelating properties of pyridine-2,6-bis(thiocarboxylic acid) produced by Pseudomonas spp. And the biological activities of the formed complexes| s2cid = 5545637 }} In a proposed biosynthetic sequence pyridine-2,6-dicarboxylic acid, a known bacterial metabolite, is activated as its bis-adenosine monophosphate (AMP) derivative. The sulfur donor and its activation remain uncertain.{{cite journal | doi = 10.1023/A:1024012015127 | year = 2003 | last1 = Budzikiewicz | first1 = H. | journal = Biodegradation | volume = 14 | issue = 2 | pages = 65–72 | pmid = 12877462 | title = Heteroaromatic monothiocarboxylic acids from Pseudomonas spp| s2cid = 29898226 }}
Coordination chemistry
PDTC binds to both Fe2+ and Fe3+. The ferric complex is brown, whereas the ferrous complex is blue. In the presence of air, the ferrous complex oxidizes to the ferric compound.Ockels, W., Roemer, A., Budzikiewicz, H., Korth, H., Pulverer, G., "Bacterial constituents. II. An iron(II) complex of pyridine-2,6-di-(monothiocarboxylic acid) - a novel bacterial metabolic product", Tetrahedron Lett. 1978, 3341. {{doi|10.1016/S0040-4039(01)85634-3}} It is iron selective as only the Fe complex is soluble in water. PDTC is produced mainly during the exponential phase of bacterial growth. The conditions at which Pseudomonas produces PDTC is 25 °C, pH=8 and sufficient aeration.
See also
References
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{{DEFAULTSORT:Pyridinedicarbothioic acid, 2,6-}}