Names | |
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Preferred IUPAC name
Pyridine-2,6-dicarboxylic acid | |
Other names
2,6-Pyridinedicarboxylic acid
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Identifiers | |
3D model (
JSmol)
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131629 | |
ChEBI | |
ChEMBL | |
ChemSpider | |
DrugBank | |
ECHA InfoCard | 100.007.178 |
EC Number |
|
50798 | |
PubChem
CID
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|
UNII | |
CompTox Dashboard (
EPA)
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|
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Properties | |
C7H5NO4 | |
Molar mass | 167.120 g·mol−1 |
Melting point | 248 to 250 °C (478 to 482 °F; 521 to 523 K) |
Hazards | |
GHS labelling: [2] | |
Warning | |
H315, H319, H335 | |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
|
Dipicolinic acid (pyridine-2,6-dicarboxylic acid or PDC and DPA) is a chemical compound which plays a role in the heat resistance of bacterial endospores. It is also used to prepare dipicolinato ligated lanthanide and transition metal complexes for ion chromatography. [1]
Dipicolinic acid composes 5% to 15% of the dry weight of Bacillus subtilis spores. [3] [4] It has been implicated as responsible for the heat resistance of the endospore, [3] [5] although mutants resistant to heat but lacking dipicolinic acid have been isolated, suggesting other mechanisms contributing to heat resistance are at work. [6] Two genera of bacterial pathogens are known to produce endospores: the aerobic Bacillus and anaerobic Clostridium. [7]
Dipicolinic acid forms a complex with calcium ions within the endospore core. This complex binds free water molecules, causing dehydration of the spore. As a result, the heat resistance of macromolecules within the core increases. The calcium-dipicolinic acid complex also functions to protect DNA from heat denaturation by inserting itself between the nucleobases, thereby increasing the stability of DNA. [8]
The high concentration of DPA in and specificity to bacterial endospores has long made it a prime target in analytical methods for the detection and measurement of bacterial endospores. A particularly important development in this area was the demonstration by Rosen et al. of an assay for DPA based on photoluminescence in the presence of terbium, [9] although this phenomenon was first investigated for using DPA in an assay for terbium by Barela and Sherry. [10]
Simple substituted pyridines vary significantly in environmental fate characteristics, such as volatility, adsorption, and biodegradation. [11] Dipicolinic acid is among the least volatile, least adsorbed by soil, and most rapidly degraded of the simple pyridines. [12] A number of studies have confirmed dipicolinic acid is biodegradable in aerobic and anaerobic environments, which is consistent with the widespread occurrence of the compound in nature. [13] With a high solubility (5g/liter) and limited sorption (estimated Koc = 1.86), utilization of dipicolinic acid as a growth substrate by microorganisms is not limited by bioavailability in nature. [14]