2,6-Dihydroxypyridine
Encyclopedia
2,6-Dihydroxypyridine is an alkaloid
with the molecular formula C5H3N(OH)2. It is a colorless solid. 2,6-Dihyroxypyridine is an intermediate in the degradation of nicotine
.
The figure represents the pathway for the degradation of L-nicotine by A. nicotinovorans to 2,6-dihydroxypyridine
Another reaction of 2,6-dihydroxypyridine highlights its function as a substrate for oxygenase
. One example is the enzyme monooxygenase, which oxidizes the substrate by transferring one oxygen atom of O2 to the substrate. The other oxygen atom is reduced to water. The product of the oxidase reaction was determined to be 2,3,6-tri-hydroxypyridine because of the results of the stoichiometry as well as the results of the ultraviolet spectrum. This reaction can be shown by the following equation:
Arthrobacter oxydans, when grown on agar plate
s, were most active in the oxidation of 2,6-dihydroxypyridine.
s:
The distribution of these tautomers is solvent-dependent. Studies show that tautonomer II is most common in ethanol, water, and DMSO.
2,6-dihydroxypyridine hydroxylase is a dimeric flavoprotein, with one bound FAD molecule attached. The reaction is NADH-dependent and the enzyme only accepts 2,6-dihydroxypyridine as a substrate. Furthermore, the enzyme is inhibited by 2,6-dimethoxypyridine and 2,3-dihydroxypyridine.
Alkaloid
Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids...
with the molecular formula C5H3N(OH)2. It is a colorless solid. 2,6-Dihyroxypyridine is an intermediate in the degradation of nicotine
Nicotine
Nicotine is an alkaloid found in the nightshade family of plants that constitutes approximately 0.6–3.0% of the dry weight of tobacco, with biosynthesis taking place in the roots and accumulation occurring in the leaves...
.
Preparation
2,6-Dihydroxypyridine is an intermediate in the degradation of nicotine by the aerobic bacterium Arthrobacter nicotinovorans. The following reaction shows the formation of the intermediate from L-nicotine of tobacco.The figure represents the pathway for the degradation of L-nicotine by A. nicotinovorans to 2,6-dihydroxypyridine
Another reaction of 2,6-dihydroxypyridine highlights its function as a substrate for oxygenase
Oxygenase
An oxygenase is any enzyme that oxidizes a substrate by transferring the oxygen from molecular oxygen O2 to it. The oxygenases form a class of oxidoreductases; their EC number is EC 1.13 or EC 1.14....
. One example is the enzyme monooxygenase, which oxidizes the substrate by transferring one oxygen atom of O2 to the substrate. The other oxygen atom is reduced to water. The product of the oxidase reaction was determined to be 2,3,6-tri-hydroxypyridine because of the results of the stoichiometry as well as the results of the ultraviolet spectrum. This reaction can be shown by the following equation:
Arthrobacter oxydans, when grown on agar plate
Agar plate
An agar plate is a Petri dish that contains a growth medium used to culture microorganisms or small plants like the moss Physcomitrella patens.Selective growth compounds may also be added to the media, such as antibiotics....
s, were most active in the oxidation of 2,6-dihydroxypyridine.
Structure and properties
2,6-Dihydroxypyridine in principle can exist in five tautomerTautomer
Tautomers are isomers of organic compounds that readily interconvert by a chemical reaction called tautomerization. This reaction commonly results in the formal migration of a hydrogen atom or proton, accompanied by a switch of a single bond and adjacent double bond...
s:
The distribution of these tautomers is solvent-dependent. Studies show that tautonomer II is most common in ethanol, water, and DMSO.
Other Applications
2,6-Dihydroxypyridine has been investigated in an oxidation method of dyeing hair. The process utilizes 2,6-dihydroxypyridine as a coupling agent, and 2,4,5,6-tetraaminopyrimidine as a primary intermediate. This oxidation method intensifies the color of the dyed hair for several days.Main Reactions
2,6-dihydroxypyridine is a key intermediate in the degradation of nicotine by certain bacteria. The enzyme 2,6-dihydroxypyridine-3-hydroxylase, which is produced in Escherichia coli, is responsible for catalyzing the sixth step of nicotine degradation in the bacterium Arthrobacter nicotinovoran. 2,6-dihydroxypyridine is hydroxylated by hydroperoxy-FAD. This reaction yields 2,3,6-tri-hydroxypyridine. This is shown in the following reaction::2,6-dihydroxypyridine hydroxylase is a dimeric flavoprotein, with one bound FAD molecule attached. The reaction is NADH-dependent and the enzyme only accepts 2,6-dihydroxypyridine as a substrate. Furthermore, the enzyme is inhibited by 2,6-dimethoxypyridine and 2,3-dihydroxypyridine.