Phenazine
Encyclopedia
Phenazine also called azophenylene, dibenzo-p-diazine, dibenzopyrazine, and acridizine, is a dibenzo annulated
pyrazine
and the parent substance of many dye
stuffs, such as the eurhodines, toluylene red, indulines and safranines.
(1901). Other methods are known, e.g.:
Phenazine crystal
lizes in yellow needles which melt at 174-177 °C, and are only sparingly soluble in alcohol
. Sulfuric acid
dissolves it, forming a deep-red solution.
with ferric chloride; when a mixture of para-aminodimethylaniline and meta-toluylenediamine is oxidized in the cold, toluylene blue, an indamine, being formed as an intermediate product and passing into the red when boiled; and also by the oxidation of dimethylparaphenylene diatnine with metatoluylene diamine. It crystallizes in orange-red needles and its alcoholic solution fluoresces strongly. It dyes silk
and mordanted cotton
a fine scarlet. It is known commercially as neutral red
. For the phenazonium salt
s, see safranine. Phenazone
is an isomer
of phenazine, to which it bears the same relation that phenanthrene
bears to anthracene
.
spp., Streptomyces
spp., and Pantoea agglomerans. These phenazine natural products have been implicated in the virulence and competitive fitness of producing organisms. For example, the phenazine pyocyanin produced by Pseudomonas aeruginosa
contributes to its ability to colonise the lungs of cystic fibrosis
patients. Similarly, phenazine-1-carboxylic acid, produced by a number of Pseudomonas, increases survival in soil environments and has been shown to be essential for the biological control
activity of certain strains.
at a point subsequent to chorismic acid
. Two molecules of this chorismate-derived intermediate are then brought together in a diagonally-symmetrical fashion to form the basic phenazine scaffold. Sequential modifications then lead to a variety of phenazine with differing biological activities
.
Annulation
Annulation in organic chemistry is a chemical reaction in which a new ring is constructed on another molecule ....
pyrazine
Pyrazine
Pyrazine is a heterocyclic aromatic organic compound with the chemical formula C4H4N2.Pyrazine is a symmetrical molecule with point group D2h. Derivatives like phenazine are well known for their antitumor, antibiotic and diuretic activity. Pyrazine is less basic in nature than pyridine, pyridazine...
and the parent substance of many dye
Dye
A dye is a colored substance that has an affinity to the substrate to which it is being applied. The dye is generally applied in an aqueous solution, and requires a mordant to improve the fastness of the dye on the fiber....
stuffs, such as the eurhodines, toluylene red, indulines and safranines.
Synthesis
A classic method for the synthesis of phenazine is the reaction of nitrobenzene and aniline in the Wohl-Aue reactionWohl-Aue reaction
The Wohl-Aue reaction is an organic reaction between an aromatic nitro compound and an aniline to form a phenazine in presence of an alkali base. An example is the reaction between nitrobenzene and aniline:The reaction is named after Alfred Wohl and W. Aue....
(1901). Other methods are known, e.g.:
- by distilling the bariumBariumBarium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in Group 2, a soft silvery metallic alkaline earth metal. Barium is never found in nature in its pure form due to its reactivity with air. Its oxide is historically known as baryta but it reacts with...
saltSaltIn chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
of azobenzoate - by passing anilineAnilineAniline, phenylamine or aminobenzene is an organic compound with the formula C6H5NH2. Consisting of a phenyl group attached to an amino group, aniline is the prototypical aromatic amine. Being a precursor to many industrial chemicals, its main use is in the manufacture of precursors to polyurethane...
vapor over lead oxideLead oxideLead oxide may refer to:* Lead oxide, PbO, litharge, massicot* Lead oxide, Pb3O4, minium, red lead* Lead dioxide , PbO2Less common lead oxides are:* Lead oxide, Pb2O3, lead sesquioxide... - by the oxidation of dihydrophenazine, which is prepared by heating pyrocatechin with o-phenylenediamineO-Phenylenediamineo-Phenylenediamine is a organic compound with the formula C6H42. This aromatic diamine is an important precursor to many heterocyclic compounds...
. - It is also formed when ortho-aminodiphenylamine is distilled over lead peroxide.
Phenazine crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
lizes in yellow needles which melt at 174-177 °C, and are only sparingly soluble in alcohol
Alcohol
In chemistry, an alcohol is an organic compound in which the hydroxy functional group is bound to a carbon atom. In particular, this carbon center should be saturated, having single bonds to three other atoms....
. Sulfuric acid
Sulfuric acid
Sulfuric acid is a strong mineral acid with the molecular formula . Its historical name is oil of vitriol. Pure sulfuric acid is a highly corrosive, colorless, viscous liquid. The salts of sulfuric acid are called sulfates...
dissolves it, forming a deep-red solution.
Derivatives
- The more complex phenazines, such as the naphthophenazines, naphthazines and naphthotolazines, may be prepared by condensing ortho-diamineToluidineThere are three isomers of toluidine, which are organic compounds. These isomers are o-toluidine, m-toluidine, and p-toluidine. The o- stands for ortho- , m- stands for meta- , and p- stands for para-...
s with ortho-quinoneQuinoneA quinone is a class of organic compounds that are formally "derived from aromatic compounds [such as benzene or naphthalene] by conversion of an even number of –CH= groups into –C– groups with any necessary rearrangement of double bonds," resulting in "a fully conjugated cyclic dione structure."...
s or by the oxidation of an ortho-diamine in the presence of α-naphtholNaphtholNaphthol may refer to:* 1-Naphthol* 2-Naphthol...
, and by the decomposition of ortho-anilido-(-toluidido- et cetera)- azo compoundAzo compoundAzo compounds are compounds bearing the functional group R-N=N-R', in which R and R' can be either aryl or alkyl. IUPAC defines azo compounds as: "Derivatives of diazene , HN=NH, wherein both hydrogens are substituted by hydrocarbyl groups, e.g. PhN=NPh azobenzene or diphenyldiazene." The more...
s with dilute acidAcidAn acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...
s. - If alkyl or aryl-ortho-diamines be used, azonium baseBase (chemistry)For the term in genetics, see base A base in chemistry is a substance that can accept hydrogen ions or more generally, donate electron pairs. A soluble base is referred to as an alkali if it contains and releases hydroxide ions quantitatively...
s are obtained. The azines are mostly yellow in color, distill unchanged and are stable to oxidants. They add on alkyl iodides readily, forming alkyl azonium salts, anhydride formation also taking place between these hydroxylHydroxylA hydroxyl is a chemical group containing an oxygen atom covalently bonded with a hydrogen atom. In inorganic chemistry, the hydroxyl group is known as the hydroxide ion, and scientists and reference works generally use these different terms though they refer to the same chemical structure in...
groups. It dissolves in concentrated sulfuric acid with a yellowish-green fluorescenceFluorescenceFluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation of a different wavelength. It is a form of luminescence. In most cases, emitted light has a longer wavelength, and therefore lower energy, than the absorbed radiation...
. - The rhodamineRhodamineRhodamine is a family of related chemical compounds, fluorone dyes. Examples are Rhodamine 6G and Rhodamine B. They are used as a dye and as a dye laser gain medium. They are often used as a tracer dye within water to determine the rate and direction of flow and transport...
s, which are closely related to the phthaleins, are formed by the condensation of the alkyl metaaminophenols with phthalic anhydridePhthalic anhydridePhthalic anhydride is the organic compound with the formula C6H42O. It is the anhydride of phthalic acid. This colourless solid is an important industrial chemical, especially for the large-scale production of plasticizers for plastics. In 2002, approximately 4.6 billion kilograms were...
in the presence of sulfuric acid. Their saltSaltIn chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
s are fine red dyes. By the entrance of amino or hydroxylHydroxylA hydroxyl is a chemical group containing an oxygen atom covalently bonded with a hydrogen atom. In inorganic chemistry, the hydroxyl group is known as the hydroxide ion, and scientists and reference works generally use these different terms though they refer to the same chemical structure in...
groups into the moleculeMoleculeA molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
dyestuffs are formed. The mono-amino derivatives or eurhodines are obtained when the arylmonamines are condensed with orthoamino azo compounds; by condensing quinone dichlorimide or para-nitrosodimethyl aniline with monamines containing a free para position, or by oxidizing ortho-hydroxydiaminodipbenylamines. They are yellowish-red solids, which behave as weak baseBase (chemistry)For the term in genetics, see base A base in chemistry is a substance that can accept hydrogen ions or more generally, donate electron pairs. A soluble base is referred to as an alkali if it contains and releases hydroxide ions quantitatively...
s, their salts undergoing hydrolytic dissociation in aqueous solutionAqueous solutionAn aqueous solution is a solution in which the solvent is water. It is usually shown in chemical equations by appending aq to the relevant formula, such as NaCl. The word aqueous means pertaining to, related to, similar to, or dissolved in water...
. When heated with concentrated hydrochloric acidHydrochloric acidHydrochloric acid is a solution of hydrogen chloride in water, that is a highly corrosive, strong mineral acid with many industrial uses. It is found naturally in gastric acid....
the amino group is replaced by the hydroxyl group and the phenolicPhenolPhenol, also known as carbolic acid, phenic acid, is an organic compound with the chemical formula C6H5OH. It is a white crystalline solid. The molecule consists of a phenyl , bonded to a hydroxyl group. It is produced on a large scale as a precursor to many materials and useful compounds...
eurhodols are produced.
Diaminophenazine
The symmetrical diaminophenazine is the parent substance of the important dyestuff toluylene red or dimethyldiaminotoluphenazine. It is obtained by the oxidation of orthophenylene diamineAmine
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...
with ferric chloride; when a mixture of para-aminodimethylaniline and meta-toluylenediamine is oxidized in the cold, toluylene blue, an indamine, being formed as an intermediate product and passing into the red when boiled; and also by the oxidation of dimethylparaphenylene diatnine with metatoluylene diamine. It crystallizes in orange-red needles and its alcoholic solution fluoresces strongly. It dyes silk
Silk
Silk is a natural protein fiber, some forms of which can be woven into textiles. The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity...
and mordanted cotton
Cotton
Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
a fine scarlet. It is known commercially as neutral red
Neutral red
Neutral Red is a eurhodin dye used for staining in histology. It stains lysosomes red. It is used as a general stain in histology, as a counterstain in combination with other dyes, and for many staining methods. Together with Janus Green B, it is used to stain embryonal tissues and supravital...
. For the phenazonium salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
s, see safranine. Phenazone
Phenazone
Phenazone , phenazon, antipyrine , or analgesine is an analgesic and antipyretic. It was first synthesized by Ludwig Knorr in 1883. It is formed by reducing diortho- dinitrodiphenyl with sodium amalgam and methyl alcohol, or by heating diphenylene-ortho-dihydrazine with hydrochloric acid to...
is an isomer
Isomer
In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...
of phenazine, to which it bears the same relation that phenanthrene
Phenanthrene
Phenanthrene is a polycyclic aromatic hydrocarbon composed of three fused benzene rings. The name phenanthrene is a composite of phenyl and anthracene. In its pure form, it is found in cigarette smoke and is a known irritant, photosensitizing skin to light...
bears to anthracene
Anthracene
Anthracene is a solid polycyclic aromatic hydrocarbon consisting of three fused benzene rings. It is a component of coal-tar. Anthracene is used in the production of the red dye alizarin and other dyes...
.
Natural products
Many phenazine compounds are found in nature and are produced by bacteria such as PseudomonasPseudomonas
Pseudomonas is a genus of gammaproteobacteria, belonging to the family Pseudomonadaceae containing 191 validly described species.Recently, 16S rRNA sequence analysis has redefined the taxonomy of many bacterial species. As a result, the genus Pseudomonas includes strains formerly classified in the...
spp., Streptomyces
Streptomyces
Streptomyces is the largest genus of Actinobacteria and the type genus of the family Streptomycetaceae. Over 500 species of Streptomyces bacteria have been described. As with the other Actinobacteria, streptomycetes are gram-positive, and have genomes with high guanine and cytosine content...
spp., and Pantoea agglomerans. These phenazine natural products have been implicated in the virulence and competitive fitness of producing organisms. For example, the phenazine pyocyanin produced by Pseudomonas aeruginosa
Pseudomonas aeruginosa
Pseudomonas aeruginosa is a common bacterium that can cause disease in animals, including humans. It is found in soil, water, skin flora, and most man-made environments throughout the world. It thrives not only in normal atmospheres, but also in hypoxic atmospheres, and has, thus, colonized many...
contributes to its ability to colonise the lungs of cystic fibrosis
Cystic fibrosis
Cystic fibrosis is a recessive genetic disease affecting most critically the lungs, and also the pancreas, liver, and intestine...
patients. Similarly, phenazine-1-carboxylic acid, produced by a number of Pseudomonas, increases survival in soil environments and has been shown to be essential for the biological control
Biological pest control
Biological control of pests in agriculture is a method of controlling pests that relies on predation, parasitism, herbivory, or other natural mechanisms...
activity of certain strains.
Biosynthesis
Phenazine biosynthesis branches off the shikimic acid pathwayShikimic acid
Shikimic acid, more commonly known as its anionic form shikimate, is an important biochemical metabolite in plants and microorganisms. Its name comes from the Japanese flower shikimi , from which it was first isolated....
at a point subsequent to chorismic acid
Chorismic acid
Chorismic acid, more commonly known as its anionic form chorismate, is an important biochemical intermediate in plants and microorganisms...
. Two molecules of this chorismate-derived intermediate are then brought together in a diagonally-symmetrical fashion to form the basic phenazine scaffold. Sequential modifications then lead to a variety of phenazine with differing biological activities
Biological activity
In pharmacology, biological activity or pharmacological activity describes the beneficial or adverse effects of a drug on living matter. When a drug is a complex chemical mixture, this activity is exerted by the substance's active ingredient or pharmacophore but can be modified by the other...
.