Pyocyanine

a-Methoxyphenasine condensation). Two hundred grams (0.42 mole) of powdered lead dioxide (Note 1) is added to a solution of 10 g. (0.07 mole) of pyrogallol monomethyl ether (p. 90) in 3 1. of dry benzene in a 1-gal. narrow-necked acid bottle. The bottle and contents are placed in a shaking machine and shaken for 10-20 minutes (Note 2). The reddish brown solid is filtered through an 11-cm. Buchner funnel, and the filter cake is washed once with 400 ml. of benzene. To this filtrate there is added, immediately and with mechanical stirring, a solution of 6 g. (0.06 mole) of o-phenylenediamine (Note 3) in a mixture of 80 ml. of glacial acetic acid and 200 ml. of benzene. The solu- 

a-Hydroxyphenazine (demethylalion). A solution of 4.2 g. (0.02 mole) of a-methoxyphenazine, from A above, in 125 ml. of 55% hydrobromic acid (Note 7) is placed in a 250-ml. round-bottomed flask fitted with a reflux condenser. The flask is immersed in an oil bath, and the solution is heated to 110-120° for 5 hours the evolved gases are absorbed with water in a trap. The reaction mixture is cooled to room temperature, diluted with about 125 ml. of water, almost neutralized with sodium hydro.xide (Note 8), and extracted six times with 30- to 40-ml. portions of ether. The combined ether extracts arc extracted with 25-ml. portions of 10% sodium hydroxide solution (Note 9) until no more purple sodium salt is remox ed from the ether. The aqueous extracts are combined, made acid to litmus with dilute acetic acid, and re-extracted four times with 50-ml. portions of ether. The combined ether extracts are dried over anhydrous sodium sulfate, and the ether is removed by distillation on a steam bath. The residue is recrystallized as follows It is dissolved in the least possible amount of hot alcohol, water 

Pyocyanine alkylation). A solution of 2 g. (0.011 mole) of a-hydroxyphenazine in 13.4 g. (10 ml., 0.1 mole) of methyl sulfate (Note 10) is placed in a 250-ml. Erlenmeyer flask fitted with a calcium chloride drying tube and heated at 100° (oil bath) for 10 minutes. The solution is allowed to cool to room temperature, and about 7.5 ml. of dry ether is added. The dark brown solid is filtered on a 7-cm. Eiichner funnel and washed with about ISO ml. of dry ether in several portions (Note 11). 

The dry methosulfate, dissolved in about 30 ml. of water, is made alkaline with 2-3 ml. of 10% sodium hydroxide, and the solution is then extracted exhaustively with successive 15-ml. portions of chloroform until no more blue substance is remov ed from the aqueous solution (Note 12). The combined chloroform solutions are extracted three times with 20-ml. portions of 5% hydrochloric acid. The combined acid extracts are made alkaline to phenolphthalein with 10% sodium hydroxide and reextracted exhaustively with 25-ml. portions of chloroform until no more blue substance is removed from the aqueous solution (Note 12). The combined chloroform solutions are dried over anhydrous sodium sulfate and decanted, and the chloroform is removed by distillation under reduced pressure. The blue crystalline residue is recrystallized by dissohnng it in the least possible amount of water at 60° and then cooling the solution in an ice bath. The product is filtered on a 5-cm. Buchner funnel and dried in the dark in a v acuum desiccator over calcium chloride. The yield is 1.35 g. (58%) of dark blue needles that melt at 133° (Note 13). 

Lead peroxide analytical reagent of low manganese content was used. 

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This series of reactions is essentially the one described by Wrede and Strack. Pyocyanine can also be prepared by the photochemical oxidation of phenazinc methosulfate. ... 

Pyocyanine (l-hydroxy-5-methylphenazinium zwitterion) [85-66-5] M 210.2, m 133 (sublimes and dec on further heating). Crystd from H2O as dark blue needles. Picrate has m 190° dec. 

Aeruginosine A (254) (69JCS(C)2514) and B (255) (61MI2), shown in Scheme 83, are metabolites of the pyocyanine producing Pseudomonas aeruginosa. They are isoconjugate with the odd alternant 1-isopropenyl-anthracene anion (class 13). 

Phenazines — The phenazines are biosynthesized by the shikimic acid pathway, through the intermediate chorismic acid. The process was studied using different strains of Pseudomonas species, the major producers of phenazines. The best-known phenazine, pyocyanine, seems to be produced from the intermediate phenazine-1-carboxylic acid (PCA). Although intensive biochemical studies were done, not all the details and the intermediates of conversion of chorismic acid to PCA are known. In the first step, PCA is N-methylated by a SAM-dependent methyltransferase. The second step is a hydroxylative decarboxylation catalyzed by a flavoprotein monooxygenase dependent on NADH. PCA is also the precursor of phenazine-1-carboxamide and 1-hydroxyphenazine from Pseudomonas species. - - ... 

Phenazines — This large class of compounds includes more than 6,000 natural and synthetic representatives. Natural phenazines are secondary metabolites of certain soil and marine microorganisms. The main phenazine producers are Pseudomonas and Streptomyces species. Pseudomonas strains produce the most simple phenazines tubermycin B (phenazine-1-carboxylic acid), chlororaphine, pyocyanin, and iodinine. Pyocyanin is a blue pigment while chlororaphine is green both are produced by Pseudomonas aeruginosa. They can be seen in infected wounds of animal and human skins. Iodinine is a purple phenazine produced by Pseudomonas aureofaciens. 

Mavrodi DV, RE Bonall, SMK Delaney, MJ Soule, G Phillips, LS Thomashow (2001) Eunctional analysis of genes for biosynthesis of pyocyanin and phenazine-l-carboxamide from Pseudomonas aeruginosa PAGE J Bacterial 183 6454-6465. 

The best-studied system producing antibiotics in the rhizosphere are fluorescent pseudomonads, producing up to seven different compounds, as summarized in Fig. 9 2-hydroxyphenazine-l-carboxylate, phenazine-l-carboxylate, 2-hydroxy-phenazine, pyrrolnitrin, pyocyanine, 2.4-diacetylphloroglucinol. and pyoluteorin (48). Nine genes have been identified in the synthesis of phenazine-1-carboxylic... 

The leuco form is readily oxidized to a paramagnetic green ion-radical and thence to pyocyanine itself. 

H 0 A-butanoyl-L-homoserine lactone, BHL or C4-HSL Aeromomas hydrophila Aeromonas salmonicida Pseudomonas aeruginosa, Serratia liquefaciens Extracellular protease, biofilm formation. Extracellular protease. Virulence factors - alkaline protease, cyanide, elastase, haemolysin, lectins, pyocyanin, rhaminolipid, RpoS Swarming, protease. 

Naturally occurring phenazines from bacteria have been known since the middle of the nineteenth century [1,2]. The first examples included pyocyanine (1),... 

The same problem occurs with the synthesis of lavanducyanin (65) [85,87] and phenazinomycin (67) [88]. Here, Kitahara et al. used the same approach in that they first generated the phenazine skeleton and performed the AT-allylation as the last step. While the AT-methylation of the unprotected 1-hydroxyphenazine (109) proceeds without any major problems and provides pyocyanin (1) in acceptable yields [89], model experiments already indicate that the allylation of 110 could not be so readily accomplished. As expected, the yields were poor. The only way to bring about the synthesis of 65 is under high-pressure conditions by reaction of 110 with 111, and even so the yield of the natural product remains quite low. Similar problems are encountered with the synthesis of 67 by allylation of 110 with the terpenoid component 112. 

The bacteria Pseudomonas spp. produce tabtoxin and pyocyanine, alkaloids with a relatively powerful biological activity. 

It is important to emphasize that systems in which the lone pair originates at a starred position can be represented by dipolar canonical forms as well as by purely covalent structures and that sometimes these dipolar structures are a better representation of the molecule. Examples of this are the antibiotic pyocyanine (28 29) and the berberine derivative 30+->31, 5 In... 

Claudia J. Nachef was born in Saida, Lebanon. She holds a B.S. degree from the Saint-Joseph University, Lebanon, and a M.S. degree (Doctor Jean-Yves Winum) from the University of Montpellier II, France. She is currently a research assistant at the American University of Beirut (Professor M. J. Haddadin). She worked on sulfonylureas for her M.S. degree and has been working on benzofurazan oxides, quinoxaline 1,4-dioxides, phenazines, and pyocyanins. 

Ferrocene was one of the earliest mediators used [10] but is somewhat hydrophobic so derivatives of the molecule are often employed [39-43]. Ferricyanide can also be used, and the use of MWCNT with this mediator was shown to enhance its effectiveness [33]. Other groups have studied a wide diversity of novel mediator systems such as poly(vinylferrocene-co-acrylamide) dispersed within an alumina nanoparticle membrane [34], ruthenium [35] and osmium [36,37] complexes, and the phenazine pigment pyocyanin, which is produced by the bacteria Pseudomonas aeruginosa [38]. 

K. Ohfuji, N. Sato, N. Hamada-Sato, T. Kobayashi, C. Imada, H. Okuma and E. Watanabe, Construction of a glucose sensor based on a screen-printed electrode and a novel mediator pyocyanin from Pseudomonas aeruginosa, Biosens. Bioelectron., 19 (2004) 1237-1244. 

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