Phloroglucinol Carboxylic Acid Research Articles

The utilization of flavonoid compounds by yeasts and yeast-like fungi.

Three hundred cultures of yeasts and yeast-like fungi were tested for their ability to metabolize flavonoid compounds. Rutin, quercitrin, taxifolin, and naringin were used by strains of Pullularia and by the asporogenous yeasts Cryptococcus albidus and Cryptococcus diffluens. Catechin and 5, 7-dihydroxyiso-flavone were not used by any of the cultures tested.The utilization of flavonoid compounds was dependent upon the nutritional complexity of the medium used. When a complex organic nitrogen source was used in the medium, not only were quercetin glycosides metabolized at a faster rate but yeasts, which were inactive on a synthetic medium, utilized varying amounts of the glycosides. The aglycone quercetin was utilized only in the presence of organic nitrogen compounds. Culture filtrates were inactive but cell-free extracts of a Pullularia sp. and of strains of C. albidus and C. diffluens degraded rutin, in the presence of air, to glucose, rhamnose, protocatechuic acid, phloroglucinol carboxylic acid, and carbon monoxide. The metabolism of flavonol glycosides by yeasts is discussed as a taxonomic characteristic and the pathway used is compared to the known microbiological routes for the utilization of these compounds.

MICROBIOLOGICAL DEGRADATION OF QUERCITRIN

A number of molds and bacteria were screened for their ability to degrade quercitrin. The molds, but not the bacteria, were particularly active and produced carbon monoxide. The degradation of quercitrin is dependent upon the synthesis of an inducible glycosidase (quercitrinase). This enzyme is synthesized by only a few members of the Aspergillus flavus group. Two of these strains synthesized quercitrinase and excreted it and other enzymes into the culture medium. Maximum production of quercitrinase was obtained with organic nitrogen sources such as yeast extract or phytone. Quercitrinase is induced by readily metabolized flavonols and flavonol-glycosides. The glycosidase is quite specific, liberating the rhamnose from the 3-position of quercitrin and myricitrin and the 7-position of robinin. The aglycone, quercetin, is subsequently metabolized to carbon monoxide and the depside of phloroglucinol-carboxylic acid and proto-catechuic acid. Evidence is also presented for an alternative pathway for the metabolism of the flavonol nucleus.

プルラリア菌によるフラボノールの分解

1. Rutin is decomposed into protocatechuic acid, phloroglucinol carboxylic acid and protocatechuoyl-phloroglucinol carboxylic acid by the enzyme preparation from Pullularia fermentans var. candida.2. The activity of the oxidase, which attacks rutin, is neither inhibited by potassium cyanide nor activated by flavin adenine dinucleotide (nor flavin mononucleotide).3. Protocatechuoyl-phloroglucinol carboxylic acid is hydrolyzed by mold-depsidase into protocatechuic acid and phloroglucinol carboxylic acid.4. Pholoroglucinol carboxylic acid decarboxylase is found in the organism.5. Quercetin is decomposed by the organism in the presence of sucrose, rutinose. nucleic acids or nucleobases.6. The substance, which is conceived to be quercetin fructoside is found as an intermediate in the culture medium, when quercetin is decomposed in the presence of sucrose.7. Kaempferol, quercetin, myricetin and their glycosides are shown to be attacked by the organism, but other flavonoids are not.

Microbial production of carbon monoxide from flavonoids.

Aspergillus flavus degrades rutin to protocatechuic acid, phloroglucinol carboxylic acid, rutinose and carbon monoxide, the last-named being derived from carbon 3 of the flavonoid molecule1,2. The extent of distribution of this degradative pathway in microorganisms and the structural requirements for the production of carbon monoxide were determined by comparing the amount of carbon monoxide produced after the growth of micro-organisms on various flavonoid compounds. The cultures studied were grown in sealed flasks of known volume3. A medium containing N—Z amine1 was used when the substrates tested could be analysed by the aluminium chloride reaction. A synthetic medium4 was employed with substrates that were difficult to determine directly and the amount of oxygen consumed was therefore used as the criterion of substrate utilization. Carbon monoxide and oxygen were determined by gas phase chromatography using a molecular sieve column.

Microbiol decomposition of rutin.

A number of molds, streptomycetes, and bacteria, obtained from culture collections and by enrichment techniques, were tested for their ability to degrade rutin. The molds, particularly Aspergillus fiavus and A. niger, appeared to be more active than either the streptomycetes or bacteria. The aspergilli when grown on either rutin or quercetin produced extracellular enzymes that degraded both rutin and quercetin but not quercitrin. Rutinose, protocatechuic acid, phloroglucinol carboxylic acid, and a phloroglucmo! carboxylic acid – protocatechuic acid ester were identified by paper chromatography as the products.

Preliminary studies on degradation products of quercetin in the rat's gastrointestinal tract

Paper chromatographic studies of the ether extracts of the lyophilized rat stomach and its contents were made following the feeding of randomly labeled quercetin-C 14. Radioactive phloroglucinol carboxylic acid, phloroglucinol, and protocatechuic acid were identified. A fourth radioactive compound still not identified plus a radioactive “quercetin-like” compound were also noted. Protocatechuic acid, phloroglucinol carboxylic acid, and phloroglucinol were also found following incubation of quercetin with a porcine gastric mucin preparation.

Oxidation of meta-polyhydroxyphenols by enzymes from Piricularia oryzae and Polyporus versicolor

Culture filtrates and mycelia of the rice blast fungus Piricularia oryzae and of the wood-rotting fungus Polyporus versicolor contain, in addition to the classical tyrosinase and laccase, an enzyme which catalyzes the oxidation of meta-polyhydroxyphenols such as resorcinol, orcinol, 2,4-dichlororesorcinol, phloroglucinol, methylphloroglucinol, phloroglucinolcarboxylic acid, 3,5-dichloro-β-resorcylic acid, and 2,5-dihydroxybenzoquinone. The name metapolyphenoloxidase is proposed for this enzyme, and some of its properties are described.

A modified method for esterification of some polyhydroxy aromatic acids

A new method of esterification of acids is described. In this method the esterification is carried out in a dry medium (acetone) in presence of neutral substance like sodium or potassium bicarbonate with alkyl halide or alkyl sulphate. Yields of methyl esters varying from 50–80% are obtained on esterification ofo- andp-orsellinic acids,a- and β-resorcylic acids, phloroglucinol carboxylic acid, 3-acetyl-p-orsellinic acid and 3∶5-diacetyl-o-orsellinic acid. However, only 25% yield of methyl benzoate was obtained from benzoic acid.

62. Halogen derivatives of the methyl ethers of orcinol, p-orsellinic acid and phloroglucinolcarboxylic acid

62. Halogen derivatives of the methyl ethers of orcinol, p-orsellinic acid and phloroglucinolcarboxylic acid