Protocatechuic add

Proto-cocasaure,/. protococaic add. -katechu-saure,/. protocatechuic add. 

Food 4-Hydroxy benzoic acid Protocatechuic add Gallic add... 

Piperonylic Acid. l,3-Benzodioxole-5-corboxyiic acid 3,4-methylenedioxybenzoic add protocatechuic add methylene ether. C,H(04 mol wt 166.13. C 57.83%, H 3.64%, O 38.52%. Occurs in Paracoto berk. Prepd by permanganate oxidation of piperonal Shriner, Kldderer,... 

The only practical method for the preparation of protocatechuic add is by the alkaline fudon of vanillin. ... 

Occurs in many plants, e.g., Leguminosai Besedacece, Euphorbiaeece, Und>eMiferce, Scro-phviariaceeB. Yellow needles + HjO from EtOH. M.p. 328-30°. Sublimes in high vacuum. Sol. EtOH, EtjO. Spar. sol. HgO. Sol, alkalis to yellow sols. KOH fusion —> phlorogludnol -f protocatechuic add. 

Fig. 3.7 Standard curves. Absorbance of caffeic acid (CAF), ferulic acid (FER), p-coumaric acid (PCO),p-hydroxybenzoic acid (POH), protocatechuic add (PRO), sinapic add (SIN), syringicadd (SYR), and vanillic acid (VAN) after reacting with the FoUn Ciocalteu s phenol reagent. Figure reproduced from Blum et al. (1991). Plenum Publishing Corporation, figure used with permission of Springer Science and Business Media...

Control Protocatechuic add / Hydroxybcnzoic add Cafletc add Vanillic add Syringk add Kaempferol Apigaiin... 

Figure 5.6 Ortho and meta fission of aromatic ring of protocatechuic add and catechol (Jtihasz Naidu, 2000, Guzik et al. 2013).

Protocatechuic acid is soluble in water, and melts at 199°. Ferric chloride colors its aqueous solution bluish-green, the color changing to blue and finally to red on the addition of alkalies. The acid reduces an ammoniacal solution of silver nitrate, but does not reduce Fehling s solution. It decomposes into pyrocatechol and carbon dioxide when distilled. Bromine in the cold forms bromoprotocatechuic acid at 100° the carboxyl group is eliminated and tetrabromopyrocatechol is formed. The monomethyl ether, C6H3(OH)(OCH3)COOH(4, 3, 1), is called vanillic acid, as it is formed by the oxidation of vanillin. The dimethyl ether, veratric acid, and the methylene ether, CH2 02 C6H3C00H, piperonylic add, are obtained from a number of substances which occur in nature. 

Standards catechin and gallic acid, 3,4 dihydroxybenzoic add (protocatechuic acid), chlorogenic acid, rutin were purchased from Across Organics (France), p-coumaric acid, isovitexin and quercetin 3-fi-D-glucoside were obtained from Fluka Chemical Company (France). 

Utilization of phenolic acids by microbes can be substantial as long as conditions are appropriate, e.g., adequate nutrition, moisture, pH, and temperature. However, a variety of other factors can also influence microbial utilization of phenolic acids. For example, phenolic acid utilization by microbes was reduced when more readily available carbon sources were present in the soil such as glucose and phenylalanine (Fig. 2.24 Blum et al. 1993 Pue et al. 1995) or other sources of available carbon, i.e., roots (Blum et al. 1999a). The presence of methionine, however, did not influence the rate of phenolic acid utilization by soil microbes (Pue et al. 1995). Differential utilization of carbon sources by soil microbes is fairly common (Martin and Haider 1979 Harder and Dijkhuizen 1982 Papanastasiou 1982 Sugi and Schimel 1993). Thus the relationship between phenolic acid-utilizing microbes and their carbon environment is complex. There is yet another aspect that adds to this complexity. Initial microbial breakdown products of phenolic acids are frequently other phenolic acids. For example, ferulic acid is converted to caffeic acid or vanillic acid and these are converted to protocatechuic acid. Next the ring structure of the... 

The degradation pathways of cypermethrin, deltamethrin and fenpropathrin have been smdied. The fenpropathrin metabolism pathway of Achromobacter sp. (Fig. 3.21a) was proposed by Wang et al., it was suggested that fenpropathrin was hydrolyzed to 2,2,3,3-tetramethylcyclopropanecarboxylic add and 3-phenoxybenzaldehyde, which was later converted to 3-phenoxybenzoic acid. The phenoxybenzoic acid was transformed to 3-(4-hydroxyphenoxy)benzoic acid, which was oxidized to 3,4-dihydroxybenzoic acid (protocatechuate) and p-hydroquinone. The protocatechuate was further oxidized through an ortfe>-cleavage pathway, and p-hydroquinone was degraded via the metabolite benzene-1,2,4-triol (Wang etal. 2011). 

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