m-Hydroxybenzoic acid 4-hydroxylase from Aspergillus niger

1969 ◽  
Vol 47 (8) ◽  
pp. 825-827 ◽  
Author(s):  
R. Premkumar ◽  
P. V. Subba Rao ◽  
N. S. Sreeleela ◽  
C. S. Vaidyanathan

m-Hydroxybenzoic acid 4-hydroxylase was isolated and partially purified from Aspergillus niger grown in presence of m-hydroxybenzoic acid. The enzyme catalyzed the stoichiometric formation of protocatechuic acid (3,4-dihydroxybenzoic acid) from m-hydroxybenzoic acid with the consumption of NADPH and molecular oxygen. The reaction proceeded best at pH 7.2 and showed a requirement for FAD.

1977 ◽  
Vol 23 (10) ◽  
pp. 1496-1499 ◽  
Author(s):  
D. N. Ramakrishna Rao ◽  
C. S. Vaidyanathan

Preliminary studies on the metabolism of mandelic acid by Neurospora crassa reveal the operation of a pathway for its degradation which involves benzoyl formic acid, benzaldehyde, benzoic acid, 4-hydroxybenzoic acid, and protocatechuic acid as the intermediates. This pathway is different from that followed by bacterial systems and is the same as that observed in Aspergillus niger.


Author(s):  
G. Beaven ◽  
A. Bowyer ◽  
P. Erskine ◽  
S. P. Wood ◽  
A. McCoy ◽  
...  

The enzyme 2,4′-dihydroxyacetophenone dioxygenase (or DAD) catalyses the conversion of 2,4′-dihydroxyacetophenone to 4-hydroxybenzoic acid and formic acid with the incorporation of molecular oxygen. Whilst the vast majority of dioxygenases cleave within the aromatic ring of the substrate, DAD is very unusual in that it is involved in C—C bond cleavage in a substituent of the aromatic ring. There is evidence that the enzyme is a homotetramer of 20.3 kDa subunits each containing nonhaem iron and its sequence suggests that it belongs to the cupin family of dioxygenases. By the use of limited chymotrypsinolysis, the DAD enzyme fromAlcaligenessp. 4HAP has been crystallized in a form that diffracts synchrotron radiation to a resolution of 2.2 Å.


1958 ◽  
Vol 36 (5) ◽  
pp. 491-497 ◽  
Author(s):  
J. Pellerin ◽  
A. D'Iorio

3,4-Dihydroxybenzoic acid, 3,4-dihydroxyphenylacetic acid, 3,4-dihydroxymandelic acid, and 3,4-dihydroxycinnamic acid were separately incubated with L-methionine-methyl-C14 in the presence of rat liver or kidney homogenate. In each case, the radioactive metabolite separated by paper chromatography was found to have migrating properties similar to those of the 3-methoxy-4-hydroxyphenolic acid. This reaction was enhanced by the addition of ATP, Mg++, and reduced glutathione. When 3-hydroxybenzoic acid was incubated in this medium no methylated derivative was obtained. Preliminary experiments indicated that the enzymatic activity was contained mostly in the supernatant fraction. It was also noted that liver homogenate was much more active than kidney homogenate in methylating catechol acids.


1964 ◽  
Vol 19 (9) ◽  
pp. 781-783 ◽  
Author(s):  
Hans Grisebach ◽  
Karl-Otto Vollmer

Further investigations on the biosynthesis of benzoic acids in Gaultheria procumbens L. have shown that besides salicylic acid all the other benzoic acids (gentisinic acid, p-hydroxybenzoic acid, protocatechuic acid, o-pyrocatechuic acid(?), syringic acid and vanillinic acid) can be formed from cinnamic acid. In the case of vanillinic acid it was proved that the total activity is located in the carboxyl group when cinnamic acid-[3-14C] is the precursor.Formiat-14C is incorporated into the methylester group of methylsalicylate.


2018 ◽  
Vol 13 (12) ◽  
pp. 1934578X1801301 ◽  
Author(s):  
Nguyen Quang Hung ◽  
Nguyen Thi Luyen ◽  
Nguyen The Cuong ◽  
Tran Huy Thai ◽  
Nguyen Thanh Tung ◽  
...  

A rare noriridoid and six known phenolic compounds were isolated from the parasite plant Rhopalocnemis phalloides. Using spectroscopic methods, these compounds were identified as 10-acetoxy- cis-2-oxabicyclo[4.3.0]nonan-7-en-3-one (1), p-hydroxybenzoic acid (2), protocatechuic acid (3), gallic acid (4), coniferyl aldehyde (5), l- O-trans-cinnamoyl-β-D-glucoside (6), and coniferin (7). The noriridoid compound is the first reported from the family Balanophoraceae. Of the isolated compounds, coniferyl aldehyde had the strongest inhibitory effect on nitric oxide production (IC50 = 8.24 μM).


2003 ◽  
Vol 58 (5-6) ◽  
pp. 351-354 ◽  
Author(s):  
Ammar Saleem ◽  
Henri Kivelä

AbstractA modified in vitro lipid peroxidation inhibition assay was used to guide the fractionation and the isolation of antioxidative principles of Finnish pine bark extract. This approach yielded 3,4-dihydroxybenzoic acid (protocatechuic acid) and taxifolin-3-O-β-glucopyranoside as major antioxidative compounds from the plant material. The structural elucidation of these compounds was undertaken with the help of HPLC-DAD and HPLC-ESI-MS analyses. Their IC50 values, in comparison to trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), were: trolox (1.78 ± 0.56 μm) < protocatechuic acid (5.77 ± 1.63 μm) < taxifolin-3- O-β-glucopyranoside (16.30 ± 1.98 μm). The method for the determination of antioxidant activity proved reproducible and quick for routine analyses with 96 well plates.


1964 ◽  
Vol 19 (5) ◽  
pp. 398-405 ◽  
Author(s):  
M. H. Zenk ◽  
G. Müller

Feeding experiments with glucose- (2-14C), phenylalanine- (3-14C), tyrosine- (3-14C) and p-coumaric acid- (3-14C) showed that the latter three substances are incorporated in good yields into p-hydroxybenzoic acid in leaves of Catalpa ovata. Kinetic experiments showed that p-hydroxybenzoic acid is formed from phenylalanine via p-coumaric acid and the subsequent β-oxidation of the side chain. p-Hydroxybenzoic acid can also be synthetised by hydroxylation of benzoic acid, but this does not seem to be the biosynthetic route in Catalpa.Phenylalanine- (3-14C) is also incorporated into benzoic acid, protocatechuic acid, and vanillic acid by different plants; the radioactivity of the β-C atom of the amino acid was found in each case to be located in the carboxyl group of the C6 — C1 acid. This suggests that in higher plants the benzoic acids are formed from the corresponding cinnamic acids via β-oxidation.


1975 ◽  
Vol 5 (3) ◽  
pp. 500-502 ◽  
Author(s):  
W. A. G. Morsink ◽  
V. G. Smith

Softwood cuttings of one clone and one juvenile population of basswood were rooted under intermittent mist, using a 2-min basal dip of indolebutyric acid (IBA) at concentrations of 1000, 5000, and 10 000 parts per million (ppm) in combination with one of salicylic acid, p-hydroxybenzoic acid, 3,5-, 2,5-, and 2,6-dihydroxybenzoic acids at concentrations of 5, 50, and 100 ppm. None of the phenolic compounds showed any root-promoting effect when used singly. In combination with IBA, 2,5-dihydroxybenzoic acid showed a root-promoting effect when applied to cuttings of the population but not for cuttings of the single clone.A root-promoting effect at certain of the higher concentrations of the rest of the phenols when combined with IBA could not clearly be distinguished from sample variation. IBA alone or in combination with any of the phenols had a much smaller root-promoting effect when applied to the cuttings of the single clone.


2017 ◽  
Vol 901 ◽  
pp. 26-31 ◽  
Author(s):  
Dian Susanthy ◽  
Fadliah ◽  
Endang Tri Wahyuni ◽  
Sri Juari Santosa

Synthesis of silver nanoparticles (AgNPs) by reduction of AgNO3 with o-hydroxybenzoic, p-hydroxybenzoic and o,p-dihydroxybenzoic acids as reducing agents was investigated. This research was conducted to determine the effect of the position and number of hydroxyl groups towards the size, shape and stability of the resulted AgNPs. Surface Plasmon Resonance (SPR) of AgNPs was characterized by UV/Vis spectrophotometer, the shape and size of AgNPs was determined by Transmission Electron Microscope (TEM). The results showed that the reducing agent that has substituents in the para position (p-hydroxybenzoic acid) has the higher reduction ability than the others. AgNPs were yielded by all types of reducing agents in alkaline system. Reducing agents which have greater number of substituents (o,p-dihydroxybenzoic acid) could produce AgNPs with smaller concentration of AgNO3 than the others. AgNPs that was produced by reducing agent having substituents on the para position (p-hydroxybenzoic acid) was more stable and smaller particle size, i.e. 34 ± 1.78 nm than reducing agent that has substituent on the ortho para positions (with particle size 45 + 3.67 nm) and ortho positions (with particle size 70 ± 4.96 nm).


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