121-34-6Relevant articles and documents
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Pearl
, p. 85,88 (1947)
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Pearl,Beyer
, p. 376 (1950)
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Direct comparison of the enzymatic characteristics and superoxide production of the four aldehyde oxidase enzymes present in mouse
Kücükg?ze, G?khan,Terao, Mineko,Garattini, Enrico,Leimkühler, Silke
, p. 947 - 955 (2017)
Aldehyde oxidases (AOXs) are molybdoflavoenzymes with an important role in the metabolism and detoxification of heterocyclic compounds and aliphatic as well as aromatic aldehydes. The enzymes use oxygen as the terminal electron acceptor and produce reduced oxygen species during turnover. Four different enzymes, mAOX1, mAOX3, mAOX4, and mAOX2, which are the products of distinct genes, are present in the mouse. A direct and simultaneous comparison of the enzymatic properties and characteristics of the four enzymes has never been performed. In this report, the four catalytically active mAOX enzymes were purified after heterologous expression in Escherichia coli. The kinetic parameters of the four mouse AOX enzymes were determined and compared with the use of six predicted substrates of physiologic and toxicological interest, i.e., retinaldehyde, N1-methylnicotinamide, pyridoxal, vanillin, 4-(dimethylamino)cinnamaldehyde (p-DMAC), and salicylaldehyde. While retinaldehyde, vanillin, p-DMAC, and salycilaldehyde are efficient substrates for the four mouse AOX enzymes, N1-methylnicotinamide is not a substrate of mAOX1 or mAOX4, and pyridoxal is not metabolized by any of the purified enzymes. Overall, mAOX1, mAOX2, mAOX3, and mAOX4 are characterized by significantly different KM and kcat values for the active substrates. The four mouse AOXs are also characterized by quantitative differences in their ability to produce superoxide radicals. With respect to this last point, mAOX2 is the enzyme generating the largest rate of superoxide radicals of around 40% in relation to moles of substrate converted, and mAOX1, the homolog to the human enzyme, produces a rate of approximately 30% of superoxide radicals with the same substrate.
Two lignans and an aryl alkanone from Myristica dactyloides
Herath, H. M. T. Bandara,Priyadarshani, A. M. Anoma
, p. 1439 - 1442 (1996)
Chemical investigation of the hot hexane extract of the stem bark of Myristica dactyloides has resulted in the isolation of two new lignans, rel- (8S,8'R)-dimethyl-(7S,7'R)-bis(3,4-methylenedioxyphenyl)tetrahydrofuran and rel-(8R,8'R)-dimethyl-(7S,7'R)-bis(3,4-methylenedioxyphenyl)tetrahydrofuran, a new diaryl alkanone, 1-(2,6-dihydroxyphenyl)-9-(4-hydroxy-3- methoxyphenyl)nonan-1-one, sitosterol and six other previously reported aryl alkanones. The structures of the new compounds were deduced from their spectral data and chemical transformations.
Demethoxylation and hydroxylation of methoxy- and hydroxybenzoic acids by OH-radicals. Processes of potential importance for food irradiation
Gaisberger,Solar
, p. 394 - 404 (2001)
The hydroxylation process for methoxy- and hydroxy-benzoic acids (MBA, HBA) induced by γ-radiation is compared. 2-, 3-, and 4-methoxybenzoic acid as well as 3-hydroxybenzoic acid have been irradiated in N2O and aerated solutions up to 1.5 kGy. The products were analyzed by HPLC. The results for 2- and 4-HBA have been taken from literature data. The OH·-adduct distribution is generally the same for the hydroxy- as well as for the methoxy-benzoic acid isomers. With both 4-HBA and 4-MBA more than 65% C3-adducts and about 15% C4-adducts are formed, which could be proved by their reactions with K3 Fe(CN)6. Oxidation of the nonipso-adducts of 3-HBA and 3-MBA results in 84 and 87% of the corresponding phenols. Whereas in N2O-saturated solutions only part of the OH·-radicals leads to substrate decomposition, in the presence of air, the degradation of both kinds of compounds is equivalent to [OH·]. The nonipso OH·-adducts of the HBAs are converted into 68-77% hydroxylation products. With the MBAs, the hydroxylation process is ≤10%. This is attributed to different decay pathways of the peroxyl radicals, intermediates formed by O2 addition to the OH·-adducts. The hydroxyperoxycyclohexadienyl radicals of the HBAs decay mainly by HO2· elimination to the corresponding phenols, those of the MBAs decay predominantly by fragmentation of the benzene ring, yielding to nonidentified aliphatic products. The replacement of -OCH3 by -OH is practically not influenced by the presence of oxygen, it increases in the sequence 3-MBA 4-MBA 2-MBA. For 2-MBA, yields of more than 15% are obtained. Both processes, hydroxylation as well as demethoxylation, might be of importance for the recognition of radiolytical changes in foodstuff.
CYP199A4 catalyses the efficient demethylation and demethenylation of para-substituted benzoic acid derivatives
Coleman, Tom,Chao, Rebecca R.,Bruning, John B.,De Voss, James J.,Bell, Stephen G.
, p. 52007 - 52018 (2015)
The cytochrome P450 enzyme CYP199A4, from Rhodopseudomonas palustris strain HaA2, can efficiently demethylate 4-methoxybenzoic acid via hemiacetal formation and subsequent elimination of formaldehyde. Oxidative demethylation of a methoxy group para to the carboxyl moiety is strongly favoured over reaction at one in the ortho or meta positions. Dimethoxybenzoic acids containing a para-methoxy group were also efficiently demethylated exclusively at the para position. The presence of additional methoxy substituents reduces the substrate binding affinity and the activity compared to 4-methoxybenzoic acid. The addition of the smaller hydroxy group to the ortho or meta positions or of a nitrogen heteroatom in the aromatic ring of the 4-methoxybenzoate skeleton was better tolerated by the enzyme and these analogues were also readily demethylated. There was no evidence of methylenedioxy ring formation with 3-hydroxy-4-methoxybenzoic acid, an activity which is observed with certain plant CYP enzymes with analogous substrates. CYP199A4 is also able to deprotect the methylenedioxy group of 3,4-(methylenedioxy)benzoic acid to yield 3,4-dihydroxybenzoic acid and formic acid. This study defines the substrate range of CYP199A4 and reveals that substrates without a para substituent are not oxidised with any significant activity. Therefore para-substituted benzoic acids are ideal substrate scaffolds for the CYP199A4 enzyme and will aid in the design of optimised probes to investigate the mechanism of this class of enzymes. They also allow an assessment of the potential of CYP199A4 for synthetic biocatalytic processes involving selective oxidative demethylation or demethenylation.
Kadyrov et al.
, (1972)
ESTERS FROM Ferula stylosa
Bagirov, V. Yu.,Sheichenko, V. I.,Aliev, G. V.,Pimenov, M. G.
, p. 562 - 563 (1980)
From the total extractive substances of the roots of Ferula stylosa two esters have been isolated: chimganin and a new one - stylosin.The structure of stylosin is suggested as the ester of 4-hydroxy-3-methoxybenzoic acid and the monoterpene alcohol fenchol.
Fried
, p. 123,124,125 (1971)
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Pearl
, p. 1100 (1946)
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Aripova et al.
, (1977)
ISOFLAVONES OF TWO IRIS SPECIES
Agarwal, W. K.,Thappa, R. K.,Agarwal, S. G.,Mehra, M. S.,Dhar, K. L.
, p. 2703 - 2704 (1984)
Analysis of the methanol extracts of the rhizomes of Iris milesii resulted in the isolation of a new isoflavone, 5,6,7,4'-tetrahydroxy-3'-methoxyisoflavone and that of Iris kumaonensis, iriskumaonin methyl ether, iriskumaonin, irisflorentin, junipegenin-A, irigenin and iridin.Key Word Index - Iris milesii; Iris kumaonensis; Iridaceae; rhizomes; isoflavones.
Synthesis and characterization of biobased polyesters derived from vanillin-based schiff base and cinnamic acid derivatives
Sun, Hong,Kanehashi, Shinji,Tsuchiya, Kousuke,Ogino, Kenji
, p. 439 - 441 (2016)
Renewable resources-based homo- and copolyesters were prepared from novel vanillin-based Schiff base and biobased cinnamic acid derivatives by transesterification. Chemical structures of the Schiff base and resulting polyesters were confirmed by FT-IR, 1HNMR, and 13CNMR. Glass-transition temperatures of polymers were determined by DSC and showed over 100 °C. Photoluminescence properties were investigated for the Schiff base and polyesters. For polymers, broader emission spectra were observed compared with monomers, which probably originated from intramolecular charge transfer in each monomeric unit.
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Pearl
, p. 2180 (1946)
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Synthesis of Lignin-based Phenol Terminated Hyperbranched Polymer
Longe, Lionel,Garnier, Gil,Saito, Kei
, (2019)
In this work, we proved the efficient synthesis of a bio-based hyper-branched polyphenol from a modified lignin degradation fragment. Protocatechuic acid was readily obtained from vanillin, a lignin degradation product, via alkaline conditions, and further polymerised to yield high molecular weight hyperbranched phenol terminated polyesters. Vanillic acid was also subjected to similar polymerisation conditions in order to compare polymerisation kinetics and differences between linear and hyperbranched polymers. Overall, protocatechuic acid was faster to polymerise and more thermostable with a degradation temperature well above linear vanillic acid polyester. Both polymers exhibited important radical scavenging activity (RSA) compared to commercial antioxidant and present tremendous potential for antioxidant applications.
Golovina et al.
, (1978)
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Pearl
, p. 2008 (1948)
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Kinetics and mechanism of the oxidation of vanillin by hexacyanoferrate(III) in aqueous alkaline medium
Jose, Timy P.,Nandibewoor, Sharanappa T.,Tuwar, Suresh M.
, p. 51 - 62 (2006)
The title reaction was investigated in aqueous alkaline medium. A first-order dependence in hexacyanoferrate(III) concentration and a fractional order in both vanillin and alkali were obtained at the concentrations studied. The added product, hexacyanoferrate(II), had a retarding effect on the rate of reaction. Ionic strength and dielectric constant of the reaction medium have little effect on the reaction rate. The effect of temperature on the rate of reaction has also been studied and activation parameters have been evaluated. A mechanism based on the experimental results is proposed and the rate law is derived. The reaction constants are calculated and used to regenerate the k obs values, which are compared with the experimental values.
Oxidative cleavage of C-C double bond in cinnamic acids with hydrogen peroxide catalysed by vanadium(v) oxide
Horvat, Monika,Iskra, Jernej
, p. 2073 - 2081 (2022/04/07)
We have developed a cheap, green, mild and environmentally friendly method for the selective cleavage of carbon-carbon double bonds with a 30% aqueous solution of hydrogen peroxide as the oxidant and vanadium(v) oxide as the catalyst. The selectivity of the oxidative cleavage of cinnamic acid derivatives 1 depends on the substituents and the solvent used (DME - MeOCH2CH2OMe, TFE - 2,2,2-trifluoroethanol or MeCN). In DME, p-hydroxy derivatives were selectively converted to benzaldehyde derivatives 2, in TFE, oxidative cleavage led to the formation of benzoquinone derivatives 4, while in MeCN, cinnamic acid derivatives were selectively converted to benzoic acid derivatives 3. Ferulic acid 1a was quantitatively and selectively converted to vanillin 2a in a 91% isolated yield on a gram scale. Dimeric difurandione 1a′ was isolated as an intermediate, which was confirmed by in situ ATR-IR spectroscopy, while the formation of diols or epoxides was not observed. The analogous styrene derivative, 4-vinylguaiacol 1e was also selectively converted to either vanillin 2a or 2-methoxyquinone 4a in a high yield. The green metric for the conversion of ferulic acid to vanillin by different methods was calculated and compared to our method, and showed that our method has better environmental parameters.
An efficient environmentally friendly CuFe2O4/SiO2catalyst for vanillyl mandelic acid oxidation in water under atmospheric pressure and a mechanism study
Mao, Haifang,Wang, Hongzhao,Meng, Tao,Wang, Chaoyang,Hu, Xiaojun,Xiao, Zuobing,Liu, Jibo
, p. 982 - 992 (2021/01/25)
With the aim of the green production of vanillin, a highly efficient environmentally friendly oxidation system was introduced to oxidize vanillyl mandelic acid (VMA) with a porous CuFe2O4/SiO2 component nano-catalyst in aqueous solution under atmospheric pressure. The N2 adsorption-desorption pattern indicated that CuFe2O4/SiO2 possessed a much higher specific surface area (49.98 m2 g-1) than that of CuFe2O4 (5.02 m2 g-1), which further indicated that the SiO2 substrate restrained the aggregation of CuFe2O4 nanoparticles. The conversion for VMA and selectivity for vanillin reached 98% and 96%, respectively, under atmospheric pressure. The excellent catalytic performance was attributed to the synergistic effect of the catalytic capacity of CuFe2O4 and the adsorption capacity for the reactant of SiO2. Simultaneously, the effect of different reaction conditions for catalyst activity and selectivity were investigated. Furthermore, the probable mechanism of VMA oxidation was investigated by in situ ATR-FTIR, H2-TPR, XPS and 1H NMR. More importantly, the decarboxylation was verified to proceed in basic conditions rather than in conventional acidic conditions. This journal is
