121-34-6Relevant articles and documents
Analysis of Fluorescence Spectra of Citrus Polymethoxylated Flavones and Their Incorporation into Mammalian Cells
Gon?alves, Danielle R.,Manthey, John A.,Da Costa, Paulo I.,Rodrigues, Marilia C. M.,Cesar, Thais B.
, p. 7531 - 7541 (2018)
Citrus polymethoxylated flavones (PMFs) influence biochemical cascades in human diseases, yet little is known about how these compounds interact with cells and how these associations influence the actions of these compounds. An innate attribute of PMFs is their ultraviolet-light-induced fluorescence, and the fluorescence spectra of 14 PMFs and 7 PMF metabolites were measured in methanol. These spectra were shown to be strongly influenced by the compounds' hydroxy and methoxy substituents. For a subset of these compounds, the fluorescence spectra were measured when bound to human carcinoma Huh7.5 cells. Emission-wavelength maxima of PMF metabolites with free hydroxyl substituents exhibited 70-80 nm red shifts when bound to the Huh7.5 cells. Notable solvent effects of water were observed for nearly all these compounds, and these influences likely reflect the effects of localized microenvironments on the resonance structures of these compounds when bound to human cells.
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.
A new glucoside with a potent α-glucosidase inhibitory activity from Lycium schweinfurthii
Elbermawi, Ahmed,Halim, Ahmed F.,Mansour, El-Sayed S.,Ahmad, Kadria F.,Ashour, Ahmed,Amen, Yhiya,Shimizu, Kuniyoshi
, p. 976 - 983 (2021)
A new glucoside, 3-methoxy-4-O-β-D-glucopyranosyl-methyl benzoate, has been isolated from Lycium schweinfurthii along with five known compounds through bioactivity guided fractionation of the total plant methanolic extract towards α-glucosidase inhibitory activity. All the isolated compounds were tested for their inhibitory effect on α-glucosidase enzyme. As a result, four of them showed a potent inhibitory activity and thus constitute a therapeutic approach to decrease postprandial hyperglycemia in diabetic patients.
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.
A dual-phase oscillatory behavior in Belousov Zhabotinsky system with vanillin as the substrate
Sridevi,Ramaswamy
, p. 201 - 206 (1998)
Dual-phase oscillations are observed in Belousov-Zhabotinsky system with 4-hydroxy-3-methoxybenzaldehyde (vanillin) as the substrate and manganous sulphate or ammonium Ce(IV) sulphate as the catalyst. The nonoscillatory period of time between the two phases decreases with increase in the concentration of the catalyst and the substrate. Under uncatalyzed and ferroin catalyzed conditions the system exhibits single-phase oscillations. The first-phase oscillations are due to vanillin whereas the second-phase oscillations are brought about by 4-hydroxy-3-methoxybenzoic acid (vanillic acid) formed during the course of the first-phase reactions. The reactions are explained with relevant steps of the FKN mech- anism. 1998 lohn Wiley & Sons, Inc.
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.
Oxidation of vanillin by diperiodatocuprate(III) in aqueous alkaline medium: A kinetic and mechanistic study by stopped flow technique
Hiremath,Kiran,Nandibewoor
, p. 236 - 244 (2007)
The kinetics of oxidation of vanillin (VAN) by diperiodatocuprate(III) (DPC) in alkaline medium at a constant ionic strength of 0.50 mol dm -3 was studied spectrophotometrically. The reaction between DPC and vanillin in alkaline medium exhibits 1:2 stoichiometry (vanillin: DPC). The reaction is of first order in [DPC] and has less than unit order in both [VAN] and [alkali]. Intervention of free radicals was observed in the reaction. Increase in periodate concentration decreases the rate. The oxidation reaction in alkaline medium has been shown to proceed via a monoperiodatocuprate(III)- vanillin complex, which decomposes slowly in a rate-determining step followed by other fast steps to give the products. The main products were identified by spot test, IR, and MS studies. The reaction constants involved in the different steps of the mechanism are calculated. The activation parameters with respect to slow step of the mechanism are computed and discussed, and thermodynamic quantities are also determined.
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.
C-glucosyl flavones from the seeds of ziziphus jujuba var. spinosa
Wu, Yi,He, Feng,Pan, Qin,Shi, Yao,Min, Zhida,Liang, Jingyu
, p. 369 - 372 (2011)
A new C-glucosyl flavone, 6'-vanilloylspinosin (1), was isolated from the seeds of Ziziphus jujuba var. spinosa, together with three known C-glucosyl flavones, spinosin (2), 6'-feruloylspinosin (3), and isospinosin (4). The structure of 1 was elucidated by spectral methods (1D NMR, ESI-MS, HR-MS, 2D NMR).
