3690-05-9Relevant articles and documents
Characterization and Elimination of Undesirable Protein Residues in Plant Cell Wall Materials for Enhancing Lignin Analysis by Solution-State Nuclear Magnetic Resonance Spectroscopy
Kim, Hoon,Padmakshan, Dharshana,Li, Yanding,Rencoret, Jorge,Hatfield, Ronald D.,Ralph, John
, p. 4184 - 4195 (2017)
Protein polymers exist in every plant cell wall preparation, and they interfere with lignin characterization and quantification. Here, we report the structural characterization of the residual protein peaks in 2D NMR spectra in corn cob and kenaf samples and note that aromatic amino acids are ubiquitous and evident in spectra from various other plants and tissues. The aromatic correlations from amino acid residues were identified and assigned as phenylalanine and tyrosine. Phenylalanine's 3/5 correlation peak is superimposed on the peak from typical lignin p-hydroxyphenyl (H-unit) structures, causing an overestimation of the H units. Protein contamination also occurs when using cellulases to prepare enzyme lignins from virtually protein-free wood samples. We used a protease to remove the protein residues from the ball-milled cell walls, and we were able to reveal H-unit structures in lignins more clearly in the 2D NMR spectra, providing a better basis for their estimation.
Assessment of a putative proton relay in Arabidopsis cinnamyl alcohol dehydrogenase catalysis
Lee, Choonseok,Bedgar, Diana L.,Davin, Laurence B.,Lewis, Norman G.
, p. 1127 - 1134 (2013)
Extended proton relay systems have been proposed for various alcohol dehydrogenases, including the Arabidopsis thaliana cinnamyl alcohol dehydrogenases (AtCADs). Following a previous structural biology investigation of AtCAD5, the potential roles of three amino acid residues in a putative proton relay system, namely Thr49, His52 and Asp57, in AtCAD5, were investigated herein. Using site-directed mutagenesis, kinetic and isothermal titration calorimetry (ITC) analyses, it was established that the Thr49 residue was essential for overall catalytic conversion, whereas His52 and Asp57 residues were not. Mutation of the Thr49 residue to Ala resulted in near abolition of catalysis, with thermodynamic data indicating a negative enthalpic change (ΔH), as well as a significant decrease in binding affinity with NADPH, in contrast to wild type AtCAD5. Mutation of His52 and Asp57 residues by Ala did not significantly change either catalytic efficiency or thermodynamic parameters. Therefore, only the Thr49 residue is demonstrably essential for catalytic function. ITC analyses also suggested that for AtCAD5 catalysis, NADPH was bound first followed by p-coumaryl aldehyde.
Action of diverse peroxidases and laccases on six cell wall-related phenolic compounds
Wallace, Graham,Fry, Stephen C.
, p. 769 - 773 (1999)
Four peroxidases and four laccases were compared as to reaction rates catalysed with six phenolic substrates of relevance to the plant cell wall. When each phenolic substrate was tested at 670 μM and pH 6.0, in the presence of 670 μM H2O2 or ~270 μM O2 as the electron acceptor, all the peroxidases and laccases had similar substrate preferences: reaction rates were in the order sinapyl > coniferyl > p-coumaryl alcohols, and feruloyl > p-coumaroyl esters. Specific activities were in the order basic peroxidase > acidic peroxidase>>laccase. The data are consistent with the view that peroxidases rather than laccases play a major role in phenolic cross-linking in the cell wall.
Microbial Production of Natural and Unnatural Monolignols with Escherichia coli
Aschenbrenner, Jennifer,Marx, Patrick,Pietruszka, J?rg,Marienhagen, Jan
, p. 949 - 954 (2019/02/26)
Phenylpropanoids and phenylpropanoid-derived plant polyphenols find numerous applications in the food and pharmaceutical industries. In recent years, several microbial platform organisms have been engineered towards producing such compounds. However, for the most part, microbial (poly)phenol production is inspired by nature, so naturally occurring compounds have predominantly been produced to date. Here we have taken advantage of the promiscuity of the enzymes involved in phenylpropanoid synthesis and exploited the versatility of an engineered Escherichia coli strain harboring a synthetic monolignol pathway to convert supplemented natural and unnatural phenylpropenoic acids into their corresponding monolignols. The performed biotransformations showed that this strain is able to catalyze the stepwise reduction of chemically interesting unnatural phenylpropenoic acids such as 3,4,5-trimethoxycinnamic acid, 5-bromoferulic acid, 2-nitroferulic acid, and a “bicyclic” p-coumaric acid derivative, in addition to six naturally occurring phenylpropenoic acids.
Comparative transcriptomics analysis for gene mining and identification of a cinnamyl alcohol dehydrogenase involved in methyleugenol biosynthesis from asarum sieboldii miq
Liu, Jinjie,Xu, Chong,Zhang, Honglei,Liu, Fawang,Ma, Dongming,Liu, Zhong
, (2018/12/13)
Asarum sieboldii Miq., one of the three original plants of TCM ASARI RADIX ET RHIZOMA, is a perennial herb distributed in central and eastern China, the Korean Peninsula, and Japan. Methyleugenol has been considered as the most important constituent of Asarum volatile oil, meanwhile asarinin is also employed as the quality control standard of ASARI RADIX ET RHIZOMA in Chinese Pharmacopeia. They both have shown wide range of biological activities. However, little was known about genes involved in biosynthesis pathways of either methyleugenol or asarinin in Asarum plants. In the present study, we performed de novo transcriptome analysis of plant tissues (e.g., roots, rhizomes, and leaves) at different developmental stages. The sequence assembly resulted in 311,597 transcripts from these plant materials, among which 925 transcripts participated in ‘secondary metabolism’ with particularly up to 20.22% of them falling into phenylpropanoid biosynthesis pathway. The corresponding enzymes belong to seven families potentially encoding phenylalanine ammonia-lyase (PAL), trans-cinnamate 4-monooxygenase (C4H), p-coumarate 3-hydroxylase (C3H), caffeoyl-CoA O-methyltransferase (CCoAOMT), cinnamoyl-CoA reductase (CCR), cinnamyl alcohol dehydrogenase (CAD), and eugenol synthase (EGS). Moreover, 5 unigenes of DIR (dirigent protein) and 11 unigenes of CYP719A (719A subfamily of cytochrome P450 oxygenases) were speculated to be involved in asarinin pathway. Of the 15 candidate CADs, four unigenes that possessed high FPKM (fragments per transcript kilobase per million fragments mapped) value in roots were cloned and characterized. Only the recombinant AsCAD5 protein efficiently converted p-coumaryl, coniferyl, and sinapyl aldehydes to their corresponding alcohols, which are key intermediates employed not only in biosynthesis of lignin but also in that of methyleugenol and asarinin. qRT-PCR revealed that AsCAD5 had a high expression level in roots at three developmental stages. Our study will provide insight into the potential application of molecular breeding and metabolic engineering for improving the quality of TCM ASARI RADIX ET RHIZOMA.
METHODS OF PRODUCING SUGAR-SPHINGOSINE AND SPHINGO BASE
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Paragraph 0053; 0054, (2016/12/01)
PROBLEM TO BE SOLVED: To provide a method of producing sphingo base in which sugar-ceramide is used as a row material, a method by which sugar-sphingosine can be selectively produced with high yield by hydrolyzing sugar-ceramide, and a method by which sphingo base can be selectively produced with high yield by hydrolyzing sugar-sphingosine. SOLUTION: The method of producing sugar-sphingosine is provided which includes obtaining sugar-sphingosine by hydrolyzing sugar-ceramide. The hydrolysis includes heating sugar-ceramide at a temperature of 100°C or higher under the presence of aqueous solution of alcoholic organic compound and alkali metal hydroxide, having a boiling point of 100°C or higher to obtain sugar-sphingosine. The method of producing sphingo base is also provided which includes obtaining sphingo base by hydrolyzing sugar-sphingosine. The hydrolysis includes causing sugar hydrolase to act on sugar-sphingosine to obtain sphingo base, and sugar-sphingosine may be produced by the method. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
β-Cyclodextrin/IBX in water: Highly facile biomimetic one pot deprotection of THP/MOM/Ac/Ts ethers and concomitant oxidative cleavage of chalcone epoxides and oxidative dehydrogenation of alcohols
Kumar, Sumit,Ahmed, Naseem
supporting information, p. 648 - 656 (2016/02/12)
A mild and efficient one-pot deprotection of THP/MOM/Ac/Ts ethers, and concomitant oxidative cleavage of epoxides and oxidative dehydrogenation of alcohols to form β-hydroxy 1,2-diketones, 1,2,3-triketones and conjugated aromatic carbonyl systems (chalcones) using β-cyclodextrin/IBX in water has been developed. o-Iodoxybenzoic acid, a readily available hypervalent iodine(v) reagent, was found to be highly effective with β-cyclodextrin in carrying out the deprotection and subsequent transformations under an eco-friendly environment. The reaction gave moderate to excellent yields ranging from 50-99% at 60°C in 40 min to 6 h.
Multifunctional novel Diallyl disulfide (DADS) derivatives with β-amyloid-reducing, cholinergic, antioxidant and metal chelating properties for the treatment of Alzheimer's disease
Manral, Apra,Saini, Vikas,Meena, Poonam,Tiwari, Manisha
, p. 6389 - 6403 (2015/10/05)
A series of novel Diallyl disulfide (DADS) derivatives were designed, synthesized and evaluated as chemical agents, which target and modulate multiple facets of Alzheimer's disease (AD). The results showed that the target compounds 5a-l and 7e-m exhibited significant anti-Aβ aggregation activity, considerable acetylcholinesterase (AChE) inhibition, high selectivity towards AChE over butyrylcholinesterase (BuChE), potential antioxidant and metal chelating activities. Specifically, compounds 7k and 7l exhibited highest potency towards self-induced Aβ aggregation (74% and 71.4%, 25 μM) and metal chelating ability. Furthermore, compounds 7k and 7l disaggregated Aβ fibrils generated by Cu2+-induced Aβ aggregation by 80.9% and 78.5%, later confirmed by transmission electron microscope (TEM) analysis. Besides, 7k and 7l had the strongest AChE inhibitory activity with IC50 values of 0.056 μM and 0.121 μM, respectively. Furthermore, molecular modelling studies showed that these compounds were capable of binding simultaneously to catalytic active site (CAS) and peripheral anionic site (PAS) of AChE. All the target compounds displayed moderate to excellent antioxidant activity with ORAC-FL values in the range 0.546-5.86 Trolox equivalents. In addition, absorption, distribution, metabolism and excretion (ADME) profile and toxicity prediction (TOPKAT) of best compounds 7k and 7l revealed that they have drug like properties and possess very low toxic effects. Collectively, the results strongly support our assertion that these compounds could provide good templates for developing new multifunctional agents for AD treatment.
Discovery of a negative allosteric modulator of GABAB receptors
Chen, Lin-Hai,Sun, Bing,Zhang, Yang,Xu, Tong-Jie,Xia, Zhi-Xiong,Liu, Jian-Feng,Nan, Fa-Jun
supporting information, p. 742 - 747 (2014/08/05)
Initialized from the scaffold of CGP7930, an allosteric agonist of GABAB receptors, a series of noncompetitive antagonists were discovered. Among these compounds, compounds 3, 6, and 14 decreased agonist GABA-induced maximal effect of IP3 production in HEK293 cells overexpressing GABAB receptors and Gqi9 proteins without changing the EC50. Compounds 3, 6, and 14 not only inhibited agonist baclofen-induced ERK1/2 phosphorylation but also blocked CGP7930-induced ERK1/2 phosphorylation in HEK293 cells overexpressing GABAB receptors. The results suggested that compounds 3, 6, and 14 are negative allosteric modulators of GABAB receptors. The representative compound 14 decreased GABA-induced IP3 production with IC50 of 37.9 μM and had no effect on other GPCR Class C members such as mGluR1, mGluR2, and mGluR5. Finally, we showed that compound 14 did not bind to the orthosteric binding sites of GABAB receptors, demonstrating that compound 14 negatively modulated GABAB receptors activity as a negative allosteric modulator.
Nitric oxide donating anilinopyrimidines: Synthesis and biological evaluation as EGFR inhibitors
Han, Chun,Huang, Zhangjian,Zheng, Chao,Wan, Ledong,Lai, Yisheng,Peng, Sixun,Ding, Ke,Ji, Hongbin,Zhang, Yihua
, p. 82 - 90 (2013/10/01)
To search for potent nitric oxide (NO) donating epidermal growth factor receptor (EGFR) inhibitors, a series of phenylsulfonylfuroxan-based anilinopyrimidines 10a-h were synthesized and biologically evaluated. Compounds 10f-h exhibited potent inhibitory activity against EGFR L858R/T790M and were as potent as WZ4002 in inhibition of H1975 cells harboring EGFR L858R/T790M. Additionally, 10h produced high levels of NO in H1975 cells but not in normal human cells, and its antiproliferative activity was diminished by hemoglobin, an NO scavenger. Furthermore, 10h inhibited EGFR activation and downstream signaling in H1975 cells. These results suggest that the strong antiproliferative activity of 10h could be attributed to the synergic effects of high levels of NO production and inhibition of EGFR and downstream signaling in the cancer cells.
