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Anja Tetzner, Maura Naughton, Kinga Gebolys, Jenny Eichhorst, Esther Sala, Óscar Villacañas, Thomas Walther
The heptapeptide angiotensin (Ang)-(1-7) is part of the beneficial arm of the renin-angiotensin system. Ang-(1-7) has cardiovascular protective effects, stimulates regeneration, and opposes the often detrimental effects of Ang II. We recently identified the G protein-coupled receptors Mas and MrgD as receptors for the heptapeptide. Ala1 -Ang-(1-7) (Alamandine), a decarboxylated form of Ang-(1-7), has similar vasorelaxant effects, but has been described to only stimulate MrgD. Therefore, this study aimed to characterise the consequences of the lack of the carboxyl group in amino acid 1 on intracellular signalling and to identify the receptor fingerprint for Ala1 -Ang-(1-7)...
May 21, 2018: European Journal of Pharmacology
Fei He, Hitomi Nakamura, Shotaro Hoshino, Joyce Seow Fong Chin, Liang Yang, Huiping Zhang, Fumiaki Hayashi, Ikuro Abe
Four new catechol derivatives, hinduchelins A-D (1-4), composed of 2,3- dihydroxybenzoic acid, threonine, and decarboxylated phenylalanine, were isolated from Streptoalloteichus hindustanus. Their structures and absolute configurations were elucidated by interpretation of NMR and HRMS data and quantum chemical ECD calculations. The iron-binding properties of the compounds were evaluated by a pyoverdine production assay in Pseudomonas aeruginosa, and compound 4 showed moderate ability to induce pyoverdine production at 50 μM...
May 24, 2018: Journal of Natural Products
Feng-Cheng Jia, Cheng Xu, Yu-Wei Wang, Zhi-Peng Chen, Yun-Feng Chen, An-Xin Wu
A copper-catalyzed cascade reaction using isatins and amidine hydrochlorides for the synthesis of 2-(1,3,5-triazin-2-yl)aniline derivatives has been developed. This reaction features commercially available starting materials, mild reaction conditions and good functional group tolerance.
May 23, 2018: Organic & Biomolecular Chemistry
Shalini Verma, Pawan K Mishra, Manoj Kumar, Souvik Sur, Akhilesh K Verma
An efficient approach for the synthesis of functionalized tetrahydro-pyrido/quinolinocarbazoles from 2-alkynylindole-3-carbaldehydes and L-proline utilizing a metal-free decarboxylative cyclization, ring expansion, and ring contraction strategy via the generation of azomethine ylide has been developed. The reaction of 2-alkynylindole-3-carbaldehydes with L-thioproline leads to the formation of γ-carbolines. By virtue of this expedient method, a diverse range of biologically active hetero-annulated carbazoles can be synthesized efficiently...
May 23, 2018: Journal of Organic Chemistry
Hong Yu, Xiaoqian Li, Fabienne Duchoud, Derrick S Chuang, James C Liao
The Calvin-Benson-Bassham (CBB) cycle is presumably evolved for optimal synthesis of C3 sugars, but not for the production of C2 metabolite acetyl-CoA. The carbon loss in producing acetyl-CoA from decarboxylation of C3 sugar limits the maximum carbon yield of photosynthesis. Here we design a synthetic malyl-CoA-glycerate (MCG) pathway to augment the CBB cycle for efficient acetyl-CoA synthesis. This pathway converts a C3 metabolite to two acetyl-CoA by fixation of one additional CO2 equivalent, or assimilates glyoxylate, a photorespiration intermediate, to produce acetyl-CoA without net carbon loss...
May 22, 2018: Nature Communications
Swatishree Sradhanjali, Mamatha M Reddy
Cancer cells alter their metabolism to support the uninterrupted supply of biosynthetic molecules required for continuous proliferation. Glucose metabolism is frequently reprogrammed in several tumors in addition to fatty acid, amino acid and glutamine metabolism. Pyruvate dehydrogenase kinase (PDK) is a gatekeeper enzyme involved in altered glucose metabolism in tumors. There are four isoforms of PDK (1 to 4) in humans. PDK phosphorylates E1α subunit of pyruvate dehydrogenase complex (PDC) and inactivates it...
May 22, 2018: Current Topics in Medicinal Chemistry
Peihe Li, Nuannuan Ma, Zheng Wang, Qipu Dai, ChangWen Hu
A general and effective method for the synthesis of alkylamine via intramolecular decarboxylation of alkanoyloxycarbamates is described. The alkanoyloxycarbamates are readily prepared with alkyl carboxylic acids and hydroxylamine. The reaction shows broad range of substrates (primary, secondary alkyl) with functional tolerance and the corresponding products were obtained in good yield under mild conditions.
May 22, 2018: Journal of Organic Chemistry
Changqing Ye, Bo Qian, Yajun Li, Min Su, Daliang Li, Hongli Bao
This paper reports a new method for the generation of substituted 1,3-enynes, whose synthesis by other methods could be a challenge. The dehydrative decarboxylative cascade coupling reaction of propargyl alcohol with alkyl peroxides is enabled by an iron catalyst and alkylating reagents. Primary, secondary, and tertiary alkyl groups can be introduced into 1,3-enynes, affording various substituted 1,3-enynes in moderate to good yields. Mechanistic studies suggest the involvement of a radical-polar crossover pathway...
May 22, 2018: Organic Letters
Alicia A DeColli, Natasha S Nemeria, Ananya Majumdar, Gary J Gerfen, Frank Jordan, Caren L Freel Meyers
The underexploited antibacterial target 1-deoxy-D-xyluose 5-phosphate (DXP) synthase, catalyzes the thiamin diphosphate (ThDP)-dependent formation of DXP from pyruvate and D-glyceraldehyde 3-phosphate (D-GAP). DXP is an essential intermediate in the biosynthesis of ThDP, pyridoxal phosphate, and isoprenoids in many pathogenic bacteria. DXP synthase catalyzes a distinct mechanism in ThDP decarboxylative enzymology in which the first enzyme-bound pre-decarboxylation intermediate, C2α-lactylThDP (LThDP), is stabilized by DXP synthase in the absence of D-GAP, and D-GAP then induces efficient LThDP decarboxylation...
May 21, 2018: Journal of Biological Chemistry
Yuan Yuan, Xuenan Li, Huangyou Liu, Yating Qu, Wantong Zhang, Huilin Yu, Jiaojiao Zhang, Hong Zhuang
Carnitine is demonstrated as an effective methyl donor in the formation of the plant growth regulator N, N-dimethylpiperidinium (mepiquat), encompassing either N-methylation / decarboxylation of pipecolic acid, or Maillard pathways followed by transmethylation reactions. The formation of mepiquat and the intermediate compounds was monitored (180-300 °C, up to 180 min) using HPLC-MS/MS in different binary or ternary model systems comprised of (i) lysine/fructose/carnitine, (ii) lysine/glucose/carnitine, or (iii) pipecolic acid (PipAc)/carnitine...
May 22, 2018: Journal of Agricultural and Food Chemistry
Wen-Long Wang, Qian-Yuan Wu, Nan Huang, Zi-Bin Xu, Min-Yong Lee, Hong-Ying Hu
UV based advanced oxidation processes (UV-AOPs) that efficiently eliminate organic pollutants during water treatment have been the subject of numerous investigations. Most organic pollutants are not completely mineralized during UV-AOPs but are partially oxidized into transformation products (TPs), thereby adding complexity to the treated water and posing risks to humans, ecological systems, and the environment. While the degradation kinetics and mechanisms of pollutants have been widely documented, there is little information about the risks associated with TPs...
May 15, 2018: Water Research
Li Ren, Huan Cong
A decarboxylative alkylation of benzylic C(sp3 )-H bonds of N-aryl tetrahydroisoquinolines under the irradiation of blue light is reported, featuring a broad substrate scope, low cost, heavy-metal-free, and mild conditions. A preliminary mechanistic study indicated that radical intermediates are involved during the course of the reaction.
May 21, 2018: Organic Letters
Jacob M Quibell, Gregory J P Perry, Diego M Cannas, Igor Larrosa
Methods for the conversion of aliphatic acids to alkyl halides have progressed significantly over the past century, however, the analogous decarboxylative bromination of aromatic acids has remained a longstanding challenge. The development of efficient methods for the synthesis of aryl bromides is of great importance as they are versatile reagents in synthesis and are present in many functional molecules. Herein we report a transition metal-free decarboxylative bromination of aromatic acids. The reaction is applicable to many electron-rich aromatic and heteroaromatic acids which have previously proved poor substrates for Hunsdiecker-type reactions...
April 21, 2018: Chemical Science
Qiong Wang, Xiaohua Liu, Jinheng Fu, Shuixing Wang, Yuanhong Chen, Kunpeng Chang, Haixing Li
BACKGROUND: Gamma-aminobutyric acid (GABA) plays a significant role in the food and drug industries. Our previous study established an efficient fed-batch fermentation process for Lactobacillus brevis NCL912 production of GABA from monosodium L-glutamate; however, monosodium L-glutamate may not be an ideal substrate, as it can result in the rapid increase of pH due to decarboxylation. Thus, in this study, L-glutamic acid was proposed as a substrate. To evaluate its potential, key components of the fermentation medium affecting GABA synthesis were re-screened and re-optimized to enhance GABA production from L...
May 19, 2018: Microbial Cell Factories
Mengxin Geng, Leif Smith
Mutacin 1140 belongs to the epidermin family of type AI lantibiotics. This family has a broad spectrum of activity against Gram-positive bacteria. The binding of mutacin 1140 to lipid II leads to the inhibition of cell wall synthesis. Pharmacokinetic experiments on type AI lantibiotics are generally discouraging for clinical applications due to their short half-life. The unprotected dehydrated and protease susceptible residues outside of the lanthionine rings may play a role in their short half-life in physiological settings...
May 18, 2018: Applied and Environmental Microbiology
Laura Santamaría, Inés Reverón, Félix López de Felipe, Blanca de Las Rivas, Rosario Muñoz
Lactobacillus plantarum is the lactic acid bacterial species most frequently found in plant-food fermentations where hydroxycinnamic acids are abundant. L. plantarum efficiently decarboxylates these compounds, and also reduces them, yielding substituted phenylpropionic acids. Although the reduction step is known to be induced by a hydroxycinnamic acid, the enzymatic machinery responsible for this reduction pathway has not been yet identified and characterized. A previous study on the transcriptomic response of L...
May 18, 2018: Applied and Environmental Microbiology
Junior Gonzales, Naga Venkata Satya Dinesh Kumar Bhupathiraju, Daniel Hart, Man Yuen, Maria Pia Sifuentes, Bleron Samarxhiu, Mark Maranan, Naxhije Berisha, James Batteas, Charles Michael Drain
Chlorins have unique photophysical properties that are exploited in diverse biological and materials applications. De novo chlorin synthesis with specific exocyclic motifs can be challenging and many are not stable to photobleaching and/or oxidation. A facile approach to a stable synthetic chlorin with a fused N-methyl pyrrolidine uses cyclo addition of a sarcosine-based azomethine ylide on 5,10,15,20-tetrakis-(2,3,4,5,6-pentafluorophenyl)-porphyrin (TPPF20) is reported, but this approach has limitations. We report the synthesis of stable chlorin scaffolds starting with TPPF20 using a new glycine-based N-(hydroxymethyl)-N-methelenemethanideaminium ylide...
May 18, 2018: Journal of Organic Chemistry
Man-Yi Han, Hong Pan, Jing Lin, Wei Li, Pinhua Li, Lei Wang
A catalyst-controlled switchable reaction of β-keto acids to silyl glyoxylates was developed under mild conditions, providing two distinct products in good yields. Compared to decarboxylative addition-Brook rearrangement, the decarboxylative addition products could be controlled by using a simple bifunctional organocatalyst thiourea derivative instead of DABCO. This new reaction model of silyl glyoxylates offered a facile and alternative route to organosilicon compounds.
May 18, 2018: Organic & Biomolecular Chemistry
G M Kubiak, A R Tomasik, K Bartus, R Olszanecki, P Ceranowicz
Adenosine triphosphate (ATP) is an essential substrate metabolite in human beings. Mitochondrial oxidative phosphorylation provides > 95% of ATP with the remainder derived from glycolysis or tricarboxylic acid cycle (TCA). In normal hearts, acetyl-CoA is synthesized from the β-oxidation of free fatty acids (FFA) and the oxidation of pyruvate. Pyruvate is synthesized from glycolysis and can be submitted either for decarboxylation to acetyl-CoA or for dehydrogenation to lactate. Moreover, pyruvate, as well as lactate, plays a key role in aerobic glucose metabolism which is highly dependent on ubiquitous regulatory mechanisms...
February 2018: Journal of Physiology and Pharmacology: An Official Journal of the Polish Physiological Society
Maria L Amaya, Daniel A Pollyea
Acute myeloid leukemia (AML) is an aggressive disease with a poor prognosis. A large percentage of patients succumb to this disease, in spite of aggressive treatments with chemotherapy. Recent advances with mutational analysis led to the discovery of isocitrate dehydrogenase (IDH) mutations in AML. IDH2 is an enzyme that catalyzes the oxidative decarboxylation of isocitrate to alpha-ketoglutarate; its mutated version leads to the accumulation of the oncometabolite (R)-2 hydroxyglutarate, which disrupts several cell processes and leads to a blockage in differentiation...
May 16, 2018: Clinical Cancer Research: An Official Journal of the American Association for Cancer Research
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