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Junguo Wu, Canjun Zhu, Liusong Yang, Zhonggang Wang, Lina Wang, Songbo Wang, Ping Gao, Yongliang Zhang, Qingyan Jiang, Gang Shu, Xiaotong Zhu
N-acyl amino acids (NAAAs) are conjugate products of fatty acids and amino acids, which are available in animal-derived food. We compared the effects of N-arachidonoyl glycine (NAGly), N-arachidonoyl serine (NASer), and N-Oleoylglycine (OLGly) on in vivo food intake and in vitro [Ca2+]i of AgRP neurons to identify the role of these compounds in energy homeostasis. The hypothalamic neuropeptide expression and anxiety behavior in response to OLGly were also tested. To further identify the underlying mechanism of OLGly on food intake, we first detected the expression level of potential OLGly receptors...
January 19, 2017: Journal of Agricultural and Food Chemistry
Utpal Bose, Catharine A Ortori, Sarir Sarmad, David A Barrett, Amitha K Hewavitharana, Mark P Hodson, John A Fuerst, P Nicholas Shaw
The structures of acyl homoserine lactone (AHL) compounds and their quantification was accomplished using an integrated liquid chromatography-mass spectrometry approach. The precursor and product ions, along with retention times of peaks, were searched against an in-house database of AHLs and structures confirmed by accurate mass and by comparison with authentic AHL standards. The two compounds, N-(3-oxodecanoyl)-L-homoserine lactone and N-(3-oxododecanoyl)-L-homoserine lactone were characterised and quantified in Salinispora sp...
January 12, 2017: FEMS Microbiology Letters
Arun Suneja, Rajshekhar A Unhale, Vinod K Singh
An efficient route to pharmacologically interesting isoindolinone-based α-amino phosphonates is described via asymmetric hydrophosphonylation of in situ generated ketimines catalyzed by BINOL-derived phosphoric acid. The reaction proceeds smoothly at ambient temperature affording a variety of α-amino phosphonates with a quaternary stereogenic center embedded in isoindolinone motif in high yields with excellent enantiomeric ratios (up to 98.5:1.5 er). Several interesting transformations of the products into valuable synthetic intermediates are also depicted...
January 11, 2017: Organic Letters
Ravindra S Phatake, Venkannababu Mullapudi, Vivek C Wakchaure, Chepuri V Ramana
The possibility of fluoride-mediated selective dephosphonylation of α-diazo-β-carbonyl phosphonates such as the Ohira-Bestmann reagent has been proposed and executed. The resulting α-diazocarbonyl intermediates undergo a (3 + 2)-cycloaddition at room temperature with conjugated olefins and benzynes. Interestingly, under the current conditions, the resulting cycloaddition products underwent either N-acylation (with excess α-diazo-β-carbonyl phosphonates) or Michael addition (with conjugated olefins).
December 30, 2016: Organic Letters
Andrew J Mitchell, Noah P Dunham, Jonathan A Bergman, Bo Wang, Qin Zhu, Wei-Chen Chang, Xinyu Liu, Amie K Boal
Enzymatic installation of chlorine/bromine into unactivated carbon centers provides a versatile, selective, and environmentally friendly alternative to chemical halogenation. Iron(II) and 2-(oxo)-glutarate (Fe(II)/2OG)-dependent halogenases are powerful biocatalysts that are capable of cleaving aliphatic C-H bonds to introduce useful functional groups, including halogens. Using the structure of the Fe/2OG halogenase, WelO5, in complex with its small molecule substrate, we identified a similar N-acyl amino acid hydroxylase, SadA, and reprogrammed it to halogenate its substrate, thereby generating a new chiral haloalkyl center...
January 11, 2017: Biochemistry
Shuxin Zhou, An Zhang, Hongping Yin, Weihua Chu
Quorum sensing (QS) is a cell density dependent process that enables bacteria to communicate with each other based on the production, secretion and sensing of the auto-inducer molecules and then subsequently regulate virulence associated gene expression. Interrupting quorum sensing may represent a novel alternative approach to combat bacterial pathogen. Several bacteria can produce quorum quenching (QQ) enzymes. However, the role of QQ bacteria in shaping the microbiota and the level of N-acyl-homoserine lactones (AHLs, a prevalent type of QS molecules) producing bacteria remains largely unknown...
2016: Frontiers in Cellular and Infection Microbiology
Shengcai Han, Dan Li, Eva Trost, Klaus F Mayer, A Corina Vlot, Werner Heller, Michael Schmid, Anton Hartmann, Michael Rothballer
Quorum sensing auto-inducers of the N-acyl homoserine lactone (AHL) type produced by Gram-negative bacteria have different effects on plants including stimulation on root growth and/or priming or acquirement of systemic resistance in plants. In this communication the influence of AHL production of the plant growth promoting endophytic rhizosphere bacterium Acidovorax radicis N35 on barley seedlings was investigated. A. radicis N35 produces 3-hydroxy-C10-homoserine lactone (3-OH-C10-HSL) as the major AHL compound...
2016: Frontiers in Plant Science
Erin B Divito, Kristin M Kroniser, Michael Cascio
Recognition of the contributions of lipids to cellular physiology, both as structural components of the membrane and as modulatory ligands for membrane proteins, has increased in recent years with the development of the biophysical and biochemical tools to examine these effects. Their modulatory roles in ion channels and transporters function have been extensively characterized, with the molecular mechanisms of these activities being the subject of intense scrutiny. The physiological significance of lipids in biochemistry is expanding as numerous fatty acyls are discovered to possess signaling properties...
2016: Frontiers in Physiology
Jinfeng Wang, Lili Ding, Kan Li, Wilhelm Schmieder, Jinju Geng, Ke Xu, Yan Zhang, Hongqiang Ren
N-Acylated-l-homoserine lactones (AHLs) play a vital role in Gram-negative bacteria communication by promoting the formation of extracellular polymeric substances (EPS) and biofilms. However, the low concentration of these AHL signals makes the process difficult to understand. A robust and sensitive pretreatment method for AHL detection was developed in this work. Compared with eight different solid-phase extraction (SPE) columns and three various solid extraction method, we found that the UE (ultrasonic extraction) and an Oasis hydrophilic-lipophilic-balanced (HLB) sorbent in column format combined with ultra-performance liquid chromatography linked to tandem mass spectrometry (UPLC-MS/MS) can be successfully used for systematic pretreating moving bed biofilm reactor (MBBR) biological samples to extract AHLs and determine concentration of AHLs in wastewater treatment biofilms...
January 15, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Mette M B Nielsen, Kate L Lambertsen, Bettina H Clausen, Morten Meyer, Dhaka R Bhandari, Søren T Larsen, Steen S Poulsen, Bernhard Spengler, Christian Janfelt, Harald S Hansen
Focal cerebral ischaemia has an initial phase of inflammation and tissue injury followed by a later phase of resolution and repair. Mass spectrometry imaging (desorption electrospray ionization and matrix assisted laser desorption ionization) was applied on brain sections from mice 2 h, 24 h, 5d, 7d, and 20d after permanent focal cerebral ischaemia. Within 24 h, N-acyl-phosphatidylethanolamines, lysophosphatidylcholine, and ceramide accumulated, while sphingomyelin disappeared. At the later resolution stages, bis(monoacylglycero)phosphate (BMP(22:6/22:6)), 2-arachidonoyl-glycerol, ceramide-phosphate, sphingosine-1-phosphate, lysophosphatidylserine, and cholesteryl ester appeared...
December 22, 2016: Scientific Reports
Valentin Friedrich, Bettina Janesch, Markus Windwarder, Daniel Maresch, Matthias L Braun, Zoë A Megson, Evgeny Vinogradov, Marie-France Goneau, Ashu Sharma, Friedrich Altmann, Paul Messner, Ian C Schoenhofen, Christina Schäffer
Tannerella forsythia is an anaerobic, Gram-negative periodontal pathogen. A unique O-linked oligosaccharide decorates the bacterium's cell surface proteins and was shown to modulate the host immune response. In our study, we investigated the biosynthesis of the nonulosonic acid (NulO) present at the terminal position of this glycan. A bioinformatic analysis of T. forsythia genomes revealed a gene locus for the synthesis of pseudaminic acid (Pse) in the type strain ATCC 43037 while strains FDC 92A2 and UB4 possess a locus for the synthesis of legionaminic acid (Leg) instead...
December 16, 2016: Glycobiology
Simone Rankl, Benet Gunsé, Tina Sieper, Christoph Schmid, Charlotte Poschenrieder, Peter Schröder
While colonizing the rhizosphere, bacterial intra- and inter-specific communication is accomplished by N-Acyl-homoserine-lactones (AHLs) in a density-dependent manner. Moreover, plants are naturally exposed to AHLs and respond with tissue-specificity. In the present study, we investigated the influence of N-hexanoyl- (C6-HSL), N-octanoyl- (C8-HSL) and N-dodecanoyl-d/l-homoserine lactone (C12-HSL) on growth and root development in barley (Hordeum vulgare L.), and identified initial reactions in root cells after AHL exposures using physiological, staining, and electrophysiological methods...
December 2016: Plant Science: An International Journal of Experimental Plant Biology
Nozomu Okino, Makoto Ito
Pseudomonas aeruginosa, an opportunistic, but serious multidrug-resistant pathogen, secretes a ceramidase capable of cleaving the N-acyl linkage of ceramide to generate fatty acids and sphingosine. We previously reported that the secretion of P. aeruginosa ceramidase was induced by host-derived sphingolipids, through which phospholipase C-induced hemolysis was significantly enhanced. We herein investigated the gene(s) regulating sphingolipid-induced ceramidase expression and identified SphR, which encodes a putative AraC family transcriptional regulator...
December 12, 2016: Scientific Reports
Lukáš Opálka, Andrej Kováčik, Jaroslav Maixner, Kateřina Vávrová
Omega-O-acylceramides (acylCer), a subclass of sphingolipids with an ultralong N-acyl chain (from 20 to 38 carbons, most usually 30 and 32 carbons), are crucial components of the skin permeability barrier. AcylCer are involved in the formation of the long periodicity lamellar phase (LPP, 12-13 nm), which is essential for preventing water loss from the body. Lower levels of acylCer and LPP accompany skin diseases, such as atopic dermatitis, lamellar ichthyosis, and psoriasis. We studied how the concentration and structure of acylCer influence the organization and permeability barrier properties of model lipid membranes...
December 6, 2016: Langmuir: the ACS Journal of Surfaces and Colloids
Madhur S Joshi, F Christopher Pigge
Alkylidene dihydropyridines (anhydrobases) prepared via dearomatization of N-acylated 4-(aminomethyl)pyridines participate in [3 + 2] cyclocondensation reactions with aryldiazonium cations to afford substituted 1,2,4-triazolium salts or neutral 1,2,4-triazoles in high isolated yield. The reaction proceeds in the presence of a variety of N-acyl groups and aryl-susbtituted diazonium salts and offers a general route to pyridyl-substituted 1,2,4-triazoles.
November 18, 2016: Organic Letters
Alan R Healy, Herman Nikolayevskiy, Jaymin R Patel, Jason M Crawford, Seth B Herzon
Precolibactins and colibactins represent a family of natural products that are encoded by the clb gene cluster and are produced by certain commensal, extraintestinal, and probiotic E. coli. clb(+) E. coli induce megalocytosis and DNA double-strand breaks in eukaryotic cells, but paradoxically, this gene cluster is found in the probiotic Nissle 1917. Evidence suggests precolibactins are converted to genotoxic colibactins by colibactin peptidase (ClbP)-mediated cleavage of an N-acyl-d-Asn side chain, and all isolation efforts have employed ΔclbP strains to facilitate accumulation of precolibactins...
December 7, 2016: Journal of the American Chemical Society
Byung Kwon Jung, Abdur Rahim Khan, Sung-Jun Hong, Gun-Seok Park, Yeong-Jun Park, Chang Eon Park, Hwang-Ju Jeon, Sung-Eun Lee, Jae-Ho Shin
The genus Serratia incorporates many agriculturally important species. Serratia fonticola strain GS2, isolated from a sesame rhizosphere, can produce N-acyl homoserine lactone quorum sensing signal molecules and indole-3-acetic acid (IAA). Here we report the complete genome sequence and phenotypic characteristics based on genomic information of this bacterium. The complete genome sequence of S. fonticola strain GS2 consists of a chromosome of 6.1 Mbp and two plasmids of 132 kbp and 94 kbp. The genome clusters for IAA and N-acyl homoserine lactone biosynthesis were identified in the genome...
January 10, 2017: Journal of Biotechnology
Xiao-Li Zhang, Min-Hua Zong, Ning Li
BACKGROUND: Enzymatic approaches have become promising alternatives to chemical methods for the production of semi-synthetic β-lactam antibiotics. In this work, enzymatic synthesis of N-bromoacetyl-7-aminocephalosporanic acid (N-bromoacetyl-7-ACA), the key intermediate for the production of cefathiamidine, was reported for the first time. RESULTS: Of the immobilized penicillin acylases (PAs) tested, PGA-750 was the best biocatalyst. Optimization of the biocatalytic process was conducted...
2016: Bioresources and Bioprocessing
Jessica Grote, Dagmar Krysciak, Katrin Petersen, Simon Güllert, Christel Schmeisser, Konrad U Förstner, Hari B Krishnan, Harald Schwalbe, Nina Kubatova, Wolfgang R Streit
Plant-released flavonoids induce the transcription of symbiotic genes in rhizobia and one of the first bacterial responses is the synthesis of so called Nod factors. They are responsible for the initial root hair curling during onset of root nodule development. This signal exchange is believed to be essential for initiating the plant symbiosis with rhizobia affiliated with the Alphaproteobacteria. Here, we provide evidence that in the broad host range strain Sinorhizobium fredii NGR234 the complete lack of quorum sensing molecules results in an elevated copy number of its symbiotic plasmid (pNGR234a)...
2016: Frontiers in Microbiology
Thomas Ledger, Sandy Rojas, Tania Timmermann, Ignacio Pinedo, María J Poupin, Tatiana Garrido, Pablo Richter, Javier Tamayo, Raúl Donoso
Abiotic stress has a growing impact on plant growth and agricultural activity worldwide. Specific plant growth promoting rhizobacteria have been reported to stimulate growth and tolerance to abiotic stress in plants, and molecular mechanisms like phytohormone synthesis and 1-aminocyclopropane-1-carboxylate deamination are usual candidates proposed to mediate these bacterial effects. Paraburkholderia phytofirmans PsJN is able to promote growth of several plant hosts, and improve their tolerance to chilling, drought and salinity...
2016: Frontiers in Microbiology
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