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https://www.readbyqxmd.com/read/29793211/synthesis-and-evaluation-of-novel-triazolyl-quinoline-derivatives-as-potential-antileishmanial-agents
#1
Akanksha Upadhyay, Pragati Kushwaha, Sampa Gupta, Ranga Prasad Dodda, Karthik Ramalingam, Ruchir Kant, Neena Goyal, Koneni V Sashidhara
The high potential of quinoline containing natural products and their derivatives in medicinal chemistry led us to discover novel series of 25 compounds for the development of new antileishmanial agents. A series of triazolyl 2-methyl-4-phenylquinoline-3-carboxylate derivatives has been synthesized via click chemistry inspired molecular hybridization approach and evaluated against Leishmania donovani. Most of the screened derivatives exhibited significant in vitro anti-leishmanial activity against promastigote (IC50 ranging from 2...
May 12, 2018: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/29792931/engineering-the-production-of-dipicolinic-acid-in-e-coli
#2
Maria K McClintock, Grant W Fahnhorst, Thomas R Hoye, Kechun Zhang
Dicarboxylic acids, such as the phthalic acids and their derivatives, are monomeric components in several important polyesters and polyamides. In most cases, these compounds are derived from fossil fuels and are not easily biodegradable. Dipicolinic acid (DPA) is a biologically derived aromatic di-acid that has a similar structure to isophthalic acid. Furthermore, DPA has been shown to make polyesters, is readily biodegradable, and is non-toxic. DPA is naturally produced by Bacillus and Clostridium species during sporulation and can comprise up to 15% of the dry weight...
May 21, 2018: Metabolic Engineering
https://www.readbyqxmd.com/read/29792805/a-cheminformatic-insight-into-the-differences-between-terrestrial-and-marine-originated-natural-products
#3
Jun Shang, Ben Hu, Junmei Wang, Feng Zhu, Yu Kang, Dan Li, Huiyong Sun, De-Xin Kong, Tingjun Hou
This is a new golden age for the drug discovery based on natural products derived from both marine and terrestrial sources. Herein, a straightforward but important question is what are the major structural differences between marine natural products (MNPs) and terrestrial natural products (TNPs). To answer this question, we analyzed the important physicochemical properties, structural features and drug-likeness of the two types of natural products and discussed their differences from the perceptive of evolution...
May 24, 2018: Journal of Chemical Information and Modeling
https://www.readbyqxmd.com/read/29792712/targeted-discovery-and-combinatorial-biosynthesis-of-polycyclic-tetramate-macrolactam-combamides-a-e
#4
Yan Liu, Haoxin Wang, Rentai Song, Jining Chen, Tianhong Li, Yaoyao Li, Liangcheng Du, Yuemao Shen
Polycyclic tetramate macrolactams (PoTeMs) are a growing class of natural products with distinct structure and diverse biological activities. By promoter engineering and heterologous expression of the cryptic cbm gene cluster, four new PoTeMs, combamides A-E (1-4), were identified. Additionally, two new derivatives, combamides E (5) and F (6), were generated via combinatorial biosynthesis. Together, our findings provide a sound base for expanding the structure diversities of PoTeMs through genome mining and combinatorial biosynthesis...
May 24, 2018: Organic Letters
https://www.readbyqxmd.com/read/29792705/total-synthesis-of-boletopsin-11-enabled-by-directed-ortho-c-sp-2-h-arylation
#5
Meng Yao Zhang, Russell A Barrow
A nine-step synthesis of boletopsin 11 (1), a bioactive fungal natural product, is disclosed. Key features include a one-pot [O]-oxa-Michael cascade to establish the polyoxygenated dibenzofuran core followed by a Pd-catalyzed directed ortho-C(sp2 )-H arylation to complete the fully functionalized carbon skeleton. Exploration of the latter transformation led to the discovery of an unexpected tandem ortho-C(sp2 )-H arylation event, and the scope of the directed ortho-C(sp2 )-H reaction was further investigated with coupling partners varying in stereoelectronic properties...
May 24, 2018: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/29792672/biosynthesis-of-lincosamide-antibiotics-reactions-associated-with-degradation-and-detoxification-pathways-play-a-constructive-role
#6
Daozhong Zhang, Zhijun Tang, Wen Liu
Natural products typically are small molecules produced by living organisms. These products possess a wide variety of biological activities and thus have historically played a critical role in medicinal chemistry and chemical biology either as chemotherapeutic agents or as useful tools. Natural products are not synthesized for use by human beings; rather, living organisms produce them in response to various biochemical processes and environmental concerns, both internal and external. These processes/concerns are often dynamic and thus motivate the diversification, optimization, and selection of small molecules in line with changes in biological function...
May 24, 2018: Accounts of Chemical Research
https://www.readbyqxmd.com/read/29792525/modelling-category-goodness-judgments-in-children-with-residual-sound-errors
#7
Sarah Hamilton Dugan, Noah Silbert, Tara McAllister, Jonathan L Preston, Carolyn Sotto, Suzanne E Boyce
This study investigates category goodness judgments of /r/ in adults and children with and without residual speech errors (RSEs) using natural speech stimuli. Thirty adults, 38 children with RSE (ages 7-16) and 35 age-matched typically developing (TD) children provided category goodness judgments on whole words, recorded from 27 child speakers, with /r/ in various phonetic environments. The salient acoustic property of /r/ - the lowered third formant (F3) - was normalized in two ways. A logistic mixed-effect model quantified the relationships between listeners' responses and the third formant frequency, vowel context and clinical group status...
May 24, 2018: Clinical Linguistics & Phonetics
https://www.readbyqxmd.com/read/29792322/metabolism-of-phenolic-compounds-in-lps-stimulated-raw264-7-cells-can-impact-their-anti-inflammatory-efficacy-indication-of-hesperetin
#8
Yong Ma, Yu He, Taijun Yin, Haoqing Chen, Song Gao, Ming Hu
Raw264.7 is a murine macrophage-like cell line commonly used to study the anti-inflammatory efficacy of natural compounds. However, the impacts of long-time incubation on the tested compounds are often inappropriately ignored. Among 77 natural phenolic compounds (mainly flavonoids), only 36 remain more than 70% after a 15-hour incubation in cell culture medium at 37 °C. Interestingly, for those compounds with a relatively good chemical stability, the presence of Raw264.7 cells could accelerate their disappearance in the medium, indicating that cellular metabolism occurred...
May 24, 2018: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/29792274/ex-vivo-expanded-natural-regulatory-t-cells-from-patients-with-end-stage-renal-disease-or-kidney-transplantation-are-useful-for-autologous-cell-therapy
#9
Sybille Landwehr-Kenzel, Anne Zobel, Henrike Hoffmann, Niels Landwehr, Michael Schmueck-Henneresse, Thomas Schachtner, Andy Roemhild, Petra Reinke
Novel concepts employing autologous, ex vivo expanded natural regulatory T cells (nTreg) for adoptive transfer has potential to prevent organ rejection after kidney transplantation. However, the impact of dialysis and maintenance immunosuppression on the nTreg phenotype and peripheral survival is not well understood, but essential when assessing patient eligibility. The current study investigates regulatory T-cells in dialysis and kidney transplanted patients and the feasibility of generating a clinically useful nTreg product from these patients...
June 2018: Kidney International
https://www.readbyqxmd.com/read/29792199/nanoparticle-delivery-of-grape-seed-derived-proanthocyanidins-to-airway-epithelial-cells-dampens-oxidative-stress-and-inflammation
#10
S Castellani, A Trapani, A Spagnoletta, L di Toma, T Magrone, S Di Gioia, D Mandracchia, G Trapani, E Jirillo, M Conese
BACKGROUND: Chronic respiratory diseases, whose one of the hallmarks is oxidative stress, are still incurable and need novel therapeutic tools and pharmaceutical agents. The phenolic compounds contained in grape are endowed with well-recognized anti-oxidant, anti-inflammatory, anti-cancer, and anti-aging activities. Considering that natural anti-oxidants, such as proanthocyanidins, have poor water solubility and oral bioavailability, we have developed a drug delivery system based on solid lipid nanoparticles (SLN), apt to encapsulate grape seed extract (GSE), containing proanthocyanidins...
May 23, 2018: Journal of Translational Medicine
https://www.readbyqxmd.com/read/29791905/disparities-in-chronic-kidney-disease-prevalence-among-males-and-females-in-195-countries-analysis-of-the-global-burden-of-disease-2016-study
#11
Boris Bikbov, Norberto Perico, Giuseppe Remuzzi
BACKGROUND: Chronic kidney disease (CKD) imposes a substantial burden on health care systems. There are some especially vulnerable groups with a high CKD burden, one of which is women. We performed an analysis of gender disparities in the prevalence of all CKD stages and renal replacement therapy (defined as impaired kidney function [IKF]) in 195 countries. METHODS: We used estimates produced by the Global Burden of Disease (GBD) Study 2016 revision using a Bayesian-regression analytic tool, DisMoD-MR 2...
May 23, 2018: Nephron
https://www.readbyqxmd.com/read/29791888/boosted-nutritional-quality-of-food-by-co-2-enrichment-fails-to-offset-energy-demand-of-herbivores-under-ocean-warming-causing-energy-depletion-and-mortality
#12
Jonathan Y S Leung, Ivan Nagelkerken, Bayden D Russell, Camilo M Ferreira, Sean D Connell
The CO2 -boosted trophic transfer from primary producers to herbivores has been increasingly discovered at natural CO2 vents and in laboratory experiments. Despite the emerging knowledge of this boosting effect, we do not know the extent to which it may be enhanced or dampened by ocean warming. We investigated whether ocean acidification and warming enhance the nutritional quality (C:N ratio) and energy content of turf algae, which is speculated to drive higher feeding rate, greater energy budget and eventually faster growth of herbivores...
May 20, 2018: Science of the Total Environment
https://www.readbyqxmd.com/read/29791877/enzyme-assisted-extraction-chemical-characteristics-and-immunostimulatory-activity-of-polysaccharides-from-korean-ginseng-panax-ginseng-meyer
#13
Young-Ran Song, Su-Kyung Sung, Mi Jang, Tae-Gyu Lim, Chang-Won Cho, Chun-Ji Han, Hee-Do Hong
In this study, enzyme-assisted extraction was used to isolate functional polysaccharides from Korean ginseng (Panax ginseng Meyer) and the physicochemical and biological properties of the extracted polysaccharides were investigated, comparing with those from traditional hot-water extraction (FGWP). In macrophages, their effects on cytokines production could be ordered as FGEP-CA ≥ FGEP-A > FGEP-C > FGWP, suggesting that FGEP-CA (combined cellulase- and α-amylase-extracted polysaccharide) is a potent immunostimulator...
May 20, 2018: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/29791799/oxidation-of-microcystins-by-permanganate-ph-and-temperature-dependent-kinetics-effect-of-dom-characteristics-and-oxidation-mechanism-revisited
#14
Min Sik Kim, Hye-Jin Lee, Ki-Myeong Lee, Jiwon Seo, Changha Lee
Oxidative degradation of six representative microcystins (MCs) (MC-RR, -LR, -YR, -LF, -LW and -LA) by potassium permanganate (KMnO4; Mn(VII)) was investigated, focusing on the temperature- and pH-dependent reaction kinetics, the effect of dissolved organic matter (DOM), and the oxidation mechanisms. Second-order rate constants for the reactions of the six MCs with Mn(VII) (kMn(VII),MC) were determined to be 160.4-520.1 M-1 s-1 (MC-RR > -LR  -YR > -LF  -LW > -LA) at pH 7.2 and 21°C. The kMn(VII),MC values exhibited activation energies ranging from 15...
May 23, 2018: Environmental Science & Technology
https://www.readbyqxmd.com/read/29791786/matrine-suppresses-kras-driven-pancreatic-cancer-growth-by-inhibiting-autophagy-mediated-energy-metabolism
#15
Young-Ra Cho, Ji Hyeon Lee, Ji Hye Kim, So-Yeon Lee, Suna Yoo, Min-Kyo Jung, Su Jung Kim, Hyun Ju Yoo, Chang-Gi Pack, Jin Kyung Rho, Jaekyoung Son
Matrine is a natural compound extracted from the herb Sophora flavescens Ait which is widely used in traditional Chinese medicine for treating various diseases. Recently, matrine was reported to have antitumor effects against a variety of cancers without any obvious side effects; however, the molecular mechanisms of its antiproliferative effects on cancer are unclear. Here, we report that matrine inhibits autophagy-mediated energy metabolism, which is necessary for pancreatic cancer growth. We found that matrine significantly reduces pancreatic cancer growth in vitro and in vivo by insufficiently maintaining mitochondrial metabolic function and energy level...
May 23, 2018: Molecular Oncology
https://www.readbyqxmd.com/read/29791700/closing-the-gap-novel-abdominal-wound-closure-techniques
#16
James Dana Kondrup, Alaina M Qayyum
Traditionally, surgical procedures within the realm of both general and gynecological surgery employ the use of staples and interrupted sutures that run continuously with knot tying or subcuticular sutures to ensure closure of large wound incisions, subcuticular incisions, and fascial repair. However, these methods may not always be cosmetically favorable and, thus, result in an unpleasant outcome for the patient, adding to their surgery-related stress. It is, therefore, imperative that surgeons and gynecologists are aware of alternative methods of wound closure that are not only cosmetically favorable, but also ensure rapid wound recovery and infection control...
June 1, 2018: Surgical Technology International
https://www.readbyqxmd.com/read/29791446/nitrogen-limitation-toxin-synthesis-potential-and-toxicity-of-cyanobacterial-populations-in-lake-okeechobee-and-the-st-lucie-river-estuary-florida-during-the-2016-state-of-emergency-event
#17
Benjamin J Kramer, Timothy W Davis, Kevin A Meyer, Barry H Rosen, Jennifer A Goleski, Gregory J Dick, Genesok Oh, Christopher J Gobler
Lake Okeechobee, FL, USA, has been subjected to intensifying cyanobacterial blooms that can spread to the adjacent St. Lucie River and Estuary via natural and anthropogenically-induced flooding events. In July 2016, a large, toxic cyanobacterial bloom occurred in Lake Okeechobee and throughout the St. Lucie River and Estuary, leading Florida to declare a state of emergency. This study reports on measurements and nutrient amendment experiments performed in this freshwater-estuarine ecosystem (salinity 0-25 PSU) during and after the bloom...
2018: PloS One
https://www.readbyqxmd.com/read/29791145/slow-starter-enzymes-role-of-active-site-architecture-in-the-catalytic-control-in-the-biosynthesis-of-taxadiene-by-taxadiene-synthase
#18
Tamar Ansbacher, Yehoshua Freud, Dan Thomas Major
Taxadiene synthase (TXS) catalyzes the formation of the natural product Taxa-4(5),11(12)-diene (henceforth Taxadiene). Taxadiene is the precursor in the formation of Taxol, which is an important natural anti-cancer agent. In the current study, we present a detailed mechanistic view of the biosynthesis of Taxadiene by TXS, using a hybrid quantum mechanics-molecular mechanics potential in conjunction with free energy simulation methods. The obtained free energy landscape displays initial endergonic steps followed by a step-wise downhill profile, which is an emerging free energy fingerprint for type I terpene synthases...
May 23, 2018: Biochemistry
https://www.readbyqxmd.com/read/29791074/access-to-the-enantiopure-axially-chiral-cyclophane-isoplagiochin-d-via-atropo-diastereoselective-heck-coupling
#19
Andreas Speicher, Daniel Meidlinger, Lisa Marx, Catalina Bordeianu, Sabine Choppin, Françoise Colobert
The macrocyclization uses to be the key step in the syntheses of cyclophane type natural products. Considering cyclophanes with axially chiral biaryl moieties, the control of atroposelectivity is - referring to synthesis and biological activities - essential and challenging. We report on an atroposelective approach involving Heck cyclization, allowing for the first time the total synthesis of an enantiopure macrocyclic bis(bibenzyl), namely isoplagiochin D. An enantiopure sulfinyl auxiliary in ortho-position of a biaryl axis (still flexible) was used to induce an atropo-diastereoselective Heck coupling (up to 98 % de)...
May 23, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/29791052/high-performance-liquid-chromatography-quantification-of-enantiomers-of-a-dihydroxylated-tetrahydrofuran-natural-product
#20
Ke Li, Skye D Fissette, Tyler J Buchinger, Zoe E Middleton, Alistair Boyer, Weiming Li
Both enantiomers of petromyroxol are putative pheromones in sea lamprey (Petromyzon marinus). Here, we describe the separation and quantification of the petromyroxol enantiomers using high-performance liquid chromatography tandem mass spectrometry. The separation was tested on a wide range of chiral columns with normal phases, and effects of the chromatographic parameters such as mobile phase and temperature on the separation were optimized. The AD-H column showed the best separation of enantiomers with n-hexane and ethanol as the mobile phase...
May 23, 2018: Chirality
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