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Yuriko Matsuzaki, Tetsushi Sakuma, Takashi Yamamoto, Hideyuki Saya
Phosphatase and tensin homolog (PTEN) is a lipid and protein phosphatase that antagonizes signaling by the phosphatidylinositol 3-kinase (PI3K)-AKT signaling pathway. The PTEN gene is a major tumor suppressor, with mutations of this gene occurring frequently in tumors of humans and mice. We have now developed mutant medaka deficient in PTEN with the use of transcription activator-like effector nuclease (TALEN) technology. Medaka possesses two pten genes, ptena and ptenb, similar to zebrafish. We established 16 ptena mutant lines and two ptenb mutant lines...
2017: PloS One
Jae Yeon Kim, Byung Chul Kang, Do Hyun Ryu
A catalytic enantioselective Roskamp reaction of silyl diazoalkane to synthesize a highly optically active α-silyl ketone from aldehydes is described. In the presence of a chiral oxazaborolidinium ion catalyst, the reaction provides α-chiral silyl ketones with good yields (up to 97%) and high enantioselectivities (up to >99% ee). In addition, a one-pot procedure using an asymmetric Roskamp/reduction strategy gives highly optically active syn-β-hydroxysilane in good yields (up to 94%) with high enantioselectivities (up to 99% ee) and syn stereoselectivities (>20:1)...
October 20, 2017: Organic Letters
Radhakrishna Gattu, Prasanta Ray Bagdi, R Sidick Basha, Abu Taleb Khan
A simple and an efficient one-pot three component reaction of arylamines, aromatic aldehydes and cyclic ketones was described for the synthesis of various fused quinoline, benzoquinoline and napthoquinoline derivatives by using camphorsulfonic acid as a catalyst. The exploitation of pregnenolone steroid for benzoquinolines and terephthalaldehyde for bis-benzoquinolines synthesis was achieved with 68-75% yields. The reactivity of aryl amines and the mechanistic study for the formation of benzoquinoline was described precisely...
October 20, 2017: Journal of Organic Chemistry
Andreas Dominik Benischke, Lucile Anthore-Dalion, Guillaume Berionni, Paul Knochel
nBu2LaMe allows a fast and convenient halogen-lanthanum exchange of aryl- and heteroaryl halides (X = Br, I) leading to functionalized diaryl- and diheteroaryl-lanthanum derivatives. Their subsequent trappings with selected electrophiles, such as ketones, aldehydes and amides proceeded smoothly at -50 °C in THF affording polyfunctionalized alcohols and carbonyl derivatives. Competitive kinetic measurements show a similar reactivity trend as the Br/Mg-exchange, but 10^6 faster rates making it comparable to the Br/Li-exchange...
October 20, 2017: Angewandte Chemie
Denise Biagini, Tommaso Lomonaco, Silvia Ghimenti, Francesca Giuseppa Bellagambi, Massimo Onor, Maria Chiara Scali, Valentina Barletta, Mario Marzilli, Pietro Salvo, Maria Giovanna Trivella, Roger Fuoco, Fabio Di Francesco
The analytical performances of needle trap micro-extraction (NTME) coupled with gas chromatography tandem mass spectrometry were evaluated by analyzing a mixture of twenty-two representative breath VOCs belonging to different chemical classes (i.e. hydrocarbons, ketones, aldehydes, aromatics and sulfurs). NTME is an emerging technique that guarantees detection limits in pptv range by pre-concentrating low volumes of sample, and it is particularly suitable for breath analysis. For most VOCs, detection limits between 20 and 500 pptv were obtained by pre-concentrating 25 mL of a humidified standard gas mixture at a flow rate of 15 mL/min...
October 20, 2017: Journal of Breath Research
K C Nicolaou, Pengxi Chen, Shugao Zhu, Quan Cai, Rohan D Erande, Ruofan Li, Hongbao Sun, Kiran Kumar Pulukuri, Stephan Rigol, Monette Aujay, Joseph Sandoval, Julia Gavrilyuk
A streamlined total synthesis of the naturally occurring antitumor agents trioxacarcins is described, along with its application to the construction of a series of designed analogues of these complex natural products. Biological evaluation of the synthesized compounds revealed a number of highly potent, and yet structurally simpler, compounds that are effective against certain cancer cell lines, including a drug-resistant line. A novel one-step synthesis of anthraquinones and chloro anthraquinones from simple ketone precursors and phenylselenyl chloride is also described...
October 20, 2017: Journal of the American Chemical Society
Wei Chen, Yingquan Chen, Haiping Yang, Kaixu Li, Xu Chen, Hanping Chen
Biomass (bamboo waste) nitrogen-enriched pyrolysis was carried out in a fixed bed with NH3 atmosphere at 400-800 °C, and formation mechanism of N-containing species was explored in depth. Results showed that N-enriched pyrolysis greatly increased bio-oil and gas yields. H2 yield increased sharply to 130 mL/g (32.93 vol%) and became the main composition at higher temperature, while CH4 and CO yields deceased, and the lower heating value of gas reached ∼14 MJ/Nm(3). For bio-oil, the content of phenols (main compositions) and N-containing species increased significantly, and the maximums reached 61...
October 7, 2017: Bioresource Technology
Bing Zhang, Huai-Wei Wang, Yan-Shang Kang, Ping Zhang, Hua-Jin Xu, Yi Lu, Wei-Yin Sun
A general method for selective ortho C-H arylation of ketone, with boron reagent enabled by rhodium complexes with excellent yields, is developed. The transformation is characterized by the use of air-stable Rh catalyst, high monoarylation selectivity, and excellent yields of most of the substrates.
October 19, 2017: Organic Letters
Tsuyoshi Mita, Satoshi Hanagata, Kenichi Michigami, Yoshihiro Sato
By using Co(acac)2/Xantphos with AlMe3, the C(sp(3))-H bonds of allylarene derivatives were cleaved for reaction with various ketones, affording the homoallylic alcohols in moderate to good yields. The branch/linear selectivity depended on the steric and electronic factors of the ketone electrophiles. The intermediate in this reaction is thought to be a low-valent allylcobalt(I) species, which exhibits high nucleophilicity toward ketones.
October 19, 2017: Organic Letters
Zhen-Kang Wen, Xue-Hua Liu, Yu-Fang Liu, Jian-Bin Chao
A new strategy to prepare β-acyl allylic methylsulfides and -sulfones through acid promoted direct cross-coupling of methyl ketones with dimethyl sulfoxide (DMSO) is reported. The reaction proceeded through the nucleophilic attack of enamine intermidiates derived from ketones to in situ generated thionium ion species, followed by elimination of methanthiol to give ketoallylic methylsulfides. With the prolonged reaction time, such products could be further reacted with a methyl sulfonyl radical, which might be generated from a methylthiosulfonate species, to afford ketoallylic methylsulfones in high yields...
October 19, 2017: Organic Letters
Jinming Fan, Tao Wang, Chenchen Li, Rui Wang, Xiaoyu Lei, Yong Liang, Zunting Zhang
A concise and efficient photoinduced rearrangement of (E)-3-arylvinyl-4H-chromen-4-ones for the synthesis of benzoaryl-5-yl(2-hydroxyphenyl)methanones is described. Benzoaryl-5-yl-(2-hydroxyphenyl)methanones were obtained in 77-95% yields via the irradiation of (E)-3-arylvinyl-chromones in the 95% EtOH with a high-pressure mercury lamp at room temperature under Ar atmosphere. The reported method provides a novel procedure for the synthesis of α,α'-diaryl ketone derivatives without addition of any transition metals and oxidants or other additives...
October 19, 2017: Organic Letters
Jaya Kishore Vandavasi, XiYe Hua, Hamdi Ben Halima, Stephen G Newman
The use of transition metal catalysis to enable the coupling of readily available organic molecules has greatly enhanced the chemist's ability to access complex chemical structures. In this work, an intermolecular coupling reaction that unites organotriflates and aldehydes is presented. A unique catalyst system is identified to enable this reaction, featuring a Ni(0) precatalyst, a tridentate Triphos ligand, and a bulky amine base. This transformation provides access to a variety of ketone-containing products without the selectivity and reactivity-related challenges associated with more traditional Friedel-Crafts reactions...
October 18, 2017: Angewandte Chemie
Shane O'Reilly, Roger Summons, Gerald Mayr, Jakob Vinther
Although various kinds of organic molecules are known to occur in fossils and rocks, most soft tissue preservation in animals is attributed to melanin or porphyrins. Lipids are particularly stable over time-as diagenetically altered 'geolipids' or as major molecular constituents of kerogen or fossil 'geopolymers'-and may be expected to be preserved in certain vertebrate tissues. Here we analysed lipid residues from the uropygial gland of an early Eocene bird using pyrolysis gas chromatography mass spectroscopy...
October 25, 2017: Proceedings. Biological Sciences
Jian Wen, Hanchao Cheng, Gerhard Raabe, Carsten Bolm
A Cp*Rh(III) complex has been used as catalyst for the preparation of unprecedented 1,2-benzothiazepine 1-oxides by [4 + 3] cyclization of NH-sulfoximines with α,β-unsaturated ketones. For a wide range of substrates with various functional groups, moderate to good product yields were obtained.
October 18, 2017: Organic Letters
Juanjuan Feng, Xiuqin Wang, Yu Tian, Chuannan Luo, Min Sun
An in-tube solid-phase microextraction device was developed by packing poly(ionic liquids)-coated stainless-steel wires into a polyether ether ketone tube. An anion-exchange process was performed to enhance the extraction performance. Surface properties of poly(ionic liquids)-coated stainless-steel wires were characterized by scanning electron microscopy and energy dispersive X-ray spectrometry. The extraction device was connected to high-performance liquid chromatography equipment to build an online enrichment and analysis system...
October 17, 2017: Journal of Separation Science
Danielle Schultz, François Lévesque, Daniel A DiRocco, Mikhail Reibarkh, Yining Ji, Leo A Joyce, James F Dropinski, Huaming Sheng, Benjamin D Sherry, Ian W Davies
Remotely oxygenated aliphatic amines represent an important class of synthetic building blocks to which there are currently no direct means of access. Reported here is an efficient and scalable solution that relies upon decatungstate photocatalysis under acidic conditions using either H2O2 or O2 as the terminal oxidant. Using these conditions a series of simple and unbiased aliphatic amine starting materials can be oxidized to value added ketone products. Lastly, in situ LED-irradiated NMR spectroscopy was utilized to monitor the kinetics of the reaction, enabling direct translation of the reaction in flow...
October 16, 2017: Angewandte Chemie
Daud H Khan, Steven A Roberts, John Robert Cressman, Nitin Agrawal
Hypoxic regions exist within most solid tumors and often lead to altered cellular metabolism, metastasis, and drug resistance. Reliable generation and detection of biomimetic gaseous gradients in vitro is challenging due to low spatiotemporal resolution and poor longevity of gradients utilizing microfluidic techniques. Here, we present a novel and simplistic approach for producing gradients of dissolved oxygen (DO) within a lab-on-a-chip platform. Linear and stable DO gradients with high spatial resolution are established by introducing pre-gassed media into the gradient generating network...
October 18, 2017: Scientific Reports
Zhang Bo, Chen Sitong, Guo Weiming, Zhang Weijing, Wang Lin, Yang Li, Zhang Jianguo
The generally thought unstable diol compound tetrazyl gem-diol (1, H2DTMdiol·2H2O), was firstly obtained in crystalline form by culturing the filtrate for ten days after acidification and filtration of aqueous solution of potassium salt of ketone (2, [K(HDTMone)·2H2O]n). The stability of this novel gem-diol compound is found owning to the hydrogen bonds with lattice water molecules and electrophilic tetrazolyl groups. Meanwhile, the undissolved ketone (3, H2DTMone) was separated during the filtration in the process of gem-diol compound production...
October 18, 2017: Scientific Reports
Mohammed Abul Monjur Khan, Nicholas C Manoukis, Terry Osborne, Idris M Barchia, Geoff M Gurr, Olivia L Reynolds
Queensland fruit fly, Bactrocera tryoni (Froggatt), is the most significant pest of Australia's $9 billion horticulture industry. The sterile insect technique (SIT) and cue-lure (a synthetic analogue of raspberry ketone (RK))-based male annihilation technique (MAT) are two of the most effective management tools against this pest. However, combining these two approaches is considered incompatible as MAT kills sterile and 'wild' males indiscriminately. In the present study we tested the effect of pre-release feeding of B...
October 17, 2017: Scientific Reports
Abbi R Hernandez, Caesar M Hernandez, Keila T Campos, Leah M Truckenbrod, Yasemin Sakarya, Joseph A McQuail Ph D, Christy S Carter, Jennifer L Bizon, Andrew P Maurer, Sara N Burke
Nutritional ketosis is induced by high fat/low carbohydrate dietary regimens, which produce high levels of circulating ketone bodies, shifting metabolism away from glucose utilization. While ketogenic diets (KD) were initially introduced to suppress seizures, they are garnering attention for their potential to treat a myriad of neurodegenerative and metabolic disorders that are associated with advanced age. The feasibility and physiological impact of implementing a long-term KD in old animals, however, has not been systematically examined...
October 12, 2017: Journals of Gerontology. Series A, Biological Sciences and Medical Sciences
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