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Jiun-Yan Wu, Jen-Hung Liao, Chwen-Jen Shieh, Feng-Chia Hsieh, Yung-Chuan Liu
In this study, the precursor effect for iturin A production was quantitatively analyzed. A strain identified as Bacillus amyloliquefaciens BPD1 (Ba-BPD1) was selected due to its ability to produce iturin A. The enhancement of iturin A production in a submerged culture was tested using various additives, including palmitic acid, oils, and complex amino acids. Among these, complex amino acids triggered the highest yield at 559 mg/L. The respective amino acids that contribute to the structure of iturin A were used as precursors...
June 12, 2018: Journal of Bioscience and Bioengineering
María I Herrera, Lucas D Udovin, Nicolás Toro-Urrego, Carlos F Kusnier, Juan P Luaces, Matilde Otero-Losada, Francisco Capani
Metabolic syndrome (MetS) is a cluster of risk factors that lead to microvascular dysfunction and chronic cerebral hypoperfusion (CCH). Long-standing reduction in oxygen and energy supply leads to brain hypoxia and protein misfolding, thereby linking CCH to Alzheimer's disease. Protein misfolding results in neurodegeneration as revealed by studying different experimental models of CCH. Regulating proteostasis network through pathways like the unfolded protein response (UPR), the ubiquitin-proteasome system (UPS), chaperone-mediated autophagy (CMA), and macroautophagy emerges as a novel target for neuroprotection...
2018: Frontiers in Neuroscience
Hee Jin Jung, A Kyoung Lee, Yeo Jin Park, Sanggwon Lee, Dongwan Kang, Young Suk Jung, Hae Young Chung, Hyung Ryong Moon
Ultraviolet (UV) radiation exposure is the primary cause of extrinsic skin aging, which results in skin hyperpigmentation and wrinkling. In this study, we investigated the whitening effect of (2 E ,5 E )-2,5-bis(3-hydroxy-4-methoxybenzylidene)cyclopentanone (BHCP) on B16F10 melanoma and its anti-wrinkle activity on Hs27 fibroblasts cells. BHCP was found to potently inhibit tyrosinase, with 50% inhibition concentration (IC50 ) values of 1.10 µM and 8.18 µM for monophenolase (l-tyrosine) and diphenolase (l-DOPA), and the enzyme kinetics study revealed that BHCP is a competitive-type tyrosinase inhibitor...
June 11, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Prashamsa Koirala, Su Hui Seong, Yajuan Zhou, Srijan Shrestha, Hyun Ah Jung, Jae Sue Choi
Kuwanon G (KG) and benzofuran flavonoids such as mulberrofuran G (MG) and albanol B (AB) isolated from Morus sp. are reported to exhibit anti-Alzheimer’s disease, anti-inflammatory, fungicidal, anti-cancer, anti-bacterial, and anti-tyrosinase properties. We investigated the inhibition of mono- and diphenolase activity of mushroom tyrosinase by KG, MG, and AB. KG and MG displayed acceptable inhibition activity compared to kojic acid. AB did not show any activity up to 350 µM. MG displayed six-fold higher inhibition of l -tyrosine oxidation (IC50 = 6...
June 11, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Emilio Fernández-Espejo, Cristian Bis-Humbert
3-iodo-L-tyrosine might play a role in Parkinson's disease since this molecule is able, at high concentration, to inhibit tyrosine-hydroxylase activity, the rate-limiting enzyme in dopamine biosynthesis. The possible Parkinson-like effects of 3-iodo-L-tyrosine were tested on three experimental approaches in mice: cultured substantia nigra neurons, the enteric nervous system of the jejunum after intra-peritoneal infusions, and the nigrostriatal system following unilateral intrabrain injections. 3-iodo-L-tyrosine, a physiological molecule, was used at concentrations higher than its serum levels in humans...
June 6, 2018: Neurotoxicology
Natalia Miękus, Ilona Olędzka, Darya Harshkova, Ivan Liakh, Alina Plenis, Piotr Kowalski, Tomasz Bączek
The determination of neurotransmitters (NTs) as relevant potential biomarkers in the study of various central nervous system (CNS) pathologies has been demonstrated. Knowing that NTs-related diseases mostly occupy individual regions of the nervous system, as observed, for instance, in neurodegenerative diseases (Alzheimer’s and Parkinson’s Diseases), the analysis of brain slices is preferred to whole-brain analysis. In this report, we present sample preparation approaches, such as solid-phase extraction, solid-phase microextraction, and dispersive liquid⁻liquid microextraction, and discuss the pitfalls and advantages of each extraction method...
May 24, 2018: International Journal of Molecular Sciences
Yasuaki Tanaka, Mari Fujiwara, Asako Shindo, Guojun Yin, Takio Kitazawa, Hiroki Teraoka
Contamination with polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the environment is a major concern due to their persistent bioaccumulative toxicity that can disturb neurobehavioral functions including movements. Recently, it was reported that some PBDE including BDE-47 stimulates locomotor activities of zebrafish embryos by unknown mechanism. In this study, motor movements of the zebrafish embryo were used as a model system to evaluate the neuronal toxicity of a non-coplanar PCB-dominant mixture (Aroclor 1254) and BDE-47...
February 2018: Chemosphere
Jang Hoon Kim, In Sook Cho, Yang Kang So, Hyeong-Hwan Kim, Young Ho Kim
Tyrosinase is known for an enzyme that plays a key role in producing the initial precursor of melanin biosynthesis. Inhibition of the catalytic reaction of this enzyme led to some advantage such as skin-whitening and anti-insect agents. To find a natural compound with inhibitory activity towards tyrosinase, the five flavonoids of kushenol A (1), 8-prenylkaempferol (2), kushenol C (3), formononetin (4) and 8-prenylnaringenin (5) were isolated by column chromatography from a 95% methanol extract of Sophora flavescens...
December 2018: Journal of Enzyme Inhibition and Medicinal Chemistry
Nicole J Kus, Monika B Dolinska, Kenneth L Young, Emilios K Dimitriadis, Paul T Wingfield, Yuri V Sergeev
Human tyrosinase (hTyr) is a Type 1 membrane bound glycoenzyme that catalyzes the initial and rate-limiting steps of melanin production in the melanosome. Mutations in the Tyr gene are linked to oculocutaneous albinism type 1 (OCA1), an autosomal recessive disorder. Currently, the application of enzyme replacement therapy for a treatment of OCA1 is hampered by the absence of pure hTyr. Here, full-length hTyr (residues 1-529) was overexpressed in Trichoplusia ni larvae infected with a baculovirus, solubilized with detergent and purified using chromatography...
2018: PloS One
Md Amdadul Huq, Shahina Akter, Muhammad Zubair Siddiqi, Sri Renukadevi Balusamy, Sathishkumar Natarajan, Jae-Hyun Yoon, Sun-Young Lee
A yellow-pigmented novel bacterial strain, MAH-12T , was isolated from a soil sample of Korean radish garden and was characterized using a polyphasic approach. Cells were Gram-staining negative, non-motile and rod-shaped. The strain was aerobic, catalase positive, optimum growth temperature and pH were 28-30 °C and 6.0, respectively. The novel strain is able to hydrolyze L-tyrosine, starch, esculin and 4-nitrophenyl-β-D-galactopyranoside. On the basis of 16S rRNA gene sequence analysis, strain MAH-12T belongs to the genus Sphingobium and is most closely related to several Sphingobium type strains (97...
June 4, 2018: Archives of Microbiology
Jesper Tranekjær Jørgensen, Kamilla Norregaard, Marina Simón Martín, Lene Broeng Oddershede, Andreas Kjaer
Rationale: Since its first implementation nanoparticle-assisted photothermal cancer therapy has been studied extensively, although mainly with focus on optimal nanoparticle design. However, development of efficient treatment protocols, as well as reliable and early evaluation tools in vivo , are needed to push the therapy towards clinical translation. Positron emission tomography (PET) is a non-invasive imaging technique that is currently finding extensive use for early evaluation of cancer therapies; an approach that has become of increasing interest due to its great potential for personalized medicine...
2018: Nanotheranostics
Minami Matsuura, Mariko Ohshima, Yuki Hiruta, Tomohiro Nishimura, Kenichi Nagase, Hideko Kanazawa
L-type amino acid transporter 1 (LAT1) is more highly expressed in cancer cells compared with normal cells. LAT1 targeting probes would therefore be a promising tool for cancer cell imaging. In this study, LAT1-targeting thermoresponsive fluorescent polymer probes based on poly( N -isopropylacrylamide- co - N , N -dimethylacrylamide) (P(NIPAAm- co -DMAAm)) were synthesized and their affinity for LAT1 was evaluated. The synthesized polymer probes interacted with LAT1 on HeLa cells, and inhibition of l-[³H]-leucine, one of the substrates for LAT1 uptake, was investigated...
June 1, 2018: International Journal of Molecular Sciences
Tamar E Sztal, Emily A McKaige, Caitlin Williams, Viola Oorschot, Georg Ramm, Robert J Bryson-Richardson
Nemaline myopathies are heterogeneous congenital muscle disorders causing skeletal muscle weakness and, in some cases, death soon after birth. Mutations in nebulin, encoding a large sarcomeric protein required for thin filament function, are responsible for approximately 50% of nemaline myopathy cases. Despite the severity of the disease there is no effective treatment for nemaline myopathy with limited research to develop potential therapies. Several supplements, including L-tyrosine, have been suggested to be beneficial and consequently self-administered by nemaline myopathy patients without any knowledge of their efficacy...
May 30, 2018: Acta Neuropathologica Communications
Carina Stegmayr, Gabriele Stoffels, Elena Rota Kops, Philipp Lohmann, Norbert Galldiks, Nadim J Shah, Bernd Neumaier, Karl-Josef Langen
PURPOSE: O-(2-[18 F]fluoroethyl)-L-tyrosine ([18 F]FET) is an established positron emission tomography (PET) tracer for brain tumor imaging. This study explores the influence of dexamethasone therapy on [18 F]FET uptake in the normal brain and its influence on the maximum and mean tumor-to-brain ratio (TBR). PROCEDURES: [18 F]FET PET scans of 160 brain tumor patients were evaluated (80 dexamethasone treated, 80 untreated; each group with 40 men/40 women). The standardized uptake value of [18 F]FET uptake in the normal brain (SUVbrain ) in the different groups was compared...
May 29, 2018: Molecular Imaging and Biology: MIB: the Official Publication of the Academy of Molecular Imaging
Ganesan Vaidyanathan, Choong Mo Kang, Darryl McDougald, Il Minn, Mary Brummet, Martin G Pomper, Michael R Zalutsky
INTRODUCTION: Radiolabeled, low-molecular-weight prostate-specific membrane antigen (PSMA) inhibitors based on the Glu-ureido pharmacophore show promise for the detection and treatment of castration-resistant prostate cancer; however, high renal retention of activity, related in part to overexpression of PSMA in kidneys can be problematic. The goal of the current study was to investigate the use of brush border enzyme-cleavable linkers as a strategy for reducing kidney activity levels from radiolabeled PSMA inhibitors...
May 5, 2018: Nuclear Medicine and Biology
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
Han Sol Doh, Hyun Jin Park
Abalone is one of the most valuable marine products found in East Asia because it is rich in nutritious substances including iodine. In this study, the in vitro dialyzability approach was used to assess the bio-available iodine species in abalone. Iodide, iodate, 3-iodo-L-tyrosine (MIT), and 3,5-diiodo-L-tyrosine (DIT) were separated by high-performance liquid chromatography hyphenated with inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). To assure the consistency, reliability, and accuracy of the data, the method was validated...
May 22, 2018: Journal of Food Science
Natalia Miękus, Ilona Olędzka, Natalia Kossakowska, Alina Plenis, Piotr Kowalski, Adam Prahl, Tomasz Bączek
Nowadays, ionic liquids (ILs) are receiving more attention in various fields of analytical chemistry. Their contribution to the enhancement of the clean-up, extraction, separation and determination of trace amounts of various biologically important compounds in distinct matrices is well documented. Moreover, their importance as "green chemistry" solvents has been pointed out. Advanced analytical methods based on the IL-assisted microextraction and electrophoretic determination of minute concentrations of neurotransmitters (NTs) in samples are presented here for the first time...
August 15, 2018: Talanta
Sied Kebir, Laurèl Rauschenbach, Gerrit H Gielen, Niklas Schäfer, Theophilos Tzaridis, Björn Scheffler, Frank A Giordano, Lazaros Lazaridis, Ulrich Herrlinger, Martin Glas
In a subset of glioblastoma (GBM) patients, the differentiation between tumor progression and tumor pseudoprogression (PsP) is challenging. This case describes a male patient suffering from isocitrate dehydrogenase 1 (IDH1) mutant GBM who demonstrated an increasing contrast-enhancing (CE) lesion on a cranial magnetic resonance imaging (cMRI) scan 8 months after radiochemotherapy. In accordance with the response assessment in neuro-oncology (RANO) criteria, the cMRI lesion was classified as recurrent tumor, although 18 F-fluoroethyl-L-tyrosine positron emission tomography (18 F-FET-PET) did not indicate vital tumor tissue...
May 10, 2018: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
Jianwen Hou, Margarita Vázquez-González, Michael Fadeev, Xia Liu, Ronit Lavi, Itamar Willner
Catalyzed oxygen insertion into C-H bonds represents a continuous challenge in chemistry. Particularly, driving this process at ambient temperatures and aqueous media represent a "holy grail" in catalysis. We report on the catalyzed cascade transformations of L-tyrosine or L-phenylalanine to dopachrome in the presence of L-ascorbic acid/H2 O2 oxidizing mixture and CuFe-Prussian Blue-like nanoparticles, Fe3 O4 nanoparticles or Au nanoparticles as catalysts. The process involves the primary transformation of L-tyrosine to L-DOPA that is further oxidized to dopachrome...
May 10, 2018: Nano Letters
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