bluuebunny/crossref_metadata_2025 huggingface dataset:
Obstructive Sleep Apnoea in Patients Treated for Head and Neck Cancer: A Systematic Review of the Literature
Authors: Ralli Massimo , Campo Flaminia , Angeletti Diletta , Allegra Eugenia , Minni Antonio , Polimeni Antonella , Greco Antonio , de Vincentiis Marco
Published: August 2020

Background and objectives: Obstructive sleep apnoea (OSA) is clinically defined by signs of daytime sleepiness and objective measures of disordered breathing during sleep. The literature is still controversial on the incidence and aetiology of OSA secondary to head and neck cancer treatment. The aim of this systematic review is to evaluate and discuss the prevalence of OSA in patients treated with surgery and/or chemo/radiotherapy for head and neck cancer. Materials and methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic search was performed on May 2020 using the MEDLINE database, Scopus, and Google Scholar. The searches were conducted using combinations of the following terms: head and neck cancer, OSA, radiotherapy, chemotherapy, partial laryngectomy, laryngeal cancer, neoplasm, tumour, carcinoma, and oropharyngeal cancer. Results: Our results suggest that head and neck cancer patients have a higher incidence of OSA (59.78%) compared to the general population; differences may occur based on the type of treatment. Conclusions: Clinicians should recognise the higher prevalence of OSA in patients treated for head and neck cancer and should consider a comprehensive sleep history as part of the evaluation and management of these patients. Further research is needed to evaluate the exact prevalence, aetiology, and correct management of OSA after treatment for head and neck cancer.
Changes of Exhaled Volatile Organic Compounds in Postoperative Patients Undergoing Analgesic Treatment: A Prospective Observational Study
Authors: Löser Benjamin , Grabenschröer Alina , Pugliese Giovanni , Sukul Pritam , Trefz Phillip , Schubert Jochen K , Miekisch Wolfram
Published: August 2020

Assessment and treatment of postoperative pain can be challenging as objective examination techniques to detect and quantify pain are lacking. We aimed to investigate changes of exhaled volatile organic compounds (VOCs) in patients with postoperative pain before and after treatment with opioid analgesics. In an observational study in 20 postoperative patients, we monitored for postoperative pain, hemodynamic parameters, and catecholamines before and during treatment. VOCs in the patients were determined by direct real-time proton transfer reaction time-of-flight mass spectrometry prior (0 min) and after piritramide application (15 min as well as 30 min). Cardiovascular variables changed and norepinephrine levels decreased during treatment. The VOCs acetonitrile (<0.001), acetaldehyde (p = 0.002), benzopyran (p = 0.004), benzene (p < 0.001), hexenal (p = < 0.001), 1-butanethiol (p = 0.004), methanethiol (p < 0.001), ethanol (p = 0.003), and propanol (p = < 0.001) changed significantly over time. Patients with Numeric Rating Scale (NRS) < 4 showed a significantly lower concentration of hexenal compared to patients with NRS > 4 at the time points 15 min (45.0 vs. 385.3 ncps, p = 0.047) and 30 min (38.3 vs. 334.6 ncps, p = 0.039). Breath analysis can provide additional information for noninvasive monitoring for analgesic treatment in postoperative patients.
Comparative Metabolomic Analysis of Dendrobium officinale under Different Cultivation Substrates
Authors: Zuo Si-Min , Yu Hai-Dong , Zhang Weimin , Zhong Qiuping , Chen Wenxue , Chen Weijun , Yun Yong-Huan , Chen Haiming
Published: August 2020

Dendrobium officinale, a precious herbal medicine, has been used for a long time in Chinese history. The metabolites of D. officinale, regarded as its effective components to fight diseases, are significantly affected by cultivation substrates. In this study, ultra-performance liquid chromatography mass spectrometry (UPLC-MS/MS) was conducted to analyze D. officinale stems cultured in three different substrates: pine bark (PB), coconut coir (CC), and a pine bark: coconut coir 1:1 mix (PC). A total of 529 metabolites were identified. Multivariate statistical analysis methods were employed to analyze the difference in the content of metabolites extracted from different groups. By the criteria of variable importance in projection (VIP) value ≥1 and absolute log2 (fold change) ≥1, there were a total of 68, 51, and 57 metabolites, with significant differences in content across groups being filtrated out between PB and PC, PB and CC, and PC and CC, respectively. The comparisons among the three groups revealed that flavonoids were the metabolites that fluctuated most. The results suggested the D. officinale stems from the PB group possessed a higher flavonoid content. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis indicated that the significantly regulated metabolites were mainly connected with flavonoid biosynthesis. A comprehensive profile of the metabolic differentiation of D. officinale planted in different substrates was provided, which supports the selection of an optimum cultivation substrate for a higher biomass yield of D. officinale.
Comparative Study of the Proteins Involved in the Fermentation-Derived Compounds in Two Strains of Saccharomyces cerevisiae during Sparkling Wine Second Fermentation
Authors: González-Jiménez María del Carmen , García-Martínez Teresa , Mauricio Juan Carlos , Sánchez-León Irene , Puig-Pujol Anna , Moreno Juan , Moreno-García Jaime
Published: August 2020

Sparkling wine is a distinctive wine. Saccharomyces cerevisiae flor yeasts is innovative and ideal for the sparkling wine industry due to the yeasts’ resistance to high ethanol concentrations, surface adhesion properties that ease wine clarification, and the ability to provide a characteristic volatilome and odorant profile. The objective of this work is to study the proteins in a flor yeast and a conventional yeast that are responsible for the production of the volatile compounds released during sparkling wine elaboration. The proteins were identified using the OFFGEL fractionator and LTQ Orbitrap. We identified 50 and 43 proteins in the flor yeast and the conventional yeast, respectively. Proteomic profiles did not show remarkable differences between strains except for Adh1p, Fba1p, Tdh1p, Tdh2p, Tdh3p, and Pgk1p, which showed higher concentrations in the flor yeast versus the conventional yeast. The higher concentration of these proteins could explain the fuller body in less alcoholic wines obtained when using flor yeasts. The data presented here can be thought of as a proteomic map for either flor or conventional yeasts which can be useful to understand how these strains metabolize the sugars and release pleasant volatiles under sparkling wine elaboration conditions.
Considerations About Bi and Pb in the Crystal Structure of Cu-Bearing Tourmaline
Authors: Ertl Andreas , Bačík Peter
Published: August 2020

Copper- and Mn-bearing elbaitic tourmaline (“Paraíba tourmaline”) sometimes contains significant amounts of Pb and Bi. Their position in the tourmaline crystal structure was studied with correlation analysis and bond valence calculations. Correlations between the F content and the X-site charge allow predicting the X-site occupancy. Three sets of tourmaline analyses were studied: (1) Pb-rich tourmalines from the Minh Tien pegmatite, Vietnam; (2) Cu-, Pb- and Bi-bearing tourmalines from the Mulungu mine, Brazil; (3) Cu- and Bi-bearing tourmalines from the Alto dos Quintos mine, Brazil. Two correlations were plotted: (1) the charge by considering only Na1+, Ca2+ and K1+; (2) the charge by adding Pb2+ and Bi3+ to the X-site charge. When plotting correlations for the Minh Tien tourmalines, the correlation significantly improves by adding Pb2+ to the X site. For the Alto dos Quintos tourmalines, only a slight increase of the correlation coefficient is observed, while such a correlation for tourmalines from Mulungu interestingly shows a slight decrease of the correlation coefficient. Bond valence calculations revealed that Bi3+ and Pb2+ can indeed occupy the X site via BiLi(NaAl)−1, PbLi(NaCu)−1 and possibly PbCu(NaAl)−1 substitutions as seen in the investigated tourmaline samples. At the Y site, Pb4+ can be substituted via PbLi(AlCu)−1, and PbVO(AlVOH)−1, while Bi5+ does not have any stable arrangement in Cu-bearing fluor-elbaite. The occurrence of Pb4+ at the Y site could be one explanation for the results of the correlations of the Mulungu tourmalines. Another explanation could be that during the tourmaline crystallization some additional Bi and Pb came into the pegmatitic system and hence disturbed the correlation between the average X-site charge and the F content. Further plots of such correlations in “Paraíba tourmaline” samples might also help to distinguish between the worldwide localities of these rare and sought-after tourmalines.
The Effect of Fe3O4 Nanoparticle Size on Electrical Properties of Nanofluid Impregnated Paper and Trapping Analysis
Authors: Du Bin , Liu Qian , Shi Yu , Zhao Yushun
Published: August 2020

This paper systematically studies the effect of Fe3O4 nanoparticle size on the insulation performance of nanofluid impregnated paper. Three kinds of Fe3O4 nanoparticles with different sizes and their nanofluid impregnated papers were prepared. Environmental scanning electron microscopy (ESEM) and infrared spectroscopy were used to analyze the combination of Fe3O4 nanoparticles and nanofluid impregnated paper. The effect of nanoparticle size on breakdown voltage and several dielectric characteristics, e.g., permittivity, dielectric loss, of the nanofluid impregnated paper were comparatively investigated. Studies show that the Fe3O4 nanoparticles were bound to impregnated paper fibers by O–H bonds, while the relative permittivity and dielectric loss of the nanofluid impregnated papers were increased. Meanwhile, the increase of trap depth, caused by the nanoparticles, can trap the electric charge and improve the breakdown strength. The test results show that the direct current (DC) and alternating current (AC) breakdown voltages of nanofluid impregnated paper increased by 9.1% and 10.0% compared to FR3 nanofluid impregnated paper, respectively.
Acorn Flour as a Source of Bioactive Compounds in Gluten-Free Bread
Authors: Beltrão Martins Rita , Gouvinhas Irene , Nunes Maria Cristiana , Alcides Peres José , Raymundo Anabela , Barros Ana I.R.N.A.
Published: August 2020

Polyphenols are important bioactive compounds whose regular ingestion has shown different positive impacts in health. Celiac patients have nutritional deficiencies, bringing many problems to their health. Thus, it is important to develop gluten-free (GF) products, such as bread, with nutritional benefits. The acorn is the fruit of holm oak and cork oak, being an underexploited resource nowadays. Its nutritional and functional characteristics are remarkable: rich in unsaturated fatty acids and fiber, vitamin E, chlorophylls, carotenoids, phenolic compounds, and antioxidant properties. The purpose of this study was to assess the use of acorn flour as a bioactive compounds source and natural GF ingredient for baking GF bread. Bread loaves were prepared with buckwheat, rice, acorn flour, and potato starch. Two levels of acorn flour (23% and 35% of the flour mixture) were tested. The physical, nutritional, and sensory characteristics of the bread were analysed, as well as the composition of phenolic compounds: total phenols, ortho-diphenols, and flavonoids. The phenolic profile was assessed by Reverse Phase–High-Performance Liquid Chromatography–Diode Array Detector (RP-HPLC-DAD). The antioxidant activity of the bread extracts was determined by 2,2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), diphenyl-1-picrylhidrazyl radical (DPPH), and ferric reducing antioxidant power (FRAP) methodologies. Acorn flour can be considered a good source of bioactive compounds and antioxidants in GF bread. Acorn flour showed good technological properties in GF baking, improving bread nutritional and sensory characteristics.
Immune Activity of Polysaccharide Fractions Isolated from Korean Red Ginseng
Authors: Youn Soo Hyun , Lee Sang Min , Han Chang-Kyun , In Gyo , Park Chae-Kyu , Hyun Sun Hee
Published: August 2020

Korean red ginseng (KRG)’s pharmacological efficacy and popular immunomodulatory effects have already been proven in many studies; however, the component of KRG that is effective in immune activity has not been studied before. Therefore, this study extracted and separated KRG for an immune activity comparison. In the water fraction obtained by extracting KRG powder with water, a red ginseng neutral polysaccharide (RGNP) fraction and a red ginseng acidic polysaccharide (RGAP) fraction were obtained. Each fraction was orally administered for 10 days to mice with reduced immunity, and the number of IgM antibody-forming cells (AFCs) in splenocytes was measured to compare the immune activity of the water fractions. The results showed that the RGAP fraction has the greatest number of AFCs. To set the optimal dose of the RGAP fraction, which had the highest immune activity, the AFCs, macrophage activity, and splenocyte subtype in the mice were analyzed. As a result, the number of AFCs was significantly increased in the RGAP fraction compared to RGNP. The intraperitoneal macrophage phagocytosis activity and the number of T cells, B cells, and macrophages in the spleen increased significantly. It can, therefore, be confirmed that immune activity increases by a fraction containing higher RGAP content, and we hypothesize that RGAP activates immune activity.
Fabrication and Biological Analysis of Highly Porous PEEK Bionanocomposites Incorporated with Carbon and Hydroxyapatite Nanoparticles for Biological Applications
Authors: Swaminathan P. D. , Uddin Md. Nizam , Wooley P. , Asmatulu Ramazan
Published: August 2020

Bone regeneration for replacing and repairing damaged and defective bones in the human body has attracted much attention over the last decade. In this research, highly porous polyetheretherketone (PEEK)/hydroxyapatite (HA) bionanocomposite scaffolds reinforced with carbon fiber (CF) and carbon nanotubes (CNTs) were fabricated, and their structural, mechanical, and biological properties were studied in detail. Salt porogen (200–500 µm size) leaching methods were adapted to produce porous PEEK structures with controlled pore size and distribution, facilitating greater cellular infiltration and biological integration of PEEK composites within patient tissue. In biological tests, nanocomposites proved to be non-toxic and have very good cell viability. In addition, bone marrow cell growth was observed, and PEEK/HA biocomposites with carbon particles showed increased cell attachment over the neat PEEK/HA composites. In cell viability tests, bionanocomposites with 0.5 wt% CNTs established good attachment of cells on disks compared to neat PEEK/HA biocomposites. A similar performance was seen in culture tests of bone marrow cells (osteoblasts and osteoclasts). The 0.5 wt% CF for osteoblasts and 1 wt% CNTs for osteoclasts showed higher cell attachment. The addition of carbon-based nanomaterials into PEEK/HA has been identified as an effective approach to improve cell attachment as well as mechanical and biological properties. With confirmed cell attachment and sustained viability and proliferation of the fabricated PEEK/HA/CNTs, CF bionanocomposites were confirmed to possess excellent biocompatibility and will have potential uses in bone scaffolding and other biomedical applications.
β-Cyclodextrin Inhibits Monocytic Adhesion to Endothelial Cells through Nitric Oxide-Mediated Depletion of Cell Adhesion Molecules
Authors: Jang Sujeong , Lee Seongsoo , Park Heonyong
Published: August 2020

Cyclodextrins (CDs) are used as drug delivery agents. In this study, we examined whether CDs have an inflammatory effect on endothelial cells. First, we found that β-CD promoted cell proliferation in bovine aortic endothelial cells and elevated nitric oxide (NO) production through dephosphorylation of threonine-495 (T-495) in endothelial nitric oxide synthetase (eNOS). Dephosphorylation of T-495 is known to activate eNOS. Phosphorylation of T-495 was found to be catalyzed by protein kinase Cε (PKCε). We then found that β-CD inhibits binding of PKCε to diacylglycerol (DAG) via formation of a β-CD-DAG complex, indicating that β-CD inactivates PKCε. Furthermore, β-CD controls activation of PKCε by reducing the recruitment of PKCε into the plasma membrane. Finally, β-CD inhibits expression of intercellular and vascular cell adhesion molecule-1 by increasing NO via control of PKCε/eNOS and suppression of THP-1 cell adhesion to endothelial cells. These findings imply that β-CD plays an important role in anti-inflammatory processes.
1,4-Disubstituted 1,2,3-Triazoles as Amide Bond Surrogates for the Stabilisation of Linear Peptides with Biological Activity
Authors: Rečnik Lisa-Maria , Kandioller Wolfgang , Mindt Thomas L.
Published: August 2020

Peptides represent an important class of biologically active molecules with high potential for the development of diagnostic and therapeutic agents due to their structural diversity, favourable pharmacokinetic properties, and synthetic availability. However, the widespread use of peptides and conjugates thereof in clinical applications can be hampered by their low stability in vivo due to rapid degradation by endogenous proteases. A promising approach to circumvent this potential limitation includes the substitution of metabolically labile amide bonds in the peptide backbone by stable isosteric amide bond mimetics. In this review, we focus on the incorporation of 1,4-disubstituted 1,2,3-triazoles as amide bond surrogates in linear peptides with the aim to increase their stability without impacting their biological function(s). We highlight the properties of this heterocycle as a trans-amide bond surrogate and summarise approaches for the synthesis of triazole-containing peptidomimetics via the Cu(I)-catalysed azide-alkyne cycloaddition (CuAAC). The impacts of the incorporation of triazoles in the backbone of diverse peptides on their biological properties such as, e.g., blood serum stability and affinity as well as selectivity towards their respective molecular target(s) are discussed.
Chinese Yellow Rice Wine Processing with Reduced Ethyl Carbamate Formation by Deleting Transcriptional Regulator Dal80p in Saccharomyces cerevisiae
Authors: Wei Tianyu , Jiao Zhihua , Hu Jingjin , Lou Hanghang , Chen Qihe
Published: August 2020

Ethyl carbamate (EC) is a potential carcinogen that forms spontaneously during Chinese rice wine fermentation. The primary precursor for EC formation is urea, which originates from both external sources and arginine degradation. Urea degradation is suppressed by nitrogen catabolite repression (NCR) in Saccharomyces cerevisiae. The regulation of NCR is mediated by two positive regulators (Gln3p, Gat1p/Nil1p) and two negative regulators (Dal80p/Uga43p, Deh1p/Nil2p/GZF3p). DAL80 revealed higher transcriptional level when yeast cells were cultivated under nitrogen-limited conditions. In this study, when DAL80-deleted yeast cells were compared to wild-type BY4741 cells, less urea was accumulated, and genes involved in urea utilization were up-regulated. Furthermore, Chinese rice wine fermentation was conducted using dal80Δ cells; the concentrations of urea and EC were both reduced when compared to the BY4741 and traditional fermentation starter. The findings of this work indicated Dal80p is involved in EC formation possibly through regulating urea metabolism and may be used as the potential target for EC reduction.
Asoprisnil, a Selective Progesterone Receptor Modulator (SPRM), Inhibits Melanosome Export in B16F10 Cells and HEMn-DP Melanocytes
Authors: Goenka Shilpi , R. Simon Sanford
Published: August 2020

Previous studies have reported that estrogen hormone promotes melanogenesis while progesterone inhibits it. A selective estrogen receptor modulator (SERM), tamoxifen, has been shown to promote melanogenesis; however, to date, there have been no reports on the effects of a selective progesterone receptor modulator (SPRM) on melanogenesis. In the present study, we hypothesized that asoprisnil (AP), a SPRM, inhibits melanogenesis. AP was tested for cytotoxicity to B16F10 mouse melanoma cells for screening the nontoxic concentrations using MTS cytotoxicity assay. Extracellular and intracellular melanin levels were estimated at nontoxic concentrations of AP. To evaluate the direct effect of AP on tyrosinase enzyme, tyrosinase activity and copper chelating activities were measured. Next, the effects of AP on melanogenesis were tested in normal human melanocytes, neonatal, darkly pigmented (HEMn-DP). Our results demonstrate that AP was nontoxic at a concentration range of 10–50 μM in B16F10 cells; AP at 50 μM significantly suppressed extracellular melanin levels comparable to kojic acid at 500 μM, with no significant effect on intracellular melanin levels. The mechanism of melanogenesis inhibition was studied to assess if AP downregulated tyrosinase activity in cell lysates or in a cell-free system. However, AP was found to increase intracellular tyrosinase activity without any effect on tyrosinase enzyme activity or copper chelating activity in a cell-free system, indicating that AP inhibits melanogenesis by mechanisms other than direct effects on tyrosinase enzyme activity. The capacity of AP to inhibit melanosome export was further validated in HEMn-DP cells; AP significantly suppressed dendricity at concentrations of 20 and 30 μM in the absence of effects on melanin synthesis or intracellular tyrosinase activity. In addition, AP was nontoxic to human keratinocytes (HaCaT) at these concentrations, validating its safety for topical use. Taken together, our preliminary results demonstrate that AP might be repurposed as a candidate therapeutic for treatment of hyperpigmentation disorders via a unique mechanism, which encompasses a selective inhibition of melanosome export.
Water-Extracted Ganoderma lucidum Induces Apoptosis and S-Phase Arrest via Cyclin-CDK2 Pathway in Glioblastoma Cells
Authors: Cheng An-Yi , Chien Yi-Chung , Lee Han-Chung , Hsieh Yi-Hsien , Yu Yung-Luen
Published: August 2020

Glioblastoma is one of the most common and most aggressive brain cancers. The current treatment is mainly surgery, chemotherapy, and radiation therapy, but the results are not satisfactory. Ganoderma lucidum (G. lucidum), also called “Lingzhi”, is a medicinal mushroom that has been used as a therapeutic agent for the treatment of numerous diseases, including cancer. However, whether it is effective for treating cancer is still unclear. In the present study, the anti-tumor effect of a water extract of G. lucidum was investigated using brain tumor cells. We used an analysis of cell viability, flow cytometry, the IncuCyte live-cell analysis system, and Western blotting to study its effects. The water extract from G. lucidum inhibited cell proliferation in a dose- and time-dependent manner, and it induced mitochondria-mediated apoptosis and cell cycle arrest at S phase via the cyclin-CDK2 pathway in human brain tumor cells. In addition, the G. lucidum extract significantly inhibited cell migration and mesenchymal marker expression based on the IncuCyte live-cell assay and qRT-PCR analysis. In summary, these anti-tumor effects in brain tumor cells suggest that G. lucidum may be useful for treating brain tumors.
Phytochemical Composition and Antimicrobial Activity of Corydalis solida and Pseudofumaria lutea
Authors: Zielińska Sylwia , Dziągwa-Becker Magdalena , Piątczak Ewelina , Jezierska-Domaradzka Anna , Brożyna Malwina , Junka Adam , Kucharski Mariusz , Çiçek Serhat Sezai , Zidorn Christian , Matkowski Adam
Published: August 2020

Corydalis and Pseudofumaria are two closely related genera from the Papaveraceae subfamily Fumarioideae with Corydalis solida (C. solida) and Pseudofumaria lutea (P. lutea) as two representative species. Phytochemical analysis revealed significant differences in the quality and quantity of isoquinoline alkaloids, phenolic compounds and non-phenolic carboxylic acids between aerial and underground parts of both species. Using the Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) technique, 21 compounds were identified: five protoberberine derivatives, three protopine derivatives, four phenanthridine derivatives, as well as three carboxylic acids, two hydroxycinnamic acids, one chlorogenic acid, one phenolic aldehyde, and two flavonoids. Moroever, significant differences in the content of individual compounds were observed between the two studied species. The phytochemical profile of C. solida showed a higher variety of compounds that were present in lower amounts, whereas P. lutea extracts contained fewer compounds but in larger quantities. Protopine was one of the most abundant constituents in C. solida (440–1125 µg/g d.w.) and in P. lutea (1036–1934 µg/g d.w.). Moreover, considerable amounts of coptisine (1526 µg/g) and quercetin (3247 µg/g) were detected in the aerial parts of P. lutea. Extracts from aerial and underground parts of both species were also examined for the antimicrobial potential against S. aureus, P. aeruginosa and C. albicans. P. lutea herb extract was the most effective (MIC at 0.39 mg/L) against all three pathogens.
Rhodium-Catalyzed Synthesis of Organosulfur Compounds Involving S-S Bond Cleavage of Disulfides and Sulfur
Authors: Arisawa Mieko , Yamaguchi Masahiko
Published: August 2020

Organosulfur compounds are widely used for the manufacture of drugs and materials, and their synthesis in general conventionally employs nucleophilic substitution reactions of thiolate anions formed from thiols and bases. To synthesize advanced functional organosulfur compounds, development of novel synthetic methods is an important task. We have been studying the synthesis of organosulfur compounds by transition-metal catalysis using disulfides and sulfur, which are easier to handle and less odiferous than thiols. In this article, we describe our development that rhodium complexes efficiently catalyze the cleavage of S-S bonds and transfer organothio groups to organic compounds, which provide diverse organosulfur compounds. The synthesis does not require use of bases or organometallic reagents; furthermore, it is reversible, involving chemical equilibria and interconversion reactions.
Pro-Oxidant Activity of an ALS-Linked SOD1 Mutant in Zn-Deficient Form
Authors: Nagao Chise , Kuroi Kunisato , Wakabayashi Taiyu , Nakabayashi Takakazu
Published: August 2020

Cu, Zn superoxide dismutase (SOD1) is a representative antioxidant enzyme that catalyzes dismutation of reactive oxygen species in cells. However, (E,E)-SOD1 mutants in which both copper and zinc ions were deleted exhibit pro-oxidant activity, contrary to their antioxidant nature, at physiological temperatures, following denaturation and subsequent recombination of Cu2+. This oxidative property is likely related to the pathogenesis of amyotrophic lateral sclerosis (ALS); however, the mechanism by which Cu2+ re-binds to the denatured (E,E)-SOD1 has not been elucidated, since the concentration of free copper ions in cells is almost zero. In this study, we prepared the (Cu,E) form in which only a zinc ion was deleted using ALS-linked mutant H43R (His43→Arg) and found that (Cu,E)-H43R showed an increase in the pro-oxidant activity even at physiological temperature. The increase in the pro-oxidant activity of (Cu,E)-H43R was also observed in solution mimicking intracellular environment and at high temperature. These results suggest that the zinc-deficient (Cu,E) form can contribute to oxidative stress in cells, and that the formation of (E,E)-SOD1 together with the subsequent Cu2+ rebinding is not necessary for the acquisition of the pro-oxidant activity.
Safety Evaluation of an Alpha-Emitter Bismuth-213 Labeled Antibody to (1→3)-β-Glucan in Healthy Dogs as a Prelude for a Trial in Companion Dogs with Invasive Fungal Infections
Authors: Helal Muath , Allen Kevin J. H. , Burgess Hilary , Jiao Rubin , Malo Mackenzie E. , Hutcheson Matthew , Dadachova Ekaterina , Snead Elisabeth
Published: August 2020

Background: With the limited options available for therapy to treat invasive fungal infections (IFI), radioimmunotherapy (RIT) can potentially offer an effective alternative treatment. Microorganism-specific monoclonal antibodies have shown promising results in the experimental treatment of fungal, bacterial, and viral infections, including our recent and encouraging results from treating mice infected with Blastomyces dermatitidis with 213Bi-labeled antibody 400-2 to (1→3)-β-glucan. In this work, we performed a safety study of 213Bi-400-2 antibody in healthy dogs as a prelude for a clinical trial in companion dogs with acquired invasive fungal infections and later on in human patients with IFI. Methods: Three female beagle dogs (≈6.1 kg body weight) were treated intravenously with 155.3, 142.5, or 133.2 MBq of 213Bi-400-2 given as three subfractions over an 8 h period. RBC, WBC, platelet, and blood serum biochemistry parameters were measured periodically for 6 months post injection. Results: No significant acute or long-term side effects were observed after RIT injections; only a few parameters were mildly and transiently outside reference change value limits, and a transient atypical morphology was observed in the circulating lymphocyte population of two dogs. Conclusions: These results demonstrate the safety of systemic 213Bi-400-2 administration in dogs and provide encouragement to pursue evaluation of RIT of IFI in companion dogs.
Comparative Proteomic Analysis of Dipsacus asperoides Roots from Different Habitats in China
Authors: Jin Haijun , Yu Hua , Wang Haixia , Zhang Jia
Published: August 2020

Dipsacus asperoides is a kind of Chinese herbal medicine with beneficial health properties. To date, the quality of D. asperoides from different habitats has shown significant differences. However, the molecular differences in D. asperoides from different habitats are still unknown. The aim of this study was to investigate the differences in protein levels of D. asperoides from different habitats. Isobaric tags for relative and absolute quantification (iTRAQ) and 2DLC/MS/MS were used to detect statistically significant changes in D. asperoides from different habitats. Through proteomic analysis, a total of 2149 proteins were identified, of which 42 important differentially expressed proteins were screened. Through in-depth analysis of differential proteins, the protein metabolism energy and carbohydrate metabolism of D. asperoides from Hubei Province were strong, but their antioxidant capacity was weak. We found that three proteins, UTP-glucose-1-phosphate uridylyltransferase, allene oxide cyclase, and isopentyl diphosphate isomerase 2, may be the key proteins involved in dipsacus saponin VI synthesis. Eight proteins were found in D. asperoides in response to environmental stress from different habitats. Quantitative real-time PCR analysis confirmed the accuracy and authenticity of the proteomic analysis. The results of this study may provide the basic information for exploring the cause of differences in secondary metabolites in different habitats of D. asperoides and the protein mechanism governing differences in quality.
A DFT Study on FeI/FeII/FeIII Mechanism of the Cross-Coupling between Haloalkane and Aryl Grignard Reagent Catalyzed by Iron-SciOPP Complexes
Authors: Sharma Akhilesh , Nakamura Masaharu
Published: August 2020

To explore plausible reaction pathways of the cross-coupling reaction between a haloalkane and an aryl metal reagent catalyzed by an iron–phosphine complex, we examine the reaction of FeBrPh(SciOPP) 1 and bromocycloheptane employing density functional theory (DFT) calculations. Besides the cross-coupling, we also examined the competitive pathways of β-hydrogen elimination to give the corresponding alkene byproduct. The DFT study on the reaction pathways explains the cross-coupling selectivity over the elimination in terms of FeI/FeII/FeIII mechanism which involves the generation of alkyl radical intermediates and their propagation in a chain reaction manner. The present study gives insight into the detailed molecular mechanic of the cross-coupling reaction and revises the FeII/FeII mechanisms previously proposed by us and others.
Effects of Storage Time and Temperature on Antioxidants in Juice from Momordica charantia L. and Momordica charantia L. var. abbreviata Ser.
Authors: Lin Yung-Sheng , Huang Wen-Ying , Ho Pang-Yen , Hu Shiou-Yih , Lin Ying-Yi , Chen Cheng-You , Chang Min-Yun , Huang Shu-Ling
Published: August 2020

This study determined the antioxidant activities of juice from Momordica charantia L. (MC) and MC var. abbreviata Ser. (MCVAS) by analyzing 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging ability, ferric reducing power (FRP), and total phenolic content (TPC). The effects of storage time and storage temperature on these antioxidant activities were investigated. Liquid chromatography–mass spectrometry was conducted to identify the major components of MC and MCVAS. The results revealed that the antioxidant activity of MCVAS was better than that of MC, possibly because of richer components of MCVAS. For MC and MCVAS, the scavenging concentrations of 50% DPPH were 3.33 and 1.19 mg/mL, respectively; moreover, the FRP values were 68.93 and 118.14 mg ascorbic acid equivalent/g dry weight, respectively; and the TPC values were 8.15 and 11.47 mg gallic acid equivalent/g dry weight, respectively. The antioxidant activities of MC and MCVAS decreased with storage time. High storage temperature decreased antioxidant activity more quickly than a low temperature. In addition, MC had exhibited a faster decline in DPPH scavenging ability and FRP than MCVAS during 24-day storage, but no difference was observed in TPC.
15N NMR Shifts of Eumelanin Building Blocks in Water: A Combined Quantum Mechanics/Statistical Mechanics Approach
Authors: Assis Oliveira Leonardo Bruno , L. Fonseca Tertius , Cabral Benedito J. C.
Published: August 2020

Theoretical results for the magnetic shielding of protonated and unprotonated nitrogens of eumelanin building blocks including monomers, dimers, and tetramers in gas phase and water are presented. The magnetic property in water was determined by carrying out Monte Carlo statistical mechanics sampling combined with quantum mechanics calculations based on the gauge-including atomic orbitals approach. The results show that the environment polarization can have a marked effect on nitrogen magnetic shieldings, especially for the unprotonated nitrogens. Large contrasts of the oligomerization effect on magnetic shielding show a clear distinction between eumelanin building blocks in solution, which could be detected in nuclear magnetic resonance experiments. Calculations for a π-stacked structure defined by the dimer of a tetrameric building block indicate that unprotonated N atoms are significantly deshielded upon π stacking, whereas protonated N atoms are slightly shielded. The results stress the interest of NMR experiments for a better understanding of the eumelanin complex structure.
Characterization of Anti-Inflammatory and Antioxidant Constituents from Scutellaria baicalensis Using LC-MS Coupled with a Bioassay Method
Authors: Han Yoo Kyong , Kim Hyunwoo , Shin Hyeji , Song Jiyeon , Lee Mi Kyeong , Park Byoungduck , Lee Ki Yong
Published: August 2020

An effective and previously demonstrated screening method for active constituents in natural products using LC-MS coupled with a bioassay was reported in our earlier studies. With this, the current investigation attempted to identify bioactive constituents of Scutellaria baicalensis through LC-MS coupled with a bioassay. Peaks at broadly 17–20 and 24–25 min on the MS chromatogram displayed an inhibitory effect on NO production in lipopolysaccharide-induced BV2 microglia cells. Similarly, peaks at roughly 17–19 and 22 min showed antioxidant activity with an 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS)/2,2-diphenyl-1- picrylhydrazyl (DPPH) assay. For confirmation of LC-MS coupled with a bioassay, nine compounds (1–9) were isolated from an MeOH extract of S. baicalensis. As we predicted, compounds 1, 8, and 9 significantly reduced lipopolysaccharide (LPS)-induced NO production in BV2 cells. Likewise, compounds 5, 6, and 8 exhibited free radical-scavenging activities with the ABTS/DPPH assay. In addition, the structural similarity of the main components was confirmed by analyzing the total extract and EtOAc fractions through molecular networking. Overall, the results suggest that the method comprised of LC-MS coupled with a bioassay can effectively predict active compounds without an isolation process, and the results of molecular networking predicted that other components around the active compound node may also be active.
Natural Ingredient-Based Polymeric Nanoparticles for Cancer Treatment
Authors: Wong Ka Hong , Lu Aiping , Chen Xiaoyu , Yang Zhijun
Published: August 2020

Cancer is a global health challenge. There are drawbacks to conventional chemotherapy such as poor bioavailability, development of drug resistance and severe side effects. Novel drug delivery system may be an alternative to optimize therapeutic effects. When such systems consist of natural materials, they offer important advantages: they are usually highly biocompatible, biodegradable, nontoxic and nonimmunogenic. Furthermore, natural materials can be easily modified for conjugation with a wide range of therapeutic agents and targeting ligands, according to the therapeutic purpose. This article reviews different natural ingredients and their applications in drug delivery systems for cancer therapy. Firstly, an overview of the polysaccharides and protein-based polymers that have been extensively investigated for drug delivery are described. Secondly, recent advances in using various natural ingredient-based polymeric nanoparticles for cancer therapy are reviewed. The characteristics of these delivery systems are summarized, followed by a discussion of future development and clinical potential. This review aims to summarize current knowledge and provide a basis for developing effective tailor-made formulations for cancer therapy in the future.
Analyses of Skin Secretions of Vipera ammodytes (Linnaeus, 1758) (Reptilia: Serpentes), with Focus on the Complex Compounds and Their Possible Role in the Chemical Communication
Authors: Andonov Kostadin , Dyugmedzhiev Angel , Lukanov Simeon , Slavchev Miroslav , Vacheva Emiliya , Stanchev Nikola , Popgeorgiev Georgi , Duhalov Deyan , Kornilev Yurii V. , Nedeltcheva-Antonova Daniela , Naumov Borislav
Published: August 2020

Snakes rely heavily on chemical cues when foraging, searching for mates, etc. Snakes’ sex attractiveness pheromones comprise mainly heavy, semi-volatile compounds such as ketones. Here we investigated the composition of skin secretions of adult Vipera ammodytes (Linnaeus, 1758) individuals. The samples were analyzed by gas chromatography/mass spectrometry and the identification of the compounds was performed using commercial mass spectral libraries and retention times. The relative concentrations of all detected compounds were tested for significant differences between (1) male vs. female live individuals, (2) shed skin vs. live individuals, and (3) pre-reproductive vs. reproductive live individuals. We detected fifty-nine compounds of which six were ketones. Two ketones (2-pentacosanone and 2-heptacosanone) were present in many of the samples and thus may have an important role in the V. ammodytes chemical communication. We did not find significant differences between the relative concentrations of the compounds between male and female individuals (only three compounds are exceptions). Significant differences were found between extracts from shed skins and live individuals and between live pre-reproductive individuals and live reproductive individuals. The results of the study suggest that chemical communication in V. ammodytes involves less compounds in comparison to the known literature data for other species.
Rindera graeca (Boraginaceae) Phytochemical Profile and Biological Activities
Authors: Ganos Christos , Aligiannis Nektarios , Chinou Ioanna , Naziris Nikolaos , Chountoulesi Maria , Mroczek Tomasz , Graikou Konstantia
Published: August 2020

Rindera graeca is a Greek endemic plant of the Boraginaceae family which has never been studied before. Consequently, this study attempted to phytochemically examine the aerial parts of this species. Nine phenolic secondary metabolites were identified, consisting of seven caffeic acid derivatives and two flavonol glucosides, namely rutin and quercetin-3-rutinoside-7-rhamnoside. These flavonoids, together with rosmarinic acid, were isolated via column chromatography and structurally determined through spectral analysis. Quercetin-3-rutinoside-7-rhamnoside is an unusual triglycoside, which is identified for the first time in Rindera genus and among Boraginaceae plants. This metabolite was further examined with thermal analysis and its 3D structure was simulated, revealing some intriguing information on its interaction with biological membrane models, which might have potential applications in microcirculation-related conditions. R. graeca was also analyzed for its pyrrolizidine alkaloids content, and it was found to contain echinatine together with echinatine N-oxide and rinderine N-oxide. Additionally, the total phenolic and flavonoid contents of R. graeca methanol extract were determined, along with free radical inhibition assays. High total phenolic content and almost complete inhibition at experimental doses at the free radical assays indicate a potent antioxidant profile for this plant. Overall, through phytochemical analysis and biological activity assays, insight was gained on an endemic Greek species of the little-studied Rindera genus, while its potential for further applications has been assessed.
The Application of Biomass-Based Catalytic Materials in the Synthesis of Cyclic Carbonates from CO2 and Epoxides
Authors: Guo Li , Zhang Ran , Xiong Yuge , Chang Dandan , Zhao Haoran , Zhang Wenbo , Zheng Wei , Chen Jialing , Wu Xiaoqin
Published: August 2020

The synthesis of cyclic carbonates from carbon dioxide (CO2) and epoxides is a 100% atom economical reaction and an attractive pathway for CO2 utilisation. Because CO2 is a thermodynamically stable molecule, the use of catalysts is mandatory in reducing the activation energy of the CO2 conversion. Considering environmental compatibility and the high-efficiency catalytic conversion of CO2, there is the strong need to develop green catalysts. Biomass-based catalysts, a type of renewable resource, have attracted considerable attention due to their unique properties—non-toxic, low-cost, pollution-free, etc. In this review, recent advances in the development of biomass-based catalysts for the synthesis of cyclic carbonates by CO2 and epoxides coupling are summarized and discussed in detail. The effect of biomass-based catalysts, functional groups, reaction conditions, and co-catalysts on the catalytic efficiency and selectivity of synthesizing cyclic carbonates process is discussed. We intend to provide a comprehensive understanding of recent experimental and theoretical progress of CO2 and epoxides coupling reaction and pave the way for both CO2 conversion and biomass unitization.
Release of Melamine and Formaldehyde from Melamine-Formaldehyde Plastic Kitchenware
Authors: Ebner Ingo , Haberer Steffi , Sander Stefan , Kappenstein Oliver , Luch Andreas , Bruhn Torsten
Published: August 2020

The release of melamine and formaldehyde from kitchenware made of melamine resins is still a matter of great concern. To investigate the migration and release behavior of the monomers from melamine-based food contact materials into food simulants and food stuffs, cooking spoons were tested under so-called hot plate conditions at 100 °C. Release conditions using the real hot plate conditions with 3% acetic acid were compared with conditions in a conventional migration oven and with a release to deionized water. Furthermore, the kinetics of the release were studied using Arrhenius plots giving an activation energy for the release of melamine of 120 kJ/mol. Finally, a correlation between quality of the resins, specifically the kind of bridges between the monomers, and the release of melamine, was confirmed by CP/MAS 13C-NMR measurements of the melamine kitchenware. Obviously, the ratio of methylene bridges and dimethylene ether bridges connecting the melamine monomers during the curing process can be directly correlated with the amount of the monomers released into food.
Developing 3D-Printable Cathode Electrode for Monolithically Printed Microbial Fuel Cells (MFCs)
Authors: Theodosiou Pavlina , Greenman John , Ieropoulos Ioannis A.
Published: August 2020

Microbial Fuel Cells (MFCs) employ microbial electroactive species to convert chemical energy stored in organic matter, into electricity. The properties of MFCs have made the technology attractive for bioenergy production. However, a challenge to the mass production of MFCs is the time-consuming assembly process, which could perhaps be overcome using additive manufacturing (AM) processes. AM or 3D-printing has played an increasingly important role in advancing MFC technology, by substituting essential structural components with 3D-printed parts. This was precisely the line of work in the EVOBLISS project, which investigated materials that can be extruded from the EVOBOT platform for a monolithically printed MFC. The development of such inexpensive, eco-friendly, printable electrode material is described below. The electrode in examination (PTFE_FREE_AC), is a cathode made of alginate and activated carbon, and was tested against an off-the-shelf sintered carbon (AC_BLOCK) and a widely used activated carbon electrode (PTFE_AC). The results showed that the MFCs using PTFE_FREE_AC cathodes performed better compared to the PTFE_AC or AC_BLOCK, producing maximum power levels of 286 μW, 98 μW and 85 μW, respectively. In conclusion, this experiment demonstrated the development of an air-dried, extrudable (3D-printed) electrode material successfully incorporated in an MFC system and acting as a cathode electrode.
Hydrogen Bond-Mediated Conjugates Involving Lanthanide Diphthalocyanines and Trifluoroacetic Acid (Lnpc2@TFA): Structure, Photoactivity, and Stability
Authors: Dyrda Gabriela , Zakrzyk Maja , Broda Małgorzata A. , Pędziński Tomasz , Mele Giuseppe , Słota Rudolf
Published: August 2020

The interaction between lanthanide diphthalocyanine complexes, LnPc2 (Ln = Nd, Sm, Eu, Gd, Yb, Lu; Pc = C32H16N8, phthalocyanine ligand) and trifluoroacetic acid (TFA) was investigated in benzene, and the stability of the resulting molecular system was assessed based on spectral (UV-Vis) and kinetic measurements. Structural Density Functional Theory (DFT) calculations provided interesting data regarding the nature of the bonding and allowed estimating the interaction energy between the LnPc2 and TFA species. Conjugates are created between the LnPc2 and TFA molecules via hydrogen bonds of moderate strength (>N∙∙H··) at the meso- -bridges of the Pc moieties, which renders the sandwich system to flatten. Attachment of TFA is followed by rearrangement of electronic density within the chromophore system of the macrocycles manifested in considerable changes in their UV-Vis spectra and consequently the color of the studied solutions (from green to orange). The LnPc2@TFA conjugates including Nd, Sm, Eu, and Gd appeared evidently less photostable when exposed to UV radiation than the related mother compounds, whereas in the case of Yb and Lu derivatives some TFA-prompted stabilizing effect was noticed. The conjugates displayed the capacity for singlet oxygen generation in contrast to the LnPc2s itself. Photon upconversion through sensitized triplet–triplet annihilation was demonstrated by the TFA conjugates of Nd, Sm, Eu, and Gd.