scholarly journals Revisit of the Photoirradiation of α-Lipoic Acid—Role of Hydrogen Sulfide Produced in the Reaction

BioChem ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 148-158
Author(s):  
Naoki Wada ◽  
Seiichi Matsugo
Keyword(s):  
Hydrogen Sulfide ◽  
Lipoic Acid ◽  
Photochemical Reaction ◽  
Dimethyl Disulfide ◽  
Polymeric Materials ◽  
Reduced Form ◽  
Product Analysis ◽  
Plausible Mechanism ◽  
Ph Dependent

α-Lipoic acid (LA) has the specific absorption band at 330 nm and is quite vulnerable to UV irradiation, affording a variety of compounds including polymeric materials and hydrogen sulfide. A better understanding of the photochemical reaction of LA has already been carried out focusing mainly on the reaction product analysis derived from LA. We re-investigated the photochemical reaction of LA focusing our attention on the fate of hydrogen sulfide (H2S) produced in the photochemical reaction procedure. The photoirradiation of LA in the presence of oxidized glutathione (GSSG) formed glutathione trisulfide (GSSSG) and a reduced form of glutathione (GSH). Similar results were obtained in the co-presence of cystine and dimethyl disulfide. The concentration of H2S was reaching the maximum concentration, which was gradually decreasing within 10 min after photoirradiation, while the concentration of GSSSG was increasing with the decrease of H2S concentration. The structural confirmation of GSSSG and the plausible mechanism for the formation of GSSSG are proposed based on the time-dependent and pH-dependent profile of the photoirradiation.

scholarly journals The Role of Oral Microbiota in Intra-Oral Halitosis

2020 ◽  
Vol 9 (8) ◽  
pp. 2484 ◽  
Author(s):  
Katarzyna Hampelska ◽  
Marcelina Maria Jaworska ◽  
Zuzanna Łucja Babalska ◽  
Tomasz M. Karpiński
Keyword(s):  
Hydrogen Sulfide ◽  
Dimethyl Sulfide ◽  
Anaerobic Bacteria ◽  
Dimethyl Disulfide ◽  
Oral Bacteria ◽  
Oral Microbiota ◽  
Low Concentrations ◽  
Aldehydes And Ketones ◽  
Common Ailment

Halitosis is a common ailment concerning 15% to 60% of the human population. Halitosis can be divided into extra-oral halitosis (EOH) and intra-oral halitosis (IOH). The IOH is formed by volatile compounds, which are produced mainly by anaerobic bacteria. To these odorous substances belong volatile sulfur compounds (VSCs), aromatic compounds, amines, short-chain fatty or organic acids, alcohols, aliphatic compounds, aldehydes, and ketones. The most important VSCs are hydrogen sulfide, dimethyl sulfide, dimethyl disulfide, and methyl mercaptan. VSCs can be toxic for human cells even at low concentrations. The oral bacteria most related to halitosis are Actinomyces spp., Bacteroides spp., Dialister spp., Eubacterium spp., Fusobacterium spp., Leptotrichia spp., Peptostreptococcus spp., Porphyromonas spp., Prevotella spp., Selenomonas spp., Solobacterium spp., Tannerella forsythia, and Veillonella spp. Most bacteria that cause halitosis are responsible for periodontitis, but they can also affect the development of oral and digestive tract cancers. Malodorous agents responsible for carcinogenesis are hydrogen sulfide and acetaldehyde.

Baboon Fibrinogen Adsorption and Platelet Adhesion to Polymeric Materials

1991 ◽  
Vol 65 (05) ◽  
pp. 608-617 ◽  
Author(s):  
Joseph A Chinn ◽  
Thomas A Horbett ◽  
Buddy D Ratner
Keyword(s):  
Platelet Adhesion ◽  
Coagulation Factor ◽  
Polymeric Materials ◽  
Platelet Suspension ◽  
Perfusion Chamber ◽  
Static Conditions ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Fibrinogen Adsorption

SummaryThe role of fibrinogen in mediating platelet adhesion to polymers exposed to blood plasma was studied by comparison of the effect of plasma dilution on fibrinogen adsorption and platelet adhesion, and by the use of coagulation factor deficient plasmas. Polyetherurethane substrates were first preadsorbed with dilute plasma, then contacted with washed platelets suspended in a modified, apyrase containing Tyrode’s buffer. Platelet adhesion was studied under static conditions in Multiwell dishes, and also under shearing conditions using a parallel plate perfusion chamber. Fibrinogen adsorption and platelet adhesion were measured using 125I radiolabeled baboon fibrinogen and min radiolabeled baboon platelets, respectively. Surfaces were characterized by electron spectroscopy for chemical analysis (ESCA).When fibrinogen adsorption to Biomer was measured after 2 h contact with a series of dilute plasma solutions under static conditions, a peak in adsorption was observed from 0.26% plasma, i.e., adsorption was greater from 0.26% plasma than from either more or less dilute plasma. A peak in subsequent platelet adhesion to the plasma preadsorbed surfaces, measured after 2 h static incubation with washed platelets, was also observed but occurred on Biomer preadsorbed with 1.0% plasma.When fibrinogen adsorption was measured after 5 min contact under shearing conditions, the fibrinogen adsorption peak occurred on surfaces that had been exposed to 1.0% plasma. A peak in platelet adhesion to these preadsorbed surfaces, measured after 5 min contact with the platelet suspensions under shearing conditions, was observed on Biomer preadsorbed with 0.1% plasma. Shifts between the positions of the peaks in protein adsorption and platelet adhesion occurred on other polymers tested as well.Platelet adhesion was almost completely inhibited when baboon and human plasmas lacking fibrinogen (i. e., serum, heat defibrinogenated plasma, and congenitally afibrinogénémie plasma) were used. Platelet adhesion was restored to near normal when exogenous fibrinogen was added to fibrinogen deficient plasmas. Adhesion was also inhibited completely when a monoclonal antibody directed against the glycoprotein IIb/IIIa complex was added to the platelet suspension. Platelet adhesion to surfaces preadsorbed to von Willebrand factor deficient plasma was the same as to surfaces preadsorbed with normal plasma.While it appears that surface bound fibrinogen does mediate the initial attachment of platelets to Biomer, the observation that the fibrinogen adsorption and platelet adhesion maxima do not coincide exactly also suggests that the degree of subsequent platelet adhesion is dictated not only by the amount of surface bound fibrinogen but also by its conformation.

Role of Exosomes in Photodynamic Anticancer Therapy

2020 ◽  
Vol 27 (40) ◽  
pp. 6815-6824 ◽  
Author(s):  
Yuan Jiang ◽  
Chuanshan Xu ◽  
Wingnang Leung ◽  
Mei Lin ◽  
Xiaowen Cai ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Basic Principle ◽  
Photochemical Reaction ◽  
Cell Communication ◽  
Anticancer Therapy ◽  
Bioactive Molecules ◽  
Promising Alternative ◽  
Tumor Tissues ◽  
Significant Attention

Photodynamic Therapy (PDT) is a promising alternative treatment for malignancies based on photochemical reaction induced by Photosensitizers (PS) under light irradiation. Recent studies show that PDT caused the abundant release of exosomes from tumor tissues. It is well-known that exosomes as carriers play an important role in cell-cell communication through transporting many kinds of bioactive molecules (e.g. lipids, proteins, mRNA, miRNA and lncRNA). Therefore, to explore the role of exosomes in photodynamic anticancer therapy has been attracting significant attention. In the present paper, we will briefly introduce the basic principle of PDT and exosomes, and focus on discussing the role of exosomes in photodynamic anticancer therapy, to further enrich and boost the development of PDT.

The Role of Reactive Oxygen Species, Kinases, Hydrogen Sulfide, and Nitric Oxide in the Regulation of Autophagy and Their Impact on Ischemia and Reperfusion Injury in the Heart

2020 ◽  
Vol 16 ◽  
Author(s):  
Andrey Krylatov ◽  
Leonid Maslov ◽  
Sergey Y. Tsibulnikov ◽  
Nikita Voronkov ◽  
Alla Boshchenko ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Hydrogen Sulfide ◽  
Ischemia Reperfusion ◽  
Reactive Oxygen ◽  
Ischemia And Reperfusion ◽  
Oxygen Species ◽  
Ischemia And Reperfusion Injury ◽  
Adaptive Process

: There is considerable evidence in the heart that autophagy in cardiomyocytes is activated by hypoxia/reoxygenation (H/R) or in hearts by ischemia/reperfusion (I/R). Depending upon the experimental model and duration of ischemia, increases in autophagy in this setting maybe beneficial (cardioprotective) or deleterious (exacerbate I/R injury). Aside from the conundrum as to whether or not autophagy is an adaptive process, it is clearly regulated by a number of diverse molecules including reactive oxygen species (ROS), various kinases, hydrogen sulfide (H2S) and nitric oxide (NO). The purpose this review is to address briefly the controversy regarding the role of autophagy in this setting and to examine a variety of disparate molecules that are involved in its regulation.

scholarly journals Oxidation of Terpenoids to Achieve High-Value Flavor and Fragrances—Questioning Microalgae Oxidative Capabilities in the Biotransformation of the Sesquiterpene Valencene and of Selected Natural Apocarotenoids

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 821-830
Author(s):  
Davide De Simeis ◽  
Stefano Serra ◽  
Alessandro Di Fonzo ◽  
Francesco Secundo
Keyword(s):  
Experimental Data ◽  
Natural Products ◽  
Aqueous Medium ◽  
Photochemical Reaction ◽  
Substrate Oxidation ◽  
Market Size ◽  
Chlorella Sp ◽  
General Opinion ◽  
Natural Way

Natural flavor and fragrance market size is expected to grow steadily due to the rising consumer demand of natural ingredients. This market request is guided by the general opinion that the production of natural compounds leads to a reduction of pollution, with inherent advantages for the environment and people’s health. The biotransformation reactions have gained high relevance in the production of natural products. In this context, few pieces of research have described the role of microalgae in the oxidation of terpenoids. In this present study, we questioned the role of microalgal based oxidation in the synthesis of high-value flavors and fragrances. This study investigated the role of three different microalgae strains, Chlorella sp. (211.8b and 211.8p) and Chlorococcum sp. (JB3), in the oxidation of different terpenoid substrates: α-ionone, β-ionone, theaspirane and valencene. Unfortunately, the experimental data showed that the microalgal strains used are not responsible for the substrate oxidation. In fact, our experiments demonstrate that the transformation of the four starting compounds is a photochemical reaction that involves the oxygen as oxidant. Even though these findings cast a shadow on the use of these microorganisms for an industrial purpose, they open a new possible strategy to easily obtain nootkatone in a natural way by just using an aqueous medium, oxygen and light.

Taurine treatment reverses protein malnutrition-induced endothelial dysfunction of the pancreatic vasculature: the role of hydrogen sulfide

Metabolism ◽  
2021 ◽  
pp. 154701
Author(s):  
Daniele M. Guizoni ◽  
Israelle N. Freitas ◽  
Jamaira A. Victorio ◽  
Isabela R. Possebom ◽  
Thiago R. Araujo ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Endothelial Dysfunction ◽  
Protein Malnutrition ◽  
Taurine Treatment

scholarly journals In Situ Generation of Green Hybrid Nanofibrillar Polymer-Polymer Composites—A Novel Approach to the Triple Shape Memory Polymer Formation

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1900
Author(s):  
Ramin Hosseinnezhad ◽  
Iurii Vozniak ◽  
Fahmi Zaïri
Keyword(s):  
Polymer Blends ◽  
Shape Memory ◽  
Shape Memory Polymer ◽  
Cellulose Nanofibers ◽  
Polymeric Materials ◽  
Novel Approach ◽  
Phase Transition Temperatures ◽  
Triple Shape Memory

The paper discusses the possibility of using in situ generated hybrid polymer-polymer nanocomposites as polymeric materials with triple shape memory, which, unlike conventional polymer blends with triple shape memory, are characterized by fully separated phase transition temperatures and strongest bonding between the polymer blends phase interfaces which are critical to the shape fixing and recovery. This was demonstrated using the three-component system polylactide/polybutylene adipateterephthalate/cellulose nanofibers (PLA/PBAT/CNFs). The role of in situ generated PBAT nanofibers and CNFs in the formation of efficient physical crosslinks at PLA-PBAT, PLA-CNF and PBAT-CNF interfaces and the effect of CNFs on the PBAT fibrillation and crystallization processes were elucidated. The in situ generated composites showed drastically higher values of strain recovery ratios, strain fixity ratios, faster recovery rate and better mechanical properties compared to the blend.

scholarly journals Recent Advances in Fabrication of Non-Isocyanate Polyurethane-Based Composite Materials

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3497
Author(s):  
Piotr Stachak ◽  
Izabela Łukaszewska ◽  
Edyta Hebda ◽  
Krzysztof Pielichowski
Keyword(s):  
Raw Materials ◽  
Synthesis Method ◽  
Polymeric Materials ◽  
Original Research ◽  
Significant Group ◽  
Oh Groups ◽  
New Class ◽  
Hazardous Chemical ◽  
Wide Range

Polyurethanes (PUs) are a significant group of polymeric materials that, due to their outstanding mechanical, chemical, and physical properties, are used in a wide range of applications. Conventionally, PUs are obtained in polyaddition reactions between diisocyanates and polyols. Due to the toxicity of isocyanate raw materials and their synthesis method utilizing phosgene, new cleaner synthetic routes for polyurethanes without using isocyanates have attracted increasing attention in recent years. Among different attempts to replace the conventional process, polyaddition of cyclic carbonates (CCs) and polyfunctional amines seems to be the most promising way to obtain non-isocyanate polyurethanes (NIPUs) or, more precisely, polyhydroxyurethanes (PHUs), while primary and secondary –OH groups are being formed alongside urethane linkages. Such an approach eliminates hazardous chemical compounds from the synthesis and leads to the fabrication of polymeric materials with unique and tunable properties. The main advantages include better chemical, mechanical, and thermal resistance, and the process itself is invulnerable to moisture, which is an essential technological feature. NIPUs can be modified via copolymerization or used as matrices to fabricate polymer composites with different additives, similar to their conventional counterparts. Hence, non-isocyanate polyurethanes are a new class of environmentally friendly polymeric materials. Many papers on the matter above have been published, including both original research and extensive reviews. However, they do not provide collected information on NIPU composites fabrication and processing. Hence, this review describes the latest progress in non-isocyanate polyurethane synthesis, modification, and finally processing. While focusing primarily on the carbonate/amine route, methods of obtaining NIPU are described, and their properties are presented. Ways of incorporating various compounds into NIPU matrices are characterized by the role of PHU materials in copolymeric materials or as an additive. Finally, diverse processing methods of non-isocyanate polyurethanes are presented, including electrospinning or 3D printing.

Role of hydrogen sulfide in cerebrovascular alteration during aging

2019 ◽  
Vol 42 (5) ◽  
pp. 446-454 ◽  
Author(s):  
Juyeon Mun ◽  
Hye-Min Kang ◽  
Junyang Jung ◽  
Chan Park
Keyword(s):  
Hydrogen Sulfide
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