The metabolites of Talaromycesflavus: Part 2. Biological activity and biosynthetic studies

1990 ◽  
Vol 68 (11) ◽  
pp. 2095-2101 ◽  
Author(s):  
William A. Ayer ◽  
Julie S. Racok
Keyword(s):  
Hydrogen Peroxide ◽  
Biological Control ◽  
Biological Activity ◽  
Antifungal Activity ◽  
Sodium Acetate ◽  
Soil Fungus ◽  
Water Soluble ◽  
Fungal Metabolites ◽  
Biosynthetic Studies ◽  
Catalyzed Oxidation

The soil fungus Talaromycesflavus (Klöcker) Stolk and Samson is an effective biological control for Verticillium wilt of eggplant (Solanummelongena L.), a disease caused by the fungus Verticilliumdahliae Kleb. The water soluble metabolites isolated from the broth when the fungus is grown in liquid still culture, hydroxymethylmaltol (1), 5,6-dihydro-3,5-dihydroxy-6-hydroxymethyl-2H-pyran-2-one (3), and D-glucono-1,4-lactone (5), do not show antifungal activity against V. dahliae; however, hydrogen peroxide displays this inhibition. This peroxide has been detected in the T. flavus broth and it, together with 5, is the product of the glucose oxidase catalyzed oxidation of D-glucose. The results of the search for this antifungal activity are presented. [1-13C] Labelled sodium acetate was utilized as a precursor for studying the biosynthesis of the T. flavus metabolites 4,6-dihydroxy-5-methylphthalide (7), methyl 4-carboxy-5-hydroxyphthalaldehydate (8), and talaroflavone (9). The incorporation of label into these compounds is discussed. Keywords: Talaromycesflavus, fungal metabolites, hydrogen peroxide, biosynthesis, talaroflavone.

The metabolites of Talaromycesflavus: Part 1. Metabolites of the organic extracts

1990 ◽  
Vol 68 (11) ◽  
pp. 2085-2094 ◽  
Author(s):  
William A. Ayer ◽  
Julie S. Racok
Keyword(s):  
Biological Control ◽  
Verticillium Wilt ◽  
Related Compound ◽  
Soil Fungus ◽  
Higher Order ◽  
Fungal Metabolites ◽  
Organic Extracts

The soil fungus Talaromycesflavus (Klöcker) Stolk and Samson is an effective biological control for Verticillium wilt of eggplant (Solanummelongena L.), a disease caused by the fungus Verticilliumdahliae Kleb. The organic soluble metabolites produced when the fungus is grown in liquid still culture include D-glucono-1,4-lactone (1), 5-hydroxymethylfurfural (5), the previously unreported tetraketides, 4,6-dihydroxy-5-methylphthalide (3) and methyl 4-carboxy-5-hydroxyphthalaldehydate (8), a hexaketide, 7-hydroxy-2,5-dimethylchromone (6), and a metabolite believed to be 3-hydroxymethyl-6,8-dimethoxycoumarin (10). A number of higher order polyketides have been isolated including altenusin (11), dehydroaltenusin (12), and the previously unreported desmethyldehydroaltenusin (14). A structurally and biosynthetically interesting spirocyclic metabolite, which we have named talaroflavone (16), as well as a related compound, deoxytalaroflavone (18), have also been obtained. Keywords: Talaromycesflavus, fungal metabolites, talaroflavone, 4,6-dihydroxy-5-methylphthalide.

Lactoperoxidase-catalyzed oxidation of [4-14C]estradiol

1978 ◽  
Vol 56 (3) ◽  
pp. 203-206 ◽  
Author(s):  
P. H. Jellinck ◽  
Shirley Cleveland
Keyword(s):  
Hydrogen Peroxide ◽  
Water Soluble ◽  
Low Concentrations ◽  
Estradiol Metabolites ◽  
Catalyzed Oxidation ◽  
Effect Of Inhibitors

The conversion of [4-14C]estradiol to water-soluble products by lactoperoxidase (EC 1.11.1.7) in the presence of added or generated H2O2 was studied using albumin or tyrosine as acceptor. The enzyme was able to catalyze the oxidation and binding of estradiol to albumin even in the absence of 2,4-dichlorophenol at very low concentrations of hydrogen peroxide. Other systems in which H2O2 was replaced by oxygen and Mn2+, light-sensitized riboflavin or glutathione was also shown to be active in the conversion of estradiol to water-soluble products and the effect of inhibitors on these reactions was investigated. Possible mechanisms for the peroxidase-catalyzed formation of these estradiol metabolites are discussed.

Neurotoxicity and Neuroprotective Effects of Polyimides (PI) and Polyphenylenevinylene (PPV) against Hydrogen Peroxide (H2O2)

2011 ◽  
Vol 8 (2) ◽  
pp. 33
Author(s):  
Norfaezah Mazalan ◽  
Mazatulikhma Mat Zain ◽  
Nor Saliyana Jumali ◽  
Norhanim Mohalid ◽  
Zurina Shaameri ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Drug Delivery Systems ◽  
Neuronal Cells ◽  
Water Soluble ◽  
Brain Delivery ◽  
Specific Therapy ◽  
Neuroprotective Effects ◽  
Water Soluble Polymer ◽  
Site Specific ◽  
Novel Drugs

Recently, research and development in the field of drug delivery systems (DDS) facilitating site-specific therapy has reached significant progression. DDS based on polymer micelles, coated micro- and nanoparticles, and various prodrug systems including water-soluble polymer have been prepared and extensively studied as novel drugs designed for cancer chemotherapy and brain delivery. Since polymers are going to be used in human, this study has the interest of testing two types of polymer, polyimides (PI) and polyphenylenevinylene (PPV) on neuronal cells. The objective of this study was to determine the possible neurotoxicity and potential neuroprotective effects of PI and PPV towards SH-SY5Y neuronal cells challenged by hydrogen peroxide (H2O2) as an oxidant. Cells were pretreated with either PI or PPV for 1 hour followed by incubation for 24 hour with 100 µM of H2O2. MTS assay was used to assess cell viability. Results show that PI and PPV are not harmful within the concentration up to 10 µM and 100 µM, respectively. However, PI and PPV do not protect neuronal cells against toxicity induced by H2O2 or further up the cell death.

Complexes of Cu (II) with a-Ketoglutaric Acid and 1- (o-tolyl) Biguanide Synthesis, characterization and biological Activity

2019 ◽  
Vol 70 (10) ◽  
pp. 3603-3610
Author(s):  
Madalina Mihalache ◽  
Cornelia Guran ◽  
Aurelia Meghea ◽  
Vasile Bercu ◽  
Ludmila Motelica ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Activity ◽  
Antibacterial Activity ◽  
Biological Activity ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Copper Complexes ◽  
Substrate Adhesion ◽  
Inert Substrate

The three copper complexes having a-ketoglutaric acid (H2A) and 1- (o-tolyl) biguanide (TB) ligands have been synthesized and characterized. The proposed formulas for these complexes are: [Cu(TB)(HA)]Cl (C1), [Cu(TB)(HA)CH3COO]�H2O (C2) and [Cu(TB)(HA)](NO3) (C3) where HA represents deprotonated H2A. The complexes obtained were tested for antibacterial activity against Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa ATCC 27853, antifungal activity on Candida albicans ATCC 10231 and antitumor activity on HeLa tumor cells. Due to the antitumor, antifungal, antimicrobial activity and inhibition of inert substrate adhesion, complexes synthesized could be used for potential therapeutic applications.

scholarly journals Metal-catalyzed oxidation renders silver intensification selective. Applications for the histochemistry of diaminobenzidine and neurofibrillary changes.

1986 ◽  
Vol 34 (12) ◽  
pp. 1667-1672 ◽  
Author(s):  
F Gallyas ◽  
J R Wolff
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidative Polymerization ◽  
Silver Coating ◽  
Neurofibrillary Changes ◽  
Iodide Ions ◽  
Tissue Sections ◽  
Metal Catalyzed Oxidation ◽  
Pre Treatment ◽  
Metal Catalyzed ◽  
Catalyzed Oxidation

Physical developers can increase the visibility of end products of certain histochemical reactions, such as oxidative polymerization of diaminobenzidine and selective binding of complex silver iodide ions to Alzheimer's neurofibrillary changes. Unfortunately, this intensification by silver coating is generally superimposed on a nonspecific staining originating from the argyrophil III reaction, which also takes place when tissue sections are treated with physical developers. The present study reveals that the argyrophil III reaction can be suppressed when tissue sections are treated with certain metal ions and hydrogen peroxide before they are transferred to the physical developer. The selective intensification of Alzheimer's neurofibrillary changes requires a pre-treatment with lanthanum nitrate (10 mM/liter) and 3% hydrogen peroxide for 1 hr. The diaminobenzidine reaction can be selectively intensified when physical development is preceded by consecutive treatments with copper sulfate (10 mM/liter, pH 5, 10 min) and hydrogen peroxide (3%, pH 7, 10 min). In peroxidase histochemistry, this high-grade intensification may help to increase specificity and reduce the threshold of detectability in tracing neurons with horseradish peroxidase or in immunohistochemistry when the peroxidase-antiperoxidase method is used.

The biological activity of glucagon–phospholipid complexes

1983 ◽  
Vol 61 (7) ◽  
pp. 688-691 ◽  
Author(s):  
J. J. Liepnieks ◽  
P. Stoskopf ◽  
E. A. Carrey ◽  
C. Prosser ◽  
R. M. Epand
Keyword(s):  
Biological Activity ◽  
Adenylate Cyclase ◽  
Plasma Membranes ◽  
Bovine Brain ◽  
Water Soluble ◽  
Dipalmitoyl Phosphatidylcholine ◽  
Dimyristoyl Phosphatidylcholine ◽  
Lipoprotein Complex ◽  
Stimulation Of

Glucagon can form water-soluble complexes with phospholipids. The incorporation of glucagon into these lipoprotein particles reduces the biological activity of the hormone. The effect is observed only at temperatures below the phase transition temperature of the phospholipid and results in a decreased stimulation of the adenylate cyclase of rat liver plasma membranes by the lipoprotein complex as compared with the hormone in free solution. Two- to five-fold higher concentrations of glucagon are required for half-maximal stimulation of adenylate cyclase when the hormone is complexed with dimyristoyl phosphatidylcholine, dipalmitoyl phosphatidylcholine, or bovine brain sphingomyelin. A possible role of lipoprotein-associated hormones in the development of insulin resistance is discussed.

ChemInform Abstract: Sulfonic Acid Resin-Catalyzed Oxidation of Aldehydes to Carboxylic Acids by Hydrogen Peroxide.

ChemInform ◽  
2013 ◽  
Vol 44 (29) ◽  
pp. no-no
Author(s):  
Xiaomei Yang ◽  
Si Tang ◽  
Tianliang Lu ◽  
Chen Chen ◽  
Lipeng Zhou ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Carboxylic Acids ◽  
Sulfonic Acid ◽  
Acid Resin ◽  
Catalyzed Oxidation ◽  
Sulfonic Acid Resin

Decoloration of Azo Dyes by Hydrogen Peroxide Catalyzed by Water-Soluble Manganese Porphyrins

1999 ◽  
Vol 69 (12) ◽  
pp. 956-960 ◽  
Author(s):  
J. Tokuda ◽  
R. Ohura ◽  
T. Iwasaki ◽  
Y. Takeuchi ◽  
A. Kashiwada ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Azo Dyes ◽  
Water Soluble ◽  
Manganese Porphyrins

scholarly journals Characterizing Wool Keratin

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Jeanette M. Cardamone ◽  
Alberto Nuñez ◽  
Rafael A. Garcia ◽  
Mila Aldema-Ramos
Keyword(s):  
Hydrogen Peroxide ◽  
Gel Electrophoresis ◽  
Water Soluble ◽  
Alkaline Solutions ◽  
Biodegradable Material ◽  
Alkaline Hydrogen Peroxide ◽  
Cortical Cells ◽  
Sds Page ◽  
Fibrous Matrices ◽  
Wool Keratin

Keratin from wool is a reactive, biocompatible, and biodegradable material. As the biological structural component of skin (soft keratins) and of nails, claws, hair, horn, feathers, and scales (hard keratins) pure keratin comprises up to 90% by weight of wool. Wool was treated in alkaline solutions to extract from 68% to 82% keratin within 2 to 5 hours of exposure at . The keratin products were water-soluble and were confirmed to contain intermediate filament and microfibrillar component-proteins of fractured, residual cuticle, and cortical cells. Oxidation of wool by peroxycarboximidic acid in alkaline hydrogen peroxide produced keratin products with distinct microcrystalline structures: descaled fibers, fibrous matrices, and lyophilized powders. Morphology and confirmation of peptide functionality were documented by SEM, Amino Acid Analysis, SDS-PAGE gel electrophoresis, MALDI-TOF/TOF, and FTIR analyses. The reactivity of keratin from wool models the reactivity of keratin from low-value sources such as cattle hair.

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