Detection and Characterization of Viroids via Biological Assays on Herbaceous Hosts

2021 ◽  
pp. 23-28
Author(s):  
Rosemarie W. Hammond
Keyword(s):  
Biological Assays

scholarly journals Isolation and Characterization of Strain Exiguobacterium sp. KRL4, a Producer of Bioactive Secondary Metabolites from a Tibetan Glacier

2021 ◽  
Vol 9 (5) ◽  
pp. 890
Author(s):  
Pietro Tedesco ◽  
Fortunato Palma Esposito ◽  
Antonio Masino ◽  
Giovanni Andrea Vitale ◽  
Emiliana Tortorella ◽  
...  
Keyword(s):  
Phenotypic Analysis ◽  
Biological Assays ◽  
C Elegans ◽  
Isolation And Characterization ◽  
Wide Range ◽  
Protein Encoding ◽  
Nematocidal Activity ◽  
Extremophilic Microorganisms ◽  
Unique Source

Extremophilic microorganisms represent a unique source of novel natural products. Among them, cold adapted bacteria and particularly alpine microorganisms are still underexplored. Here, we describe the isolation and characterization of a novel Gram-positive, aerobic rod-shaped alpine bacterium (KRL4), isolated from sediments from the Karuola glacier in Tibet, China. Complete phenotypic analysis was performed revealing the great adaptability of the strain to a wide range of temperatures (5–40 °C), pHs (5.5–8.5), and salinities (0–15% w/v NaCl). Genome sequencing identified KRL4 as a member of the placeholder genus Exiguobacterium_A and annotation revealed that only half of the protein-encoding genes (1522 of 3079) could be assigned a putative function. An analysis of the secondary metabolite clusters revealed the presence of two uncharacterized phytoene synthase containing pathways and a novel siderophore pathway. Biological assays confirmed that the strain produces molecules with antioxidant and siderophore activities. Furthermore, intracellular extracts showed nematocidal activity towards C. elegans, suggesting that strain KRL4 is a source of anthelmintic compounds.

scholarly journals Synthesis and Characterization of Novel Ruthenium(III) Complexes with Histamine

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Jakob Kljun ◽  
Saša Petriček ◽  
Dušan Žigon ◽  
Rosana Hudej ◽  
Damijan Miklavčič ◽  
...  
Keyword(s):  
Cancer Treatment ◽  
Side Chain ◽  
Synthesis And Characterization ◽  
Medical Applications ◽  
Amino Group ◽  
Heterocyclic Derivative ◽  
Biological Assays ◽  
X Ray ◽  
Protonated Amino Group

Novel ruthenium(III) complexes with histamine[RuCl4(dmso-S)(histamineH)]⋅O(1a) and[RuCl4(dmso-S)(histamineH)](1b) have been prepared and characterized by X-ray structure analysis. Their crystal structures are similar and show a protonated amino group on the side chain of the ligand which is not very common for a simple heterocyclic derivative such as histamine. Biological assays to test the cytotoxicity of the compound1bcombined with electroporation were performed to determine its potential for future medical applications in cancer treatment.

Comparative Characterization of Microbiological and Biological Assays of Protein Quality of Some Foodstuffs

Nahrung/Food ◽  
1974 ◽  
Vol 18 (3) ◽  
pp. 243-249 ◽  
Author(s):  
S. G. Kharatyan ◽  
M. G. Kerimova ◽  
A. D. Ignatyev ◽  
M. E. Rozhansky
Keyword(s):  
Protein Quality ◽  
Biological Assays ◽  
Comparative Characterization

scholarly journals Functional characterization of synthetic leukotriene B and its stereochemical isomers.

1981 ◽  
Vol 154 (4) ◽  
pp. 1243-1248 ◽  
Author(s):  
R A Lewis ◽  
E J Goetzl ◽  
J M Drazen ◽  
N A Soter ◽  
K F Austen ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Neutrophil Infiltration ◽  
Eicosatetraenoic Acid ◽  
Human Neutrophils ◽  
Racemic Mixture ◽  
Hydroxyl Groups ◽  
Biological Assays ◽  
Neutrophil Chemotactic Activity

Leukotriene B (LTB), a potent lipid chemotactic factor for neutrophils, is 5S,12R-dihydroxy-6,14-cis,8,10-trans-eicosatetraenoic acid (Fig 1), based upon direct comparison of natural LTB with synthetic 5S,12R-dihydroxy-6,8,10,14-eicosatetraenoic acid (5,12-di-HETE) stereoisomers in three biological assays. Of the six synthetic stereoisomers evaluated, only the 5S,12R,6,14-cis,8,10-trans compound had chemotactic potency for human neutrophils in vitro that was comparable to that of natural LTB, with a concentration of 3 X 10(9-9) M eliciting a one-half maximum response. In contrast, the racemic mixture of 5R,12R- and 5S,12S-6,10-trans,8,14-cis, the racemic mixture of 5S,12R- and 5R,12S-6,10-trans,8,14-cis, the 5S,12R-6,8-trans,10,14-cis, the 5S,12R-6,8,10-trans,14-cis, and the 5S,12S-6,8,10-trans,14-cis stereoisomers required concentrations of 3 X 10(-7) to 1 X 10(-6) M to elicit comparable responses. Only natural LTB and its synthetic counterpart elicited a local neutrophil infiltration when injected into the skin of the rhesus monkey at 10 ng and 100 ng per site. Natural and synthetic LTB at a concentration of 3 X 10(-8) M each provoked an EC25 contractile response of guinea pig pulmonary parenchymal strips in vitro, whereas the other four tested stereoisomers of 5,12-di-HETE were inactive at this concentration. Structure-function analyses suggest that the neutrophil chemotactic activity depends critically upon the C-1 to C-12 domain, including the stereochemistry of the 6-,8-,and 10-olefinic bonds and the presence of both hydroxyl groups.

scholarly journals Absolute Configuration Reassignment of Natural Products: An Overview of the Last Decade

2021 ◽  
Author(s):  
Andrea Batista ◽  
Bianca Angrisani ◽  
Maria Emanuelle Lima ◽  
Stephanie da Silva ◽  
Vitória Schettini ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Natural Products ◽  
Magnetic Resonance ◽  
Organic Synthesis ◽  
Absolute Configuration ◽  
Biological Assays ◽  
Crucial Step ◽  
X Ray ◽  
X Ray Crystallography

The assignment of absolute configuration (AC) is a crucial step in the structural characterization of natural products, especially for those subjected to biological assays. Methods such as X-ray crystallography, stereocontrolled organic synthesis, nuclear magnetic resonance (NMR), and chiroptical spectroscopies are commonly used to determine the AC of chiral natural compounds. Even with these well-established techniques, however, unambiguous stereochemical assignments of natural products remain a challenge, resulting in an increasing number of structural misassignments being reported every year. Herein, we will present the main techniques that have been used in AC reassignments of natural products over the last 10 years, along with some selected examples. Special attention will be paid to the strengths and weaknesses of each approach. With this, we expect to provide the readers with critical information to help them to choose the appropriate methods for correct AC determinations.

In Vitro and Ex Vivo Characterization of Sigma-1 and Sigma-2 Receptors: Agonists and Antagonists in Biological Assays

2009 ◽  
Vol 9 (3) ◽  
pp. 161-171 ◽  
Author(s):  
Nicola Colabufo ◽  
Marialessandra Contino ◽  
Carmela Inglese ◽  
Mauro Niso ◽  
Roberto Perrone ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Biological Assays ◽  
Sigma 1

scholarly journals Sesquiterpene Lactones, Acyl Phenyl Propanoids and Other Constituents from Schkuhria pinnata var. wislizeni. Antioxidant Evaluation

2019 ◽  
Vol 53 (3) ◽  
Author(s):  
Alejandra León ◽  
Blanca M. Reyes ◽  
María Isabel Chávez ◽  
Rubén A. Toscano ◽  
Guillermo Delgado
Keyword(s):  
Antioxidant Activity ◽  
Spectroscopic Analysis ◽  
Sesquiterpene Lactones ◽  
Diels Alder ◽  
Chemical Investigation ◽  
Biological Assays ◽  
Aerial Parts ◽  
Antioxidant Evaluation ◽  
Alder Adduct

Chemical investigation of aerial parts of Schkuhria pinnata var wislizeni (Asteraceae) allowed the characterization of the sesquiterpene lactones 1, 2 and 5, the flavonoids 3 and 4, and the acyl phenyl propanoids 10 and 11. Structure 2, named dischkuhriolin, was confirmed as a Diels Alder adduct of 1 as dienophile and a guaianolide as diene. Spectroscopic analysis of 5 and its diacetyl derivative allowed the structural correction of compounds previously reported from Schkuhria. 2, 10 and 11 are new natural compounds. Biological assays indicated that the mixture 10 + 11 showed antioxidant activity expressed as inhibition of AAPH-induced damage in rat pancreatic homogenate.

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