Biological activities and secondary structures of variant forms of human salivary cystatin SN produced in Escherichia coli

The work exposed in this paper joins in the research of medecine by means of the modelling by digital simulation (method in silico). This method allows to plan the biological activities of new molecules and to design others more active than existing molecules against a given infection . The generated and validated models are used here in the research for molecules potentially more active against Escherichia coli which causes diarrheic infections at the human beings. Here, we report works the synthesis of our works of structural determination, of forecast of biological activity and conception of molecules bioactive again Eschericha coli.

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Thymus mastichina: Composition and Biological Properties with a Focus on Antimicrobial Activity

Pharmaceuticals ◽

10.3390/ph13120479 ◽

2020 ◽

Vol 13 (12) ◽

pp. 479

Author(s):

Márcio Rodrigues ◽

Ana Clara Lopes ◽

Filipa Vaz ◽

Melanie Filipe ◽

Gilberto Alves ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Activity ◽

Antioxidant Activity ◽

Essential Oil ◽

Biological Activities ◽

Scientific Information ◽

Biological Properties ◽

Fusarium Spp ◽

Candida Spp ◽

Pharmaceutical Industries

Thymus mastichina has the appearance of a semishrub and can be found in jungles and rocky lands of the Iberian Peninsula. This work aimed to review and gather available scientific information on the composition and biological properties of T. mastichina. The main constituents of T. mastichina essential oil are 1,8-cineole (or eucalyptol) and linalool, while the extracts are characterized by the presence of flavonoids, phenolic acids, and terpenes. The essential oil and extracts of T. mastichina have demonstrated a wide diversity of biological activities. They showed antibacterial activity against several bacteria such as Escherichia coli, Proteus mirabilis, Salmonella subsp., methicillin-resistant and methicillin-sensitive Staphylococcus aureus, Listeria monocytogenes EGD, Bacillus cereus, and Pseudomonas, among others, and antifungal activity against Candida spp. and Fusarium spp. Additionally, it has antioxidant activity, which has been evaluated through different methods. Furthermore, other activities have also been studied, such as anticancer, antiviral, insecticidal, repellent, anti-Alzheimer, and anti-inflammatory activity. In conclusion, considering the biological activities reported for the essential oil and extracts of T. mastichina, its potential as a preservative agent could be explored to be used in the food, cosmetic, or pharmaceutical industries.

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Analysis of Pyrrolizidine Alkaloids and Evaluation of Some Biological Activities of Algerian Senecio Delphinifolius (Asteraceae)

Natural Product Communications ◽

10.1177/1934578x1300800406 ◽

2013 ◽

Vol 8 (4) ◽

pp. 1934578X1300800 ◽

Cited By ~ 2

Author(s):

Soukaina Tidjani ◽

Philippe N. Okusa ◽

Amar Zellagui ◽

Laetitia Moreno Y Banuls ◽

Caroline Stévigny ◽

...

Keyword(s):

Escherichia Coli ◽

Cytotoxic Effect ◽

Pyrrolizidine Alkaloids ◽

Antibacterial Effect ◽

Biological Activities ◽

Human Tumor ◽

Tumor Cell Lines ◽

Human Tumor Cell ◽

Human Tumor Cell Lines ◽

Butanolic Extract

Although Senecio species are known as sources of potentially toxic pyrrolizidine alkaloids (PAs), some species of this genus are traditionally used as remedies, notably in Algeria. In this paper, the evaluation of biological activities and the analysis of PAs of Algerian specimens of Senecio delphinifolius Vahl are reported. The n-butanolic extract of the herb showed a weak antibacterial effect against Escherichia coli with a MIC of 1 mg/mL, but was inactive against Staphylococcus aureus and Pseudomonas aeruginosa. The n-butanolic extracts of the roots, stems and herb showed a modest antioxidant activity, scavenging the free radical DPPH with respective IC50 values of 55.3, 50.2 and 13.3 μg/mL. A cytotoxic effect against a series of human tumor cell lines was observed with the n-butanolic extract from stems (IC50 ranging between 34 and 88 μg/mL). The herb of the evaluated sample contains 140 ppm of PAs (senecionine, seneciphylline, integerrimine, senkirkine) and PA-related alkaloids (dehydrosenkirkine and neosenkirkine). As the major PAs belong to the toxic series (1,2-unsaturation in the pyrrolizidine cycle and macrocyclic diester), the use of S. delphinifolius should be discouraged in traditional medicine.

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In vivo characterization of the activities of novel cyclodipeptide oxidases: new tools for increasing chemical diversity of bioproduced 2,5-diketopiperazines in Escherichia coli

Microbial Cell Factories ◽

10.1186/s12934-020-01432-y ◽

2020 ◽

Vol 19 (1) ◽

Author(s):

Fabien Le Chevalier ◽

Isabelle Correia ◽

Lucrèce Matheron ◽

Morgan Babin ◽

Mireille Moutiez ◽

...

Keyword(s):

Escherichia Coli ◽

Biological Activities ◽

Gene Clusters ◽

Chemical Diversity ◽

E Coli ◽

Chemical Structures ◽

In Vivo Characterization ◽

Culture Supernatants

Abstract Background Cyclodipeptide oxidases (CDOs) are enzymes involved in the biosynthesis of 2,5-diketopiperazines, a class of naturally occurring compounds with a large range of pharmaceutical activities. CDOs belong to cyclodipeptide synthase (CDPS)-dependent pathways, in which they play an early role in the chemical diversification of cyclodipeptides by introducing Cα-Cβ dehydrogenations. Although the activities of more than 100 CDPSs have been determined, the activities of only a few CDOs have been characterized. Furthermore, the assessment of the CDO activities on chemically-synthesized cyclodipeptides has shown these enzymes to be relatively promiscuous, making them interesting tools for cyclodipeptide chemical diversification. The purpose of this study is to provide the first completely microbial toolkit for the efficient bioproduction of a variety of dehydrogenated 2,5-diketopiperazines. Results We mined genomes for CDOs encoded in biosynthetic gene clusters of CDPS-dependent pathways and selected several for characterization. We co-expressed each with their associated CDPS in the pathway using Escherichia coli as a chassis and showed that the cyclodipeptides and the dehydrogenated derivatives were produced in the culture supernatants. We determined the biological activities of the six novel CDOs by solving the chemical structures of the biologically produced dehydrogenated cyclodipeptides. Then, we assessed the six novel CDOs plus two previously characterized CDOs in combinatorial engineering experiments in E. coli. We co-expressed each of the eight CDOs with each of 18 CDPSs selected for the diversity of cyclodipeptides they synthesize. We detected more than 50 dehydrogenated cyclodipeptides and determined the best CDPS/CDO combinations to optimize the production of 23. Conclusions Our study establishes the usefulness of CDPS and CDO for the bioproduction of dehydrogenated cyclodipeptides. It constitutes the first step toward the bioproduction of more complex and diverse 2,5-diketopiperazines.

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Biological Characterization of Endotoxins Released from Antibiotic-Treated Pseudomonas aeruginosa and Escherichia coli

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.42.5.1015 ◽

1998 ◽

Vol 42 (5) ◽

pp. 1015-1021 ◽

Cited By ~ 18

Author(s):

Teruo Kirikae ◽

Fumiko Kirikae ◽

Shinji Saito ◽

Kaoru Tominaga ◽

Hirohi Tamura ◽

...

Keyword(s):

Escherichia Coli ◽

Pseudomonas Aeruginosa ◽

Lipid A ◽

Biological Activities ◽

Polymyxin B ◽

Mitogen Activated Protein Kinase ◽

No Production ◽

Endotoxic Activity

ABSTRACT The supernatants taken from Pseudomonas aeruginosa andEscherichia coli cultures in human sera or chemically defined M9 medium in the presence of ceftazidime (CAZ) contained high levels of endotoxin, while those taken from the same cultures in the presence of imipenem (IPM) yielded a very low level of endotoxin. The biological activities of endotoxin in the supernatants were compared with those of phenol water-extracted lipopolysaccharide (LPS). The endotoxin released from the organisms as a result of CAZ treatment (CAZ-released endotoxin) contained a large amount of protein. The protein, however, lacked endotoxic activity, since the endotoxin did not show any in vivo toxic effects in LPS-hyporesponsive C3H/HeJ mice sensitized with d-(+)-galactosamine (GalN) or any activation of C3H/HeJ mouse macrophages in vitro. The activities of CAZ- and IPM-released endotoxin (as assessed by a chromogenicLimulus test) were fundamentally the same as those ofP. aeruginosa LPS, since their regression lines were parallel. The CAZ-released endotoxin was similar to purified LPS with respect to the following biological activities in LPS-responsive C3H/HeN mice and LPS-hyporesponsive C3H/HeJ mice: lethal toxicity in GalN-sensitized mice, in vitro induction of tumor necrosis factor- and NO production by macrophages, and mitogen-activated protein kinase activation in macrophages. The macrophage activation by CAZ-released endotoxin as well as LPS was mainly dependent on the presence of serum factor and CD14 antigen. Polymyxin B blocked the activity. These findings indicate that the endotoxic activity of CAZ-released endotoxin is due primarily to LPS (lipid A).

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