scholarly journals Biological Activities of Novel Gyrase Inhibitors of the Aminocoumarin Class

2008 ◽  
Vol 52 (6) ◽  
pp. 1982-1990 ◽  
Author(s):  
Christine Anderle ◽  
Martin Stieger ◽  
Matthew Burrell ◽  
Stefan Reinelt ◽  
Anthony Maxwell ◽  
...  

ABSTRACT Thirty-one aminocoumarin antibiotics derived from mutasynthesis experiments were investigated for their biological activities. Their inhibitory activities toward Escherichia coli DNA gyrase were determined in two different in vitro assays: an ATPase assay and a DNA supercoiling assay. The assays gave a similar rank order of the activities of the compounds tested, although the absolute 50% inhibitory concentrations (IC50s) obtained in each assay were different. To confirm that the compounds also acted as gyrase inhibitors in vivo, reporter gene assays were carried out with E. coli by using gyrA and sulA promoter fusions with the luxCDABE operon. A strong induction of both promoters was observed for those compounds that showed gyrase inhibitory activity in the biochemical assays. Compounds carrying analogs of the prenylated benzoyl moiety (ring A) of clorobiocin that were structurally very different showed high levels of activity both in the biochemical assay and in the reporter gene assay, indicating that the structure of this moiety can be varied considerably without a loss of affinity for bacterial gyrase. The experimentally determined IC50s were compared to the binding energies calculated in silico, which indicated that a shift of the pyrrole carboxylic acid moiety from the O-3″ to the O-2″ position of the deoxysugar moiety has a significant impact on the binding mode of the compounds. The aminocoumarin compounds were also investigated for their MICs against different bacterial pathogens. Several compounds showed high levels of activity against staphylococci, including a methicillin-resistant Staphylococcus aureus strain. However, they showed only poor activities against gram-negative strains.

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Alberto Celma ◽  
Geeta Mandava ◽  
Agneta Oskarsson ◽  
Juan Vicente Sancho ◽  
Lubertus Bijlsma ◽  
...  

Abstract Background Fresh water bodies represent less than 1% of overall amount of water on earth and ensuring their quality and sustainability is pivotal. Although several campaigns have been performed to monitor the occurrence of micropollutants by means of chemical analysis, this might not cover the whole set of chemicals present in the sample nor the potential toxic effects of mixtures of natural and anthropogenic chemicals. In this sense, by selecting relevant toxicity endpoints when performing in vitro bioanalysis, effect-based methodologies can be of help to perform a comprehensive assessment of water quality and reveal biological activities relevant to adverse health effects. However, no prior bioanalytical study was performed in wetland water samples from the Spanish Mediterranean coastline. Methods Eleven samples from relevant water bodies from the Spanish Mediterranean coastline were collected to monitor water quality on 8 toxicity endpoints. Aryl hydrocarbon receptor (AhR), androgenicity (AR+ and AR−), estrogenicity (ER+ and ER−), oxidative stress response (Nrf2) and vitamin D receptor (VDR+ and VDR−) reporter gene assays were evaluated. Results AhR was the reporter gene assay showing a more frequent response over the set of samples (activated by 9 out of 11 samples), with TCDD-eq in the range 7.7–22.2 pM. For AR, ER and VDR assays sporadic activations were observed. Moreover, no activity was observed on the Nrf2 reporter gene assay. Wastewater and street runaway streams from Valencia could be responsible for enhanced activities in one of the water inputs in the Natural Park ‘L’Albufera’. Conclusions Water quality of relevant wetlands from the Spanish Mediterranean coastline has been evaluated. The utilization of a panel of 5 different bioassays to cover for different toxicity endpoints has demonstrated to be a good tool to assess water quality.


2015 ◽  
Vol 49 (10) ◽  
pp. 6319-6326 ◽  
Author(s):  
Masaru Ihara ◽  
Tomokazu Kitamura ◽  
Vimal Kumar ◽  
Chang-Beom Park ◽  
Mariko O. Ihara ◽  
...  

1996 ◽  
Vol 23 (1) ◽  
pp. 75 ◽  
Author(s):  
SR Mudge ◽  
WR Lewis-Henderson ◽  
RG Birch

Luciferase genes from Vibrio harveyi (luxAB) and firefly (luc) were introduced into E. coli, Agrobacteriurn, Arabidopsis and tobacco. Transformed bacteria and plants were quantitatively assayed for luciferase activity using a range of in vitro and in vivo assay conditions. Both lux and luc proved efficient reporter genes in bacteria, although it is important to be aware that the sensitive assays may detect expression due to readthrough from distant promoters. LUX activity was undetectable by liquid nitrogen-cooled CCD camera assays on intact tissues of plants which showed strong luxAB expression by in vitro assays. The decanal substrate for the lux assay was toxic to many plant tissues, and caused chemiluminescence in untransformed Arabidopsis leaves. These are serious limitations to application of the lux system for sensitive, non-toxic assays of reporter gene expression in plants. In contrast, LUC activity was readily detectable in intact tissues of all plants with luc expression detectable by luminometer assays on cell extracts. Image intensities of luc-expressing leaves were commonly two to four orders of magnitude above controls under the CCD camera. Provided adequate penetration of the substrate luciferin is obtained, luc is suitable for applications requiring sensitive, non-toxic assays of reporter gene expression in plants.


2019 ◽  
Vol 20 (18) ◽  
pp. 4512 ◽  
Author(s):  
Alberto Jorge Oliveira Lopes ◽  
Cleydlenne Costa Vasconcelos ◽  
Francisco Assis Nascimento Pereira ◽  
Rosa Helena Moraes Silva ◽  
Pedro Felipe dos Santos Queiroz ◽  
...  

The stingless bee, Melipona fasciculata Smith (Apidae, Meliponini), is a native species from Brazil. Their products have high biotechnological potential, however there are no studies about the biological activities of pollen collected by M. fasciculata. In this context, the present study investigated the chemical composition, anti-oxidant, anti-inflammatory, and analgesic activities of hydroethanolic pollen extracts collected by M. fasciculata in three cities in Maranhão State, Brazil. We verified the antioxidant activity of the extracts and inhibitory activity against the cyclooxygenase enzyme using in vitro assays and in allowed to select the extract with higher efficiency to be used on in vivo assays. In these trials, the selected extract showed high anti-inflammatory activity as well as nociceptive effects at central and peripheral level, suggesting that this extract acts on inhibition of histamine release and decreased synthesis of prostaglandins and the in-silico study suggested that polyphenols and acids fatty acids in the extract may be associated with these activities. The results of the present study report the high biological potential of pollen extract and we conclude that the pollen collected by M. fasciculata can be considered as the object of research for new pharmacological alternatives.


1979 ◽  
Vol 82 (2) ◽  
pp. 253-262 ◽  
Author(s):  
M. R. SAIRAM

SUMMARY A modified bovine testicular receptor was used to evaluate highly purified follicle-stimulating hormone (FSH) from a number of species. The particulate receptor obtained from adult bovine testes could be stored frozen or lyophilized for long periods without appreciable decrease in the binding of the ligand facility or in loss of specificity. The bovine testis receptor binds twice as much 125I-labelled ovine FSH as 125I-labelled human hormone. When FSH from different species was compared against NIH-FSH-S10, using various FSH ligands, the ovine hormone was clearly the most active, although many had comparable in-vivo biological potencies. The results suggest that there is probably some species specificity in the hormone–receptor interactions. As the ovine hormone is structurally closer to the bovine, from which the receptor was derived, it appears to have the highest activity in vitro. Marked differences in the biological activities of the different preparations between the human chorionic gonadotrophin-augmentation test and the in-vitro assays have been observed. In the in-vitro assays, all preparations, with the exception of the porcine hormone preparation, were less active and the ratio of bioassay/radioreceptor assay varied widely. In the radioreceptor assays, all FSH preparations except pregnant mare serum gonadotrophin (PMSG) showed parallel inhibition curves. The three different PMSG preparations examined gave inhibition lines that were parallel to each other.


Foods ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 220 ◽  
Author(s):  
María Ángeles Toledano Medina ◽  
Tania Merinas-Amo ◽  
Zahira Fernández-Bedmar ◽  
Rafael Font ◽  
Mercedes del Río-Celestino ◽  
...  

White and three types of black garlic (13, 32, and 45 days of aging, named 0C1, 1C2, and 2C1, respectively) were selected to study possible differences in their nutraceutic potential. For this purpose, garlic were physicochemically characterized (Brix, pH, aW, L, polyphenol, and antioxidant capacity), and both in vivo and in vitro assays were carried out. Black garlic samples showed higher polyphenol content and antioxidant capacity than the white ones. The biological assays showed that none of the samples (neither raw nor black garlic) produced toxic effects in the Drosophila melanogaster animal genetic model, nor exerted protective effects against H2O2, with the exception of the 0C1 black garlic. Moreover, only white garlic was genotoxic at the highest concentration. On the other hand, 0C1 black garlic was the most antigenotoxic substance. The in vivo longevity assays showed significant extension of lifespan at some concentrations of white and 0C1and 1C2 black garlic. The in vitro experiments showed that all of the garlic samples induced a decrease in leukemia cell growth. However, no type of garlic was able to induce proapoptotic internucleosomal DNA fragmentation. Taking into account the physicochemical and biological data, black garlic could be considered a potential functional food and used in the preventive treatment of age-related diseases. In addition, our findings could be relevant for black-garlic-processing agrifood companies, as the economical and timing costs can significantly be shortened from 45 to 13 days of aging.


2000 ◽  
Vol 21 (1) ◽  
pp. 5-22 ◽  
Author(s):  
Matthew P. Rose ◽  
Rose E. Gaines Das ◽  
Adam H. Balen

Abstract FSH has a key role in the development and function of the reproductive system and is widely used both diagnostically and therapeutically in developmental and reproductive medicine. The accurate measurement of FSH levels, in patients for diagnosis and monitoring and in therapeutic preparations for clinical use, is essential for safe and successful treatment. Historically, FSH was defined on the basis of classical in vivo endocrine activity, and early therapeutic preparations were calibrated using in vivo bioassays. There was early recognition that reference preparations were required for calibration if the results from different laboratories were to be comparable. In response to the perceived need, the World Health Organization established the first standard for such preparations in 1959. Subsequent developments in biotechnology have led to recognition that there is no single molecule that can be uniquely defined as FSH, and that FSH can induce a range of biological activities. Several highly purified standards for FSH are now available, but discontinuity and heterogeneity of estimates of FSH activity in terms of these standards made using in vitro assays and binding assays have been noted. It is thus essential that any measurement of FSH include specification both of the standard with which the measured FSH is compared and the assay method used for that comparison.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1201
Author(s):  
Ana Flavia Burlec ◽  
Łukasz Pecio ◽  
Solomiia Kozachok ◽  
Cornelia Mircea ◽  
Andreia Corciovă ◽  
...  

Tagetes erecta L. is a popular ornamental plant of the Asteraceae family, which is widely cultivated not only for its decorative use, but also for the extraction of lutein. Besides carotenoid representatives, which have been extensively studied, other important classes of secondary metabolites present in the plant, such as polyphenols, could exhibit important biological activities. The phytochemical analysis of a methanolic extract obtained from T. erecta inflorescences was achieved using liquid chromatography–mass spectrometry (LC-MS) techniques. The extract was further subjected to a multistep purification process, which allowed the separation of different fractions. The total extract and its fractions contain several polyphenolic compounds, such as hydroxybenzoic and hydroxycinnamic acid derivatives, flavonols (especially quercetagetin glycosides), and several aglycons (e.g., quercetin, patuletin). One of the fractions, containing mostly quercetagitrin, was subjected to two different antioxidant assays (metal chelating activity and lipoxygenase inhibition) and to in vitro cytotoxicity assessment. Generally, the biological assays showed promising results for the investigated fraction compared to the initial extract. Given the encouraging outcome of the in vitro assays, further purification and structural analysis of compounds from T. erecta extracts, as well as further in vivo investigations are justified.


Processes ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 485
Author(s):  
Tania Merinas-Amo ◽  
Rocío Merinas-Amo ◽  
Rafael Font ◽  
Mercedes del Río Celestino ◽  
Ángeles Alonso-Moraga

Although many benefits drawn from beer consumption are claimed, the epidemiological records are contradictory with respect to cancer prevention. The purpose of this study was to investigate the possible health-related activities involving genome safety and the ageing processes of two types of lyophilised ale beers (blond and stout), as well as two of their bioactive compounds (tyrosol and iso-alpha humulone). A multipurpose trial set of in vivo toxicity, antitoxicity, mutagenicity, antimutagenicity, lifespan and healthspan assays using Drosophila melanogaster were used. In parallel, several in vitro assays were designed using the cancer cell line HL-60 in order to establish the possible chemopreventive activity of the selected substances, where epigenetic modulation of DNA methylation changes, clastogenic activity and tumour cell inhibition growth were evaluated. The safety of the four substances was confirmed: lyophilised blond ale beer (LBAB), lyophilised stout ale beer (LSAB), tyrosol and iso-alpha humulone were neither toxic nor genotoxic. Moreover, all substances, except tyrosol, revealed the ability to protect individual genomes against oxidative radicals and to exert antimutagenic activity against the genotoxin hydrogen peroxide. With respect to the degenerative process indicators of lifespan and healthspan, tyrosol was the only compound that did not exert any influence on the life extension of Drosophila; LBAB induced a significant lifespan extension in D. melanogaster; LSAB and its distinctive compound iso-alpha humulone induced a reduction in longevity. The in vitro assays showed the cytotoxic activity of LBAB, LSAB and tyrosol against HL-60 cells. Moreover, proapoptotic DNA fragmentation or DNA strand breakage was observed for both types of beers and iso-alpha humulone at different concentrations. Furthermore, the lyophilised ale beers and tyrosol exhibited an increasing genome-wide methylation status, while iso-alpha humulone exhibited a demethylation status in repetitive cancer cell sequences. Although the biological activities assigned to beer consumption cannot be linked to any specific molecule/element due to the complexity of the phenolic profile, as well as the multifactor brewing process, the results obtained let us propose lyophilised ale beers as safe potential nutraceutical beverages when consumed in moderate amounts. The prevention of toxicity and genetic oxidative damage, as well as the induction of tumor cell death and modulation of the methylation status, are the key activities of beer that were shown in the present research.


Marine Drugs ◽  
2020 ◽  
Vol 18 (6) ◽  
pp. 326
Author(s):  
Dawrin Pech-Puch ◽  
Mar Pérez-Povedano ◽  
Marta Martinez-Guitian ◽  
Cristina Lasarte-Monterrubio ◽  
Juan Carlos Vázquez-Ucha ◽  
...  

The pyrrole-imidazoles, a group of alkaloids commonly found in marine sponges belonging to the genus Agelas, display a wide range of biological activities. Herein, we report the first chemical study of the secondary metabolites of the sponge A. dilatata from the coastal area of the Yucatan Peninsula (Mexico). In this study, we isolated eight known alkaloids from an organic extract of the sponge. We used NMR and MS analysis and comparison with existing databases to characterize the alkaloids: ageliferin (1), bromoageliferin (2), dibromoageliferin (3), sceptrin (4), nakamuric acid (5), 4-bromo-1H-pyrrole-2-carboxylic acid (6), 4,5-dibromopyrrole-2-carboxylic acid (7) and 3,7-dimethylisoguanine (8). We also evaluated, for the first time, the activity of these alkaloids against the most problematic multidrug-resistant (MDR) pathogens, i.e., the Gram-negative bacteria Pseudomonas aeruginosa, Klebsiella pneumoniae and Acinetobacter baumannii. Bromoageliferin (2) displayed significant activity against P. aeruginosa. Comparison of the antibacterial activity of ageliferins 1–3 (of similar structure) against P. aeruginosa revealed some relationship between structure and activity. Furthermore, in in vitro assays, 2 inhibited growth and biofilm production in clinical strains of P. aeruginosa. Moreover, 2 increased the survival time in an in vivo Galleria mellonella model of infection. The findings confirm bromoageliferin (2) as a potential lead for designing new antibacterial drugs.


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