Search results for " metabolite"
showing 10 items of 122 documents
Metabolic activation to a mutagen of 3-hydroxy-trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene, a secondary metabolite of benzo[a]pyrene
1987
3-Hydroxy-trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (3-OH-BP-7,8-diol) was isolated from arylsulfatase/beta-glucuronidase-treated bile of rats to which 3-hydroxybenzo[a]pyrene (3-OH-BP) has been administered. This triol was investigated for mutagenicity in Salmonella typhimurium (reversion to histidine prototrophy of strains TA 97, TA 98, TA 100 and TA 1537) and in V79 Chinese hamster cells (acquisition of resistance to 6-thioguanine). When no exogenous metabolizing system was added the triol was inactive, while 3-OH-BP showed weak mutagenic effects with all four bacterial strains. In the presence of NADPH-fortified postmitochondrial supernatant fraction (S9 mix) of liver homogenate fro…
Synergistic platelet antiaggregatory effects of the adenylate cyclase activator iloprost and the guanylate cyclase activating agent SIN-1 in vivo
1993
The aim of our study was to evaluate the platelet antiaggregatory and hemodynamic effects of the stable prostacyclin analog iloprost and the NO-donor SIN-1, an active metabolite of molsidomine. The number of circulating platelets was determined in anesthetized male Wistar rats as a measure of in vivo platelet aggregation. Platelet count decreased from 648 +/- 25 to 476 +/- 15 x 10(3) platelets/microliter and from 578 +/- 36 to 411 +/- 40 (mean +/- SEM) in response to two repetitive injections of collagen (70 micrograms/kg body weight). Treatment with SIN-1 bolus injections (0.3 or 1 mg/kg bw) and/or continuous i.v. infusion of iloprost (0.2 or 0.4 micrograms/kg bw/min) was initiated 15 min …
Lipid peroxidation and nitric oxide metabolites in a group of subjects with obstructive sleep apnea syndrome.
2015
It is known that in OSAS the plasma lipid peroxidation has an opposite behavior in comparison with nitric oxide metabolites. In the re-examination of our survey of OSAS subjects we calculated the ratio between thiobarbituric acid reactive substances (TBARS) and nitric oxide metabolites (NOx) in relation to OSAS severity. The study has regarded 48 OSAS subjects subdivided in two subgroups according to the apnea/hypopnea index - AHI- (Low = 21 subjects with AHI30 and High = 27 subjects with AHI30). From the obtained data it is evident that the TBARS/NOx ratio is significantly higher in the H subgroup compared to L subgroup as well as this ratio is reduced in L subgroup in comparison with the …
The Importance of Lipidomic Approach for Mapping and Exploring the Molecular Networks Underlying Physical Exercise: A Systematic Review
2021
Maintaining appropriate levels of physical exercise is an optimal way for keeping a good state of health. At the same time, optimal exercise performance necessitates an integrated organ system response. In this respect, physical exercise has numerous repercussions on metabolism and function of different organs and tissues by enhancing whole-body metabolic homeostasis in response to different exercise-related adaptations. Specifically, both prolonged and intensive physical exercise produce vast changes in multiple and different lipid-related metabolites. Lipidomic technologies allow these changes and adaptations to be clarified, by using a biological system approach they provide scientific u…
Seasonal variation in total phenolic content of Dictyopteris polypodioides (Dictyotaceae) and Cystoseira amentacea (Sargassaceae) from the Sicilian c…
2013
Phlorotannins are polyphenolic secondary metabolites found in almost all brown algae that function as defense against grazers, pathogens and epiphytes but are also involved in photoprotection mechanisms. These compounds, produced in the Golgi apparatus, are accumulated in cytoplasm, within vesicules called physodes, or bound to the cell wall. The concentration of phlorotannins dif-fers within and between species, shows geographical variations but may be also affected by abiotic or biotic factors. Aims of this study were to evaluate: (i) the temporal variation of total phenolic content in two brown algae, Dictyopteris polypodioides and Cystoseira amentacea, living respec-tively in the upper …
One-Year Changes in Urinary Microbial Phenolic Metabolites and the Risk of Type 2 Diabetes—A Case-Control Study
2022
The intake of polyphenols has been associated with a risk reduction of type 2 diabetes. Nevertheless, to the best of our knowledge, the molecules that might be metabolically active after ingestion are only starting to be investigated regarding this metabolic disease. To investigate the association between one-year changes in urinary microbial phenolic metabolites (MPM) and the incidence of type 2 diabetes, we performed a case-control study using data and samples of the PREDIMED trial including 46 incident type 2 diabetes cases of 172 randomly selected participants. Eight urinary MPMs were quantified in urine by liquid chromatography coupled to mass spectrometry and used to assess their asso…
Antibacterial activity and HPLC analysis of extracts from Mediterranean brown algae
2020
The antibacterial activity of methanolic extracts of eight Mediterranean brown algae belonging to the genera Cystoseira sensu lato, Dictyopteris and Padina was investigated. Extracts from Sargassaceae showed antibacterial activity. Specifically, Carpodesmia crinita and Carpodesmia brachycarpa extracts inhibited the growth of the Gram-positive strain Kocuria rhizophila whereas Cystoseira compressa and Carpodesmia amentacea extracts showed antibacterial activity against the Gram-positive strains, Kocuria rhizophila and Staphylococcus aureus. None of them inhibited the growth of the Gram-negative bacterium Escherichia coli. The extracts of Cystoseira sp. pl. and Treptacantha ballesterosii did …
Phenguignardic acid and guignardic acid, phytotoxic secondary metabolites from Guignardia bidwellii.
2012
Bioactivity-guided isolation led to the identification of phenguignardic acid (2), a new phytotoxic secondary metabolite from submerged cultures of grape black rot fungus, Guignardia bidwellii. The compound is structurally related to guignardic acid (1), a dioxolanone moiety-containing metabolite isolated previously from Guignardia species. However, in contrast to guignardic acid, which is presumably synthesized from deamination products of valine and phenylalanine, the biochemical precursor for the biosynthesis of the new phytotoxin appears to be exclusively phenylalanine. Guignardic acid was also found in extracts of cultures from Guignardia bidwellii. The phytotoxic activities of both co…
Immunoassays for trifloxystrobin analysis. Part II. Assay development and application to residue determination in food.
2014
Immunochemical assays constitute complementary analytical methods for small organic molecule determination. We herein describe the characterisation and optimisation of two competitive enzyme-linked immunosorbent assays in different formats using monoclonal antibodies to the Quinone outside inhibitor (QoI) fungicide trifloxystrobin. Antibody selectivity was evaluated using a variety of agrochemicals and the main trifloxystrobin metabolite. Acceptable tolerance of the immunoassay to methanol, ethanol, and acetonitrile was observed in all cases, whereas a dissimilar influence of buffer pH and ionic strength was found. Moreover, the influence of Tween 20 over the analytical parameters was studi…
Antifungal Activity of Bioactive Metabolites Produced by Trichoderma asperellum and Trichoderma atroviride in Liquid Medium
2020
Trichoderma spp. are known as biocontrol agents of fungal plant pathogens and have been recognized as a potential source of bioactive metabolites. The production of antimicrobial substances from strains T. atroviride (TS) and T. asperellum (IMI 393899) was investigated. The bioactivity of 10- and 30-day culture filtrate extracted with ethyl acetate was assessed against a set of pathogenic fungi and oomycetes. The 30-day extracts of both strains had significant cytotoxic effects against the tested pathogens, with values of minimum fungicidal concentration (MFC) ranging between 0.19 and 6.25 mg/mL. Dual culture assay (direct contact and nondirect contact) and the percentage inhibition of radi…