Search results for "metabolite"
showing 10 items of 551 documents
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…
Inhibition of Mycotoxigenic Fungi in Different Vegetable Matrices by Extracts of Trichoderma Species
2021
Post-harvest fungal diseases of plant products are a serious concern leading to economic losses and health risks. Moreover, the use of synthetic chemical fungicides to prevent these diseases is limited due to toxic residues. This study aimed at determining the effective dose of extracts of Trichoderma 
Comparative Genomics Analysis of Keratin-Degrading Chryseobacterium Species Reveals Their Keratinolytic Potential for Secondary Metabolite Production
2021
A promising keratin-degrading strain from the genus Chryseobacterium (Chryseobacterium sp. KMC2) was investigated using comparative genomic tools against three publicly available reference genomes to reveal the keratinolytic potential for biosynthesis of valuable secondary metabolites. Genomic features and metabolic potential of four species were compared, showing genomic differences but similar functional categories. Eleven different secondary metabolite gene clusters of interest were mined from the four genomes successfully, including five common ones shared across all genomes. Among the common metabolites, we identified gene clusters involved in biosynthesis of flexirubin-type pigment, m…
Polymeric prodrug for release of an antitumoral agent by specific enzymes.
2001
The clinical usefulness of antitumor chemotherapy has been strongly limited by the lack of specificity of most anticancer drugs, which act also against healthy cells. The aim of this work was to design, synthesize, and evaluate a macromolecular prodrug of Cytarabine, a known antitumor drug, which is a specific substrate for plasmin enzyme whose concentration is high in various kinds of tumor mass as a result of plasminogen activator secretion. alpha,beta-Poly(N-hydroxyethyl)-DL-aspartamide (PHEA), a known synthetic and biocompatible polyamino acid, was used as a drug carrier, and Cytarabine was linked to PHEA by D-Val-Leu-Lys spacer synthesized beginning from Cbz-D-Val-LeuOH dipeptide and N…
Structure and Function of CutC Choline Lyase from Human Microbiota Bacterium Klebsiella pneumoniae.
2015
CutC choline trimethylamine-lyase is an anaerobic bacterial glycyl radical enzyme (GRE) that cleaves choline to produce trimethylamine (TMA) and acetaldehyde. In humans, TMA is produced exclusively by the intestinal microbiota, and its metabolite, trimethylamine oxide, has been associated with a higher risk of cardiovascular diseases. Therefore, information about the three-dimensional structures of TMA-producing enzymes is important for microbiota-targeted drug discovery. We have cloned, expressed, and purified the CutC GRE and the activating enzyme CutD from Klebsiella pneumoniae, a representative of the human microbiota. We have determined the first crystal structures of both the choline-…
Abyssomicin E, a highly functionalized polycyclic metabolite from Streptomyces species.
2007
Abyssomicin E (1), a new polycyclic metabolite with a C19 skeleton, was isolated from Streptomyces sp. (HKI0381). Its chemical structure was determined by comprehensive NMR and MS spectroscopic analyses. For the first time in this recently discovered class of compounds, the absolute stereochemistry was directly established by subsequent single-crystal X-ray diffraction study using anomalous dispersion with copper radiation.
Biomimetic Synthesis of the Apoptosis-Inducing Thiazinoquinone Thiaplidiaquinone A
2012
A concise total synthesis of the apoptosis-inducing, marine metabolite thiaplidiaquinone A is described. The key ring forming steps are both based on biosynthetic considerations and involve the construction of the central benzo[c]chromene quinone unit by an extremely facile oxa-6π-electrocyclic ring closure reaction of an ortho-quinone intermediate, derived by tautomerization of a bis-benzoquinone, readily accessed from two simple phenolic precursors. This is followed by the installation of the 1,4-thiazine-dioxide ring by reaction of the benzo[c]chromene quinone with hypotaurine.
Stability of Morphine, Morphine-3-Glucuronide, and Morphine-6-Glucuronide in Fresh Blood and Plasma and Postmortem Blood Samples
2001
The present study was designed to determine the stability of morphine and its glucuronides in spiked fresh blood and plasma from live individuals as well as in four authentic postmortem blood specimens for a time interval of up to six months. The samples were stored in glass vials at -20 degrees C, 4 degrees C, and 20 degrees C. Additionally, spiked samples were exposed to light through window glass and subjected to a forced-degradation study at 40 degrees C. Data were established using solid-phase extraction and high-performance liquid chromatography coupled to atmospheric pressure ionization mass spectrometry for isolation and quantitation, providing a sensitive and specific detection met…
Lipid composition and metabolism of European sea bass (Dicentrarchus labrax L.) fed diets containing wheat gluten and legumes meals as substitutes fo…
2013
The role of dietary protein source on growth performance and lipid metabolism in European sea bass (Dicentrarchus labrax) was investigated, by the evaluation of fat content in different tissues, plasma metabolites, liver lipogenic activity and fatty acid composition of dorsal muscle tissue.Five isonitrogenous (490gkg-1crude protein dry-matter basis) and isolipidic (170gkg-1lipid dry-matter basis) diets with graded levels of wheat gluten, soybean and pea meal in substitution of fish meal were evaluated in European sea bass (initial body weight 23.9±0.1) for 96days. There was a significant difference (p<0.05) in dorsal muscle and liver lipid contents. Plasma glucose and cholesterol levels …
4,5-Disubstituted 1-Methylimidazoles via Cyclization of Defined α-Aminoketones: Synthesis of Fungerin and Analogues I
2016
A protocol for the chemoselective synthesis of the fungal metabolite fungerin has been developed. First the required N-methyl α-aminoketone was generated starting from sarcosine, propiolic acid, and prenyl bromide. Marckwald thioimidazole cyclization and subsequent sulfur removal delivered the target fungerin as well as an analogue, respectively, displaying defined substitution patterns.