scholarly journals Luteapyrone, a Novel ƴ-Pyrone Isolated from the Filamentous Fungus Metapochonia lutea.

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6589
Author(s):  
Roman Labuda ◽  
Markus Bacher ◽  
Hannes Gratzl ◽  
Maria Doppler ◽  
Alexandra Parich ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Filamentous Fungus ◽  
Chemical Structure ◽  
Flash Chromatography ◽  
Preparative Hplc ◽  
Microbial Metabolites ◽  
Mammalian Cell Lines ◽  
Sucrose Medium ◽  
Culture Extract ◽  
Yeast Extract Sucrose

In the process of screening for new bioactive microbial metabolites we found a novel ƴ-pyrone derivative for which we propose the trivial name luteapyrone, in a recently described microscopic filamentous fungus, Metapochonia lutea BiMM-F96/DF4. The compound was isolated from the culture extract of the fungus grown on modified yeast extract sucrose medium by means of flash chromatography followed by preparative HPLC. The chemical structure was elucidated by NMR and LC-MS. The new compound was found to be non-cytotoxic against three mammalian cell lines (HEK 263, KB-3.1 and Caco-2). Similarly, no antimicrobial activity was observed in tested microorganisms (gram positive and negative bacteria, yeast and fungi).

Antimicrobial Activity of Iron-Halide Complexes Against Gram-Positive and Gram-Negative Bacteria

2020 ◽  
Author(s):  
Nusrat Abedin ◽  
Abdullah Hamed A Alshehri ◽  
Ali M A Almughrbi ◽  
Olivia Moore ◽  
Sheikh Alyza ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Resistance ◽  
Extracellular Dna ◽  
Antibiofilm Activity ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Antimicrobial Substances ◽  
Mammalian Cell Lines

Antimicrobial resistance (AMR) has become one of the more serious threats to the global health. The emergence of bacteria resistant to antimicrobial substances decreases the potencies of current antibiotics. Consequently, there is an urgent and growing need for the developing of new classes of antibiotics. Three prepared novel iron complexes have a broad-spectrum antimicrobial activity with minimum bactericidal concentration (MBC) values ranging from 3.5 to 10 mM and 3.5 to 40 mM against Gram-positive and Gram-negative bacteria with antimicrobial resistance phenotype, respectively. Time-kill studies and quantification of the extracellular DNA confirmed the bacteriolytic mode of action of the iron-halide compounds. Additionally, the novel complexes showed significant antibiofilm activity against the tested pathogenic bacterial strains at concentrations lower than the MBC. The cytotoxic effect of the complexes on different mammalian cell lines show sub-cytotoxic values at concentrations lower than the minimum bactericidal concentrations.

Roquefortine C Occurrence in Blue Cheese

2001 ◽  
Vol 64 (2) ◽  
pp. 246-251 ◽  
Author(s):  
CARLO FINOLI ◽  
ANGELA VECCHIO ◽  
ANTONIETTA GALLI ◽  
IVAN DRAGONI
Keyword(s):  
Yeast Extract ◽  
Culture Media ◽  
Penicillium Roqueforti ◽  
Blue Cheese ◽  
Penicillium Crustosum ◽  
Sucrose Medium ◽  
Low Toxicity ◽  
Yeast Extract Sucrose ◽  
Roquefortine C

Several strains of Penicillium are used for the production of mold-ripened cheeses, and some of them are able to produce mycotoxins. The aims of the research were the determination of roquefortine C and PR toxin in domestic and imported blue cheeses, the identification of the penicillia used as starter, and the investigation of their capacity for producing toxins in culture media. Roquefortine C was always found in the cheeses at levels ranging from 0.05 to 1.47 mg/kg, whereas the PR toxin was never found. The identification of the fungal strains present in the domestic cheeses included Penicillium glabrum, Penicillium roqueforti, and Penicillium cyclopium in the Gorgonzola “dolce” and Penicillium roqueforti in the Gorgonzola “naturale”; in one case, the presence of Penicillium crustosum was observed. The strains isolated from the foreign cheeses belonged to P. roqueforti. The strains were able to produce between 0.18 and 8.44 mg/liter of roquefortine in yeast extract sucrose medium and between 0.06 and 3.08 mg/liter and less than 0.05 mg/liter when inoculated in milk at 20°C for 14 days and 4°C for 24 days, respectively. Linear relations between production of roquefortine in culture media and cheeses did not emerge. PR toxin ranged from less than 0.05 to 60.30 mg/liter in yeast extract sucrose medium and was produced in milk at 20°C from only one strain. The low levels and the relatively low toxicity of roquefortine make the consumption of blue cheese safe for the consumer.

scholarly journals Antimicrobial activity of carvacrol related to its chemical structure

2006 ◽  
Vol 43 (2) ◽  
pp. 149-154 ◽  
Author(s):  
A. Ben Arfa ◽  
S. Combes ◽  
L. Preziosi-Belloy ◽  
N. Gontard ◽  
P. Chalier
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Structure

scholarly journals Chromatographic Techniques to Purify Individual Limonoids from Seeds and Molasses of Citrus Fruits

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 752D-752
Author(s):  
Shibu M. Poulose* ◽  
Jennifer S. Brodbelt ◽  
Leonard M. Pike ◽  
Bhimanagouda S. Patil
Keyword(s):  
Ion Exchange ◽  
Flash Chromatography ◽  
Limiting Factor ◽  
Preparative Hplc ◽  
Direct Crystallization ◽  
Chromatographic Techniques ◽  
Pure Compounds ◽  
Purification Methods ◽  
The Individual ◽  
Exchange Resins

Limonoids, chemically related triterpinoids predominantly found in citrus and neem relatives, are known to play a pivotal role in the prevention of different types of cancer and cardiovascular diseases. Since the concentrations of these compounds are low in the plant tissues, the isolation of pure compounds is the limiting factor for the individual activity studies in animal models. In this study, combinations of chromatographic techniques were used to isolate limonoid aglycones and limonoid glucosides from citrus byproducts such as seeds and molasses. The compounds were initially extracted with different polar solvents and the concentrated extracts were passed through a series of adsorbent resin (SP-70) and ion-exchange resins (WA-30, Dowex-50, Q-sepharose) to remove further impurities. The use of increasing ionic strength of NaCl from 0 to 800 mm to release the exchanged compounds from the ion exchange columns further separated the limonoids from flavonoids, which was confirmed through TLC, UV, and analytical HPLC methods. Individual compounds were further purified using flash chromatography and preparative HPLC methods and identified by using LC-MS analysis. Direct crystallization of limonin resulted in a 17% increase in the yield as compared to the previously reported methods. The results suggest that application of these purification methods are useful for the bulk purification of compounds in order to further investigate their biological activity.

scholarly journals Production of Polyvinylpyrrolidone Nanowebs Containing Zinc Cyclohexane Mono Carboxylate via Electrospinning and Investigatıon of Antibacterial Effıciency

2019 ◽  
Vol 27 (6(138)) ◽  
pp. 91-96
Author(s):  
Aylin Yildiz ◽  
Riza Atav ◽  
Mine Aydin
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Structure ◽  
Antibacterial Properties ◽  
The Other ◽  
Antibacterial Efficiency ◽  
E Coli ◽  
Other Hand ◽  
Edx Analyses

In this study, after the synthesis of zinc cyclohexane mono carboxylate, its chemical structure was analysed with FTIR and TGA. Then electrospun polyvinylpyrrolidone nanofibres containing zinc cyclohexane mono carboxylate were produced and antibacterial properties of the nanowebs obtained were investigated for their use in the textile field When the FTIR results of the nanofibres containing different concentrations of zinc cyclohexane monocarbocylate are examined, an –OH peak similar to that of PVP fibres is noticed. These results clearly indicate that zinc cyclohexane monocarboxylate is included in PVP. When the TGA spectra of CHMCZn-doped nanofibres at different ratios are examined, it is seen that they give more similar results than polyvinylprolidone nanofibres alone. According to the SEM-EDX analyses, it was observed that the fibre diameters obtained were in the range of 145 - 947 nm. On the other hand, antimicrobial activity against B. subtilis, S. aureus and E. coli strains was detected, found regardless of the CHMCZn concentration.

scholarly journals Toxic Indole Diterpenes from Endophyte-Infected Perennial Ryegrass Lolium perenne L.: Isolation and Stability

Toxins ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 16 ◽  
Author(s):  
Priyanka Reddy ◽  
Myrna A. Deseo ◽  
Vilnis Ezernieks ◽  
Kathryn Guthridge ◽  
German Spangenberg ◽  
...  
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Rapid Development ◽  
Toxicity Testing ◽  
Flash Chromatography ◽  
Preparative Hplc ◽  
Purification Method ◽  
Isolation And Purification ◽  
Lolium Perenne L ◽  
Lolitrem B

The most potent of the indole diterpenes, lolitrem B, is found in perennial ryegrass (Lolium perenne L.) infected with the endophyte Epichloë festucae var. lolii (also termed LpTG-1). Ingestion causes a neurological syndrome in grazing livestock called ryegrass staggers disease. To enable the rapid development of new forage varieties, the toxicity of lolitrem B and its biosynthetic intermediates needs to be established. However, most of these indole diterpenes are not commercially available; thus, isolation of these compounds is paramount. A concentrated endophyte-infected perennial ryegrass seed extract was subjected to silica flash chromatography followed by preparative HPLC and purification by crystallization resulting in lolitrem B and the intermediate compounds lolitrem E, paspaline and terpendole B. The four-step isolation and purification method resulted in a 25% yield of lolitrem B. After isolation, lolitrem B readily degraded to its biosynthetic intermediate, lolitriol. We also found that lolitrem B can readily degrade depending on the solvent and storage conditions. The facile method which takes into consideration the associated instability of lolitrem B, led to the purification of indole diterpenes in quantities sufficient for use as analytical standards for identification in pastures, and/or for toxicity testing in pasture development programs.

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