Matjaž Ravnikar

Dr. Matjaž Ravnikar

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Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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20 February 2018 in Journal of Analytical Methods in Chemistry
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NMNevena Maljurić
Nevena Maljurić
JGJelena Golubović
Jelena Golubović
MRMatjaž Ravnikar
Matjaž Ravnikar
DŽDušan Žigon
Dušan Žigon
BŠBorut Štrukelj
Borut Štrukelj
BOBiljana Otašević
Biljana Otašević
Diabetes mellitus is one of the leading world’s public health problems. Therefore, it is of a huge interest to develop new antidiabetic drugs. Apart from traditional therapy of diabetes, nowadays, importance is given to natural substances with antidiabetic potential. Fomes fomentarius is a mushroom widely used for different purposes, due to its range of already confirmed activities. Fomentariol is a constituent of Fomes fomentarius, responsible for its antidiabetic potential. In that respect, it is important to develop a method for isolation and quantification of fomentariol from fungal material, which will be simple and efficient. Multistep, complex extraction applied in the previously reported studies was avoided with ethanol, providing rapid single-step extraction. The presence of fomentariol in ethanolic extract was confirmed by high-resolution mass spectrometry. Semipreparative HPLC method was developed and applied for isolation from ethanol extract and purification of the active compound fomentariol. It was a gradient reversed-phase method with a mobile phase consisting of acetonitrile and 0.1% formic acid in water and total run time of 15 minutes. The amount of 6.5 mg of high-purity fomentariol was determined by quantitative NMR with toluene as internal standard. The isolated and determined amount of substance can be further used for the quantitative estimation of activity of fomentariol.

11 March 2015 in AFRICAN JOURNAL OF BIOTECHNOLOGY
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MRMatjaž Ravnikar
Matjaž Ravnikar
TMTercelj Matic
Tercelj Matic
JDJanes Damjan
Janes Damjan
SBStrukelj Borut
Strukelj Borut
KSKreft Samo
Kreft Samo
Fungi, in particular endophytes are a promising source of new antimicrobial compounds. The aim of this study was to screen the extracts of conifer needle fungal endophytes for antimicrobial activity and taxonomically place fungi producing ones to determined active metabolites. Seventy three strains of endophytic fungi were isolated from plant samples, mainly from needles of conifers, and cultured. Extracts of cultured endophytic strains were tested for antimicrobial properties using a microdilution assay. Their activity was compared to that of the antibiotic ampicillin. Samples that exhibited antimicrobial properties were further examined. Genomic DNA from five active fungal strains was isolated and species-specific DNA regions (ITS regions) were amplified and sequenced allowing us to determine the identity of the samples. Active endophytic fungi were two strains of Lophodermium pinastri, two strains of Lophodermium seditiosum and one of Phoma herbarum. All of these strains are known as parasitic and can be treated as endophytes only according to the lack of symptoms in their host tissue. This work demonstrates an interesting bottom-up approach to the discovery of new antimicrobial compounds. Key words: Endophyte, antibiotic, parasitic, Lophodermium, antimicrobial, Phoma.

10 August 2021 in Plants
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KFKarsten Fatur
Karsten Fatur
MRMatjaž Ravnikar
Matjaž Ravnikar
SKSamo Kreft
Samo Kreft
The present research sought to compare the content of hyoscyamine/atropine and scopolamine in Scopolia carniolica and its contested variety, S. carniolica var. hladnikiana, with the aim of investigating differences that may be of taxonomical significance. A multi-phase liquid extraction and high-performance liquid chromatography were used to extract and analyse these alkaloids in different organs from plants collected over two years at three sites. Our results showed that hyoscyamine was almost twice as prevalent as scopolamine across our 87 samples. The differences between organ types were large, but so too were intra-organ differences; differences due to organs proved to be significant for hyoscyamine, while they were only marginally significant for scopolamine. The collection site also proved to have a significant influence, but only on hyoscyamine content. The year of collection and the variety proved to not be significant. Our results support the theory that these two varieties are likely one, a view argued by many others, though more work is needed to draw concrete taxonomical conclusions.

19 August 2009 in Biotechnology Letters
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MRMatjaž Ravnikar
Matjaž Ravnikar
AIAndreja Irman
Andreja Irman
NRNataša Radić
Nataša Radić
MLMojca Lunder
Mojca Lunder
BŠBorut Štrukelj
Borut Štrukelj

21 May 2024 in Nutraceuticals
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MRMatjaž Ravnikar
Matjaž Ravnikar
BŠBorut Štrukelj
Borut Štrukelj
BOBiljana Otašević
Biljana Otašević
MSMateja Sirše
Mateja Sirše
The present study screened various fungal species for inhibitors of alpha-glucosidase, alpha-amylase, and DPP-4, enzymes that are crucial in carbohydrate metabolism. Ethanolic extracts exhibited superior inhibitory activity compared to water extracts, suggesting their potential as sources of anti-diabetic agents. Further fractionation revealed fomentariol from Fomes fomentarius as a potent inhibitor of alpha-glucosidase and DPP-4, with higher activity against alpha-glucosidase than acarbose. Fomentariol presents a novel avenue for diabetes management, demonstrating the simultaneous inhibition of key enzymes in glucose metabolism. However, comprehensive clinical studies are needed to evaluate its safety and efficacy in humans.

4 January 2022 in Plants
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KFKarsten Fatur
Karsten Fatur
MRMatjaž Ravnikar
Matjaž Ravnikar
VFVitjan Fras
Vitjan Fras
SKSamo Kreft
Samo Kreft
The present article sought to evaluate the efficiency of various folk preparation methods commonly used in Europe for employing anticholinergic Solanaceae plants. The study aimed to uncover which folk methods were effective for the extraction of the anticholinergic tropane alkaloids of these plants, atropine and scopolamine. The folk extractions that were tested sought to simulate the preparation of teas, cold-water infusions, unguents, tinctures, fortified wines, and smoking. All preparation types and a control were then put through an extraction process to see what amount of the alkaloids had been maintained. These extractions were then analysed using high-performance liquid chromatography (HPLC). Cold- and hot-water preparations, tinctures, and fortified wines all proved to be effective means of extracting atropine and scopolamine from plant material under conditions seen in folk usage. Smoking and the oil-based unguent, however, yielded no alkaloids, suggesting a lack of efficiency for these preparations, a problem with our methodology, or possible chemical changes and losses associated with the preparation procedure.