Publications by authors named "J Cvacka"

The antioxidant activity of Scorzonera parviflora Jacq. roots were assessed by measuring their ability to scavenge ABTS and DPPH radicals. Bioactivity-guided fractionation was utilized to identify the compound(s) responsible for this activity.

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Article Synopsis
  • - Wax esters are important in biological systems for energy storage and chemical signaling, with their diversity linked to different alcohol and acyl chain characteristics.
  • - Traditional mass spectrometry methods like CID and HCD help analyze wax ester properties, but struggle with detailed structural aspects like double bond positions.
  • - This study showcases the use of 213-nm ultraviolet photodissociation (UVPD) for more precise analysis of wax esters, revealing the method's effectiveness in determining chain lengths and locations of double bonds, especially in natural wax sources like jojoba oil.
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Nucleophilic fluorination of secondary aliphatic substrates, especially of halides, still remains a challenge. Among the available reagents, TBAT belongs to one of the best choices due to its stability, affordable price and low toxicity. With the aim to improve its selectivity, we synthesized three analogues modified in the aryl part of the TBAT reagent with one or two electron donating methoxy groups or with one electron withdrawing trifluoromethyl group.

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Ambient ionization mass spectrometry allows for analysis of samples in their natural state, i.e., with no sample pre-treatment.

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Straightforward access to enantiomerically pure 3,4-diamino-3,4-dideoxyphytosphingosines, as novel analogues of natural d-ribo-phytosphingosine was accomplished, starting from two available chirons: dimethyl l-tartrate and d-isoascorbic acid. A sequential Overman rearrangement followed by late-stage introduction of the alkyl side chain moiety via olefin cross-metathesis is the cornerstone of this approach. The preliminary evaluation study of the synthesised sphingomimetics, based on their ability to inhibit a proliferation of human cancer cells, showed promising cytotoxicity against Jurkat and HeLa cells for (2R,3R,4S)-2,3,4-triaminooctadecan-1-ol trihydrochloride.

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