Browsing by Author "Kardaleva P."

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    In vitro and ex vivo studies on angiotensin-i converting enzyme (Ace) inhibitory activity of short synthetic peptides
    (2021-01-01) Yakimova B.; Mateeva P.; Kardaleva P.; Stoineva I.; Todorova P.; Zamfirova R.; Yanev S.
    In our days the interest in the studies of new angiotensin-converting-enzyme (ACE) inhibitors as modulators of the renin-angiotensin-system (RAS) is growing, not only because of their importance as drugs for arterial hypertension treatment, but also for their therapeutic potential during COVID-19 infection. This study presents data for the design and synthesis of short peptides by SPPS strategy and investigates in vitro and ex vivo their potential as ACE inhibitors in the light of structural changes. The obtained results give insight into the structure-activity relationship of peptide sequences and show differences regarding the effects of peptides in two experimental procedures (inhibitory potency on purified ACE activity and AT-I induced rat ileum contractions). Three of the newly synthesized peptides with terminal proline, LAP, LKP and VAP, showed relatively high inhibitory activities.
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    Ketoprofen-based ionic liquids: Synthesis and interactions with bovine serum albumin
    (2020-01-01) Ossowicz P.; Kardaleva P.; Guncheva M.; Klebeko J.; Świątek E.; Janus E.; Yancheva D.; Angelov I.
    The development of ionic liquids based on active pharmaceutical ingredients (API-ILs) is a possible solution to some of the problems of solid and/or hydrophobic drugs such as low solubility and bioavailability, polymorphism and an alternative route of administration could be suggested as compared to the classical drug. Here, we report for the first time the synthesis and detailed characterization of a series of ILs containing a cation amino acid esters and anion ketoprofen (KETO-ILs). The affinity and the binding mode of the KETO-ILs to bovine serum albumin (BSA) were assessed using fluorescence spectroscopy. All compounds bind in a distance not longer than 6.14 nm to the BSA fluorophores. The estimated binding constants (KA) are in order of 105 L mol-1, which is indicative of strong drug or IL-BSA interactions. With respect to the ketoprofen-BSA system, a stronger affinity of the ILs containing l-LeuOEt, l-ValOBu, and l-ValOEt cation towards BSA is clearly seen. Fourier transformed infrared spectroscopy experiments have shown that all studied compounds induced a rearrangement of the protein molecule upon binding, which is consistent with the suggested static mechanism of BSA fluorescence quenching and formation of complexes between BSA and the drugs. All tested compounds were safe for macrophages.