Browsing by Author "Stoineva I."

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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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    ISOLATION AND CHARACTERIZATION OF PEPTIDES FROM MILK AS NATURAL INHIBITORS OF ACE I AND FOOD ADDITIVES
    (2024-01-01) Yakimova B.; Alexova R.; Dobreva L.; Rainova Y.; Dobrev S.; Danova S.; Angelova S.; Stoineva I.
    Inhibition of Angiotensin-converting enzyme I (ACE I) is a modern therapeutic approach to treatment of hypertension. In recent years, research into natural ACE peptide inhibitors without side effects has become important. The aim of this study is to isolate and characterize novel bioactive peptides from skim and/or whole cow’s milk fermented with selected lactobacillus strains. Several homo/heterofermentative strains of the Lactobacillus species of dairy origin have been pre-selected and different milk fermented samples have been studied. A protocol for analyses was designed and the milk proteins were separated by centrifugation at 4°C at 10000 × g, with molecular mass cut off (MWCO) membranes of 3 and 10 kDa. The samples with molecular mass below 3 kDa were further separated by ultrafiltration by dialysis cell (cut off membrane 1 kDa) by continuous stirring at room temperature. The milk fractions under 1 kDa molecular mass were characterized by UPLC-MS. The ACE-inhibitory activity was determined using the FAPGG (N-[3-(2-Furyl) acryloyl]-L-phenylalanyl-glycyl-glycine) degradation method. All tested samples (1 kDa) exhibit ACE I inhibitory activity with IC50 in a range of 6 - 37 mg mL-1. In silico logP prediction of selected peptides was used to assess whether lipophilicity of the compounds falls within the so-called “therapeutically relevant pharmacokinetic space”.