Browsing by Author "Vezenkov L."
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Item Application of ABTS method for assessment of radical-binding effect of Creatine monohydrate(2023-01-01) Tsvetkova D.; Kostadinova I.; Landzhov B.; Vezenkov L.; Marinov L.; Ivanova I.Due to its antioxidant properties Creatine exhibits benefits on muscle, bone, and brain function, and can be of great importance for the prevention of the oxidative stress-related diseases. The aim of current study was the investigation of antiradical effect of Creatine monohydrate by the application of ABTS method. The radical-scavenging activity of Creatine monohydrate against methanol solution of ABTS radical was evaluated by measuring the decrease in the absorbance at λ = 744 nm. For the estimation of antiradical effect of the compound examined the following parameters were calculated: radical scavenging activity in [%], IC50 value; antioxidant power 1/IC50, Trolox equivalent activity. Linear relationship between the enhanced radical scavenging activity and decrease of absorbances and of not-bound ABTS-radical with the increase of concentration of Trolox (0.002 mM ÷ 0.75 mM) and Creatine monohydrate (20 mM ÷ 200 mM) has been established. Linearity was characterized by coefficients of linear regression, which were proven to be higher than 0.97. From the experimental results it was observed that Creatine monohydrate (IC50 = 100.98 mM) exerts antiradical effect, but is less active compared to Trolox (IC50 = 0.2 mM) due to higher IC50 value and lower antioxidant power (1/IC50, = 0.01) than Trolox (1/IC50 = 5).Item Determination of radical scavenging activity of Creatine lysinate against methanol solutions of ABTS(2023-01-01) Tsvetkova D.; Kostadinova I.; Vezenkov L.; Marinov L.Dietrary Creatine supplements can exert benefits against muscular dystrophic diseases, such as Duchenne muscular dystrophy, myophosphorylase deficiency (McArdle's disease), and fibromyalgia and can provide protection towards neurodegenerative disorders as Huntington, Parkinson and Amyotrophic lateral sclerosis. Creatine supplementation improves cognition and memory and can promote muscle strength. Creatine plays an important role in maintaining heart function in congestive heart failure. The current investigation's goal was to learn more about the ability of creatine lysinate to scavenge ABTS-radicals. Radiation scavenging activity [%], idex of inhibition (IC50), antioxidant power (1/IC50), and Trolox equivalent activity were calculated using the reduction in the absorbance at = 744 nm of the methanol solution of the ABTS-radical. Creatine lysinate (IC50 = 62.8 mM) exhibits an antiradical action, as shown by the experimental findings. According to the available data, creatine lysinate is less active than trolox (IC50 = 0.2 mM), which is because it has a greater IC50 value and less antioxidant capacity (1/IC50, = 0.016) than trolox (1/IC50, = 5). In current investigation was confirmed that ABTS-radical scavenging effect of Creatine lysinate is higher in comparison with Creatine monohydrate (IC50 = 100.98 mM), which was proven by the obtained higher Trolox equivalent antioxidant capacity TEAC = 0.003 of Creatine lysinate, compared with that of Creatine monohydrate (TEAC = 0.002).Item NEW DERIVATIVES OF GALANTHAMINE CONTAINING PEPTIDE FRAGMENT(2020-01-01) Vezenkov L.; Cena H.; Danalev D.; Karadjova V.; Tsekova D.; Bardarov V.; Vassilev N.New derivatives of galanthamine containing a peptide fragment with an antiaggregation activity are synthesized. Herein the process of synthesis, purification and characterization of the newly obtained compounds is described. Syntheses were performed by consecutive attachment of Boc-protected amino acids to either norgalanthamine or HGly-Ogal using TBTU/DIPEA and TCTU/DIPEA methods. The purification of final products was realized by treating with EtOAc or by HPLC. The newly compounds were characterized by TLC, NMR, m.p. and MS. Two pharmacological effects are expected to be combined in a single molecule: the anticholinesterase and the antiaggregation onesItem SYNTHESIS, ISOLATION AND BIOLOGICAL ACTIVITY STUDIES OF GALANTHAMINE DERIVATIVES INCLUDING PEPTIDE MOIETY AND TANNINS FROM MEDICINAL PLANTS(2022-01-01) Atanasov A.; Karadjova V.; Andonova A.; Tsekova D.; Lozanov V.; Parashkevova B.; Mindov I.; Todorova R.; Vezenkov L.The search of a new chemical substances influencing platelet aggregation is a very important endeavor for medical practice. Among the compounds that have antiaggregating activity are some peptides, tannins, etc. Here we present antiaggregation activity of Arg-Gly-Asp (RGD) peptide derivatives. Synthetic procedures of new peptide-galantamine derivatives including also glucose moiety designed to possess such activity are included. The in vitro effect of water extract from 20 tannins-containing plants from Bulgarian flora on aggregation of modified rat platelet-rich plasma was investigated and seven of them (Corylus avellana L, Cydonia oblonga Mill, Dryopteris filix-mas (L.) Schott, Ephedra distachya L., Geum urbanum L., Primula officinalis (L.) Hill and Punica granatum L.)were able to inhibit platelet aggregation