Browsing by Author "Penchev P."
Now showing 1 - 7 of 7
Results Per Page
Sort Options
Item Investigation of the Complexation Activity of 2,4-Dithiouracil with Au(III) and Cu(II) and Biological Activity of the Newly Formed Complexes(2024-08-01) Marinova P.; Stoitsov D.; Burdzhiev N.; Tsoneva S.; Blazheva D.; Slavchev A.; Varbanova E.; Penchev P.The goal of this study is to synthesize, determine the structure, and examine the antimicrobial properties of novel Cu(II) and Au(III) complexes of 2,4-dithiouracil and its derivatives. These complexes were obtained by mixing aqueous solutions of the corresponding metal salts with the ligand dissolved in DMSO and aqueous NaOH, using a metal-to-ligand ratio of 1:4:2. The structures of the new compounds were analyzed by melting point determination, microwave plasma atomic emission spectrometry (MP-AES) for Cu and Au, inductively coupled plasma optical emission spectrometry (ICP-OES) for S, attenuated total reflection (ATR), solution and solid-state NMR, and Raman spectroscopy. The data for 2,4-dithiouracil obtained from the 1H NMR, 13C NMR, distortionless enhancement by polarization transfer spectrum (DEPT-135), proton–proton homonuclear correlation spectrum (1H-1H COSY), long-range 1H-13C heteronuclear multiple bond correlation experiment (HMBC), and heteronuclear single quantum coherence spectra (HSQC) aided the interpretation of the NMR data for the gold and copper complexes. Furthermore, the antimicrobial effect of the free ligands and their complexes was assessed against Gram-positive and Gram-negative bacteria, as well as yeasts.Item Study on the synthesis, characterization and bioactivities of 3-methyl-9'-fluorenespiro-5-hydantoin(2016-01-01) Marinova P.; Marinov M.; Kazakova M.; Feodorova Y.; Slavchev A.; Blazheva D.; Georgiev D.; Penchev P.; Sarafian V.; Stoyanov N.This work describes a method for synthesis, as well as in vitro antiproliferative and antibacterial investigation of 3-methyl-9'-fluorenespiro-5-hydantoin. The structure of the substituted fluorenylspirohydantoin derivative was verified by UV-Vis, FT-IR, Raman, 1H NMR and 13C NMR spectroscopy, and by using a combination of 2D NMR experiments, which included 1H-1H COSY, HMQC and HMBC sequences. The geometry of the compound was optimized by the B3LYP density functional with 6-31G(d) basis set and the 1H and 13C NMR spectra were predicted with the HF/6-31G(d) calculations at the optimized geometry. The anticancer activity of the 3-methyl-9'-fluorenespiro-5-hydantoin was determined in suspension cell lines originating from tumors in humans (WERI-Rb-1). The cytotoxic effect was evaluated by WST-assay (Roche Applied Science). The antimicrobial effect of the compound against Gram-negative, Gram-positive bacteria and the yeast Candida albicans was investigated.Item Synthesis and antimicrobial study of new Pt(IV) and Ru(III) complexes of fluorenylspirohydantoins(2019-01-01) Marinova P.; Marinov M.; Georgiev D.; Becheva M.; Penchev P.; Stoyanov N.The present work presents a synthesis, characterization and antimicrobial activitiy of new Pt(IV) and Ru(III) complexes of (9’-fluorene)-spiro-5-hydantoin (HL1) and (9’-fluorene)-spiro-5-(2-thiohydantoin) (HL2). The complexes were investigated by elemental analysis, UV-Vis and IR spectroscopy. The free ligands were studied by UV-Vis, IR, 1H NMR, 13C NMR and Raman spectroscopy. The antimicrobial tests of HL1 showed week bacteriostatic effect against Staphylococcus aureus ATCC 6538. The results for [Pt(L1)2(H2O)2(OH-)2] complex showed a good antimicrobial activity against Esсherichia coli ATCC 8739, Bacillus licheniformis ATCC 6633, S. aureus and the absence of such effect on the yeasts. The HL2 and its [Pt(L2)2(H2O)2(OH-)2] and [Ru(L2)3(H2O)3] complexes do not possess antimicrobial activity against the tested bacteria and yeasts.Item SYNTHESIS AND CHARACTERIZATION OF N3-ACETYL DERIVATIVES OF SPIROHYDANTOINS(2022-01-01) Marinov M.; Frenkeva M.; Naydenova E.; Penchev P.; Stoyanov N.The following article describes the synthesis of N3-acetyl derivatives of spirohydantoins. The compounds are derived by applying the following technique: the Bucherer-Lieb method (α-series) and the Strecker method (β-series). The synthesized products are characterized by physicochemical parameters, elemental analysis, FTIR, 1H NMR, 13C NMR and 13C DEPT135 spectral data.Item Synthesis and in vitro activity of platinum(II) complexes of two fluorenylspirohydantoins against a human tumour cell line(2014-01-01) Marinova P.; Marinov M.; Kazakova M.; Feodorova Y.; Penchev P.; Sarafian V.; Stoyanov N.This paper presents a method for synthesis and cytotoxicity of new platinum(II) complexes of (9′-fluorene)-spiro-5-hydantoin (L1) and (9′-fluorene)-spiro-5-(2-thiohydantoin) (L2). The new obtained complexes were studied by elemental analysis: ultraviolet-visible, attenuated total reflection Fourier transform infrared (ATR-FTIR), and 1H- and 13C-NMR for Pt(II) compounds and additionally Raman spectroscopy for free ligands. Based on the experimental data, the most probable structure of the complexes is suggested. In the present study, we have examined cytotoxic activity of (9′-fluorene)-spiro-5-hydantoin (L1) and (9′-fluorene)-spiro-5-(2-thiohydantoin) (L2) and their Pt(II) complexes on the retinoblastoma cell line WERI-Rb-1. © 2014 The Author(s). Published by Taylor & Francis.Item Synthesis, Characterization, and Antibacterial Studies of New Cu(II) and Pd(II) Complexes with 6-Methyl-2-Thiouracil and 6-Propyl-2-Thiouracil(2023-12-01) Marinova P.; Hristov M.; Tsoneva S.; Burdzhiev N.; Blazheva D.; Slavchev A.; Varbanova E.; Penchev P.The aim of the present study is to synthesize new metal complexes of 6-methyl-2-thiouracil and 6-propyl-2-thiouracil, elucidate their structures, and investigate their biological properties. All metal complexes were obtained after mixing water solutions of the corresponding metal salts and the ligand dissolved in DMSO and water solutions of NaOH in a metal-to-ligand ratio of 1:4:2. The structures of the new compounds are discussed based on melting point analysis (MP-AES) for Cu and Pd, UV-Vis, IR, ATR, 1H NMR, 13C NMR, and Raman spectroscopy. The interpretation of complex spectra is assisted by the data for 6-methyl-2-thiouracil and 6-propyl-2-thiouracil obtained from 1H-1H COSY, DEPT-135, HMBC and HMQC spectra. In addition, the antimicrobial activity of these complexes and the free ligands are assessed against both Gram-positive and Gram-negative bacteria, as well as yeasts. In general, the addition of metal ions improved the antimicrobial activity of both 6-methyl-2-thiouracil and 6-propyl-2-thiouracil. The Cu(II) complex with 6-methyl-2-thiouracil and the Pd(II) complex with 6-propyl-2-thiouracil exhibited the highest activity against the test microorganisms.Item Synthesis, Characterization, and Antibacterial Studies of New Cu(II) and Pd(II) Complexes with 6-Methyl-2-Thiouracil and 6-Propyl-2-Thiouracil(2023-12-01) Marinova P.; Hristov M.; Tsoneva S.; Burdzhiev N.; Blazheva D.; Slavchev A.; Varbanova E.; Penchev P.The aim of the present study is to synthesize new metal complexes of 6-methyl-2-thiouracil and 6-propyl-2-thiouracil, elucidate their structures, and investigate their biological properties. All metal complexes were obtained after mixing water solutions of the corresponding metal salts and the ligand dissolved in DMSO and water solutions of NaOH in a metal-to-ligand ratio of 1:4:2. The structures of the new compounds are discussed based on melting point analysis (MP-AES) for Cu and Pd, UV-Vis, IR, ATR, 1H NMR, 13C NMR, and Raman spectroscopy. The interpretation of complex spectra is assisted by the data for 6-methyl-2-thiouracil and 6-propyl-2-thiouracil obtained from 1H-1H COSY, DEPT-135, HMBC and HMQC spectra. In addition, the antimicrobial activity of these complexes and the free ligands are assessed against both Gram-positive and Gram-negative bacteria, as well as yeasts. In general, the addition of metal ions improved the antimicrobial activity of both 6-methyl-2-thiouracil and 6-propyl-2-thiouracil. The Cu(II) complex with 6-methyl-2-thiouracil and the Pd(II) complex with 6-propyl-2-thiouracil exhibited the highest activity against the test microorganisms.