Photodiagnosis and photodynamic therapy, Jan 29, 2016
The development of new water-soluble photosensitizers for photodynamic therapy (PDT) applications... more The development of new water-soluble photosensitizers for photodynamic therapy (PDT) applications is still very actual research topic. The efforts have been made to obtain the far-red absorbing phthalocyanine complexes with molecular design that facilitates the uptake and selectivity for a high PDT efficiency. The monomolecular lutetium(III) acetate phthalocyanines (LuPcs) substituted with methylpyridyloxy groups at non-peripheral (5) and peripheral (6) positions were synthesized by following the modification of the well-known synthetical routes. The photo-physicochemical properties of the both quaternized LuPcs were evaluated by the steady-state and time-resolved spectroscopy. The photochemical technique was applied to study the generation of the singlet oxygen. Two water-soluble and cationic LuPcs were synthesized and chemically characterized. The photo-physicochemical properties of absorption (675 and 685nm) and the red shifted fluorescence (704 and 721nm) as well as the fluoresc...
Advances in Materials Science and Engineering, 2018
Two novel polyphosphoesters containing anthracene- and furan-derived aminophosphonate moieties, n... more Two novel polyphosphoesters containing anthracene- and furan-derived aminophosphonate moieties, namely, poly[oxyethylene(aminophosphonate-co-H-phosphonate)]s P-12 and P-13, were synthesized through an addition of poly(oxyethylene H-phosphonate) to 9-anthrylidene-furfurylamine and characterized. The novel polyphosphoester P-12 and a series of previously described anthracene-derived compounds including Schiff bases S-1 and S-2, α-aminophosphonates A-3–A-6, bis-aminophosphonate B-6, two enantiomers A-5a and A-5b, and polyphosphoesters P-8–P-11 containing aminophosphonate units were screened for antitumor activity against a panel of human leukemic cell lines, using cisplatin as a reference cytotoxic agent. As concluded from the cytotoxicity assays, both precursors S-1 and S-2 presented similar cytotoxicity profiles that are cisplatin-like only in the REH cell line. Leader compound of the α-aminophosphonates is A-4 with cell death-inducing properties fully equaling those of the referent ...
New tetrazolium method for the histochemical localization of dipeptidyl peptidase IV (DPP IV), ba... more New tetrazolium method for the histochemical localization of dipeptidyl peptidase IV (DPP IV), based on a newly synthesized substrate Gly-L-Pro-1-hydroxy-4-naphthylamide is proposed. Upon the enzyme hydrolysis of the substrate a strong reducing agent, i.e. 4-amino-1-naphthol is released, which reduces tetrazolium salts to water-insoluble, deeply colored formazans, that precipitate on the sites of enzyme activity, marking them accurately. No auxiliary electron acceptor is needed for the redox reaction. The incubation is performed at the optimal pH of the enzyme. Precise enzyme localization is achieved in all organs studied. Thus, the new method avoids most of the disadvantages of the methods in use and might open new possibilities in peptidases histochemistry.
Empirical force‐field calculations and ir and 1H‐nmr spectra indicate that five‐membered (C5) and... more Empirical force‐field calculations and ir and 1H‐nmr spectra indicate that five‐membered (C5) and seven‐membered (C) hydrogen‐bonded rings are the preferred conformations of acetyl‐L‐Phe p‐acetyl and p‐valeryl anilides in nonpolar media. The C5/C ratio was found to be dependent on the dryness of the solute and the solvent. This fact and the results from conformational‐energy calculations suggest that a molecule of water participates in the stabilization of the C conformation.
ABSTRACT The relative rate of the α-chymotrypsin-catalyzed hydrolysis of acetyl-l-phenylalanine p... more ABSTRACT The relative rate of the α-chymotrypsin-catalyzed hydrolysis of acetyl-l-phenylalanine p-alkoxycarbonyl anilides tends to a maximum with the increase of the leaving group bulkiness. This rate enhancement specificity appears to be entropy controlled: the bulky p-alkoxycarbonyl groups increase both enthalpy and entropy of activation. These kinetic and thermodynamic data are interpreted in terms of the stereoelectronic theory for the formation and cleavage of the tetrahedral intermediate in acyl-transfer reactions; the bulky p-alkoxycarbonyl groups favor the formation of a reactive conformation of the enzyme tetrahedral intermediate.
Background/Aim: A number of biologically active substances were proved as an alternative to conve... more Background/Aim: A number of biologically active substances were proved as an alternative to conventional anticancer medicines. The aim of the study is in vitro investigation of the anticancer activity of mono- and di-Rhamnolipids (RL-1 and RL-2) against human breast cancer. Additionally, the combination with Cisplatin was analyzed. Materials and Methods: Breast cell lines (MCF-10A, MCF-7 and MDA-MB-231) were treated with RLs and in combination with Cisplatin. The viability was analyzed using MTT assay, and investigation of autophagy was performed via acridine orange staining. Results: In contrast to the healthy cells, both tested cancer lines exhibited sensitivity to RLs treatment. This effect was accompanied by an influence on the autophagy-related acidic formation process. Only for the triple-negative breast cancer cell line (MDA-MB-231) the synergistic effect of the combined treatment (10 µM Cisplatin and 1 µg/mL RL-2) was observed. Conclusion: Based on studies on the reorganizat...
Comptes rendus de l'Académie bulgare des sciences: sciences mathématiques et naturelles
In the present study the catabolic activity of the biosurfactant-producing strain Nocardia farcin... more In the present study the catabolic activity of the biosurfactant-producing strain Nocardia farcinica BN26 was followed to prove its potential for bioreme- diation. These bacteria were examined for their degradation ability by exposing them to different temperatures and 29 ◦C was found as the optimum temper- ature. The rate of phenol mineralisation by the bacterium using different cell densities was also estimated. The adaptation capabilities of the bacterium in a semicontinuous process with multiple xenobiotic supply was studied. The cells that had undergone 10 passages on 500 mg/l phenol containing medium had the highest capacity for degrading both the aromatic and aliphatic xeno- biotics added at equal concentrations. During the biodegradation of the hy- drophilic and hydrophobic xenobiotics, the biosurfactant production increased up to 500 mg/l. A significant decrease of the surface tension to 32 mN/m was also registered, accompanied by decreased cell hydrophobicity (29%), in tha...
Photodiagnosis and photodynamic therapy, Jan 29, 2016
The development of new water-soluble photosensitizers for photodynamic therapy (PDT) applications... more The development of new water-soluble photosensitizers for photodynamic therapy (PDT) applications is still very actual research topic. The efforts have been made to obtain the far-red absorbing phthalocyanine complexes with molecular design that facilitates the uptake and selectivity for a high PDT efficiency. The monomolecular lutetium(III) acetate phthalocyanines (LuPcs) substituted with methylpyridyloxy groups at non-peripheral (5) and peripheral (6) positions were synthesized by following the modification of the well-known synthetical routes. The photo-physicochemical properties of the both quaternized LuPcs were evaluated by the steady-state and time-resolved spectroscopy. The photochemical technique was applied to study the generation of the singlet oxygen. Two water-soluble and cationic LuPcs were synthesized and chemically characterized. The photo-physicochemical properties of absorption (675 and 685nm) and the red shifted fluorescence (704 and 721nm) as well as the fluoresc...
Advances in Materials Science and Engineering, 2018
Two novel polyphosphoesters containing anthracene- and furan-derived aminophosphonate moieties, n... more Two novel polyphosphoesters containing anthracene- and furan-derived aminophosphonate moieties, namely, poly[oxyethylene(aminophosphonate-co-H-phosphonate)]s P-12 and P-13, were synthesized through an addition of poly(oxyethylene H-phosphonate) to 9-anthrylidene-furfurylamine and characterized. The novel polyphosphoester P-12 and a series of previously described anthracene-derived compounds including Schiff bases S-1 and S-2, α-aminophosphonates A-3–A-6, bis-aminophosphonate B-6, two enantiomers A-5a and A-5b, and polyphosphoesters P-8–P-11 containing aminophosphonate units were screened for antitumor activity against a panel of human leukemic cell lines, using cisplatin as a reference cytotoxic agent. As concluded from the cytotoxicity assays, both precursors S-1 and S-2 presented similar cytotoxicity profiles that are cisplatin-like only in the REH cell line. Leader compound of the α-aminophosphonates is A-4 with cell death-inducing properties fully equaling those of the referent ...
New tetrazolium method for the histochemical localization of dipeptidyl peptidase IV (DPP IV), ba... more New tetrazolium method for the histochemical localization of dipeptidyl peptidase IV (DPP IV), based on a newly synthesized substrate Gly-L-Pro-1-hydroxy-4-naphthylamide is proposed. Upon the enzyme hydrolysis of the substrate a strong reducing agent, i.e. 4-amino-1-naphthol is released, which reduces tetrazolium salts to water-insoluble, deeply colored formazans, that precipitate on the sites of enzyme activity, marking them accurately. No auxiliary electron acceptor is needed for the redox reaction. The incubation is performed at the optimal pH of the enzyme. Precise enzyme localization is achieved in all organs studied. Thus, the new method avoids most of the disadvantages of the methods in use and might open new possibilities in peptidases histochemistry.
Empirical force‐field calculations and ir and 1H‐nmr spectra indicate that five‐membered (C5) and... more Empirical force‐field calculations and ir and 1H‐nmr spectra indicate that five‐membered (C5) and seven‐membered (C) hydrogen‐bonded rings are the preferred conformations of acetyl‐L‐Phe p‐acetyl and p‐valeryl anilides in nonpolar media. The C5/C ratio was found to be dependent on the dryness of the solute and the solvent. This fact and the results from conformational‐energy calculations suggest that a molecule of water participates in the stabilization of the C conformation.
ABSTRACT The relative rate of the α-chymotrypsin-catalyzed hydrolysis of acetyl-l-phenylalanine p... more ABSTRACT The relative rate of the α-chymotrypsin-catalyzed hydrolysis of acetyl-l-phenylalanine p-alkoxycarbonyl anilides tends to a maximum with the increase of the leaving group bulkiness. This rate enhancement specificity appears to be entropy controlled: the bulky p-alkoxycarbonyl groups increase both enthalpy and entropy of activation. These kinetic and thermodynamic data are interpreted in terms of the stereoelectronic theory for the formation and cleavage of the tetrahedral intermediate in acyl-transfer reactions; the bulky p-alkoxycarbonyl groups favor the formation of a reactive conformation of the enzyme tetrahedral intermediate.
Background/Aim: A number of biologically active substances were proved as an alternative to conve... more Background/Aim: A number of biologically active substances were proved as an alternative to conventional anticancer medicines. The aim of the study is in vitro investigation of the anticancer activity of mono- and di-Rhamnolipids (RL-1 and RL-2) against human breast cancer. Additionally, the combination with Cisplatin was analyzed. Materials and Methods: Breast cell lines (MCF-10A, MCF-7 and MDA-MB-231) were treated with RLs and in combination with Cisplatin. The viability was analyzed using MTT assay, and investigation of autophagy was performed via acridine orange staining. Results: In contrast to the healthy cells, both tested cancer lines exhibited sensitivity to RLs treatment. This effect was accompanied by an influence on the autophagy-related acidic formation process. Only for the triple-negative breast cancer cell line (MDA-MB-231) the synergistic effect of the combined treatment (10 µM Cisplatin and 1 µg/mL RL-2) was observed. Conclusion: Based on studies on the reorganizat...
Comptes rendus de l'Académie bulgare des sciences: sciences mathématiques et naturelles
In the present study the catabolic activity of the biosurfactant-producing strain Nocardia farcin... more In the present study the catabolic activity of the biosurfactant-producing strain Nocardia farcinica BN26 was followed to prove its potential for bioreme- diation. These bacteria were examined for their degradation ability by exposing them to different temperatures and 29 ◦C was found as the optimum temper- ature. The rate of phenol mineralisation by the bacterium using different cell densities was also estimated. The adaptation capabilities of the bacterium in a semicontinuous process with multiple xenobiotic supply was studied. The cells that had undergone 10 passages on 500 mg/l phenol containing medium had the highest capacity for degrading both the aromatic and aliphatic xeno- biotics added at equal concentrations. During the biodegradation of the hy- drophilic and hydrophobic xenobiotics, the biosurfactant production increased up to 500 mg/l. A significant decrease of the surface tension to 32 mN/m was also registered, accompanied by decreased cell hydrophobicity (29%), in tha...
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