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Lahcène Ouahab - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and theoretical and experimental nonlinear optical studies of push–pull benzopyranic derivatives containing an oxo, Thioxo or dicyanoethylene Group as acceptor site
New Journal of Chemistry, 1998Co-Authors: Bertrand Illien, Philippe Jehan, Alain Botrel, André Darchen, Isabelle Ledoux, Joseph Zyss, Pierre Le Mague′res, Lahcène OuahabAbstract:A series of new push–pull molecules, containing 4H-1-benzopyran-4-oxo-2-yl, 4H-1-benzopyran-4-Thioxo-2-yl or 4H-1-benzopyran-4-(ylidene malononitrile)-2-yl as acceptor site and 4-dimethylaminophenyl or ferrocenyl as donor site, was synthesized and characterized. The X-ray structures of 2-(4′-dimethylaminophenyl)-4H-1-benzopyran-4-thione and 2-(4′-dimethylaminophenylethenyl)-4H-1-benzopyran-4-thione were established. Experimental dipole moments and first-order hyperpolarizability β data measured in solution by electric-field-induced second-harmonic generation (EFISHG) were compared to computed values obtained by the semiempirical PM3 method for optimized structures. The characteristics of the lowest energy singlet–singlet π→π* transitions were determined through UV/VIS spectral measurements and semiempirical CNDO/S-CIS calculations. All of the experimental and computed results point out the NLO efficiency of the acceptor Thioxo Group, which was compared to the well-known aldehyde or dicyanomethylene substituents. Synthese et e′tudes the′oriques et expe′rimentales en optique non-line′aire de compose′s benzopyraniques de type push–pull contenant des Groupes accepteurs oxo, Thioxo ou dicyanoe′thylene. Une se′rie de nouvelles mole′cules de type donneur–transmetteur–accepteur (D–T–A), comprenant un Groupement 4H-1-benzopyrane-4-oxo-2-yle, 4H-1-benzopyrane-4-Thioxo-2-yle ou 4H-1-benzopyrane-4-(ylidene malononitrile)-2-yle comme accepteur et un Groupement 4-dime′thylaminophe′nyle ou ferrocenyle comme donneur, a e′te′ synthe′tise′e puis caracte′rise′e. Les structures cristallographiques des mole′cules 2-(4′-dime′thylaminophe′nyl)-4H-1-benzopyrane-4-thione et 2-(4′-dime′thylaminophe′nyle′thenyl)-4H-1-benzopyrane-4-thione ont e′te′ e′tablies. Des mesures en solution du moment dipolaire et de l'hyperpolarisabilite′ du premier ordre β (expe′rience EFISHG) ont e′te compare′es aux valeurs calcule′es par la me′thode semi-empirique PM3 a partir de ge′ome′tries optimise′es. Les caracte′ristiques des transitions π→π* singulet–singulet de plus basses e′nergies ont e′te e′value′es a l'aide des spectres UV/VIS et de calculs semi-empiriques CNDO/S-CIS. Tous les re′sultats expe′rimentaux et the′oriques permettent de comparer l'efficacite′ du Groupement accepteur Thioxo a celle des substituants bien connus alde′hyde et dicyanome′thylene.
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synthesis and theoretical and experimental nonlinear optical studies of push pull benzopyranic derivatives containing an oxo Thioxo or dicyanoethylene Group as acceptor site
New Journal of Chemistry, 1998Co-Authors: Bertrand Illien, Philippe Jehan, Alain Botrel, André Darchen, Isabelle Ledoux, Joseph Zyss, Pierre Le Mague Res, Lahcène OuahabAbstract:A series of new push–pull molecules, containing 4H-1-benzopyran-4-oxo-2-yl, 4H-1-benzopyran-4-Thioxo-2-yl or 4H-1-benzopyran-4-(ylidene malononitrile)-2-yl as acceptor site and 4-dimethylaminophenyl or ferrocenyl as donor site, was synthesized and characterized. The X-ray structures of 2-(4′-dimethylaminophenyl)-4H-1-benzopyran-4-thione and 2-(4′-dimethylaminophenylethenyl)-4H-1-benzopyran-4-thione were established. Experimental dipole moments and first-order hyperpolarizability β data measured in solution by electric-field-induced second-harmonic generation (EFISHG) were compared to computed values obtained by the semiempirical PM3 method for optimized structures. The characteristics of the lowest energy singlet–singlet π→π* transitions were determined through UV/VIS spectral measurements and semiempirical CNDO/S-CIS calculations. All of the experimental and computed results point out the NLO efficiency of the acceptor Thioxo Group, which was compared to the well-known aldehyde or dicyanomethylene substituents. Synthese et e′tudes the′oriques et expe′rimentales en optique non-line′aire de compose′s benzopyraniques de type push–pull contenant des Groupes accepteurs oxo, Thioxo ou dicyanoe′thylene. Une se′rie de nouvelles mole′cules de type donneur–transmetteur–accepteur (D–T–A), comprenant un Groupement 4H-1-benzopyrane-4-oxo-2-yle, 4H-1-benzopyrane-4-Thioxo-2-yle ou 4H-1-benzopyrane-4-(ylidene malononitrile)-2-yle comme accepteur et un Groupement 4-dime′thylaminophe′nyle ou ferrocenyle comme donneur, a e′te′ synthe′tise′e puis caracte′rise′e. Les structures cristallographiques des mole′cules 2-(4′-dime′thylaminophe′nyl)-4H-1-benzopyrane-4-thione et 2-(4′-dime′thylaminophe′nyle′thenyl)-4H-1-benzopyrane-4-thione ont e′te′ e′tablies. Des mesures en solution du moment dipolaire et de l'hyperpolarisabilite′ du premier ordre β (expe′rience EFISHG) ont e′te compare′es aux valeurs calcule′es par la me′thode semi-empirique PM3 a partir de ge′ome′tries optimise′es. Les caracte′ristiques des transitions π→π* singulet–singulet de plus basses e′nergies ont e′te e′value′es a l'aide des spectres UV/VIS et de calculs semi-empiriques CNDO/S-CIS. Tous les re′sultats expe′rimentaux et the′oriques permettent de comparer l'efficacite′ du Groupement accepteur Thioxo a celle des substituants bien connus alde′hyde et dicyanome′thylene.
Bertrand Illien - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and theoretical and experimental nonlinear optical studies of push–pull benzopyranic derivatives containing an oxo, Thioxo or dicyanoethylene Group as acceptor site
New Journal of Chemistry, 1998Co-Authors: Bertrand Illien, Philippe Jehan, Alain Botrel, André Darchen, Isabelle Ledoux, Joseph Zyss, Pierre Le Mague′res, Lahcène OuahabAbstract:A series of new push–pull molecules, containing 4H-1-benzopyran-4-oxo-2-yl, 4H-1-benzopyran-4-Thioxo-2-yl or 4H-1-benzopyran-4-(ylidene malononitrile)-2-yl as acceptor site and 4-dimethylaminophenyl or ferrocenyl as donor site, was synthesized and characterized. The X-ray structures of 2-(4′-dimethylaminophenyl)-4H-1-benzopyran-4-thione and 2-(4′-dimethylaminophenylethenyl)-4H-1-benzopyran-4-thione were established. Experimental dipole moments and first-order hyperpolarizability β data measured in solution by electric-field-induced second-harmonic generation (EFISHG) were compared to computed values obtained by the semiempirical PM3 method for optimized structures. The characteristics of the lowest energy singlet–singlet π→π* transitions were determined through UV/VIS spectral measurements and semiempirical CNDO/S-CIS calculations. All of the experimental and computed results point out the NLO efficiency of the acceptor Thioxo Group, which was compared to the well-known aldehyde or dicyanomethylene substituents. Synthese et e′tudes the′oriques et expe′rimentales en optique non-line′aire de compose′s benzopyraniques de type push–pull contenant des Groupes accepteurs oxo, Thioxo ou dicyanoe′thylene. Une se′rie de nouvelles mole′cules de type donneur–transmetteur–accepteur (D–T–A), comprenant un Groupement 4H-1-benzopyrane-4-oxo-2-yle, 4H-1-benzopyrane-4-Thioxo-2-yle ou 4H-1-benzopyrane-4-(ylidene malononitrile)-2-yle comme accepteur et un Groupement 4-dime′thylaminophe′nyle ou ferrocenyle comme donneur, a e′te′ synthe′tise′e puis caracte′rise′e. Les structures cristallographiques des mole′cules 2-(4′-dime′thylaminophe′nyl)-4H-1-benzopyrane-4-thione et 2-(4′-dime′thylaminophe′nyle′thenyl)-4H-1-benzopyrane-4-thione ont e′te′ e′tablies. Des mesures en solution du moment dipolaire et de l'hyperpolarisabilite′ du premier ordre β (expe′rience EFISHG) ont e′te compare′es aux valeurs calcule′es par la me′thode semi-empirique PM3 a partir de ge′ome′tries optimise′es. Les caracte′ristiques des transitions π→π* singulet–singulet de plus basses e′nergies ont e′te e′value′es a l'aide des spectres UV/VIS et de calculs semi-empiriques CNDO/S-CIS. Tous les re′sultats expe′rimentaux et the′oriques permettent de comparer l'efficacite′ du Groupement accepteur Thioxo a celle des substituants bien connus alde′hyde et dicyanome′thylene.
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synthesis and theoretical and experimental nonlinear optical studies of push pull benzopyranic derivatives containing an oxo Thioxo or dicyanoethylene Group as acceptor site
New Journal of Chemistry, 1998Co-Authors: Bertrand Illien, Philippe Jehan, Alain Botrel, André Darchen, Isabelle Ledoux, Joseph Zyss, Pierre Le Mague Res, Lahcène OuahabAbstract:A series of new push–pull molecules, containing 4H-1-benzopyran-4-oxo-2-yl, 4H-1-benzopyran-4-Thioxo-2-yl or 4H-1-benzopyran-4-(ylidene malononitrile)-2-yl as acceptor site and 4-dimethylaminophenyl or ferrocenyl as donor site, was synthesized and characterized. The X-ray structures of 2-(4′-dimethylaminophenyl)-4H-1-benzopyran-4-thione and 2-(4′-dimethylaminophenylethenyl)-4H-1-benzopyran-4-thione were established. Experimental dipole moments and first-order hyperpolarizability β data measured in solution by electric-field-induced second-harmonic generation (EFISHG) were compared to computed values obtained by the semiempirical PM3 method for optimized structures. The characteristics of the lowest energy singlet–singlet π→π* transitions were determined through UV/VIS spectral measurements and semiempirical CNDO/S-CIS calculations. All of the experimental and computed results point out the NLO efficiency of the acceptor Thioxo Group, which was compared to the well-known aldehyde or dicyanomethylene substituents. Synthese et e′tudes the′oriques et expe′rimentales en optique non-line′aire de compose′s benzopyraniques de type push–pull contenant des Groupes accepteurs oxo, Thioxo ou dicyanoe′thylene. Une se′rie de nouvelles mole′cules de type donneur–transmetteur–accepteur (D–T–A), comprenant un Groupement 4H-1-benzopyrane-4-oxo-2-yle, 4H-1-benzopyrane-4-Thioxo-2-yle ou 4H-1-benzopyrane-4-(ylidene malononitrile)-2-yle comme accepteur et un Groupement 4-dime′thylaminophe′nyle ou ferrocenyle comme donneur, a e′te′ synthe′tise′e puis caracte′rise′e. Les structures cristallographiques des mole′cules 2-(4′-dime′thylaminophe′nyl)-4H-1-benzopyrane-4-thione et 2-(4′-dime′thylaminophe′nyle′thenyl)-4H-1-benzopyrane-4-thione ont e′te′ e′tablies. Des mesures en solution du moment dipolaire et de l'hyperpolarisabilite′ du premier ordre β (expe′rience EFISHG) ont e′te compare′es aux valeurs calcule′es par la me′thode semi-empirique PM3 a partir de ge′ome′tries optimise′es. Les caracte′ristiques des transitions π→π* singulet–singulet de plus basses e′nergies ont e′te e′value′es a l'aide des spectres UV/VIS et de calculs semi-empiriques CNDO/S-CIS. Tous les re′sultats expe′rimentaux et the′oriques permettent de comparer l'efficacite′ du Groupement accepteur Thioxo a celle des substituants bien connus alde′hyde et dicyanome′thylene.
Karel Waisser - One of the best experts on this subject based on the ideXlab platform.
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A TLC Study of the Lipophilicity of New Antimycobacterial Active Benzoxazine Derivatives Containing a Thioxo Group
JPC – Journal of Planar Chromatography – Modern TLC, 2011Co-Authors: Eva Petrlikova, Karel WaisserAbstract:Experimental R _M values of a series of 3-(4-alkylphenyl)-4-Thioxo-2 H -1,3-benzoxazine-2( 3H )-ones and 3-(4-alkylphenyl)- 2H -1,3-benzoxazine-2,4( 3H )-dithiones were obtained by a reversed-phase TLC system. The mobile phase was a phosphate buffer with volume fractions of acetone between 80 and 60%. The retention constants R _M^0 were compared with the partition coefficients calculated using different software products. The lipophilicity contributions of the substituents were compared with the π constants.
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A note to the biological activity of benzoxazine derivatives containing the Thioxo Group.
European journal of medicinal chemistry, 2010Co-Authors: Karel Waisser, Eva Petrlikova, Milan Peřina, Věra Klimešová, Jiří Kuneš, Karel Palát, Jarmila Kaustová, Hans-martin Dahse, Karel Waisser, Vera Klimesova, Jioi Kunes, Jarmila Kaustova, Ute MöllmannAbstract:New 3-benzyl-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones and 3-benzyl-2H-1,3-benzoxazine-2,4(3H)-dithiones were synthesized. The compounds were tested for in vitro antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium kansasii and Mycobacterium avium. The replacement of the carbonyl Group by the thiocarbonyl Group increased the antimycobacterial activity. The most active derivatives were more active than isonicotinhydrazide (INH). The cytotoxicity and the antiproliferative activity were studied as well.
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Highly active potential antituberculotics: 3-(4-alkylphenyl)-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones and 3-(4-alkylphenyl)-2H-1,3-benzoxazine-2,4(3H)-dihiones substituted in ring-B by halogen.
Archiv der Pharmazie, 2008Co-Authors: Karel Waisser, Jarmila Kaustova, Jiri Kunes, Josef Matyk, Rafael Dolezal, Hans-martin DahseAbstract:A series of 6-chloro-3-(4-alkylphenyl)-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones, 7-chloro-3-(4-alkylphenyl)-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones, 6-bromo-3-(4-alkylphenyl)-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones, 6,8-dibromo-3-(4-alkylphenyl)-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones, 6-chloro-3-(4-alkylphenyl)-2H-1,3-benzoxazine-2,4(3H)-dithiones, 7-chloro-3-(4-alkylphenyl)-2H-1,3-benzoxazine-2,4(3H)-dithiones, 6-bromo-3-(4-alkylphenyl)-2H-1,3-benzoxazine-2,4(3H)-dithiones and 6,8-dibromo-3-(4-alkylphenyl)-2H-1,3-benzoxazine-2,4(3H)-dithiones was synthesized. The compounds exhibited in-vitro activity against Mycobacterium tuberculosis, M. kansasii (two strains), and M. avium. 6-bromo-3-(4-propylphenyl)-4-Thioxo-2H-1,3-benzoxazin-2(3H)-one and 6-bromo-3-(4-propylphenyl)-2H-1,3-benzoxazin-2,4(3H)-dithione are the most active compounds against M. tuberculosis. The activity is similar to isoniazid (INH). The compounds under study have a broad spectrum of activity against potential pathogenic strains. The replacement of the oxo Group by Thioxo Group of 3-(4-alkylphenyl)-2H-1,3-benzoxazine-2,4(3H)-diones often led to an improvement in the antimycobacterial activity against M. tuberculosis.
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Similarity approach to QSAR. Application to antimycobacterial benzoxazines.
International Journal of Pharmaceutics, 2004Co-Authors: Ana Gallegos, Ramon Carbó-dorca, Robert Ponec, Karel WaisserAbstract:The antimycobacterial activity in six series of substituted 3-phenyl-2H-benzoxazine-2,4(3H)-dithiones and 3-(phenyl)-4-Thioxo-2H-benzoxazine-2,4(3H)-diones has been studied using a quantum molecular similarity approach. The approach is based on the use of fragment self-similarity measures as new universal molecular descriptors applicable for the design of novel theoretical QSAR models. Using this approach it was possible to show that while traditional QSAR models were able to describe the activity only within each of the six sets of studied molecules individually, the proposed approach is much more general and a single universal QSAR model describing the activity of all the 39 studied molecules in all the studied series together was built. The replacement of the oxo Group by the Thioxo Group in position 4 on the benzoxazine ring of the antitubercular 3-(phenyl)-2H-benzoxazine-2,4(3H)-diones increases the activity, as well as the similar replacement in position 2.
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influence of the replacement of the oxo function with the Thioxo Group on the antimycobacterial activity of 3 aryl 6 8 dichloro 2h 1 3 benzoxazine 2 4 3h diones and 3 arylquinazoline 2 4 1h 3h diones
Farmaco, 2001Co-Authors: Karel Waisser, Vera Klimesova, Jioi Kunes, Jiři Gregor, Lenka Kubicova, Hynek Dostal, Jarmila KaustovaAbstract:Series of 3-phenyl-6,8-dichloro-2H-1,3-benzoxazine-2,4(3H)-dithiones, 3-arylquinazoline-2,4(1H,3H)-diones and 3-arylquinazoline-2,4(1H,3H)-dithiones were synthesized, and the antimycobacterial activities of the derivatives evaluated in vitro. The compounds were active against Mycobacterium tuberculosis and conditionally pathogenic mycobacteria (Mycobacterium kansasii and Mycobacterium avium). The replacement of oxygen by sulfur in 3-phenyl-6,8-dichloro-2H-1,3-benzoxazine-2,4(3H)-diones and 3-arylquinazoline-2,4(1H,3H)-diones gave rise to an increase of antimycobacterial activity. The most active compound was 3-(3-chlorophenyl)-6,8-dichloro-2H-1,3-benzoxazine-2,4(3H)-dithione.
Jarmila Kaustova - One of the best experts on this subject based on the ideXlab platform.
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A note to the biological activity of benzoxazine derivatives containing the Thioxo Group.
European journal of medicinal chemistry, 2010Co-Authors: Karel Waisser, Eva Petrlikova, Milan Peřina, Věra Klimešová, Jiří Kuneš, Karel Palát, Jarmila Kaustová, Hans-martin Dahse, Karel Waisser, Vera Klimesova, Jioi Kunes, Jarmila Kaustova, Ute MöllmannAbstract:New 3-benzyl-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones and 3-benzyl-2H-1,3-benzoxazine-2,4(3H)-dithiones were synthesized. The compounds were tested for in vitro antimycobacterial activity against Mycobacterium tuberculosis, Mycobacterium kansasii and Mycobacterium avium. The replacement of the carbonyl Group by the thiocarbonyl Group increased the antimycobacterial activity. The most active derivatives were more active than isonicotinhydrazide (INH). The cytotoxicity and the antiproliferative activity were studied as well.
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Highly active potential antituberculotics: 3-(4-alkylphenyl)-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones and 3-(4-alkylphenyl)-2H-1,3-benzoxazine-2,4(3H)-dihiones substituted in ring-B by halogen.
Archiv der Pharmazie, 2008Co-Authors: Karel Waisser, Jarmila Kaustova, Jiri Kunes, Josef Matyk, Rafael Dolezal, Hans-martin DahseAbstract:A series of 6-chloro-3-(4-alkylphenyl)-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones, 7-chloro-3-(4-alkylphenyl)-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones, 6-bromo-3-(4-alkylphenyl)-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones, 6,8-dibromo-3-(4-alkylphenyl)-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones, 6-chloro-3-(4-alkylphenyl)-2H-1,3-benzoxazine-2,4(3H)-dithiones, 7-chloro-3-(4-alkylphenyl)-2H-1,3-benzoxazine-2,4(3H)-dithiones, 6-bromo-3-(4-alkylphenyl)-2H-1,3-benzoxazine-2,4(3H)-dithiones and 6,8-dibromo-3-(4-alkylphenyl)-2H-1,3-benzoxazine-2,4(3H)-dithiones was synthesized. The compounds exhibited in-vitro activity against Mycobacterium tuberculosis, M. kansasii (two strains), and M. avium. 6-bromo-3-(4-propylphenyl)-4-Thioxo-2H-1,3-benzoxazin-2(3H)-one and 6-bromo-3-(4-propylphenyl)-2H-1,3-benzoxazin-2,4(3H)-dithione are the most active compounds against M. tuberculosis. The activity is similar to isoniazid (INH). The compounds under study have a broad spectrum of activity against potential pathogenic strains. The replacement of the oxo Group by Thioxo Group of 3-(4-alkylphenyl)-2H-1,3-benzoxazine-2,4(3H)-diones often led to an improvement in the antimycobacterial activity against M. tuberculosis.
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influence of the replacement of the oxo function with the Thioxo Group on the antimycobacterial activity of 3 aryl 6 8 dichloro 2h 1 3 benzoxazine 2 4 3h diones and 3 arylquinazoline 2 4 1h 3h diones
Farmaco, 2001Co-Authors: Karel Waisser, Vera Klimesova, Jioi Kunes, Jiři Gregor, Lenka Kubicova, Hynek Dostal, Jarmila KaustovaAbstract:Series of 3-phenyl-6,8-dichloro-2H-1,3-benzoxazine-2,4(3H)-dithiones, 3-arylquinazoline-2,4(1H,3H)-diones and 3-arylquinazoline-2,4(1H,3H)-dithiones were synthesized, and the antimycobacterial activities of the derivatives evaluated in vitro. The compounds were active against Mycobacterium tuberculosis and conditionally pathogenic mycobacteria (Mycobacterium kansasii and Mycobacterium avium). The replacement of oxygen by sulfur in 3-phenyl-6,8-dichloro-2H-1,3-benzoxazine-2,4(3H)-diones and 3-arylquinazoline-2,4(1H,3H)-diones gave rise to an increase of antimycobacterial activity. The most active compound was 3-(3-chlorophenyl)-6,8-dichloro-2H-1,3-benzoxazine-2,4(3H)-dithione.
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New Groups of antimycobacterial agents: 6-chloro-3-phenyl-4-Thioxo-2H-1,3-benzoxazine-2(3H)-ones and 6-chloro-3-phenyl-2H-1,3-benzoxazine-2,4(3H)-dithiones
European Journal of Medicinal Chemistry, 2000Co-Authors: Karel Waisser, Jiri Kunes, Jiři Gregor, Lenka Kubicova, Vera Klimesova, Miloš Macháček, Jarmila KaustovaAbstract:Abstract A series of 6-chloro-3-phenyl-4-Thioxo-2 H -1,3-benzoxazine-2(3 H )-ones 3 and a series of 6-chloro-3-phenyl-2 H -1,3-benzoxazine-2,4(3 H )-dithiones 4 were synthesized by melting 6-chloro-3-phenyl-2 H -1,3-benzoxazine-2,4(3 H )-dione and its derivatives substituted on the phenyl ring 2 with tetraphosphorus decasulfide. Compounds 2c–e , 3 and 4 exhibited in vitro activity against Mycobacterium tuberculosis, M. kansasii (two strains) and M. avium better than or comparable to that of isoniazid. Replacement of the oxo Group by a Thioxo Group at position 4 led to improvement in activity against M. tuberculosis and M. kansasii. The Free-Wilson method and procedure developed by the authors were used to analyse the structure–activity and structure–antimycobacterial profile relationships, respectively.
Natalija M. Krstić - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and preliminary screening for the biological activity of some steroidal Δ4-unsaturated semicarbazone derivatives.
Steroids, 2019Co-Authors: Marijana B. Živković, Irena Novaković, Ivana Z. Matić, Dušan Sladić, Natalija M. KrstićAbstract:Abstract Eleven new steroidal mono- and bis(semicarbazones) 2a–e, 4d and 3a–e have been prepared starting from various 3-oxo-α,β-unsaturated steroids. Mono-semicarbazones 2a–e were further subjected to ethyl chloroacetate in boiling absolute ethanol but, instead of expected intramolecular cyclocondensation reaction products, the new carbazate esters 5a-e were obtained. The structures of all synthesized compounds and identification of each E/Z isomer were deduced by elemental analysis, HRMS, NMR, and IR spectroscopy. Preliminary screening for the cytotoxic activity in vitro of the new compounds has been conducted against three cancer cell lines, K562, Jurkat and HeLa cells. HeLa cells were the most sensitive while K562 cells were the least sensitive to the cytotoxic action of the novel steroid derivatives. Compounds 2e, 3c and 5e were found to have the best but still moderate cytotoxic effects. All tested compounds showed very weak antimicrobial activities. These results demonstrate that the replacement of Thioxo Group with carbonyl Group in steroidal hydrazone derivatives resulted in decrease in their biological activity.