TY  - JOUR
AU  - Krstić, Natalija
AU  - Bjelaković, Mira
AU  - Dabović, Milan
AU  - Pavlović, Vladimir D.
PY  - 2010
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/629
AB  - The reactions of selected alpha,beta-unsaturated steroidal ketones with Lawesson's reagent (LR) in CH(2)Cl(2) and toluene under the standard reaction conditions and with a combination of phosphorus pentasulfide with hexamethyldisiloxane (P(4)S(10)/HMDO) in 1,2-dichlorobenzene (ODCB) under microwave irradiation were investigated and for this purpose several cholestane, androstane and pregnane carbonyl derivatives were chosen. Depending on the reagent and the solvent, 19 new sulfur containing compounds, including dithiones 4c and 4d, alpha,beta-unsaturated 3-thiones 3a-e, dimer-sulfides 2a-e, 1,2,4-trithiolanes 5a-e and phosphonotrithioates 6b-e were synthesized. All newly prepared compounds were characterized by IR, (1)H- and (13)C-NMR spectroscopy and elemental analysis.
PB  - MDPI
T2  - Molecules
T1  - Thionation of Some alpha,beta-Unsaturated Steroidal Ketones
VL  - 15
IS  - 5
SP  - 3462
EP  - 3477
DO  - 10.3390/molecules15053462
ER  - 

@article{
author = "Krstić, Natalija and Bjelaković, Mira and Dabović, Milan and Pavlović, Vladimir D.",
year = "2010",
abstract = "The reactions of selected alpha,beta-unsaturated steroidal ketones with Lawesson's reagent (LR) in CH(2)Cl(2) and toluene under the standard reaction conditions and with a combination of phosphorus pentasulfide with hexamethyldisiloxane (P(4)S(10)/HMDO) in 1,2-dichlorobenzene (ODCB) under microwave irradiation were investigated and for this purpose several cholestane, androstane and pregnane carbonyl derivatives were chosen. Depending on the reagent and the solvent, 19 new sulfur containing compounds, including dithiones 4c and 4d, alpha,beta-unsaturated 3-thiones 3a-e, dimer-sulfides 2a-e, 1,2,4-trithiolanes 5a-e and phosphonotrithioates 6b-e were synthesized. All newly prepared compounds were characterized by IR, (1)H- and (13)C-NMR spectroscopy and elemental analysis.",
publisher = "MDPI",
journal = "Molecules",
title = "Thionation of Some alpha,beta-Unsaturated Steroidal Ketones",
volume = "15",
number = "5",
pages = "3462-3477",
doi = "10.3390/molecules15053462"
}

Krstić, N., Bjelaković, M., Dabović, M.,& Pavlović, V. D.. (2010). Thionation of Some alpha,beta-Unsaturated Steroidal Ketones. in Molecules
MDPI., 15(5), 3462-3477.
https://doi.org/10.3390/molecules15053462

Krstić N, Bjelaković M, Dabović M, Pavlović VD. Thionation of Some alpha,beta-Unsaturated Steroidal Ketones. in Molecules. 2010;15(5):3462-3477.
doi:10.3390/molecules15053462 .

Krstić, Natalija, Bjelaković, Mira, Dabović, Milan, Pavlović, Vladimir D., "Thionation of Some alpha,beta-Unsaturated Steroidal Ketones" in Molecules, 15, no. 5 (2010):3462-3477,
https://doi.org/10.3390/molecules15053462 . .

TY  - JOUR
AU  - Bjelaković, Mira
AU  - Krstić, Natalija
AU  - Todorović, Nina
AU  - Krunić, Aleksej
AU  - Tinant, Bernard
AU  - Dabović, Milan
AU  - Pavlović, Vladimir D.
PY  - 2009
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/620
AB  - In this paper a synthetic pathway to the modified 5,10:13,14-bisfragmentation cholestane derivatives 8-14 is described. The synthesis involves introduction of the 5α- and 14α-hydroxyl groups in the cholestane molecule and subsequent cleavage of the C(5)-C(10) bond in 5α,14α-dihydroxycholestan-3β-yl acetate (4) with the HgO/I2 reagent and the C(13)-C(14) bond in the stereoisomeric 14α-hydroxy-5,10-secosteroids 5 and 6 with the Pb(OAc)4/I2 reagent. Complete and unambiguous 1H and 13C NMR resonance assignments of the obtained secosteroids, as well as the solution conformations of their 10- and 9-membered rings were determined by extensive analysis of 1D and 2D NMR spectral data. The structures and the solid-state conformations of 5,10-secosteroids 5-7 were confirmed by X-ray analysis. All diseco-compounds have a novel 5,10:13,14-disecocholestane skeleton.
PB  - Oxford : Pergamon-Elsevier Science Ltd
T2  - Tetrahedron
T1  - 5,10:13,14-Disecosteroids: novel modified steroids containing 10- and 9-membered rings
VL  - 65
IS  - 46
SP  - 9557
EP  - 9568
DO  - 10.1016/j.tet.2009.09.066
ER  - 

@article{
author = "Bjelaković, Mira and Krstić, Natalija and Todorović, Nina and Krunić, Aleksej and Tinant, Bernard and Dabović, Milan and Pavlović, Vladimir D.",
year = "2009",
abstract = "In this paper a synthetic pathway to the modified 5,10:13,14-bisfragmentation cholestane derivatives 8-14 is described. The synthesis involves introduction of the 5α- and 14α-hydroxyl groups in the cholestane molecule and subsequent cleavage of the C(5)-C(10) bond in 5α,14α-dihydroxycholestan-3β-yl acetate (4) with the HgO/I2 reagent and the C(13)-C(14) bond in the stereoisomeric 14α-hydroxy-5,10-secosteroids 5 and 6 with the Pb(OAc)4/I2 reagent. Complete and unambiguous 1H and 13C NMR resonance assignments of the obtained secosteroids, as well as the solution conformations of their 10- and 9-membered rings were determined by extensive analysis of 1D and 2D NMR spectral data. The structures and the solid-state conformations of 5,10-secosteroids 5-7 were confirmed by X-ray analysis. All diseco-compounds have a novel 5,10:13,14-disecocholestane skeleton.",
publisher = "Oxford : Pergamon-Elsevier Science Ltd",
journal = "Tetrahedron",
title = "5,10:13,14-Disecosteroids: novel modified steroids containing 10- and 9-membered rings",
volume = "65",
number = "46",
pages = "9557-9568",
doi = "10.1016/j.tet.2009.09.066"
}

Bjelaković, M., Krstić, N., Todorović, N., Krunić, A., Tinant, B., Dabović, M.,& Pavlović, V. D.. (2009). 5,10:13,14-Disecosteroids: novel modified steroids containing 10- and 9-membered rings. in Tetrahedron
Oxford : Pergamon-Elsevier Science Ltd., 65(46), 9557-9568.
https://doi.org/10.1016/j.tet.2009.09.066

Bjelaković M, Krstić N, Todorović N, Krunić A, Tinant B, Dabović M, Pavlović VD. 5,10:13,14-Disecosteroids: novel modified steroids containing 10- and 9-membered rings. in Tetrahedron. 2009;65(46):9557-9568.
doi:10.1016/j.tet.2009.09.066 .

Bjelaković, Mira, Krstić, Natalija, Todorović, Nina, Krunić, Aleksej, Tinant, Bernard, Dabović, Milan, Pavlović, Vladimir D., "5,10:13,14-Disecosteroids: novel modified steroids containing 10- and 9-membered rings" in Tetrahedron, 65, no. 46 (2009):9557-9568,
https://doi.org/10.1016/j.tet.2009.09.066 . .

TY  - JOUR
AU  - Krstić, Natalija
AU  - Bjelaković, Mira
AU  - Žižak, Željko
AU  - Pavlović, Mirjana
AU  - Juranić, Zorica
AU  - Pavlović, Vladimir D.
PY  - 2007
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/363
AB  - The antiproliferative activity of previously synthesized (Z)-cholest-4-en-6-one oxime (1), (E)-cholest-4-en-6-one oxime (2), 7-aza-B-homocholest-4-en-6-one (3) and 6-aza-B-homocholest-4-en-7-one (4) and newly synthesized 6-thioxo-7-aza-B-homocholest-4-ene (5) and 6-aza-7-thioxo-B-homocholest-4-ene (6) was tested for their possible effects against two human tumor cell lines, cervical carcinoma (HeLa) and chronic myelogenous leukemia (K-562). Compounds 1-6, exerted a dose-dependent antiproliferative effect toward cell lines used in experimental design, showing high selectivity in their action for tumor cells in comparison to normal immunocompetent cells (non-stimulated PBMC and PHA-stimulated PBMC). Compounds 2, 3 and 4 exhibited a very high but selective antitumor activity, by inducing apoptosis in sensitive, for that purpose targeted tumor cell line (HeLa cells). Low toxic effect upon both non-stimulated, and PHA stimulated PBMCs from control, healthy volunteers, has been detected for compounds 1, 2, 3 and 4. The possible reasons for profound differences in the effects of this spectrum of steroidal compounds between tumor cell lines and normal stimulated and non-stimulated PBMCs are discussed. The molecular mechanisms for apoptotic events in HeLa cell line are suggested. The guidelines for further research are underlined.
PB  - Elsevier
T2  - Steroids
T1  - Synthesis of some steroidal oximes, lactams, thiolactams and their antitumor activities
VL  - 72
IS  - 5
SP  - 406
EP  - 414
DO  - 10.1016/j.steroids.2007.02.005
ER  - 

@article{
author = "Krstić, Natalija and Bjelaković, Mira and Žižak, Željko and Pavlović, Mirjana and Juranić, Zorica and Pavlović, Vladimir D.",
year = "2007",
abstract = "The antiproliferative activity of previously synthesized (Z)-cholest-4-en-6-one oxime (1), (E)-cholest-4-en-6-one oxime (2), 7-aza-B-homocholest-4-en-6-one (3) and 6-aza-B-homocholest-4-en-7-one (4) and newly synthesized 6-thioxo-7-aza-B-homocholest-4-ene (5) and 6-aza-7-thioxo-B-homocholest-4-ene (6) was tested for their possible effects against two human tumor cell lines, cervical carcinoma (HeLa) and chronic myelogenous leukemia (K-562). Compounds 1-6, exerted a dose-dependent antiproliferative effect toward cell lines used in experimental design, showing high selectivity in their action for tumor cells in comparison to normal immunocompetent cells (non-stimulated PBMC and PHA-stimulated PBMC). Compounds 2, 3 and 4 exhibited a very high but selective antitumor activity, by inducing apoptosis in sensitive, for that purpose targeted tumor cell line (HeLa cells). Low toxic effect upon both non-stimulated, and PHA stimulated PBMCs from control, healthy volunteers, has been detected for compounds 1, 2, 3 and 4. The possible reasons for profound differences in the effects of this spectrum of steroidal compounds between tumor cell lines and normal stimulated and non-stimulated PBMCs are discussed. The molecular mechanisms for apoptotic events in HeLa cell line are suggested. The guidelines for further research are underlined.",
publisher = "Elsevier",
journal = "Steroids",
title = "Synthesis of some steroidal oximes, lactams, thiolactams and their antitumor activities",
volume = "72",
number = "5",
pages = "406-414",
doi = "10.1016/j.steroids.2007.02.005"
}

Krstić, N., Bjelaković, M., Žižak, Ž., Pavlović, M., Juranić, Z.,& Pavlović, V. D.. (2007). Synthesis of some steroidal oximes, lactams, thiolactams and their antitumor activities. in Steroids
Elsevier., 72(5), 406-414.
https://doi.org/10.1016/j.steroids.2007.02.005

Krstić N, Bjelaković M, Žižak Ž, Pavlović M, Juranić Z, Pavlović VD. Synthesis of some steroidal oximes, lactams, thiolactams and their antitumor activities. in Steroids. 2007;72(5):406-414.
doi:10.1016/j.steroids.2007.02.005 .

Krstić, Natalija, Bjelaković, Mira, Žižak, Željko, Pavlović, Mirjana, Juranić, Zorica, Pavlović, Vladimir D., "Synthesis of some steroidal oximes, lactams, thiolactams and their antitumor activities" in Steroids, 72, no. 5 (2007):406-414,
https://doi.org/10.1016/j.steroids.2007.02.005 . .

TY  - JOUR
AU  - Bjelaković, Mira
AU  - Krstić, Natalija
AU  - Juranić, Nenad
AU  - Dabović, Milan
AU  - Gojković, S.V.
AU  - Kessler, M.
AU  - Kalvoda, J.
AU  - Pavlović, Vladimir D.
PY  - 2007
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/358
AB  - We report herein the synthesis of a novel modified steroid with two rigidly positioned amino acids in C- and N-protected forms (Gly-OtBu and N-Fmoc-l-Phe) at the angular positions (C-18 methylamino group and C-19 carboxylic function) of the steroid nucleus via amide bonds, starting from 18-cyanopregnenolone acetate over 10 steps. In an attempt to gain more insight into the structural and conformational features of this novel 18-Phe,19-Gly-containing steroidal compound, we describe the detailed 2D NMR spectral analysis. Despite the large size and the conformational flexibility of the amino acid units in this molecule, conformational analysis by NOESY connectivities showed the existence of mainly one conformation (∼95%) in CDCl3 solution with approximately parallel orientation of the phenylalanine and glycine moieties.
PB  - Oxford : Pergamon-Elsevier Science Ltd
T2  - Tetrahedron
T1  - Steroid template associated peptides: design, synthesis and 2D NMR characterization of a novel protected 18-Phe,19-Gly-containing steroidal compound
VL  - 63
IS  - 40
SP  - 9960
EP  - 9969
DO  - 10.1016/j.tet.2007.07.056
ER  - 

@article{
author = "Bjelaković, Mira and Krstić, Natalija and Juranić, Nenad and Dabović, Milan and Gojković, S.V. and Kessler, M. and Kalvoda, J. and Pavlović, Vladimir D.",
year = "2007",
abstract = "We report herein the synthesis of a novel modified steroid with two rigidly positioned amino acids in C- and N-protected forms (Gly-OtBu and N-Fmoc-l-Phe) at the angular positions (C-18 methylamino group and C-19 carboxylic function) of the steroid nucleus via amide bonds, starting from 18-cyanopregnenolone acetate over 10 steps. In an attempt to gain more insight into the structural and conformational features of this novel 18-Phe,19-Gly-containing steroidal compound, we describe the detailed 2D NMR spectral analysis. Despite the large size and the conformational flexibility of the amino acid units in this molecule, conformational analysis by NOESY connectivities showed the existence of mainly one conformation (∼95%) in CDCl3 solution with approximately parallel orientation of the phenylalanine and glycine moieties.",
publisher = "Oxford : Pergamon-Elsevier Science Ltd",
journal = "Tetrahedron",
title = "Steroid template associated peptides: design, synthesis and 2D NMR characterization of a novel protected 18-Phe,19-Gly-containing steroidal compound",
volume = "63",
number = "40",
pages = "9960-9969",
doi = "10.1016/j.tet.2007.07.056"
}

Bjelaković, M., Krstić, N., Juranić, N., Dabović, M., Gojković, S.V., Kessler, M., Kalvoda, J.,& Pavlović, V. D.. (2007). Steroid template associated peptides: design, synthesis and 2D NMR characterization of a novel protected 18-Phe,19-Gly-containing steroidal compound. in Tetrahedron
Oxford : Pergamon-Elsevier Science Ltd., 63(40), 9960-9969.
https://doi.org/10.1016/j.tet.2007.07.056

Bjelaković M, Krstić N, Juranić N, Dabović M, Gojković S, Kessler M, Kalvoda J, Pavlović VD. Steroid template associated peptides: design, synthesis and 2D NMR characterization of a novel protected 18-Phe,19-Gly-containing steroidal compound. in Tetrahedron. 2007;63(40):9960-9969.
doi:10.1016/j.tet.2007.07.056 .

Bjelaković, Mira, Krstić, Natalija, Juranić, Nenad, Dabović, Milan, Gojković, S.V., Kessler, M., Kalvoda, J., Pavlović, Vladimir D., "Steroid template associated peptides: design, synthesis and 2D NMR characterization of a novel protected 18-Phe,19-Gly-containing steroidal compound" in Tetrahedron, 63, no. 40 (2007):9960-9969,
https://doi.org/10.1016/j.tet.2007.07.056 . .