Preparation of amino acid derivatives of avarone and tert-butyl quinone and examination of their biological activity.

U okviru ove doktorske disertacije je sintetisana serija aminokiselinskih derivata seskviterpenskog hinona avarona, izolovanog iz morskog sunđera Dysidea avara, kao i model jedinjenja tert-butilhinona. Određena je in vitro antitumorska aktivnost svih jedinjenja prema humanim tumorskim ćelijskim linijama (HeLa, A549, Fem-X, K562, MDA-MB-453) i zdravoj MRC-5 ćelijskoj liniji. Utvrđeno je da aminokiselinski derivati avarona pokazuju jače dejstvo nego odgovarajući aminokiselinski derivati tert-butilhinona, sa IC50 vrednostima pojedinih derivata nižim od 10 μM. Rezultati analize ćelijskog ciklusa na HeLa ćelijama ukazuju da je apoptoza jedan od mogućih mehanizama dejstva derivata. Ispitan je uticaj kaspaza 3, 8 i 9 na ćelijsku smrt korišćenjem specifičnih kaspaznih inhibitora. Ispitano je i antimikrobno dejstvo derivata prema nizu Gram-pozitivnih i Gramnegativnih bakterija, kao i na tri soja gljivica, pri čemu je zabeležena vrlo dobra aktivnost derivata avarona. Ispitane su interakcije derivata sa biomakromolekulima. SDS gel-ektroforezom i masenom spektrometrijom je potvrđeno da sintetisana jedinjenja ne modifikuju lizozim. Spektrofotometrijskim ispitivanjima je zabeležena pojava hiperhromizma kao posledica interakcija između hinona i CT-DNA. Utvrđeno je da dolazi do smanjenja intenziteta fluorescencije interkalatora etidijum-bromida i boje Hoechst 33258 koja se vezuje u malu brazdu u kompleksu derivata sa CT-DNA. Spektri cirkularnog dihroizma su ukazali na izostanak interkalacije hinona u CT-DNA. Rezultati molekulskog modelovanja su sugerisali da se derivati smeštaju u malu brazdu DNA. Elektroforetska ispitivanja su potvrdila da ne dolazi do cepanja plazmida pUC19 u prisustvu derivata. Na kraju je utvrđen stepen antioksidativne aktivnosti dobijenih aminokiselinskih derivata hinona.In this doctoral dissertation, a series of amino acid derivatives of the sesquiterpene quinone avarone, isolated from the marine sponge Dysidea avara, as well as the model compund tert-butylquinone has been synthesized. In vitro cytotoxic activity of all compounds toward human cancer cell lines (HeLa, A549, Fem-X, K562, MDA-MB-453) and normal MRC-5 cell line was determined. It was found that the amino acid derivatives of avarone exhibit a stronger activity than the corresponding amino acid derivatives of tert-butylquinone, with IC50 values of some derivatives less than 10 μM. The results of the cell cycle analysis of HeLa cells indicate that apoptosis is one of the possible mechanisms of action of derivatives. The effect of caspases 3, 8, and 9 on cell death by using specific caspase inhibitors was examined. The antimicrobial effect of the derivatives on the panel of Gram-positive and Gram-negative bacteria, as well as on three fungal species, were investigated, whereby very good activity of avarone derivatives was observed. Interactions of the derivatives with biomacromolecules were studied. SDS gelelectrophoresis and mass spectrometry confirmed the absence of modifications of lysozyme by any of the synthesized compounds. Spectrophotometric studies have recorded the occurrence of hyperchromism as a result of interactions between the quinone and CT-DNA. The quenching of the fluorescence of the intercalator ethidium bromide and of the minor groove binder Hoechst 33258 in the complex with CT-DNA by the derivatives was determined. Circular dichroism spectra demonstrated a nonintercalative binding mode of the quinone derivatives to CT-DNA. The results of molecular modeling suggested that the derivatives bind to the minor groove. The electrophoretic pattern showed no cleavage of the pUC19 plasmid in the presence of any derivatives. Finally, the degree of antioxidant activity of the obtained amino acid derivatives of the quinones was determined

Supplementary material for the article: Vilipić, J. P.; Novaković, I. T.; Zlatović, M. V.; Vujčić, M. T.; Tufegdžić, S. J.; Sladić, D. M. Interactions of Cytotoxic Amino Acid Derivatives of Tert-Butylquinone with DNA and Lysozyme. Journal of the Serbian Chemical Society 2016, 81 (12), 1345–1358. https://doi.org/10.2298/JSC160725101V

Supplementary material for: [https://doi.org/10.2298/JSC160725101V]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2389

Supplementary material for the article: Vilipić, J. P.; Novaković, I. T.; Zlatović, M. V.; Vujčić, M. T.; Tufegdžić, S. J.; Sladić, D. M. Interactions of Cytotoxic Amino Acid Derivatives of Tert-Butylquinone with DNA and Lysozyme. Journal of the Serbian Chemical Society 2016, 81 (12), 1345–1358. https://doi.org/10.2298/JSC160725101V

Supplementary material for: [https://doi.org/10.2298/JSC160725101V]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2389

Supplementary data for article: Vilipić, J.; Novaković, I.; Stanojković, T.; Matić, I.; Šegan, D.; Kljajić, Z.; Sladić, D. Synthesis and Biological Activity of Amino Acid Derivatives of Avarone and Its Model Compound. Bioorganic and Medicinal Chemistry 2015, 23 (21), 6930–6942. https://doi.org/10.1016/j.bmc.2015.09.044

Supplementary material for: [https://doi.org/10.1016/j.bmc.2015.09.044]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1997]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3438

Interactions of cytotoxic amino acid derivatives of tert-butylquinone with DNA and lysozyme

The interactions of nine amino acid derivatives of tert-butylquinone with biomacromolecules were studied. Sodium dodecyl sulphate (SDS) gel electrophoresis and mass spectrometry confirmed the absence of modifications of lysozyme by any of the synthesized compounds. Spectrophotometric studies demonstrated hyperchromism, i.e., the existence of interactions between the quinones and calf thymus DNA (CT-DNA). Determination of the binding constants by absorption titration indicated weak interactions between the quinone derivatives and CT-DNA. The quenching of fluorescence of the intercalator ethidium bromide (EB) from the EB-CT-DNA system and of the minor groove binder Hoechst 33258 (H) from the H-CT-DNA system by the synthesized derivatives indicated interactions of the compounds and CT-DNA. Circular dichroism (CD) spectra demonstrated a non-intercalative binding mode of the quinone derivatives to CT-DNA. Molecular docking results confirmed binding to the minor groove. The electrophoretic pattern showed no cleavage of the pUC19 plasmid in the presence of any of the synthesized compounds. The ability of the derivatives to scavenge radicals was confirmed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) test. All the presented results suggest that the DNA minor groove binding is the principal mechanism of action of the examined amino acid derivatives

Supplementary data for article: Milenković, M. R.; Bacchi, A.; Cantoni, G.; Vilipić, J.; Sladić, D.; Vujčić, M.; Gligorijević, N.; Jovanovic, K.; Radulović, S. S. Synthesis, Characterization and Biological Activity of Three Square-Planar Complexes of Ni(II) with Ethyl (2E)-2-[2-(Diphenylphosphino) Benzylidene]Hydrazinecarboxylate and Monodentate Pseudohalides. European Journal of Medicinal Chemistry 2013, 68, 111–120. https://doi.org/10.1016/j.ejmech.2013.07.039

Supplementary material for: [https://doi.org/10.1016/j.ejmech.2013.07.039]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1436

Preparation of amino acid derivatives of avarone and tert-butyl quinone and examination of their biological activity.

U okviru ove doktorske disertacije je sintetisana serija aminokiselinskih derivata seskviterpenskog hinona avarona, izolovanog iz morskog sunđera Dysidea avara, kao i model jedinjenja tert-butilhinona. Određena je in vitro antitumorska aktivnost svih jedinjenja prema humanim tumorskim ćelijskim linijama (HeLa, A549, Fem-X, K562, MDA-MB-453) i zdravoj MRC-5 ćelijskoj liniji. Utvrđeno je da aminokiselinski derivati avarona pokazuju jače dejstvo nego odgovarajući aminokiselinski derivati tert-butilhinona, sa IC50 vrednostima pojedinih derivata nižim od 10 μM. Rezultati analize ćelijskog ciklusa na HeLa ćelijama ukazuju da je apoptoza jedan od mogućih mehanizama dejstva derivata. Ispitan je uticaj kaspaza 3, 8 i 9 na ćelijsku smrt korišćenjem specifičnih kaspaznih inhibitora. Ispitano je i antimikrobno dejstvo derivata prema nizu Gram-pozitivnih i Gramnegativnih bakterija, kao i na tri soja gljivica, pri čemu je zabeležena vrlo dobra aktivnost derivata avarona. Ispitane su interakcije derivata sa biomakromolekulima. SDS gel-ektroforezom i masenom spektrometrijom je potvrđeno da sintetisana jedinjenja ne modifikuju lizozim. Spektrofotometrijskim ispitivanjima je zabeležena pojava hiperhromizma kao posledica interakcija između hinona i CT-DNA. Utvrđeno je da dolazi do smanjenja intenziteta fluorescencije interkalatora etidijum-bromida i boje Hoechst 33258 koja se vezuje u malu brazdu u kompleksu derivata sa CT-DNA. Spektri cirkularnog dihroizma su ukazali na izostanak interkalacije hinona u CT-DNA. Rezultati molekulskog modelovanja su sugerisali da se derivati smeštaju u malu brazdu DNA. Elektroforetska ispitivanja su potvrdila da ne dolazi do cepanja plazmida pUC19 u prisustvu derivata. Na kraju je utvrđen stepen antioksidativne aktivnosti dobijenih aminokiselinskih derivata hinona.In this doctoral dissertation, a series of amino acid derivatives of the sesquiterpene quinone avarone, isolated from the marine sponge Dysidea avara, as well as the model compund tert-butylquinone has been synthesized. In vitro cytotoxic activity of all compounds toward human cancer cell lines (HeLa, A549, Fem-X, K562, MDA-MB-453) and normal MRC-5 cell line was determined. It was found that the amino acid derivatives of avarone exhibit a stronger activity than the corresponding amino acid derivatives of tert-butylquinone, with IC50 values of some derivatives less than 10 μM. The results of the cell cycle analysis of HeLa cells indicate that apoptosis is one of the possible mechanisms of action of derivatives. The effect of caspases 3, 8, and 9 on cell death by using specific caspase inhibitors was examined. The antimicrobial effect of the derivatives on the panel of Gram-positive and Gram-negative bacteria, as well as on three fungal species, were investigated, whereby very good activity of avarone derivatives was observed. Interactions of the derivatives with biomacromolecules were studied. SDS gelelectrophoresis and mass spectrometry confirmed the absence of modifications of lysozyme by any of the synthesized compounds. Spectrophotometric studies have recorded the occurrence of hyperchromism as a result of interactions between the quinone and CT-DNA. The quenching of the fluorescence of the intercalator ethidium bromide and of the minor groove binder Hoechst 33258 in the complex with CT-DNA by the derivatives was determined. Circular dichroism spectra demonstrated a nonintercalative binding mode of the quinone derivatives to CT-DNA. The results of molecular modeling suggested that the derivatives bind to the minor groove. The electrophoretic pattern showed no cleavage of the pUC19 plasmid in the presence of any derivatives. Finally, the degree of antioxidant activity of the obtained amino acid derivatives of the quinones was determined

Synthesis and biological activity of amino acid derivatives of avarone and its model compound

A series of eighteen derivatives of marine sesquiterpene quinone avarone and its model system tert-butylquinone with amino acids has been synthesized by nucleophilic addition of amino acids to the quinones. In vitro cytotoxic activity toward human cancer cell lines (HeLa, A549, Fem-X, 1(562, MDA-MB-453) and normal MRC-5 cell line was determined. Several compounds showed very strong inhibitory activity with IC50 values less than 10 mu M. Avarone derivatives were more active than the corresponding tert-butylquinone derivatives. The results of the cytofluorimetric analysis of cell cycle of HeLa cells showed that apoptosis might be one of possible mechanism of action of these compounds in cancer cells. In order to examine the influence of caspases on cell death, the apoptotic mechanisms induced by the tested compounds were determined using specific caspases 3, 8 and 9 inhibitors. For all compounds antibacterial activities against six strains of Gram-positive and four strains of Gram-negative bacteria were determined, as well as antifungal activity against three fungal species.The peer-reviewed version: [http://cer.ihtm.bg.ac.rs/handle/123456789/3141

Interactions of cytotoxic amino acid derivatives of tert-butylquinone with DNA lysozyme

The interactions of nine amino acid derivatives of tert-butylquinone with biomacromolecules were studied. SDS electrophoresis and mass spectrometry confirmed the absence of modifications of lysozyme by any of the synthesized compounds. Spectrophotometric studies demonstrated hyperchromism, i.e. existence of interactions between the quinones and CT-DNA. Determination of binding constant by absorption titration indicates weak interactions between quinone derivatives and CT-DNA. The quenching of fluorescence of intercalator ethidium bromide from EB-CT-DNA system and of minor groove binder Hoechst 33258 from H-CT-DNA system by the synthesized derivatives indicates interactions of compounds and CT-DNA. CD spectra demonstrate non-intercalative binding mode of quinone derivaties to CT-DNA. Molecular docking results confirm binding to the minor groove. Electrophoretic pattern showed no cleavage of pUC19 plasmid in the presence of any of the synthesized compounds. The ability of the derivatives to scavenge radicals was confirmed by DPPH test. All the presented results suggest that the DNA minor groove binding is the principal mechanism of action of the examined amino acid derivatives. [Projekat Ministarstva nauke Republike Srbije, br. 172055

Synthesis, characterization and biological activity of three square-planar complexes of Ni(II) with ethyl (2E)-2-[2-(diphenylphosphino)benzylidene]hydrazinecarboxylate and monodentate pseudohalides

Three square-planar complexes of nickel(II) with the tridentate condensation derivative of 2-(diphenylphosphino)benzaldehyde and ethyl carbazate, and monodentate pseudohalides, have been synthesized. Their crystal structures have been determined. All the complexes showed a significant antifungal activity, while only the azido complex displayed antibacterial activity. All the complexes were cytotoxic to a panel of six tumor cell lines, the azido complex showing a similar activity as cisplatin to leukemia cell line K562 and lower toxicity to normal MRC-5 cells than that anticancer agent. The complexes interfered with cell cycle of tumor cells and induced plasmid DNA cleavag