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Oladapo Bakare - One of the best experts on this subject based on the ideXlab platform.

  • Design, synthesis and cytotoxicity studies of Dithiocarbamate ester derivatives of emetine in prostate cancer cell lines
    Bioorganic & Medicinal Chemistry, 2015
    Co-Authors: Emmanuel S. Akinboye, Samuel R. Denmeade, Bernard Kwabi-addo, Zebalda D. Bamji, David Ejeh, Robert L. Copeland, Oladapo Bakare
    Abstract:

    Abstract A small library of emetine Dithiocarbamate ester derivatives were synthesized in 25–86% yield via derivatization of the N2′- position of emetine. Anticancer evaluation of these compounds in androgen receptor positive LNCaP and androgen receptor negative PC3 and DU145 prostate cancer cell lines revealed time dependent and dose-dependent cytotoxicity. With the exception of compound 4c , all the Dithiocarbamate ester analogs in this study showed appreciable potency in all the prostate cancer cell lines (regardless of whether it is androgen receptor positive or negative) with a cytotoxicity IC 50 value ranging from 1.312 ± 0.032 μM to 5.201 ± 0.125 μM by day 7 of treatment. Compared to the sodium Dithiocarbamate Salt 1 , all the Dithiocarbamate ester analogs ( 2 and 4a – 4g ) displayed lower cytotoxicity than compound 1 (PC3, IC 50  = 0.087 ± 0.005 μM; DU145, IC 50  = 0.079 ± 0.003 μM and LNCaP, IC 50  = 0.079 ± 0.003 μM) on day 7 of treatment. Consequently, it appears that S-alkylation of compound 1 leads to a more stable Dithiocarbamate ester derivative that resulted in lower anticancer activity in the prostate cancer cell lines.

  • Design, synthesis, and evaluation of pH-dependent hydrolyzable emetine analogues as treatment for prostate cancer.
    Journal of Medicinal Chemistry, 2012
    Co-Authors: Emmanuel S. Akinboye, Marc D. Rosen, Samuel R. Denmeade, Bernard Kwabi-addo, Oladapo Bakare
    Abstract:

    The N-2′ position of the natural product emetine has been derivatized to thiourea, urea, sulfonamide, Dithiocarbamate, carbamate, and pH responsive hydrolyzable amide analogues. In vitro studies of these analogues in PC3 and LNCaP prostate cancer cell lines showed that the analogues are generally less cytotoxic (average IC50 ranging from 0.079 to 10 μM) than emetine (IC50 ranging from 0.0237 to 0.0329 μM). The pH sensitive sodium Dithiocarbamate Salt 13 and the amide analogues 21, 22, 26 (obtained from maleic and citraconic anhydrides) showed the most promise as acid-activatable prodrugs under mildly acidic conditions found in the cancer microenvironment. These prodrugs released 12–83% of emetine at pH 6.5 and 41–95% emetine at pH 5.5. Compounds 13 and 26 were further shown to exhibit increased cytotoxicity in PC3 cell culture medium that was already below pH 7.0 at the time of treatment.

Sarah J Dolman - One of the best experts on this subject based on the ideXlab platform.

Bhisma K. Patel - One of the best experts on this subject based on the ideXlab platform.

  • A one pot synthesis of [1,3,4]-oxadiazoles mediated by molecular iodine
    RSC Advances, 2012
    Co-Authors: Srimanta Guin, Saroj Kumar Rout, Tuhin Ghosh, Nilufa Khatun, Bhisma K. Patel
    Abstract:

    A one-pot synthesis of 3-amino-1,3,4-oxadiazoles has been achieved from the corresponding Dithiocarbamate Salt, employing the thiophilic property of molecular iodine. The precursor thiosemicarbazides could be derived in situ which underwent an intramolecular cyclodesulfurization in the presence of iodine to afford 3-amino-1,3,4-oxadiazoles exclusively. Apart from being milder and environmentally sustainable, this method involves a simple, reliable approach to give good to excellent yields of the desired products and is compatible with a wide range of functional groups.

  • The thiocarbonyl ‘S’ is softer than thiolate ‘S’: A catalyst-free one-pot synthesis of isothiocyanates in water
    Organic and Biomolecular Chemistry, 2010
    Co-Authors: Latonglila Jamir, Harisadhan Ghosh, Francis A. S. Chipem, Bhisma K. Patel
    Abstract:

    Treatment of the preformed or the in situ generated aryl/alkyl Dithiocarbamates triethylammonium Salt (ArNHCSS−.Et3NH+) with methyl acrylate in an aqueous medium gave solely arylisothiocyanate (ArNCS), whereas the in situ generated aryl dithiocarbamic acid (ArNHCSS−.H+) yielded exclusively the thia-Michael adduct (ArNHCSSCH2CH2COOMe). This differential reactivity can be explained by two alternative mechanisms which is dependent both on the nature of the counter cation and on the pH of the reaction medium. Irrespective of the counter cations, the thiocarbonyl sulfur (=S) atom, having large orbital-coefficient, is softer compared to the thiol/thiolate sulfur (-SH/S−) in a Dithiocarbamate Salt and the former adds to the Michael acceptor by a 1,4-addition.

Emmanuel S. Akinboye - One of the best experts on this subject based on the ideXlab platform.

  • Design, synthesis and cytotoxicity studies of Dithiocarbamate ester derivatives of emetine in prostate cancer cell lines
    Bioorganic & Medicinal Chemistry, 2015
    Co-Authors: Emmanuel S. Akinboye, Samuel R. Denmeade, Bernard Kwabi-addo, Zebalda D. Bamji, David Ejeh, Robert L. Copeland, Oladapo Bakare
    Abstract:

    Abstract A small library of emetine Dithiocarbamate ester derivatives were synthesized in 25–86% yield via derivatization of the N2′- position of emetine. Anticancer evaluation of these compounds in androgen receptor positive LNCaP and androgen receptor negative PC3 and DU145 prostate cancer cell lines revealed time dependent and dose-dependent cytotoxicity. With the exception of compound 4c , all the Dithiocarbamate ester analogs in this study showed appreciable potency in all the prostate cancer cell lines (regardless of whether it is androgen receptor positive or negative) with a cytotoxicity IC 50 value ranging from 1.312 ± 0.032 μM to 5.201 ± 0.125 μM by day 7 of treatment. Compared to the sodium Dithiocarbamate Salt 1 , all the Dithiocarbamate ester analogs ( 2 and 4a – 4g ) displayed lower cytotoxicity than compound 1 (PC3, IC 50  = 0.087 ± 0.005 μM; DU145, IC 50  = 0.079 ± 0.003 μM and LNCaP, IC 50  = 0.079 ± 0.003 μM) on day 7 of treatment. Consequently, it appears that S-alkylation of compound 1 leads to a more stable Dithiocarbamate ester derivative that resulted in lower anticancer activity in the prostate cancer cell lines.

  • Design, synthesis, and evaluation of pH-dependent hydrolyzable emetine analogues as treatment for prostate cancer.
    Journal of Medicinal Chemistry, 2012
    Co-Authors: Emmanuel S. Akinboye, Marc D. Rosen, Samuel R. Denmeade, Bernard Kwabi-addo, Oladapo Bakare
    Abstract:

    The N-2′ position of the natural product emetine has been derivatized to thiourea, urea, sulfonamide, Dithiocarbamate, carbamate, and pH responsive hydrolyzable amide analogues. In vitro studies of these analogues in PC3 and LNCaP prostate cancer cell lines showed that the analogues are generally less cytotoxic (average IC50 ranging from 0.079 to 10 μM) than emetine (IC50 ranging from 0.0237 to 0.0329 μM). The pH sensitive sodium Dithiocarbamate Salt 13 and the amide analogues 21, 22, 26 (obtained from maleic and citraconic anhydrides) showed the most promise as acid-activatable prodrugs under mildly acidic conditions found in the cancer microenvironment. These prodrugs released 12–83% of emetine at pH 6.5 and 41–95% emetine at pH 5.5. Compounds 13 and 26 were further shown to exhibit increased cytotoxicity in PC3 cell culture medium that was already below pH 7.0 at the time of treatment.

Enaam I. Yousif - One of the best experts on this subject based on the ideXlab platform.

  • Formation of macrocyclic complexes with bis(Dithiocarbamate) ligand;synthesis, spectral characterisation and bacterial activity
    2020
    Co-Authors: Enaam I. Yousif, Hasan A. Hasan, Riyadh M. Ahmed, Mohamad J. Al-jeboori
    Abstract:

    The preparation and characterisation of Dithiocarbamate (DTC) ligand and its binuclear metal(II) Dithiocarbamatebased macrocyclic complexes are reported. The free ligand was prepared from the reaction of a bis-secondary amine, CS2 and KOH. The macrocyclic bis(Dithiocarbamate) complexes were synthesised using two approaches; (i) from the reaction of the free ligand with a metal ion, and (ii) via a one-pot reaction. In the free ligand approach, complexes were prepared by the reaction of potassium Dithiocarbamate Salt with the metal ions; MnII, CoII, and CuII. In the one-pot reaction, the complexes were prepared using a bis-secondary amine, CS2, KOH and metal(II) chloride. Ligand and its complexes were fully characterised by elemental analysis, thermal analysis, FTIR, UV-Vis, mass spectroscopy, magnetic susceptibility, conductance, melting points, and 1H, 13C- NMR spectroscopy. These studies revealed the formation of binuclear macrocyclic complexes of the general formula [M(Ln)]2 with tetrahedral geometries for MnII, CoII, and square planar geometry with CuII complex. Bacterial activity of the ligands and their metal complexes were screened for their antibacterial activity against four bacterial species (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus stubtilis), which revealed that the complexes are potentially more active against these bacterial strains, compared with the free ligand.

  • Formation of New Macrocyclic Complexes with Bis (Dithiocarbamate) Ligand;Preparation, Structural Characterisation and Bacterial Activity
    Ibn Al-Haitham Journal For Pure And Applied Science, 2017
    Co-Authors: Hasan A. Hasan, Enaam I. Yousif
    Abstract:

    The synthesis and characterisation of new macrocyclic binuclear metal(II) complexes derived from Dithiocarbamate (DTC) ligand are reported. The reaction of a bis-secondary amine, CS2 and KOH resulted in the formation of the free ligand. Two approaches were implemented to synthesis the macrocyclic bis(Dithiocarbamate) complexes; (i) from the reaction of the free ligand with a metal ion, and (ii) via a one-pot reaction. In the free ligand approach, complexes were obtained by the reaction of Dithiocarbamate Salt with the metal ions; CoII, ZnII and CdII. However, the one-pot reaction is based on the mixing of the bissecondary amine, CS2, KOH and metal(II) chloride. Physico-chemical analyses were implemented to characterise the ligand and its complexes. These include; elemental analysis, thermal analysis, FTIR, UV-Vis, mass spectroscopy, magnetic susceptibility, conductance, melting points and 1H, 13C- NMR spectroscopy. These studies indicated the formation of binuclear macrocyclic complexes of the general formula [M(L)]2 (M= CoII, ZnII and CdII), in which thier geometries about metal centers are tetrahedral. Antibacterial activity of the metal complexes indicated that they have more activity against investigated bacterial strains, compared to the free ligand.