Nickel(II) complexes of polyhydroxybenzaldehyde N4-thiosemicarbazones: synthesis, structural characterization and antimicrobial activities
作者:Hana Bashir Shawish、Mohammadjavad Paydar、Chung Yeng Looi、Yi Li Wong、Elaheh Movahed、Siti Nadiah Abdul Halim、Won Fen Wong、Mohd-Rais Mustafa、Mohd Jamil Maah
DOI:10.1007/s11243-013-9777-6
日期:2014.2
Nickel(II) complexes with 2,3-dihydroxybenzaldehyde N4-substituted thiosemicarbazone ligands (H3L1–H3L4) have been synthesized and characterized with the aim of evaluating the effect of N4 substitution in the thiosemicarbazone moiety on their coordination behavior and biological activities. Two series of nickel(II) complexes with the general formulae [Ni(H3L)(H2L)]ClO4 and [Ni2(HL)2] were characterized by analytical and spectral techniques. The molecular structure of one of the complexes, namely, [Ni(H3L4)(H2L4)]ClO4 was established by single crystal X-ray diffraction studies. The crystal structure of this complex revealed that two H3L4 ligands are coordinated to nickel(II) in different modes; one as a neutral tridentate ONS ligand and the other is as a monoanionic tridentate (ONS−) ligand. The antimicrobial activities of the compounds were tested against 25 bacterial strains via the disc diffusion method, and their minimum inhibitory concentration (MIC) and minimum microbicidal concentration were evaluated using microdilution methods. With a few exceptions, most of the compounds exhibited low-to-moderate inhibitory activities against the tested bacterial strains. However, the complexes [Ni2(HL3)2] (7) and [Ni2(HL4)2] (8) indicated higher inhibitory activity against Salmonella enterica ATCC 9068 (MIC values 15.7 and <15.7 μg/ml, respectively), compared with gentamicin as the positive control (MIC 25 μg/ml). Complex (7) also inhibited Streptococcus pneumoniae more efficiently (MIC 31.2 μg/ml), compared with gentamicin (MIC > 50 μg/ml). The toxicities of the compounds were tested on brine shrimp (Artemia salina), where no meaningful toxicity level was noted for both the free ligands and the complexes. The cytotoxicities of the compounds on cell viability were determined on MCF7, PC3, A375, and H413 cancer cells in terms of IC50; complexes [Ni(H3L3)(H2L3)]ClO4 (3), [Ni2(HL3)2] (7) and [Ni2(HL4)2] (8) exhibited significant cytotoxicity on the tested cell lines.
合成了具有2,3-二羟基苯甲醛N4取代硫半缩二氨基脲配体(H3L1~H3L4)的镍(II)配合物,并对其进行了表征,旨在评估硫半缩二氨基脲部分的N4取代对其配位行为和生物活性的影响。通过分析和光谱技术表征了两系列镍(II)配合物,其通式分别为[Ni(H3L)(H2L)]ClO4和[Ni2(HL)2]。其中一个配合物[Ni(H3L4)(H2L4)]ClO4的分子结构通过单晶X射线衍射研究确定。该配合物的晶体结构揭示了两个H3L4配体以不同的方式与镍(II)配位;一个作为中性三齿ONS配体,另一个作为单阴离子三齿(ONS−)配体。通过纸片扩散法测试了这些化合物对25种细菌菌株的抗菌活性,并使用微量稀释法评估了它们的最小抑制浓度(MIC)和最小杀菌浓度。除少数例外,大多数化合物对测试的细菌菌株表现出低至中等的抑制活性。然而,配合物[Ni2(HL3)2](7)和[Ni2(HL4)2](8)对沙门氏菌ATCC 9068表现出较高的抑制活性(MIC值分别为15.7和<15.7 μg/ml),相较于阳性对照庆大霉素(MIC 25 μg/ml)。配合物(7)对肺炎链球菌的抑制效率也更高(MIC 31.2 μg/ml),相较于庆大霉素(MIC > 50 μg/ml)。这些化合物对卤虫(Artemia salina)的毒性进行了测试,自由配体和配合物均未显示出有意义的毒性水平。通过IC50评估了这些化合物对MCF7、PC3、A375和H413癌细胞的细胞毒性,配合物[Ni(H3L3)(H2L3)]ClO4(3)、[Ni2(HL3)2](7)和[Ni2(HL4)2](8)对测试的细胞系表现出显著的细胞毒性。