Synthesis, characterization and cytotoxic activity of naturally isolated naringin-metal complexes.

High-purity naringin was isolated from the fruit peels of Citrus maxima and characterized by various spectroscopic methods like UV and NMR. The isolated compound ligand (HL) was used as ligand-metal complexes synthesis after using Ag (I), Y (III) and Ru (III) metals. These ligand-metal complexes were characterized by elemental analysis, FT-IR, UV-VIS, TGA, molar conductance and magnetic properties. Cytotoxic activity of the isolated naringin and its metal complexes were investigated against two human cancer cell lines namely, white breast Adenocarcinoma (MCF7) and Lung carcinoma (A549) using cell viability assay. Transition metal increased the cytotoxic activity of naringin when they were conjugated. LC50 of Ag ligand complex demonstrated strong cytotoxicity against MCF-7 and A549 cell line that was found higher active more than three and four times the strength, respectively when compared to LC50 of Adriamycin. While LC50 of Adriamycin compound was slightly more active only about 30% and twice the strength of the Ru ligand complex against MCF-7 and A549 cell line, respectively.

Uncaria rhynchophylla mediated Ag/NiO nanocomposites: A new insight for the evaluation of cytotoxicity, antibacterial and photocatalytic applications.

The increase of microbial resistance poses threats to human health. Therefore, efficient treatment of microbial resistance is a global challenge.. During this study, the Ag/NiO nanocomposite was fabricated via simple and ecofriendly method, using Uncaria rhynchophylla extract as a reducing and capping agent to avoid the aggregation of as synthesized nanomaterials. Here, a range of characterization techniques were employed to characterize the sample which includes UV-vis spectroscopy, X-ray diffraction, FTIR spectroscopy, electron diffraction spectroscopy (EDX), scanning electron microscopy (SEM). Furthermore, the resultant nanocomposite demonstrated an efficient ability for the inhibition of both gram-positive and gram negative pathogenic multidrug resistant bacteria. Additionally, the Ag/NiO nanocomposite showed a durable antioxidant effect against DPPH that could still reach 63% at very low concentration, i.e. 0.5 mg/mL. Interestingly, the synthesized nanocomposite is efficient for the production of reactive oxygen species (ROS) and shows no hemolytic activity. Likewise, the Ag/NiO nanocomposite displayed excellent photocatalytic activity to degrade 85% methylene blue (MB) by 4 mg/25 mL and could be used for waste water treatment. It is believed that synthesized nanostructure with desirable morphology and preparation simplicity can be promising material for antimicrobial, antioxidant and catalytic applications.

Synthesis and antitumor activity of novel benzimidazole-5-carboxylic acid derivatives and their transition metal complexes as topoisomerease II inhibitors.

N-aminomethyl-1H-benzimidazole-5-carboxylic acid derivatives 2-5 and the ligand, 1-(5 (or 6-)-carboxy-1H-benzimidazol-2-ylmethyl)pyridinium chloride (6; H2L1) have been synthesized. New benzimidazole complexes 7-9 of the ligand 6; H2L1 with Cu2+, Co2 and Zn2+ were prepared. The growth-inhibitory against a panel of 21 human cancer cell lines of the synthesized compounds 1-9 was studied. Compounds 6-9 showed potent growth-inhibitory activity against the studied cell lines. The correlation coefficients according to COMPARE analysis of the National Cancer Institute screening protocol showed that the pattern of the growth-inhibitory effect of the compounds 6-9 was similar to that of etoposide and doxorubicin but different from that of SN-38 and cisplatin. The topoisomerase II inhibitory activity of the tested compounds 6-9 was studied. Compounds 6 and 8 inhibited topoisomerase II activity at 10 times lower concentration than etoposide in relaxation assay.

Novel antiviral benzofuran-transition metal complexes.

(5-(1H-benzo[d]imidazol-2-yl)-1H-pyrrol-3-yl)(6-hydroxy-4,7-dimethoxybenzofuran-5-yl)methanone (4) and 3-(6-hydroxy-4,7-dimethoxybenzofuran-5-carbonyl)-6H-pyrimido[1,6-a]pyrimidine-6,8(7H)-dione (5) were synthesized by the reaction of 4,7-dimethoxy-5-oxo-5H-furo[3,2-g]chromene-6-carbaldehyde (1) with (1H-benzo[d]imidazol-2-yl)methanamine dihydrochloride and 4-amino-2,6-dihydroxypyrimidine, respectively, via ROR in the presence of alcoholic KOH. The metal complexes 6-9 of compound 4; H(2)L(1) with (CuCl(2), FeCl(3), ZnCl(2), and LaCl(3)) and the metal complexes 10-13 of compound 5; H(2)L(2) with (CuCl(2), FeCl(3), CoCl(2) and LaCl(3)) were synthesized to form 1:1 or 1:2 (metal: ligand) complexes. The HIV inhibitory activity of all new compounds was tested. The EC(50) values showed that, all of tested compounds were more potent than Atevirdine. Moreover, the benzoimidazolylpyrrole derivative 4 (EC(50)=9x10(-6)muM) had higher therapeutic index than the standard. The HIV-1 RT inhibitory activity showed that all of the tested compounds showed significant potency but none of them showed higher activity than Atevirdine. The HCV NS3-4A protease inhibitor activity of the tested compounds revealed that the complex formation had great positive effect on the bioactivity, where the Fe-complex 7 was the most potent compound with higher therapeutic index than VX-950, the standard. Also, the cytotoxicity of the synthesized compounds on hepatocyte cell line, showed that Cu-complex 10 was the most potent compound with potency nearly to that of the standard.

New transition metal ion complexes with benzimidazole-5-carboxylic acid hydrazides with antitumor activity.

Metal complexes of 2-methyl-1H-benzimidazole-5-carboxylic acid hydrazide (4a; L(1)) and its Schiff base 2-methyl-N-(propan-2-ylidene)-1H-benzimidazole-5-carbohydrazide (5a; L(2)) with transition metal ions e.g., copper, silver, nickel, iron and manganese were prepared. The complexes formed were 1:1 or 1:2 M:L complexes and have the structural formulae [Cu(L(1))Cl(H(2)O)]Cl x 3 H(2)O (6), [Ag(L(1))NO(3)(H(2)O)] (7), [Ni(L(1))Cl(2)(H(2)O)(2)] x H(2)O (8), [Fe(L(1))Cl(3)(H(2)O)] x 3 H(2)O (9) and [Mn(L(1))(2)Cl(H(2)O)]Cl x 3 H(2)O (10) for ligand L(1), and [Cu(L(2))Cl(2)(H(2)O)(2)] x H(2)O (11), [Ag(L(2))(2)]NO(3) x H(2)O (12), [Ni(L(2))(2)Cl(2)] x 5 H(2)O (13), [Fe(L(2))(2)Cl(2)]Cl x 2 H(2)O (14) and [Mn(L(2))Cl(2)(H(2)O)(2)] x H(2)O (15) for ligand L(2). The antitumor activity of the synthesized compounds has been studied. The silver complex 7 was found to display cytotoxicity (IC(50)=2 microM) against both human lung cancer cell line A549 and human breast cancer cell line MCF-7.