Alpha-glucosidase and carbonic anhydrase inhibition studies of Pd(II)-hydrazide complexes

This study focused on the synthesis and characterization of hydrazide ligands and their respective Pd(II) complexes and used high throughput screening to determine their α-glucosidase and carbonic anhydrase II enzyme inhibition activities. The physical, analytical (elemental analyses for C, H, N and Pd) and spectral (FT-IR, 1H NMR, 13C NMR, EI-mass) techniques utilized during characterization revealed the formation of square planar, neutral and 1:2 Pd(II)-hydrazide complexes with the general formula [PdL2Cl2]. In these Pd(II) complexes, the hydrazide ligands are monodentate; the terminal nitrogen is the donor atom. The uncoordinated hydrazide ligands were inactive against both α-glucosidase and carbonic anhydrase II enzymes; however, the respective Pd(II)-hydrazide complexes were approximately 300 times more potent α-glucosidase inhibitors than the standard compound, 1-deoxynojirimycin (DNJ). Some of the Pd(II) complexes also demonstrated potential carbonic anhydrase (CA) inhibition properties comparable to the standard compound, acetazolamide (ACZ).Higher Education Commission of Pakistan for financial support (‘The National Research Grants Program for Universities’, grant No.1862/R&D/10) and MMT acknowledges the support from Fulbright Scholar Award from The J. William Fulbright Foreign Scholarship Board. Open Access funded by King Saud University

Advances in Smart Materials and Applications

This is one of a series of special issues published in Advances in Materials Science and Engineering, focusing on the latest advances of smart materials and their applications. Evolution of engineering materials is strongly depending on the growing transformation of complexity in engineering products. New materials being designed are required to provide specific properties and demonstrate certain functional characteristics by manipulating their dimension, chemistry, and structure through various advanced technologies.Therefore, “smartness” of a material has become the topic of interest. Properties of smart materials may change accordingly to the applied external stimuli. Under the direction of the editorial team, we showcase advances of organic and inorganic based smart materials and their applications in areas of specific interest such as energy, environment, and health. A total of 9 articles are published in this special issue. Six articles are focused on production, synthesis, and optimization of smart materials; and the remaining are dedicated to application of smart materials

Synthesis, characterization, lipoxygenase, and tyrosinase inhibitory activities of non- cytotoxic titanium(III) and (IV) hydrazide complexes

Ti(III) and (IV) hydrazide complexes were synthesized, characterized, and screened for their tyrosinase and lipoxygenase inhibitory and cytotoxic activities. The geometry of Ti(III) hydrazide complexes is tentatively assigned as octahedral. Magnetic moments were found around 1.7 B.M. and electronic spectral transition in the range of 495-518 nm. Evaluation of Ti(IV) and Ti(III) hydrazide complexes for tyrosinase and lipoxygenase inhibitory activities revealed varying inhibition potential. Hydrazide ligands were inactive against tyrosinase, while significant activity was observed against lipoxygenase (LOX). Good to moderate inhibition activity was observed by Ti(IV) and Ti(III) hydrazide complexes against both enzymes. At the same time, promising results were obtained for Ti(IV) hydrazide complexes against tyrosinase enzymes suggesting their broad application as tyrosinase inhibitors. Complex 4d possess negative inhibition, thus behaving as a tyrosinase activator. The docking results showed a good correlation between complex experimental activities and binding energies. Cytotoxic investigation revealed the non-toxicity of complexes against normal cells.Z. Shaikh is thankful to the Higher Education Commission for Indigenous Scholarship No. 213-65456-2PS2-101 under Ph.D. Fellowships for 5000 scholars, HEC (Phase-II). Furthermore, the authors thank the Higher Education Commission of Pakistan for financial support (‘The National Research Grants Program for Universities’, Grant No. 1862/R&D/10)

Cytotoxic, antiglycation and carbonic anhydrase inhibition studies of chromium(III)-aroylhydrazine complexes

In order to further reveal the chemistry and biochemistry of chromium(III) complexes, the present work illuminates the formation of chromium(III) complexes with aroylhydrazine ligands with their physical, chemical and spectral studies. Another significant contribution of this study is the evaluation of the cytotoxic activity, antiglycation property and carbonic anhydrase inhibition study of synthesized chromium(III)-aroylhydrazine complexes. Synthesis and structural investigation of aroylhydrazine ligands (1-7) and their chromium(III) complexes (1a-7a) were carried out by using elemental analysis (C, H, N), physical (conductivity measurements) and spectral (EI-Mass, ESI-Mass, FTIR and UV-Visible) methods. These physical, analytical and spectral data supports that all chromium(III)-aroylhydrazine complexes exhibit an octahedral geometry in which ligand exhibits as a bidentate coordination and two water molecules coordinated at equatorial positions with general formula [Cr(L)2(H2O)2]Cl3. Cytotoxic investigations shows that synthesized chromium(III)-aroylhydrazine complexes were not found to be toxic against normal cells so these compounds were further studied for other biological activities. Moreover, aroylhydrazine ligands and their chromium(III) complexes were examined for their antiglycation activity in which ligands were found inactive whereas chromium(III)-aroylhydrazine complexes showed significant inhibition of the process of protein glycation. Similarly, in carbonic anhydrase inhibition studies all aroylhydrazine ligands were observed inactive while some of chromium(III)-aroylhydrazine complexes showed potential in carbonic anhydrase inhibition

In vitro Synthesis, Structure Elucidation, and Antioxidant Properties of Platinum(IV)-hydrazide Complexes: Molecular Modeling of Free-Hydrazides Suggested as Potent Lipoxygenase Inhibitor

Background: A combination of biologically active ligand and metal in one molecule may increase the activity and reduce the toxicity. Objectives: In this study, the synthesis and characterization of platinum(IV) complexes with bioac-tive hydrazide ligands are discussed. Method: Elemental analysis, conductivity measurements, and spectroscopic studies were used to elucidate the structure of complexes. Results: Our study suggests that hydrazide ligands coordinate with Pt(IV) in a bidentate fashion. The platinum(IV) complexes have octahedral geometry with a metal to ligand ratio of 1:2. Hydrazide ligands were coordinated with central metal platinum(IV) by oxygen of carbonyl group and nitrogen of primary amine. Synthesized complexes exhibited variable DPPH radical scavenging and lipoxy-genase inhibition activity. Furthermore, it is also found that Pt(IV)-hydrazide complexes are more potent superoxide and nitric oxide radical scavengers than their uncoordinated hydrazide ligands, while in the case of lipoxygenase enzyme inhibition, some of the free hydrazide ligands are more active than their respective Pt(IV) complexes. In silico docking technique explores molecular interactions of synthesized ligands in the active site of the lipoxygenase enzyme. Predicted docking energies are in good agreement with experimental data suggesting that in silico studies might be useful for the discovery of therapeutic candidates. Conclusion: Structure-function relationship demonstrates that the radical scavenging and enzyme inhibition activities of the Pt(IV) compounds are affected by the nature of the ligand, position of substituent, electronic and steric effects. However, electronic factors seem to play a more important role than other factors

Chemistry and antioxidant properties of titanium(IV) complexes

The synthesis of titanium(IV) complexes with biologically active hydrazide ligands has been carried out. The complexes were characterized by spectroscopic methods (IR, 1H NMR and 13C NMR), elemental analysis and conductivity studies. These studies suggest bidentate coordination of the ligands through carbonyl oxygen and primary amine nitrogen, resulting in octahedral geometries. Hydrazides with pyridyl substituents displayed 1:2 metal-to-ligand ratio, and hydrazides with imino substituents exhibited 1:3 metal-to-ligand ratio resulting in an outer sphere complex. The remaining complexes displayed inner sphere coordination with 1:1 metal-to-ligand ratio. These complexes exhibit varying degrees of radical scavenging properties against DPPH, superoxide and nitric oxide free radicals. The free ligands showed inhibition against DPPH but were inactive against superoxide and nitric oxide free radicals. The structure-activity relationships of the complexes are discussed.Authors are thankful to the Higher Education Commission of Pakistan for financial support (‘The National Research Grants Program for Universities,’ Grant No. 1862/R&D/10)

Advances in Smart Materials and Applications

[No abstract available

Tyrosinase and carbonic anhydrase enzymes inhibition studies of vanadium(V) complexes

Present study endeavors synthesis of series of vanadium(V) hydrazide complexes and its enzyme inhibition studies. Octahedral structure of complexes has been evaluated previously using conductance measurements, spectroscopic techniques involving IR, 1H-NMR and 13C-NMR, elemental analysis using CHN technique. Complexes 1c-12c have found to exhibit monomeric form with hydrazides behaving as bidentate ligand coordinating by their N and O atoms, while two oxygen atoms have also been found to show attachment with the metal centre. This study includes activity of vanadium(V) complexes to inhibit tyrosinase and carbonic anhydrase enzymes. For inhibition of carbonic anhydrase all, while for tyrosinase most of the hydrazide ligands were found to be inactive. Vanadium(V) complexes with these hydrazides have found to bear variable degree of carbonic anhydrase and tyrosinase inhibition activity. Some of the vanadium(V) hydrazide complexes were found to be potent inhibitors of tyrosinase enzyme and carbonic anhydrase as well. [ABSTRACT FROM AUTHOR] Copyright of Journal of the Chemical Society of Pakistan is the property of Knowledge Bylanes and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)S. Sultan is thankful to the Higher Education Commission for indigenous scholarship No. 112-34080-2PS1-155 under PhD fellowships for 5000 scholars, HEC (Phase-II). Authors are thankful to the Higher Education Commission of Pakistan for financial support (‘The National Research Grants Program for Universities’, Grant No. 1862/R&D/10)