scholarly journals Bis[pyrrolyl Ru(ii)] triads: a new class of photosensitizers for metal–organic photodynamic therapy

2020 ◽  
Vol 11 (44) ◽  
pp. 12047-12069
Author(s):  
Deborah A. Smithen ◽  
Susan Monro ◽  
Mitch Pinto ◽  
John Roque ◽  
Roberto M. Diaz-Rodriguez ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
New Class ◽  
Metal Organic ◽  
Organic Linker

Ten dinuclear Ru(ii) complexes based on the bis[pyrrolyl Ru(ii)] triad scaffold were prepared to evaluate the influence of the central organic linker on the spectroscopic and in vitro photodynamic therapy (PDT) properties of the compounds.

scholarly journals Ionic Liquid Facilitated Melting of the Metal-Organic Framework ZIF-8

2021 ◽  
Author(s):  
Vahid Nozari ◽  
Courtney Calahoo ◽  
Joshua M. Tuffnell ◽  
David A. Keen ◽  
Thomas Bennett ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Ionic Liquid ◽  
Metal Organic Framework ◽  
Interaction Strength ◽  
Decomposition Temperature ◽  
Zeolitic Imidazolate Framework ◽  
New Class ◽  
Metal Organic ◽  
General Guide ◽  
Organic Linker

<div>Hybrid glasses from melt-quenched metal-organic frameworks (MOFs) have been emerging as a new class of materials, which combine the functional properties of crystalline MOFs with the processability of glasses. However, only a handful of the vast variety of crystalline MOFs have been identified as being meltable. Porosity and metal-linker interaction strength have both been identified as crucial parameters in the trade-off between thermal decomposition of the organic linker and, more desirably, melting. For example, the inability of the prototypical zeolitic imidazolate framework (ZIF) ZIF-8 to melt, is ascribed to the instability of the organic linker upon dissociation from the metal center. Here, we demonstrate that the incorporation of an ionic liquid (IL) into the porous interior of ZIF-8 provides a means to reduce its melting temperature to below its thermal decomposition temperature (Tm < Td). Experimental evidence shows that the Tm of ZIF-8 obtained by IL infiltration is around 381 °C, and that the glass forming ability (Tg/Tm) of such melts is above 0.9, i.e. higher than those previously reported for other meltable MOFs. Our structural studies show that the prevention of decomposition, and successful melting, is due to the IL interactions stabilizing the rapidly dissociating ZIF-8 linkers upon heating. This understanding may act as a general guide for extending the range of meltable MOF materials and, hence, the chemical and structural variety of MOF-derived glasses.</div>

scholarly journals Ionic Liquid Facilitated Melting of the Metal-Organic Framework ZIF-8

2021 ◽  
Author(s):  
Vahid Nozari ◽  
Courtney Calahoo ◽  
Joshua M. Tuffnell ◽  
David A. Keen ◽  
Thomas Bennett ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Ionic Liquid ◽  
Metal Organic Framework ◽  
Interaction Strength ◽  
Decomposition Temperature ◽  
Zeolitic Imidazolate Framework ◽  
New Class ◽  
Metal Organic ◽  
General Guide ◽  
Organic Linker

<div>Hybrid glasses from melt-quenched metal-organic frameworks (MOFs) have been emerging as a new class of materials, which combine the functional properties of crystalline MOFs with the processability of glasses. However, only a handful of the vast variety of crystalline MOFs have been identified as being meltable. Porosity and metal-linker interaction strength have both been identified as crucial parameters in the trade-off between thermal decomposition of the organic linker and, more desirably, melting. For example, the inability of the prototypical zeolitic imidazolate framework (ZIF) ZIF-8 to melt, is ascribed to the instability of the organic linker upon dissociation from the metal center. Here, we demonstrate that the incorporation of an ionic liquid (IL) into the porous interior of ZIF-8 provides a means to reduce its melting temperature to below its thermal decomposition temperature (Tm < Td). Experimental evidence shows that the Tm of ZIF-8 obtained by IL infiltration is around 381 °C, and that the glass forming ability (Tg/Tm) of such melts is above 0.9, i.e. higher than those previously reported for other meltable MOFs. Our structural studies show that the prevention of decomposition, and successful melting, is due to the IL interactions stabilizing the rapidly dissociating ZIF-8 linkers upon heating. This understanding may act as a general guide for extending the range of meltable MOF materials and, hence, the chemical and structural variety of MOF-derived glasses.</div>

scholarly journals Ionic liquid facilitated melting of the metal-organic framework ZIF-8

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Vahid Nozari ◽  
Courtney Calahoo ◽  
Joshua M. Tuffnell ◽  
David A. Keen ◽  
Thomas D. Bennett ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Ionic Liquid ◽  
Metal Organic Framework ◽  
Interaction Strength ◽  
Decomposition Temperature ◽  
Zeolitic Imidazolate Framework ◽  
New Class ◽  
Metal Organic ◽  
General Guide ◽  
Organic Linker

AbstractHybrid glasses from melt-quenched metal-organic frameworks (MOFs) have been emerging as a new class of materials, which combine the functional properties of crystalline MOFs with the processability of glasses. However, only a handful of the crystalline MOFs are meltable. Porosity and metal-linker interaction strength have both been identified as crucial parameters in the trade-off between thermal decomposition of the organic linker and, more desirably, melting. For example, the inability of the prototypical zeolitic imidazolate framework (ZIF) ZIF-8 to melt, is ascribed to the instability of the organic linker upon dissociation from the metal center. Here, we demonstrate that the incorporation of an ionic liquid (IL) into the porous interior of ZIF-8 provides a means to reduce its melting temperature to below its thermal decomposition temperature. Our structural studies show that the prevention of decomposition, and successful melting, is due to the IL interactions stabilizing the rapidly dissociating ZIF-8 linkers upon heating. This understanding may act as a general guide for extending the range of meltable MOF materials and, hence, the chemical and structural variety of MOF-derived glasses.

Conjugates of Classical DNA/RNA Binder with Nucleobase: Chemical, Biochemical and Biomedical Applications

2019 ◽  
Vol 26 (30) ◽  
pp. 5609-5624
Author(s):  
Dijana Saftić ◽  
Željka Ban ◽  
Josipa Matić ◽  
Lidija-Marija Tumirv ◽  
Ivo Piantanida
Keyword(s):  
Molecular Weight ◽  
Small Molecules ◽  
Biomedical Applications ◽  
Protein Targets ◽  
New Class ◽  
Rna Targets ◽  
Covalently Linked ◽  
Structural Aspects

: Among the most intensively studied classes of small molecules (molecular weight < 650) in biomedical research are small molecules that non-covalently bind to DNA/RNA, and another intensively studied class is nucleobase derivatives. Both classes have been intensively elaborated in many books and reviews. However, conjugates consisting of DNA/RNA binder covalently linked to nucleobase are much less studied and have not been reviewed in the last two decades. Therefore, this review summarized reports on the design of classical DNA/RNA binder – nucleobase conjugates, as well as data about their interactions with various DNA or RNA targets, and even in some cases protein targets are involved. According to these data, the most important structural aspects of selective or even specific recognition between small molecule and target are proposed, and where possible related biochemical and biomedical aspects were discussed. The general conclusion is that this, rather new class of molecules showed an amazing set of recognition tools for numerous DNA or RNA targets in the last two decades, as well as few intriguing in vitro and in vivo selectivities. Several lead research lines show promising advancements toward either novel, highly selective markers or bioactive, potentially druggable molecules.

Anti-Mycobacterial Peroxides: A New Class of Agents for Development Against Tuberculosis

2020 ◽  
Vol 16 (3) ◽  
pp. 392-402
Author(s):  
Christiaan W. van der Westhuyzen ◽  
Richard K. Haynes ◽  
Jenny-Lee Panayides ◽  
Ian Wiid ◽  
Christopher J. Parkinson
Keyword(s):  
Subsequent Development ◽  
Antitubercular Activity ◽  
Organic Peroxide ◽  
New Drugs ◽  
Skeletal Myoblast ◽  
Artemisinin Derivatives ◽  
Malaria Therapy ◽  
New Class ◽  
Alternative Approach

Background: With few exceptions, existing tuberculosis drugs were developed many years ago and resistance profiles have emerged. This has created a need for new drugs with discrete modes of action. There is evidence that tuberculosis (like other bacteria) is susceptible to oxidative pressure and this has yet to be properly utilised as a therapeutic approach in a manner similar to that which has proven highly successful in malaria therapy. Objective: To develop an alternative approach to the incorporation of bacterial siderophores that results in the creation of antitubercular peroxidic leads for subsequent development as novel agents against tuberculosis. Methods: Eight novel peroxides were prepared and the antitubercular activity (H37Rv) was compared to existing artemisinin derivatives in vitro. The potential for toxicity was evaluated against the L6 rat skeletal myoblast and HeLa cervical cancer lines in vitro. Results: The addition of a pyrimidinyl residue to an artemisinin or, preferably, a tetraoxane peroxidic structure results in antitubercular activity in vitro. The same effect is not observed in the absence of the pyrimidine or with other heteroaromatic substituents. Conclusion: The incorporation of a pyrimidinyl residue adjacent to the peroxidic function in an organic peroxide results in anti-tubercular activity in an otherwise inactive peroxidic compound. This will be a useful approach for creating oxidative drugs to target tuberculosis.

Evaluation of Cytotoxic and Tyrosinase Inhibitory Activities of 2-phenoxy(thiomethyl) pyridotriazolopyrimidines: In Vitro and Molecular Docking Studies

2020 ◽  
Vol 20 (14) ◽  
pp. 1714-1721
Author(s):  
Hatem A. Abuelizz ◽  
El Hassane Anouar ◽  
Mohamed Marzouk ◽  
Mizaton H. Hasan ◽  
Siti R. Saleh ◽  
...  
Keyword(s):  
Molecular Docking ◽  
Kojic Acid ◽  
Docking Studies ◽  
Breast Adenocarcinoma ◽  
Amino Acid Residues ◽  
New Class ◽  
Structure Activity ◽  
Tyrosinase Inhibitors ◽  
Mcf 7

Background: The use of tyrosinase has confirmed to be the best means of recognizing safe, effective, and potent tyrosinase inhibitors for whitening skin. Twenty-four 2-phenoxy(thiomethyl)pyridotriazolopyrimidines were synthesized and characterized in our previous studies. Objective: The present work aimed to evaluate their cytotoxicity against HepG2 (hepatocellular carcinoma), A549 (pulmonary adenocarcinoma), MCF-7 (breast adenocarcinoma) and WRL 68 (embryonic liver) cell lines. Methods: MTT assay was employed to investigate the cytotoxicity, and a tyrosinase inhibitor screening kit was used to evaluate the Tyrosinase (TYR) inhibitory activity of the targets. Results: The tested compounds exhibited no considerable cytotoxicity, and nine of them were selected for a tyrosinase inhibitory test. Compounds 2b, 2m, and 5a showed good inhibitory percentages against TYR compared to that of kojic acid (reference substance). Molecular docking was performed to rationalize the Structure-Activity Relationship (SAR) of the target pyridotriazolopyrimidines and analyze the binding between the docked-selected compounds and the amino acid residues in the active site of tyrosinase. Conclusion: The target pyridotriazolopyrimidines were identified as a new class of tyrosinase inhibitors.

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