Synthesis of tricyclic pyrazolopyrimidine arylidene ester derivatives and their cytotoxic and molecular docking evaluations

Posted on by
Synthesis of tricyclic pyrazolopyrimidine arylidene ester derivatives and their cytotoxic and molecular docking evaluations

Research basis and work of this paper.


Abstract

Our research team has synthesized 33 tricyclic pyrazolopyrimidine arylidene ester derivatives using the lead compound CAM551 as a starting point. This was achieved by a designed five-step synthesis strategy. The synthesized compounds' inhibitory activities against HT-116 human colorectal adenocarcinoma cell line and HGC27 human gastric cancer cells were assessed through traditional MTT assays. The designed and synthesized compounds demonstrated superior inhibition against both types of cancer cells. Additionally, compound 7b, which contains a long-chain substituent, exhibited improved inhibition against hepatocellular carcinoma cells and a greater safety profile. These findings indicate that compound 7b has the potential as an antitumor lead compound for future research.

Hydrogen Bonds in Perovskite for Efficient and Stable Photovoltaic

Posted on by
Hydrogen Bonds in Perovskite for Efficient and Stable Photovoltaic†

In this review, we address the important role of hydrogen bonding in improving perovskite solar devices through various additives.


Comprehensive Summary

Owing to their distinctive optical and physical properties, organic-inorganic hybrid perovskite materials have gained significant attention in the field of electronic devices, especially solar cells. The achievement of high-performance solar cells hinges upon the utilization of top-notch perovskite thin films. Nevertheless, the fabrication process involving solutions and the polycrystalline nature of perovskite result in the emergence of numerous defects within the perovskite films, consequently exerting a deleterious influence on the overall performance and stability of the devices. Improving the performance and stability of perovskite solar cells by additive engineering to suppress/passivate defects is a viable approach, which involves hydrogen bond interactions in these device engineering processes. This review explores the intrinsic hydrogen bonds in methylammonium and formamidium lead triiodide, while also considering cation rotations, phase transitions, and stability. Moreover, the review classifies additives into distinct categories, including organic small molecules, polymers, nanodots, classical salts, ionic liquids, and molten salts. The various forms and characterization techniques of hydrogen bonds are discussed, as well as their potential synergistic effects in conjunction with other chemical interactions. Furthermore, this review offers insights into the potential utilization of hydrogen bonds to further enhance the performance and stability of devices.

Key Scientists

In 2009, Tsutomu Miyasaka et al. prepared the first perovskite solar cell, which kicked off the research on perovskite light-absorbing materials. However, the use of liquid electrolytes led to device instability. The transition to all-solid-state perovskite solar cells was realized by Nam-Gyu Park's team in 2012, which was the beginning of high-efficiency perovskite solar cells. Subsequently, a number of scientists have innovated the preparation ground process. Methods such as two-step deposition by Michael Grätzel in 2013 and anti-solvent extraction by Sang II Seok's team in 2014 were instrumental in advancing the development of perovskite. Liyuan Han's team then increased the cell's working area to 1 cm2 without compromising performance, making it possible to compare the performance metrics of perovskite solar cells with those of other types of solar cells on the same scale. Recently, You's team and Pan's team kept updating the world record by obtaining certified efficiencies of 25.6% and 25.8% in 2022 and 2023, respectively.

Electrocatalytic oxidation of pyrrole on a quasi‐reversible silver nanodumbbell particle surface for supramolecular porphyrin production

Posted on by
Electrocatalytic oxidation of pyrrole on a quasi-reversible silver nanodumbbell particle surface for supramolecular porphyrin production

This work reports the synthesis of meso-tetrakis(4-hydroxyphenyl)porphyrin through condensation of an electrolyzed pyrrole solution with an acidified 4-hydroxybenzaldehyde at room temperature. It describes the use of silver nanodumbbell particles as sustainable electrode materials for symmetric porphyrin production. Metalation and optical characterizations together with various techniques such as 1HNMR and 13CNMR confirm the synthesis of the targeted product.


Abstract

Photoactive supramolecular porphyrin assemblies are attractive molecules for light-harvesting applications. This is due to their relatively non-toxicity, biological activities and charge and energy exchange characteristics. However, the extreme cost associated with their synthesis and requirements for toxic organic solvents during purification pose a challenge to the sustainability characteristics of their applications. This work presents the first report on the sustainable synthesis, spectroscopic and photophysical characterizations of a near-infrared (NIR) absorbing Ca(II)-meso-tetrakis (4-hydroxyphenyl)porphyrin using an electrolyzed pyrrole solution. The latter was obtained by cycling the pyrrole solution across the silver nanodumbbell particle surface at room temperature. The electrolyzed solution condensed readily with acidified p-hydroxybenzaldehyde, producing the targeted purple porphyrin. The non-electrolyzed pyrrole solution formed a green substance with significantly different optical properties. Remarkable differences were observed in the voltammograms of the silver nanodumbbell particles and those of the conventional gold electrode during the pyrrole cycling, suggesting different routes of porphyrin formation. The rationale behind these formations and the associated mechanisms were extensively discussed. Metalation with aqueous Ca2+ ion caused a Stokes shift of 38.75 eV. The current study shows the advantage of the electrochemical method towards obtaining sustainable light-harvesting porphyrin at room temperature without the need for high-energy-dependent conventional processes.

Novel oxadiazole functionalized pyridopyrimidine derivatives; their anticancer activity and molecular docking studies

Posted on by
Novel oxadiazole functionalized pyridopyrimidine derivatives; their anticancer activity and molecular docking studies

A series of novel oxadiazole functionalized pyridopyrimidine derivatives prepared. All the final compounds 7a-l evaluated for anti cancer activity against four human cancer cell lines and promising compounds 7d and 7k have been identified and evaluated for molecular docking interactions


Abstract

A series of novel oxadiazole functionalized pyridopyrimidine derivatives prepared starting from 6-methyl/ethyl-2-oxo-4-(trifluoromethyl)-1,2-dihydropyridine-3-carbonitrile 1. This compound 1 on reaction with sulfuric acid obtained compound 2, further compound 2 on reaction with chloroacetamide followed by reaction with ethoxy methylene malonic diethyl ester coupling and further cyclization to obtain compound 5. Compound 5 on reaction with hydrazide hydrate obtained hydrazide derivatives 6. Compound 6 on reaction with diverse substituted aromatic acids to get oxadiazole derivatives 7a–l. All the final compounds 7a–l evaluated for anticancer activity against four human cancer cell lines such as HeLa—cervical cancer (CCL-2); COLO 205—colon cancer (CCL-222); HepG2—liver cancer (HB-8065); and MCF7—breast cancer (HTB-22) and promising compounds 7d and 7k have been identified and evaluated for molecular docking interactions.

Methylation Induces a Low‐energy Emissive State in N6‐methyladenine Containing Dinucleotides

Posted on by
Methylation Induces a Low-energy Emissive State in N6-methyladenine Containing Dinucleotides

We discovere that when methylation occurs in a DNA dimer, a low-energy emissive species is induced and it is distinct from the previously reported monomer-like species as well as the charge-transfer exciplex species.


Abstract

Methylation of adenine at the N6 position is a crucial epigenetic modification that profoundly influences gene regulation and expression. Moreover, this modification intricately alters the excited state dynamics of adenine nucleobases. To explore the impact of N6-methyladenine on the excited state dynamics within oligonucleotides, we conducted a comprehensive investigation of two dinucleotides containing N6-methyladenosine, in conjunction with adenosine or guanosine. Using steady-state and time-resolved absorption and fluorescence spectroscopy techniques, we not only observed the customary monomer-like and charge transfer emissive states, as reported in previous dinucleotides, but also identified an additional low-energy emissive state. This unique state exhibits an extraordinary Stokes Shift exceeding 2.3 eV and has a relatively long lifetime of 4–5 ns. We propose that this state corresponds to a bonded exciplex state, governed by ground-state geometries.

Photo‐Induced Radicals in Carbon Nitride and their Magnetic Signature

Posted on by
Photo-Induced Radicals in Carbon Nitride and their Magnetic Signature

The employment of carbon nitride as a photocatalyst is conditional to understanding its response to light and the nature of all the photogenerated species. Amongst the characterisation techniques, EPR spectroscopy occupies a central role since it permits to detect paramagnetic states and follow their fate. Here we aim to provide guidelines to employ EPR spectroscopy in the research on carbon nitride.


Abstract

As a metal-free semiconductor, carbon nitride is a promising material for sustainable photocatalysis. From the large number of studies, it seems apparent that the photocatalytic activity is related to the number and type of defects present in the structure. Many defects are paramagnetic and photoresponsive and, for these reasons, Electron Paramagnetic Resonance (EPR) spectroscopy is a powerful method to derive fundamental information on the structure – local, extended and electronic – of such defects which in turn impact the optical, magnetic and chemical properties of a material. This review aims at critically discussing the interpretation of EPR data of native and photoinduced radical defects in carbon nitride research highlighting strengths and limitations of this spectroscopic technique.

Avoiding Oxygen Removal for Photochemical Reactions – towards Water as the Solvent

Posted on by
Avoiding Oxygen Removal for Photochemical Reactions – towards Water as the Solvent

By encapsulating photosensitizers and reactants in tailored supramolecular assemblies, preservation of photoreactivity even in the presence of molecular oxygen can be observed. The focus of this concept article has been dedicated to aqueous solutions of supramolecular assemblies as potential reaction media as they present an underdeveloped and attractive solution for photochemical reaction development.


Abstract

Oxygen removing protocols have long been the standard approach to perform photoreactions. By encapsulating photosensitizers and reactants in tailored supramolecular assemblies, preservation of photoreactivity even in the presence of molecular oxygen can be observed. Herein, we showcase some of the solutions that could render time-consuming oxygen removal redundant in photochemical synthesis. A focus has been dedicated to aqueous solutions of supramolecular assemblies as potential reaction media. They present an attractive solution possibly useful not only for synthetic photochemical transformations, but also for water purification, bio-applications or biocatalysis. The included media are membranes, hydrogels, deep eutectic solvents and peptide assemblies.

NIR‐Mediated Cu2O/Au Nanomotors for Synergistically Treating Hepatoma Carcinoma Cells

Posted on by
NIR-Mediated Cu2O/Au Nanomotors for Synergistically Treating Hepatoma Carcinoma Cells

A NIR-driven Janus Cu2O/Au nanomotor had been constructed to explore the synergistical therapeutic effect on hepatoma carcinoma cells. The asymmetric Au modification causes uneven heating on both sides of the Cu2O/Au nanomotor, resulting in autonomous motion from high to low temperature, actively targeting hepatocellular carcinoma cells. Under the synergistic effects of photothermal therapy, photodynamic therapy and Cu2O′s own nanotoxicity, Cu2O/Au nanomotors exhibit highly effective killing effect on liver cancer cells.


Abstract

We presented a NIR-driven Janus Cu2O/Au nanomotor. The nanomotor has a truncated octahedral structure. By asymmetric Au evaporation, the light response range of Cu2O nanomotor is extended to near-infrared range, and the speed of Cu2O/Au nanomotors under NIR is significantly increased. In promoting apoptosis of hepatocellular carcinoma, except the nanotoxicity of Cu2O itself, the Au layer enhances the photothermal properties, allowing Cu2O/Au nanomotors to induce apoptosis in hepatocellular carcinoma cells by heating them. On the other hand, a Schottky barrier formed at the interface of Cu2O and Au, preventing the recombination of electrons, which makes more electrons react with biomolecules to produce toxic ROS to kill hepatocellular cells. The killing rate of hepatocellular carcinoma cells reached 87 % by the combined effect of nanotoxicity inhibition of proliferation and photothermal & photodynamic therapy (PTT & PDT). Nanomotors in combination with multiple approaches are explored as a new treatment to tumor in this article.