Inhibition of ?±-class cytosolic human carbonic anhydrases I II IX and XII and ?²-class fungal enzymes by carboxylic acids and their derivatives: New isoform-I selective nanomolar inhibitors

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Exploiting the Reducing Properties of Lignin for the Development of an Effective Lignin@Cu2O Pesticide

Lignin is a natural polymer produced in huge amounts by the paper industry. Innovative applications of lignin, especially in agriculture, represent a valuable way to develop a more sustainable economy. Its antioxidant and antimicrobial properties, combined with its biodegradability, make it particularly attractive for the development of plant protection products. Copper is an element that has long been used as a pesticide in agriculture. Despite its recognized antimicrobial activity, the concerns derived from its negative environmental impact is forcing research to move toward the development of more effective and sustainable copper-based pesticides. Here a simple and sustainable way of synthesizing a new hybrid material composed of Cu2O nanocrystals embedded into lignin, named Lignin@Cu2O is presented. The formation of cuprite nanocrystals leaves the biopolymer intact, as evidenced by infrared spectroscopy, gel permeation chromatography, and Pyrolysis-GC analysis. The combined activity of lignin and cuprite make Lignin@Cu2O effective against Listeria monocytogenes and Rhizoctonia solani at low copper dosage, as evidenced by in vitro and in vivo tests conducted on tomato plants

Metal–Polymer Heterojunction in Colloidal-Phase Plasmonic Catalysis

[EN] Plasmonic catalysis in the colloidal phase requires robust surface ligands that prevent particles from aggregation in adverse chemical environments and allow carrier flow from reagents to nanoparticles. This work describes the use of a water-soluble conjugated polymer comprising a thiophene moiety as a surface ligand for gold nanoparticles to create a hybrid system that, under the action of visible light, drives the conversion of the biorelevant NAD+ to its highly energetic reduced form NADH. A combination of advanced microscopy techniques and numerical simulations revealed that the robust metal-polymer heterojunction, rich in sulfonate functional groups, directs the interaction of electron-donor molecules with the plasmonic photocatalyst. The tight binding of polymer to the gold surface precludes the need for conventional transition-metal surface cocatalysts, which were previously shown to be essential for photocatalytic NAD+ reduction but are known to hinder the optical properties of plasmonic nanocrystals. Moreover, computational studies indicated that the coating polymer fosters a closer interaction between the sacrificial electron-donor triethanolamine and the nanoparticles, thus enhancing the reactivity.This work was supported by grant PID2019-111772RB-I00 funded by MCIN/AEI/10.13039/501100011033 and grant IT 1254-19 funded by Basque Government. The authors acknowl- edge the financial support of the European Commission (EUSMI, Grant 731019). S.B. is grateful to the European Research Council (ERC-CoG-2019 815128). The authors acknowledge the contributions by Dr. Adrian Pedrazo Tardajos related to sample support and electron microscopy experiments

Diketo acids inhibit the cap-snatching endonuclease of several Bunyavirales

Several fatal bunyavirus infections lack specific treatment. Here, we show that diketo acids engage a panel of bunyavirus cap-snatching endonucleases, inhibit their catalytic activity and reduce viral replication of a taxonomic representative in vitro. Specifically, the non-salt form of L-742,001 and its derivatives exhibited EC50 values between 5.6 to 6.9 μM against a recombinant BUNV-mCherry virus. Structural analysis and molecular docking simulations identified traits of both the class of chemical entities and the viral target that could help the design of novel, more potent molecules for the development of pan-bunyavirus antivirals

Photochargeable Semiconductors: in “Dark Photocatalysis” and Beyond

Funder: Max Planck Society; doi: http://dx.doi.org/10.13039/501100004189AbstractPhotochargeable semiconductors enable energy harvesting and storage in a single material. Charges separated upon absorption of photons can accumulate in highly energetic trap states if morphology, size, and chemical composition are appropriately chosen. For example, electrons can survive for several hours if hole scavengers are used to prevent their recombination with photogenerated holes, and their negative charge is balanced by positive counter‐ions. The first database of charge‐storing semiconductors is recently released, containing information from more than 50 publications within the past 40 years. Now, the database has been updated with more than 90 entries from the latest works on the topic. These materials have been largely utilized in the context of “dark photocatalysis”, that is, redox reactions enabled by photocharged semiconductors long after cessation of light irradiation. Nevertheless, a variety of further potential applications have not received enough visibility, including memory storage, steel anti‐corrosion, sensors, and micromotors. In this review, the key figures of merit of photocharged semiconductors and the empirical relationships found between them is highlighted. After showing the latest advances in dark photocatalysis, it is discussed how other application fields may benefit from these materials. For each area, promising research directions based on the findings from the database are recommended.</jats:p

Conformational changes of retinal exchanger probed with flash photolysis of novel Ca-caged compounds

3noneMORIONDO A.; ROGOLINO D; RISPOLI GMoriondo, Andrea; Rogolino, D; Rispoli, G

Making Agriculture More Sustainable: An Environmentally Friendly Approach to the Synthesis of Lignin@Cu Pesticides

Despite its high chemical value, most of lignin is nowadays burnt as low value fuel. It is therefore important to find innovative applications for its use. Copper compounds are used as plant protection products for more than 50 different diseases in viticulture, arable crops, hops, and horticulture, and they have been used for more than 100 years. Minimization of copper in agriculture has become a fundamental issue due to its negative environmental impact. Here we present a series of hybrid organic−inorganic materials (lignin@Cu), deriving from the combination of lignin with brochantite, Cu4(OH)6SO4. Optimization of the synthetic procedures has allowed us to isolate lignin-based materials containing different percentages of copper, where the brochantite crystals are featured by different morphologies and dimensions. A more environmentally safe synthesis of lignin@Cu materials by mechanochemistry is also investigated, which reduces the amount of water used and makes easier and faster the isolation of the final materials. Tests on strawberry and tomato plants in a greenhouse have highlighted a significative efficacy of the lignin@Cu materials against different pathogens at a copper content much lower than the one of copperbased commercial pesticides. A crystal morphology−activity correlation is also traced out. The synergic activity of lignin and copper ions can be used to reduce the copper content for efficient pathogen control. Moreover, the mechanochemical approach ensures a greener synthetic approach, in a perspective of a more sustainable agriculture

Modified Poly(Heptazine Imides): Minimizing H2O2 Decomposition to Maximize Oxygen Reduction.

Photocatalysis provides a sustainable pathway to produce the consumer chemical H2O2 from atmospheric O2 via an oxygen reduction reaction (ORR). Such an alternative is attractive to replace the cumbersome traditional anthraquinone method for H2O2 synthesis on a large scale. Carbon nitrides have shown very interesting results as heterogeneous photocatalysts in ORR because their covalent two-dimensional (2D) structure is believed to increase selectivity toward the two-electron process. However, an efficient and scalable application of carbon nitrides for this reaction is far from being achieved. Poly(heptazine imides) (PHIs) are a more powerful subgroup of carbon nitrides whose structure provides high crystallinity and a scaffold to host transition-metal single atoms. Herein, we show that PHIs functionalized with sodium and the recently reported fully protonated PHI exhibit high activity in two-electron ORR under visible light. The latter converted O2 to up to 1556 mmol L-1 h-1 g-1 H2O2 under 410 nm irradiation using inexpensive but otherwise chemically demanding glycerin as a sacrificial electron donor. We also prove that functionalization with transition metals is not beneficial for H2O2 synthesis, as the metal also catalyzes its decomposition. Transient photoluminescence spectroscopy suggests that H-PHIs exhibit higher activity due to their longer excited-state lifetime. Overall, this work highlights the high photocatalytic activity of the rarely examined fully protonated PHI and represents a step forward in the application of inexpensive covalent materials for photocatalytic H2O2 synthesis

A Green Approach to Copper-Containing Pesticides: Antimicrobial and Antifungal Activity of Brochantite Supported on Lignin for the Development of Biobased Plant Protection Products

After cellulose, lignin is the most abundant plant-derived polymer in nature. It provides mechanical support to plants, but it has also a defense role against pests and diseases, thanks to antioxidant, bactericidal, and antifungal properties, deriving from its polyphenolic nature. Huge quantities of technical lignins are obtained during several industrial processes and they actually represent a waste of paper pulp and bioethanol industry. Although in the last decades many efforts have been directed to obtain lignin valorization in several fields and for diverse applications, this biobased polymer is still largely underutilized. In particular, very little is known about the possibility to exploit its antioxidant, antifungal, and antibacterial properties in the agronomical field. On the other hand, pest control is often achieved by using copper-based pesticides, but environmental and health issues urge for novel solutions implying reduced copper content. We here describe novel hybrid organic-inorganic materials obtained by combining copper(II) salts with two types of technical lignins. Cu-containing materials (lignin@Cu) have been characterized by different techniques, including X-ray powder diffraction and transmission electron spectroscopy analyses, revealing nanocrystals of brochantite (Cu4SO4(OH)6) grown in the lignin matrix. Lignin@Cu was tested for its antifungal and antibacterial profile against a vast panel of pathogens of agronomical interest. Furthermore, preliminary tests on crops in a greenhouse were performed: lignin@Cu had better performances than a commercial pesticide based on copper(II) hydroxide on tomato plants against Rhizoctonia solani, indicating a great potential of these materials as plant protection products