Novel Crystalline SiO2 Nanoparticles via Annelids Bioprocessing of Agro-Industrial Wastes

The synthesis of nanoparticles silica oxide from rice husk, sugar cane bagasse and coffee husk, by employing vermicompost with annelids (Eisenia foetida) is reported. The product (humus) is calcinated and extracted to recover the crystalline nanoparticles. X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) and dynamic light scattering (DLS) show that the biotransformation allows creating specific crystalline phases, since equivalent particles synthesized without biotransformation are bigger and with different crystalline structure

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Not AvailableIn tropical regions of India, a number of diseases and insect pests cause substantial economic damage to the grape crop and timely pesticide applications are required for crop protection. At times, this results in detection of pesticide residue above the specified maximum residue levels (MRL) at harvest affecting international trade. Use of Bacillus species to enhance the degradation of the pesticide residues on grape berries is an emerging option. In this study, the bio-efficacy of a WP formulation of Bacillus subtilis DR-39 in enhancing the dissipation rate of eight pesticides was evaluated during 2016–2017 and 2017–2018 on Thompson Seedless grapes. The pesticides were applied twice as foliar spray at their recommended doses followed by application of B. subtilis DR-39 at 1.0, 2.5 and 5.0 g/l after 4 days of the second pesticide application. In 2017–2018, B. subtilis DR-39 was applied at 2.5 g/l, twice at 4 day intervals. The pesticide residues were analysed on LC–MS/MS by ethyl acetate based extraction method on a time frame and degradation kinetics were calculated. The average enhancement in dissipation by B. subtilis DR-39 was 13.7% @ 1.0 g/l, 19.0% @ 2.5 g/l and 22.7% @ 5.0 g/l. Application of B. subtilis DR-39 @ 2.5 g/l reduced the calculated half-life of the pesticides by 1–3 days, except by 5 and 6.5 days for buprofezin and hexaconazole respectively during 2016–2017, and by 6 days for hexaconazole during 2017–2018. Studies show that B. subtilis DR-39 applications in vineyards can be utilized for faster degradation of multi-class pesticide residues.Not Availabl

Mercapto-pyrimidines are reversible covalent inhibitors of the papain-like protease (PLpro) and inhibit SARS-CoV-2 (SCoV-2) replication

The papain-like protease (PLpro) plays a critical role in SARS-CoV-2 (SCoV-2) pathogenesis and is essential for viral replication and for allowing the virus to evade the host immune response. Inhibitors of PLpro have great therapeutic potential, however, developing them has been challenging due to PLpro's restricted substrate binding pocket. In this report, we screened a 115 000-compound library for PLpro inhibitors and identified a new pharmacophore, based on a mercapto-pyrimidine fragment that is a reversible covalent inhibitor (RCI) of PLpro and inhibits viral replication in cells. Compound 5 had an IC50 of 5.1 μM for PLpro inhibition and hit optimization yielded a derivative with increased potency (IC50 0.85 μM, 6-fold higher). Activity based profiling of compound 5 demonstrated that it reacts with PLpro cysteines. We show here that compound 5 represents a new class of RCIs, which undergo an addition elimination reaction with cysteines in their target proteins. We further show that their reversibility is catalyzed by exogenous thiols and is dependent on the size of the incoming thiol. In contrast, traditional RCIs are all based upon the Michael addition reaction mechanism and their reversibility is base-catalyzed. We identify a new class of RCIs that introduces a more reactive warhead with a pronounced selectivity profile based on thiol ligand size. This could allow the expansion of RCI modality use towards a larger group of proteins important for human disease