Supported copper on a diamide–diacid-bridged PMO: an efficient hybrid catalyst for the cascade oxidation of benzyl alcohols/Knoevenagel condensation

In this study, a novel periodic mesoporous organosilica (PMO) containing diamide–diacid bridges was conveniently prepared using ethylenediaminetetraacetic dianhydride to support Cu(ii) species and affording Cu@EDTAD-PMO nanoparticles efficiently.

Cytosine Palladium Complex Supported on Ordered Mesoporous Silica as Highly Efficient and Reusable Nanocatalyst for One-Pot Oxidative Esterification of Aldehydes

The synthesis of esters is one of the most fundamental and significant subjects in organic chemistry and chemical industry because they are used in high-value products such as cosmetics, biofuel, pharmaceuticals, surfactants, and food ingredients. In this study, an efficient, economic, sustainable, and green protocol for oxidative esterification reaction has been developed. A one-pot direct transformation of aliphatic, aromatic, and unsaturated aldehydes into esters in the presence of oxygen has been carried out over mesoporous organosilica-supported palladium nanocatalyst (Pd-Cyt@SBA-15) under ambient conditions. Pd-Cyt@SBA-15 efficiently catalyzed selectively large-scale conversion of aldehydes into esters in high yields and large turnover numbers (TON = 98,000). Pd-Cyt@SBA-15 nanocatalyst demonstrated excellent reusability and stability and could be recycled up to ten times without loss of significant reactivity. ICP-AES analysis showed that no leaching of active palladium species occurred during the recycling process of the heterogeneous Pd-Cyt@SBA-15 nanocatalyst.

Biodegradable reduce expenditure bioreactor for augmented sonodynamic therapy via regulating tumor hypoxia and inducing pro-death autophagy

Backgrounds Sonodynamic therapy (SDT) as an emerging reactive oxygen species (ROS)-mediated antitumor strategy is challenged by the rapid depletion of oxygen, as well as the hypoxic tumor microenvironment. Instead of the presently available coping strategies that amplify the endogenous O2 level, we have proposed a biodegradable O2 economizer to reduce expenditure for augmenting SDT efficacy in the present study. Results We successfully fabricated the O2 economizer (HMME@HMONs-3BP-PEG, HHBP) via conjugation of respiration inhibitor 3-bromopyruvate (3BP) with hollow mesoporous organosilica nanoparticles (HMONs), followed by the loading of organic sonosensitizers (hematoporphyrin monomethyl ether; HMME) and further surface modification of poly(ethylene glycol) (PEG). The engineered HHBP features controllable pH/GSH/US-sensitive drug release. The exposed 3BP could effectively inhibit cell respiration for restraining the oxygen consumption, which could alleviate the tumor hypoxia conditions. More interestingly, it could exorbitantly elevate the autophagy level, which in turn induced excessive activation of autophagy for promoting the therapeutic efficacy. As a result, when accompanied with suppressing O2-consumption and triggering pro-death autophagy strategy, the HHBP could achieve the remarkable antitumor activity, which was systematically validated both in vivo and in vitro assays. Conclusions This work not only provides a reduce expenditure means for enduring SDT, but also represents an inquisitive strategy for tumor treatments by inducing pro-death autophagy. Graphical Abstract

Enzymatic Production of Ecodiesel by Using a Commercial Lipase CALB, Immobilized by Physical Adsorption on Mesoporous Organosilica Materials

The synthesis of two biocatalysts based on a commercial Candida antarctica lipase B, CALB enzyme (E), physically immobilized on two silica supports, was carried out. The first support was a periodic mesoporous organosilica (PMO) and the second one was a commercial silica modified with octyl groups (octyl-MS3030). The maximum enzyme load was 122 mg enzyme/g support on PMO and 288 mg enzyme/g support on octyl-MS3030. In addition, the biocatalytic efficiency was corroborated by two reaction tests based on the hydrolysis of p-nitrophenylacetate (p-NPA) and tributyrin (TB). The transesterification of sunflower oil with ethanol was carried out over the biocatalysts synthesized at the following reaction conditions: 6 mL sunflower oil, 1.75 mL EtOH, 30 °C, 25 μL NaOH 10 N and 300 rpm, attaining conversion values over 80% after 3 h of reaction time. According to the results obtained, we can confirm that these biocatalytic systems are viable candidates to develop, optimize and improve a new methodology to achieve the integration of glycerol in different monoacylglycerol molecules together with fatty acid ethyl esters (FAEE) molecules to obtain Ecodiesel.