Photo-Organocatalytic Enantioselective Radical Cascade Enabled by Single-Electron Transfer Activation of Allenes

Allenes are commonly used in metal-mediated transformations, cycloaddition reactions, and radical processes. However, their activation by single-electron transfer (SET) is largely underexplored. Herein, we report a visible light-driven enantioselective organocatalytic process that uses the excited-state reactivity of chiral iminium ions to activate allenes by SET oxidation. The ensuing allene cation radicals participate in stereocontrolled cascade reactions to deliver chiral bicyclic scaffolds with good enantioselectivity and exquisite diastereoselectivity. Density Functional Theory (DFT) calculations support a mechanism that combines the peculiar chemistry of allene radical cations with polar reactivity. (Figure presented.)

A circular economy approach for olive oil industry: From olive pomace to microalgal biomass

In this work olive pomace was used to recover high added value compounds and produce biogas by anaerobic digestion. Moreover, in order to satisfy the circular economy concept, the digestate from the latter process was used as medium for the microalga Chlorella vulgaris growth

Introduction of a simple experiment for the undergraduate organic chemistry laboratory demonstrating the Lewis acid and shape-selective properties of zeolite Na-Y

A simple, inexpensive, discovery-based experiment for undergraduate organic laboratories has been developed that demonstrates the Lewis acid and shape-selective properties of zeolites. Calcined zeolite Na-Y promotes the electrophilic aromatic bromination of toluene with a significantly higher para/ortho ratio than observed under conventional conditions. The experiment can be completed in one three-hour laboratory period. The zeolite can be recovered and regenerated for later reuse. A broad range of organic course topics from orientation in electrophilic aromatic substitution to photochemistry can be discussed

The strategic choice of payment method in takeovers: The role of environmental, social and governance performance

Payment method choice in takeovers is mainly driven by both asymmetric information between the acquirer and the target and the acquirer's financial capability. In this paper, we examine whether increased transparency and better access to finance induced by environmental, social and governance (ESG) performance are associated with the strategic choice of payment method in takeovers. More specifically, we investigate how the acquirer's and the target's ESG coverage and different levels of ESG performance affect the probability of cash offers in a sample of 836 US takeovers from 1992 to 2014. In examining the target, our results suggest that ESG coverage is positively associated with the probability of cash offers, whereas we find a negative relationship for ESG concerns and no effect for ESG strengths. Upon examining the acquirer, ESG coverage and ESG concerns both increase the probability of cash offers; however, we do not find results supporting our prediction regarding the acquirer's ESG strengths. We infer that ESG coverage and level affect strategic considerations in the choice of the payment method in takeovers because they not only reduce information asymmetry, but also enhance financing capability

A Comprehensive Optimization of Ultrasound\u2010Assisted Extraction for Lycopene Recovery from Tomato Waste and Encapsulation by Spray Drying

This study aimed to extract bioactive compounds from tomato waste through ultrasoundassisted extraction (UAE), using ethanol as solvent. Process optimization was carried out by a central composite design of 33 runs for response surface modelling, simultaneously analyzing the effect of temperature (T), time (t), volume (V), liquid\u2010to\u2010solid ratio (L/S), amplitude (A), the pulser duration (on), and their interaction. The best conditions found by the desirability method (T = 65 \ub0C, t = 20 min, L/S = 72 mL/g, A = 65%, on = 33 s, V = 90 mL) were experimentally verified, leading to the production of an extract with interesting properties (total carotenoids of 1408 \ub114 \u3bcglycopene equivalents/g, lycopene yield of 1536 \ub1 53 \u3bcg/g, 36.1 \ub1 0.9 \u3bcgtrolox equivalents/g as antiradical power). Due to the instability of lycopene, the extract encapsulation by spray drying was undertaken using inulin and maltodextrins as coating agents. The evaluation of wall material composition provided high product recovery (73%), a high content of encapsulated compared to superficial lycopene (15.3 \ub1 2.9 and 0.30 \ub1 0.02 \u3bcg/g), and a product with good water solubility. The novelty of this work concerned the simultaneous study of the effect and interdependences of the UAE parameters, and the use of inulin to enhance the properties of microparticles

Cucurbit[n]uril binding of platinum anticancer complexes

The encapsulation of cisplatin by cucurbit[7]uril (Q[7]) and multinuclear platinum complexes linked via a 4,4′-dipyrazolylmethane (dpzm) ligand by Q[7] and cucurbit[8]uril (Q[8]) has been studied by NMR spectroscopy and molecular modelling. The NMR studies suggest that some cisplatin binds in the cucurbituril cavity, while cis-[PtCl(NH3)2(H2O)]+ only binds at the portals. Alternatively, the dpzm-linked multinuclear platinum complexes are quantitatively encapsulated within the cavities of both Q[7] and Q[8]. Upon encapsulation, the non-exchangeable proton resonances of the multinuclear platinum complexes show significant upfield shifts in 1H NMR spectra. The H3/H3* resonances shift upfield by 0.08 to 0.55 ppm, the H5/H5* shift by 0.9 to 1.6 ppm, while the methylene resonances shift by 0.74 to 0.88 ppm. The size of the resonance shift is dependent on the cavity size of the encapsulating cucurbituril, with Q[7] encapsulation producing larger shifts than Q[8]. The upfield shifts of the dpzm resonances observed upon cucurbituril encapsulation indicate that the Q[7] or Q[8] is positioned directly over the dpzm linking ligand. The terminal platinum groups of trans-[{PtCl(NH3)2}2μ-dpzm]2+ (di-Pt) and trans-[trans-{PtCl(NH3)2}2-trans-{Pt(dpzm)2(NH3)2}]4+ (tri-Pt) provide a barrier to the on and off movement of cucurbituril, resulting in binding kinetics that are slow on the NMR timescale for the metal complex. Although the dpzm ligand has relatively few rotamers, encapsulation by the larger Q[8] resulted in a more compact di-Pt conformation with each platinum centre retracted further into each Q[8] portal. Encapsulation of the hydrolysed forms of di-Pt and tri-Pt is considerably slower than for the corresponding Cl forms, presumably due to the high-energy cost of passing the +2 platinum centres through the cucurbituril portals. The results of this study suggest that cucurbiturils could be suitable hosts for the pharmacological delivery of multinuclear platinum complexe

Operating Parameters Optimization for the Production of Liposomes Loaded with Antibodies Using a Supercritical Fluid-Assisted Process

Encapsulation of antibodies represents a significant advance to protect and deliver these therapeutics in a controlled manner, increasing the stability requested to cover the temporal gap between particle production and their administration. Furthermore, using encapsulation, extracellular, cell surface, and intracellular targets can be reached. This work examines the feasibility of encapsulating mouse IgG isotype control antibodies within phosphatidylcholine-based liposomes using a supercritical fluid-based process called SuperLip (Supercritical-assisted Liposome formation). This process allows a continuous production of both nano- and micrometric liposomes with high encapsulation efficiency working under mild operative conditions. The effect of some operative parameters has been studied on liposome mean diameter, particle size distribution, and antibody entrapment efficiency, comparing these data with those collected working with liposomes obtained by the thin-layer hydration technique. In particular, the effect of water flow rate and of the antibody loading were studied. Antibody-loaded liposomes with mean diameters in the range between 205 and 501 nm have been obtained by using a supercritical fluid-assisted process. High entrapment efficiencies up to 94% have been calculated

Dual-polarization nonlinear Fourier transform-based optical communication system

New services and applications are causing an exponential increase in Internet traffic. In a few years, the current fiber optic communication system infrastructure will not be able to meet this demand because fiber nonlinearity dramatically limits the information transmission rate. Eigenvalue communication could potentially overcome these limitations. It relies on a mathematical technique called “nonlinear Fourier transform (NFT)” to exploit the “hidden” linearity of the nonlinear Schrödinger equation as the master model for signal propagation in an optical fiber. We present here the theoretical tools describing the NFT for the Manakov system and report on experimental transmission results for dual polarization in fiber optic eigenvalue communications. A transmission of up to 373.5 km with a bit error rate less than the hard-decision forward error correction threshold has been achieved. Our results demonstrate that dual-polarization NFT can work in practice and enable an increased spectral efficiency in NFT-based communication systems, which are currently based on single polarization channels

The Parkinson-related E193K LRRK2 variant impacts neuronal vesicles dynamics through perturbed protein interactions

The Leucine-Rich Repeat Kinase 2 (LRRK2) is a complex protein, expressed in neurons and implicated in Parkinson disease (PD). LRRK2 contains a dual enzymatic activity and several structural domains that constitute a versatile platform for multiple protein interactions at the synapses. In this study, we characterize the functional role of the N-terminal Armadillo repeats domain of LRRK2 and the impact on synaptic vesicle (SV) dynamics of a novel variant, E193K, harboured within this domain and identified in an Italian family affected by PD. Using a genetically encoded sensor of recycling, synaptopHluorine, and total internal reflection fluorescence microscopy, we visualized SV trafficking in the N2A neuroblastoma cells expressing the wild type LRRK2 protein, a mutant lacking the Armadillo domain (\u394N LRRK2) or the E193K variant. We found that expression of the \u394N construct increased the frequency and the amplitude of spontaneous synaptic events. A similar phenotype was detected in the presence of the E193K variant, suggesting that this mutation behaves as a loss-of-function mutation. A domain-based pulldown approach demonstrated that the LRRK2 N-terminus binds to cytoskeletal (\u3b2-actin and \u3b1-tubulin) and SV (synapsin I) proteins and the E193K substitution alters strength and quality of LRRK2 interactions. The results support a role of the Armadillo domain in interaction with synaptic proteins and suggest that the E193K mutation affects LRRK2 function via perturbation of its physiological network of interactors, resulting in impaired vesicular trafficking. These findings may have important implications for understanding the role of LRRK2 at the synapses and the pathophysiological mechanism for LRRK2-linked disease