Clinical success of chemotherapeutic drugs is marred by their non-specific distribution in the body leading to side effects. Thus a drug delivery method directing chemotherapeutic drugs exclusively into cancer cells is needed to increase the therapeutic index. In recent times, bio-catalyzing polymeric nanocarriers have demonstrated great promise for targeted delivery of chemotherapeutic drugs. On similar lines, in the present study, we have developed a diselenide-containing bio-endogenous stimulus (redox and pH) responsive polymeric material by covalently conjugating the pharmaceutical grade gelatin protein with 3’-3’ diselenodipropionic acid (DSePA) through amide linkage as confirmed by various spectroscopic analyses. Further, diselenide (Se-Se) containing protein matrix was used to entrap a wide-spectrum anticancer drug doxorubicin (Dox) and to prepare nanoparticles by nanoprecipitation technique. The optimized reaction condition yielded spherical nanoparticles of size 179 ± 10.5 nm with the corresponding ζ- potential value of -11.53 ± 0.59 mV. The bio-catalyzing behavior of polymeric nanocarrier was evaluated by following the release of entrapped Dox under acidic (pH 5.5) and reducing conditions (1 mM DTT / 10 mM GSH). The results clearly indicated that Gprotein-Se-Se nano-matrix catalyzed the significantly higher release of Dox under acidic and reducing environments. Since tumor cells exhibit acidic (low pH) and reducing (high GSH level) environments as compared to normal cells, the drug is expected to be released specifically within the tumor cells. Cellular studies indeed confirmed the higher uptake as well as cytotoxicity of Dox delivered through Gprotein-Se-Se nano-matrix in lung cancer cells demonstrating its potential utility in targeted chemotherapy.

All-carbon quaternary centers are widely present in many natural products, bioactive molecules and drugs. Despite their potential to be incorporated in natural product syntheses and preparation of therapeutics, developing catalytic methods to construct this interesting scaffold, have been a difficult goal to attain. Furthermore, not only is it challenging to synthesize all-carbon quaternary centers, but doing so in an enantioselective fashion is even more elusive. This is due to the strong steric repulsion between the carbon substituents; and for this reason, not many enantioselective synthetic methods have been developed to this day. This structural motif is especially difficult to install in acyclic systems where there is great conformational flexibility. In this study, the construction of enantioselective all-carbon quaternary stereocenters is reported through a Michael Initiated Ring Closure reaction. This reaction enables the formation of substituted cyclopropyl ring, with the possibility to establish quaternary and tertiary chiral centers, with both cyclic and acyclic α,β-unsaturated carbonyls. The current study involves the addition of sulfur ylides to α,β-unsaturated carbonyls using chiral Lewis acid catalysis leading to substituted cyclopropanes. Nickel(II) salts including Ni(BF₄)₂·6H₂O and Ni(ClO₄)₂·6H₂O were utilized as Lewis acids with chiral indane-derived bisoxazoline ligand, resulting in excellent enantiomeric excess as high as 93%. It is hoped that through the results of this study, a contribution can be made to the existing methodologies on the formation of enantioselective C-C bonds and specifically, to the formation of enantioselective quaternary centers.

In the last decades a lot of efforts were dedicated to the individuation of small size selenium containing molecules able to mimic the catalytic activity of the Glutathione Peroxidase (GPx). A number of tests were adopted to evaluate by UV, HPLC, NMR the ability of an organoselenium compound on reducing hydrogen peroxide in the presence of a thiol cofactor. Based on these tests a plethora of different compounds were claimed as GPx-mimetics even if, right now, no one of these compounds confirmed the excellent in vitro results when it was translated in cells or animal, and usually the most frustrating issue is the toxicity. In addition the panel of different analytical tests used to measure the GPx-like activity, including a series of different thiol cofactors, in many cases do not allow the direct comparison of the presented activity of different classes of compounds neither the real comprehension of the current mechanism in the biological environment. When DTT is used as cofactor the regeneration of the catalyst occurs thought an intramolecular thiol oxidation that have a different kinetic respect to the naturally occurring oxidation of the glutathione that is an intermolecular process. Here we also demonstrate that DMSO, used as solvent or co-solvent in a redox biological test in the presence of a selenium catalyst, could act as a co-factor in the reduction of the peroxide introducing an unpredictable and unavoidable bias that will affect any kind of analytical evaluation. Antioxidant or prooxidant that’s the problem

Methylmercury (CH₃Hg⁺) binding to thiol- and selenol- based enzymes is a key-element to explain its high toxicity. CH₃Hg⁺ is not found in its free form in biological environment, but is present as a chalcogenolate complex. Thus, chalcogen-mercury bond reactivity is implicated in the distribution of this toxicant in the human body. Particularly, Hg – S and Hg – Se bond formation and disruption is responsible for glutathione depletion and CH₃Hg⁺ delivery to target enzymes. We have investigated systematically, in silico, trends and mechanisms of nine ligand-exchange model reactions between a methylchalcogenolate and a methylmercury methylchalcogenolate complex in order to understand the role of the chalcogen (S, Se, Te) and of the environment (gas phase vs solvent).¹ We discuss trends in activation and reaction energies, highlighting a change in mechanism (from a single-well to a unimodal/double-well potential energy surface) when moving from gas to condensed phase, in analogy with S_N2 reactions. Further similarities with S_N2 reactions are quantified by means of activation strain analysis. Reactions involving S and Se display very similar energetics and (low) activation energies. Therefore, the reasons behind the biochemically challenging detoxification of CH₃Hg⁺ inhibited (seleno)proteins clearly emerge also from our minimal model, which paves the route to future mechanistic investigations.

1. A. Madabeni, M. Dalla Tiezza, O. B. Folorunsho, P. A. Nogara, M. Bortoli, J. B. Rocha, L. Orian, J. Comput. Chem. 2020, 41, 2045-2059

The Bio Innovation of a Circular Economy for Plastics (BioICEP) is a pan European-Chinese collaboration formed to reduce the burden of plastic waste in the environment. Different mixed plastic pollution environments are represented, with specific partners selected which have the expertise and facilities to carry out the necessary technical innovations.

Our approach is The Bio Innovation of a Circular Economy for Plastics (BioICEP) consortium is a pan European-Chinese collaborative formed to reduce the burden of plastic waste in the environment. The countries have been selected to represent different mixed plastic pollution environments, with specific partners selected which have the expertise and facilities to carry out the necessary technical innovations. Three innovative booster technologies are at the core of this solution accentuating, expediting, and augmenting plastics degradation to levels far in excess of those current achievable.

Our approach is a triple-action depolymerisation system where plastic waste will be broken down in three consecutive processes:

1. Mechano-biochemical disintegration processes, including a new proprietary sonic-green-chemical technology to reduce the polymer molecular weight of the base polymer to make it amenable to biodegradation;
2. Biocatalytic digestion, with enzymes enhanced through a range of innovative techniques including accelerated screening through novel fluorescent sensor and directed evolution;
3. Microbial consortia developed from best in class single microbial strains, which combined leads to highly efficient degradation of mixed plastic waste streams. The outputs from this degradation process will be used as building blocks for new polymers or other bioproducts to enable a new plastic waste-based circular economy.

The catalytic utilization of hypervalent iodine reagents, largely in consideration of economical and environmental viewpoints, is a most attractive strategy due to their unique features as extremely useful oxidants, with mild, safe, and environmentally friendly characteristics. Oxidation reactions constitute of a number of important transformations in organic synthesis. They are widely in the productions of a variety pharmaceuticals and natural products, and their intermediates.[1] As oxidants, hypervalent iodine reagents have recently received much attention due to their low toxicity, mild reactivity, ready availability, high stability, easy handling, etc.[2] For examples, phenyliodine(III) diacetate (PIDA) and phenyliodine(III) bis (trifluoroacetate) (PIFA)-induced oxidations of phenols and related reactions have been applied to many total syntheses of biologically important natural products and their pivotal intermediates.[3] This study reports a new synthetic methodology that was optimized to prepare new naphthoquinones derivatives via catalytic oxidation.

[1] Hoelderich , W. F., Kollmer, F. Pure Appl. Chem.2000, 72, 1273.

[2] (a) Zhdankin, V. V. ; Stang, P. J. Chem. Rev. 2002, 102, 2523. (b) Tohma, H. ; Kita, Y. Adv. Synth. Catal. 2004, 346, 111. (c) Moriarty, R. M. J. Org. Chem, 2005, 70, 2893. (d) Wirth, T. Angew. Chem. Int. Ed. 2005, 44, 3656. (e) Ochiai, M. Chem. Rec. 2007, 7, 12.

[3] a) Pouységu, L.; Deffieux, D.; Quideau, S. Hypervalent iodine-mediated phenol dearomatization in natural product synthesis. Tetrahedron. 2010, 66, 2235-2261.Available. b) Moriarty, R.; Prakash, O. Oxidation of phenolic compounds with organohypervalent iodine reagents in Organic Reactions. Wiley New York, 2001, 57, 327-415. C) Ladziata, U.; Zhdankin, V.V. Hypervalent iodine(V) reagents in organic synthesis. ARKIVOC, 2006, (ix), 26-58.

Chagas disease, considered by the World Health Organization as a neglected tropical disease, is responsible for the deaths of more than 10,000 people annually. The main drugs used to overcome the disease, Benzonidazole and Nifurtimox, besides being old, have limitations regarding the adverse effects related to the treatment time and consequently their toxicity. Therefore, the need for a new drug to be used against this disease becomes evident. The classes of organoselenium and aromatic heterocycles 1,2,3-triazoles are promising for this issue, since both have their known chemistry and antiparasitic activity already described. In this work, the molecular hybridization technique was used in order to combine the individual bioactive profile of both classes for further evaluation against Trypanossoma cruzi, the protozoan that causes Chagas disease. The methodology used was based on works described in the literature. Initially, benzene azides were synthesized from commercial anilines, while ethynyl(phenyl)selane came from differents aromatic diselenides. With these intermediates, a 1,3-dipolar cycle-addition was performed to obtain the new target molecules 1-phenyl-4-(phenylselanyl)-1H-1,2,3-triazoles with moderate to good yields ranged from 52 to 75%. The characterization of the final molecules is in process and when finished they will be send for evaluation of biological activity. It is possible to conclude that the method used is simple and easy to access, an important factor for potential drugs against neglect diseases. After the assessment of bioactivity, it will be possible to identify the efficiency of these substances, as well as, if necessary, the optimization of their structure.

We established a new synthetic methodology for the regioselective β-hydroxyselenilation of olefins employing benzeneseleninic acid and promoted by blue LED light, as alternative energy source. Using a novel perspective, the bezeneseleninic acid emerges as an efficient and affordable reagent to be used as electrophilic selenium source, since in the presence of visible light it is easily converted to a radical species. In this sense, the photocatalytically formed PhSe^• radical can react directly with unsaturated substrates affording a radical selenium-containing intermediate. Following, it can react with radical HO^•, generated from different reaction steps, that are present in the reaction medium, leading to the formation of the desired β-hydroxyselanyl compounds. This class of molecules have demonstrated important biological activities and versatile utilities in organic synthesis, as building blocks. For this reason, it is interesting to develop robust, effective, and environmentally benign methodologies for their preparation. The optimal reaction conditions involves the use of styrene as unsaturated substrate and 1.0 equiv. of phenylseleninic acid, as organoselenium source, in the presence of 5.0 mol% of eosin Y, an organic photocatalyst, in 1.5 mL of DMSO. The system was stirred and irradiated with blue LED light for 2 hours, resulting in an efficient and smoothly way for access β-hydroxyselanyl compounds in good yields.

Cheese whey constitutes one of the most polluting by-products of food industry. Regardless the numerous bioprocessing approaches that have been proposed for whey lactose utilization, still, valorization options are restricted by the fact that the majority of strains do not express the gene that encodes β-galactosidase. As a result, the formulation of several high value-added products is hindered, entailing at the same time definite end applications.

The aim of this work was to undertake the cost-effective production of crude enzymes, including β-galactosidase, and the subsequent exploitation of whey hydrolysate in an upstream bioconversion process resulting in bacterial cellulose (BC) production.

The ability of Aspergillus awamori to secrete β-galactosidase was evaluated via SSF using wheat bran as substrate. Specifically β-galactosidase was assessed at 60-75 % initial moisture content. Crude enzyme extracts produced, were employed in whey hydrolysis at different temperatures (50-70°C) to estimate the effect of temperature in lactose hydrolysis. Subsequently, hydrolyzed whey was used for BC production by Acetobacter xylinum.

Results demonstrate that β-galactosidase production was notably affected by moisture content and fermentation time, whereas the maximum activity of 148 U/g was observed at 70% initial moisture content after 79h of SSF. Hydrolysis kinetics showed a 93% lactose hydrolysis at 48h. The produced crude hydrolyzate was subsequently utilized in BC fermentations, leading to the production of up to 5.5 g/L of BC.

Evidently, the above findings exhibit a novel and promising approach with respect to cheese whey hydrolysis, thereby expanding the output potential for end products.

A comparison study of the effect of different carbon-containing materials used as carriers on transition metal sulfide (TMS) catalyst behavior in the synthesis gas conversion has been conducted. Supports used for the synthesis of alcohols from syngas via KCoMoS₂, in this project are γ-Al₂O₃, Carbon-Coated Alumina (CCA), Graphene coated Alumina (GCA), NiAl2O3.CuO, and different types of low-cost commercial activated carbons such as fabric active sorption (TCA), non-woven activated material (AHM), AG-3, OBC-1, DAC, and BAW. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-ray Fluorescence (XRF), and N₂ physisorption were used to characterize the carriers and catalysts. The obtained results have shown that GCA is more effective than alumina and CCA to increase the yield ratio between alcohol and hydrocarbons (Y_ROH/HCs), besides it has shown low selectivity for CO₂. The graphene ribbons have played a role in decreasing the interaction between alumina and the active phase which decreased the hydrogenation reaction. The used types of carbon materials showed different supporting efficiency to synthesis of alcohol from syngas. The activities depend on the support nature have shown trends to increase in the following order: Al₂O₃ < CCA < BAW < TCA < Ag3 < AHM > GCA.