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Our current industrial ammonia cycle is far from being sustainable – while intense energy is required to produce ammonia – almost half of it ends up in wastewater treatment plants (WWTPs) where is finally transformed and lost. This work shows the application of flat sheet membrane distillation (MD) commercial modules for the ammonia recovery from WWTPs. First, optimized operating conditions – in terms of ammonia flux, specific thermal energy (STEC) and chemical demand – were investigated in the laboratory with a 2.3 m2 MD module. Second, optimized conditions were demonstrated in a pilot installation on site operating a 14.5 m2 MD module continuously (24/7) for three months. Results showed that MD is a robust, low-maintenance technology that can be operated at low temperature and corresponding STEC (i.e. 38 °C and 13.6 kWhth per kg1 NH3, respectively) and low pH (i.e. 8.7) for the recovery of 90% of the water-bound ammonia as an ammonium sulphate (AS) solution. The AS product reached a concentration of 5 g l-1 N–NH4, lower than conventional fertilizers, however given its high quality and volume reduction factor, it constitutes a potential fertilizer solution for local needs. The maximum AS permeate concentration was limited by the increasing water vapour flux due to a higher osmotic distillation effect and a minor ammonia flux decrease with increasing permeate concentration. Further research will focus on optimizing the module configuration to minimize water flux and overall system operation for increased heat recovery and open-loop operation.

It is well known that the traditional synthetic polymers, such as Polyurethane foams, require raw materials that are not fully sustainable and are based on oil-feedstocks. For this reason, renewable resources such as biomass, polysaccharides and proteins are still recognized as one of the most promising approaches for substituting oil-based raw materials (mainly polyols). However, polyurethanes from renewable sources exhibit poor physical and functional performances. For this reason, the best technological solution is the production of polyurethane materials obtained through a partial replacement of the oil-based polyurethane precursors. This approach enables a good balance between the need to improve the sustainability of the polymer and the need to achieve suitable performances, to fulfill the technological requirements for specific applications. In this paper, a succinic-based polyol sample (obtained from biomass source) was synthesized, characterized and blended with cardanol-based polyol (Mannich-based polyol) to produce sustainable rigid polyurethane foams in which the oil-based polyol is totally replaced. A suitable amount of catalysts and surfactant, water as blowing reagent and poly-methylene diphenyl di-isocyanate as isocyanate source were used for the polyurethane synthesis. The resulting foams were characterized by means of infrared spectroscopy (FTIR) to control the cross-linking reactions, scanning electron microscopy (SEM) to evaluate the morphological structure and thermal gravimetric analysis (TGA) and thermal conductivity to evaluate thermal degradation behavior and thermal insulation properties.

Nowadays, the chemical industry is looking for sustainable chemicals to synthesize nanocomposite bio-based polyurethane foams, PUs, with the aim to replace the conventional petrochemical precursors. Some possibilities to increase the environmental sustainability in the synthesis of nanocomposite PUs include the use of chemicals and additives derived from renewable sources (such as vegetable oils or biomass wastes), which comprise increasingly wider base raw materials. Generally, sustainable PUs exhibit chemico-physical, mechanical and functional properties, which are not comparable with those of PUs produced from petrochemical precursors. In order to enhance the performances, as well as the bio-based aspect, the addition in the polyurethane formulation of renewable or natural fillers can be considered. Among these, walnut shells and cellulose are very popular wood-based waste, and due to their chemical composition, carbohydrate, protein and/or fatty acid, can be used as reactive fillers in the synthesis of Pus. Diatomite, as a natural inorganic nanoporous filler, can also be evaluated to improve mechanical and thermal insulation properties of rigid PUs. In this respect, sustainable nanocomposite rigid PU foams are synthesized by using a cardanol-based Mannich polyol, MDI (Methylene diphenyl isocyanate) as an isocyanate source, catalysts and surfactant to regulate the polymerization and blowing reactions, H2O as a sustainable blowing agent and a suitable amount (5 wt%) of ultramilled walnut shell, cellulose and diatomite as filler. The eect of these fillers on the chemico-physical, morphological, mechanical and functional performances on PU foams has been analyzed.

A new pseudopeptide epoxide inhibitor, designed for irreversible binding to HIV protease (HIV-PR), has been synthesized and characterized in solution and in the solid state. However, the crystal structure of the complex obtained by inhibitor–enzyme cocrystallization revealed that a minor isomer, with inverted configuration of the epoxide carbons, has been selected by HIV-PR during crystallization. The structural characterization of the well-ordered pseudopeptide, inserted in the catalytic channel with its epoxide group intact, provides deeper insights into inhibitor binding and HIV-PR stereoselectivity, which aids development of future epoxide-based HIV inhibitors.

Peptidomimetic inhibitors of HIV-1 PR are still a key resource in the fight against AIDS. Here we describe the synthesis and biological activity of HIV-1 PR inhibitors based on four novel dihydroxyethylene isosteres of the Phe-Pro and Pro- Pro dipeptides. The isosteres, containing four stereogenic centers, were synthesized in high yield and excellent stereoselectivity via the cyclization of epoxy amines derived from α-amino acids. The inhibitors were assembled by coupling the isosteres with suitable flanking groups and were screened against recombinant HIV PR showing activities in the subnanomolar to micromolar range. Two Phe-Pro-based inhibitors active at the nanomolar level were further investigated: both inhibitors combine the ability to suppress HIV-1 replication in infected MT-2 cells with low cytotoxicity against the same cells, thereby displaying a high therapeutic index. These results demonstrate the potential of the new Phe-Pro dihydroxyethylene isostere as a core unit of powerful HIV-1 PR inhibitors.

Two different novolac resins, named Nov-I and Nov-II, containing an amount of unreacted cardanol of 35 wt % and 20 wt %, respectively, were synthesized by the condensation reaction of cardanol and paraformaldehyde using oxalic acid as catalyst. Cardanol is the main constituent of cashew nut shell liquid, a renewable natural resource. The cardanol-based novolacs were tested as curing agents of the diglycidyl ether of bisphenol A epoxy resin employing 2-ethyl-4-methyl-imidazole as catalyst and differential scanning calorimeter and thermogravimetric studies were performed to identify the final thermal properties of the cured resins. In addition, tensile tests were carried out to evaluate the mechanical properties of the epoxy resin cured with the novolacs, which showed to deserve consideration as effective epoxy curing agents. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

A series of non-peptidic HIV protease inhibitors were synthesized starting from the same optically active precursor, (S)-glycidol. The substrate was easily converted into different indolic sulfonamides or amines by regioselective reactions. The preliminary inhibitory activity was evaluated.

An assay for routine therapeutic drug monitoring of anti-HIV HAART drugs in clinical use is highly desirable, in order to rapidly measure the pharmacokinetic parameters on single patients. We have started a project to develop a panel of enzyme-linked immunosorbent assays (ELISA) for the whole set of HAART drugs, and the development, performance and evaluation of the assay for amprenavir is described here. A diazo conjugate of amprenavir has been used in order to raise polyclonal anti-amprenavir antibodies in rabbits. Antisera have been used to set up a quantitative and rapid competitive assay. Plasma samples are simply diluted in the assay buffer after thermal inactivation, before running the assay. The assay allows the detection of amprenavir in the quantification range 400-5000 ng/ml, in a diluted plasma sample. The assay has been compared with an HPLC reference technique, on 27 samples from treated patients. Within the quantification range, the ELISA data are well correlated with the HPLC results by a regression line close to the identity, and a Bland-Altman analysis shows the agreement between the two methods.

A versatile synthesis of hydroxylated and epoxy 1-azepin 2-ones substituted at N1, C-3 and C-4 or C-7 has been developed. The sequence involves ring-closing metathesis of an amino acid derived diene amide, followed by either epoxidation or dihydroxylation, of the resulting alkene. Assay of the product epoxides (10, 18, 25) and diols (9a, 17, 24) against HIV protease reveals micromolar inhibition.

Publisher Summary Benzoxazine chemistry is well known and offers many advantages. Only recently polybenzoxazines with enhanced structural properties are successfully synthesized, alone or formulated with suitable additives. Benzoxazines offer many advantages compared with epoxies and other chemical structures, as they are halogen-free, exhibit better flame-resistance and electrical properties than epoxies, and are characterized by an excellent high temperature resistance and low water absorption values. With this combination of properties, benzoxazines hold great promise for performing in applications such as composites, coatings, adhesives, encapsulants, and others. It focuses on the synthesis of new low viscosity cardanol-based benzoxazines, as possible alternatives to the standard petroleum-based ones. This chapter describes that Cardanol is an industrial oily alkyl-phenolic product obtained by the vacuum distillation of “cashew nut shell liquid” (CNSL), a renewable natural resource obtained from the cashew nut as a byproduct during the process of removing the cashew kernel from the nut. A monofunctional liquid cardanol-based benzoxazine is prepared and used as a reactive diluent and toughening agent for a bisphenol A-based benzoxazine. The thermal, viscoelastic, and mechanical properties of benzoxazine resins obtained from the mixture of a low viscosity CA-a and the BA-a are studied in this chapter. Three different mixtures of BA-a and CA-a, containing 10%, 20%, and 30% by weight of CA-a, are prepared and studied to illustrate how different amounts of the cardanol derivative affect the properties of the final benzoxazine resins. The results obtained from the nonisothermal DSC analysis suggested a copolymerization reaction between the two benzoxazines BA-a and CA-a, occurring in a temperature range similar to that shown by the BA-a resin.

We have synthesized and evaluated a small set of dual action HIV-Protease inhibitors, consisting of a catalytic site reversible inhibitor conjugated with a dimerization peptidic inhibitor, linked via a suitable selective end-modified poly(ethylene glycol), in an effort to obtain a synergistic effect with improved biological behaviour and more powerful pharmacological features, such as water solubility and cell permeability. Low nanomolar activity and synergism were obtained by coupling a Phenylalanine – Proline pseudopeptide catalytic site inhibitor and the Val-Val-Phe tripeptide dimerization inhibitor.

The aim of this work is the development of composite pipes using renewable resources. The pipes, manufactured by filament winding technology, were obtained using an epoxy resin crosslinked with a cardanol based novolac as matrix and jute fibres as reinforcement. Cardanol is a natural oil extracted from the shell of the cashew (Anacardium occidentale L.) nut. An amount of natural materials higher than 50% by weight was achieved in the final composites. Tensile and parallel plate compression tests were carried out on the composite pipes.

A series of non-peptidic HIV protease inhibitors were synthesized starting from the same optically active precursor, (S)-glycidol. The substrate was easily converted into different indolic sulfonamides or amines by regioselective reactions. The preliminary inhibitory activity was evaluated.

Benzoxazines are a class of phenolic compounds extensively studied in polymer science because of their properties as fiber reinforcements, fire-retardants and curing agents. In this article is described a solvent-less process, based on a Mannich reaction involving a primary amine and an aldehyde, for the preparation of new benzoxazines deriving from cardanol (a well known phenol obtained as a renewable organic resource and harmful by-product of the cashew industry). Particular attention is given to the synthesis and chemical characterization (both by 1H NMR spectroscopy and HPLC), while the thermal polymerization process has been monitored by differential scanning calorimetry.

A general enantioselective synthesis of new syn-hydroxyethylamine isosteres has been developed. The approach, based on the controlled opening of functionalized optically active 2,3-epoxy amines, can be conveniently used for the preparation of new peptidomimetics with various residues. Finally the total synthesis of two diastereoisomer analogues of HIV-Protease inhibitor Saquinavir has been achieved and their biological activity evaluated. (C) 2007 Elsevier Ltd. All rights reserved.

An efficient method has been developed for the synthesis of a versatile intermediate bearing azido, hydroxyl and ester functions, a useful precursor for peptidomimetic compounds. The two main features for this synthesis were the use of the Sharpless asymmetric dihydroxylation on thiophene acrylate and the subsequent regioselective ring opening by sodium azide of the cyclic sulfite. Highly chemoselective reduction of the azido alcohol led to a key compound which was utilized for the synthesis of two analogues of commercial anti HIV PR such as nelfinavir and saquinavir. The biological activity and molecular modelling study on these two new potential drugs have been evaluated.

The synthesis of a peptide-PEG-oligonucleotide chimera is compared when starting from the peptide or from the oligonucleotide sequence.

A procedure has been developed for the preparation of peptide-PEG-oligonucleotide conjugates: the two sequences were synthesized at the extremities of the same commercial high-molecular-weight polyethylene glycol (PEG) starting both from the peptide as well as from the oligonucleotide component. The commercial PEG was modified at its terminal hydroxyl functions with two orthogonal protecting groups (DMT and Fmoc). The selective removal of those groups allowed the synthesis of the chimeras following two different, interchangeable strategies. Comparison of the final conjugates suggested that their production was equally effective. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)