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The ripening of fruits is a determinant factor on the composition of phytochemical compounds such as phenolic compounds. In this study the phenolic profile of quince fruits was determined as a function of its maturity index. Based on the total soluble solids (TSS) and the acidity (TA) of the fruits, four maturity indexes were established (12.55, 14.56, 21.86 and 24.77), using the ratio of TSS/TA. The phenolic profile of quince fruits with different maturity indexes were obtained by a reversed-phase HPLC-DAD and HPLC-DAD/MS. A PCA loading plot was generated to explain the relationship between physicochemical parameters and the phenolic compounds. The phenolic compounds identified in the quince fruits were 3-0-caffeoylquinic acid, catechin, 4-0-caffeoylquinic acid, 5-0-caffeoylquinic acid, coumaric acid, quercetin-3-0-rutinoside and quercetin-3-0-glycosides. The maturity index increase caused in general a reduction of phenolic compounds, these compounds were also influenced by pH and acidity of fruits. Quince is a valuable source of natural phenolic antioxidants, and can be used as raw material to elaborate diverse food products, providing important functional properties.

ILC3s are innate immune cells in the intestine that contribute to mucosal barrier integrity and support antimicrobial responses. Di Luccia et al. show that an mTORC1-HIF1α–mediated metabolic program sustains ILC3 numbers and activation in both mouse and human., Group 3 innate lymphoid cells (ILC3s) are the innate counterparts of Th17 that require the transcription factor RORγt for development and contribute to the defense against pathogens through IL-22 and IL-17 secretion. Proliferation and effector functions of Th17 require a specific mTOR-dependent metabolic program that utilizes high-rate glycolysis, while mitochondrial lipid oxidation and production of reactive oxygen species (mROS) support alternative T reg cell differentiation. Whether ILC3s employ a specific metabolic program is not known. Here, we find that ILC3s rely on mTOR complex 1 (mTORC1) for proliferation and production of IL-22 and IL-17A after in vitro activation and Citrobacter rodentium infection. mTORC1 induces activation of HIF1α, which reprograms ILC3 metabolism toward glycolysis and sustained expression of RORγt. However, in contrast to Th17, ILC3 activation requires mROS production; rather than inducing an alternative regulatory fate as it does in CD4 T cells, mROS stabilizes HIF1α and RORγt in ILC3s and thereby promotes their activation. We conclude that ILC3 activation relies on a metabolic program that integrates glycolysis with mROS production., Graphical Abstract

During the last decades, biomaterials have been deeply studied to perform and improve coatings for biomedical devices. Metallic materials, especially in the orthopedic field, represent the most common material used for different type of devices thanks to their good mechanical properties. Nevertheless, low/medium resistance to corrosion and low osteointegration ability characterizes these materials. To overcome these problems, the use of biocoatings on metals substrate is largely diffused. In fact, biocoatings have a key role to confer biocompatibility properties, to inhibit corrosion and thus improve the lifetime of implanted devices. In this work, the attention was focused on Hydroxyapatite-Chitosan (HA/CS) and Hydroxyapatite-Polyvinylacetate (HA/PVAc) composites, that have been studied as biocoatings for 304 SS based devices. Hydroxyapatite was selected for its osteoconductivity thanks to its chemical structure similar to bones. Furthermore, Chitosan and Polyvinylacetate are largely used yet in medical field (e.g. antibacterial agent or drug deliver) and in this work were used to create a synergic interaction with hydroxyapatite to increase the strength and bioactivity of coating. Biocotings were obtained by galvanic deposition process that does not require an external power supply. It is a spontaneous electrochemical deposition in which materials with different standard electrochemical potential were short-circuited and immersed in an electrolytic solution. Electrons supply for the cathodic reaction in the noblest material comes from oxidation of the less noble material. SEM, EDS, XRD and RAMAN were performed for chemical-physics characterization of biocoatings. Polarization and impedance measurements have been carried out to evaluate corrosion behavior. Besides, in-vitro cytotoxicity assays have been done for the biological features.

The present study analyzed the ability of primary rat astrocytes to colonize a porous scaffold, mimicking the reticular structure of the brain parenchyma extracellular matrix, as well as their ability to grow, survive and differentiate on the scaffold. Scaffolds were prepared using poly-L-lactic acid (PLLA) via thermally-induced phase separation. Firstly, the present study studied the effects of scaffold morphology on the growth of astrocytes, evaluating their capability to colonize. Specifically, two different morphologies were tested, which were obtained by changing the polymer concentration in the starting solution. The structures were characterized by scanning electron microscopy, and a pore size of 20 µm (defined as the average distance between the pore walls) was detected. For comparison, astrocytes were also cultured in the traditional 2D culture system that we have been using since 2003. Then the effects of different substrates, such as collagen I and IV, and fibronectin were analyzed. The results revealed that the PLLA scaffolds, coated with collagen IV, served as very good matrices for astrocytes, which were observed to adhere, grow and colonize the matrix, acquiring their typical morphology. In addition, under these conditions, they secreted extracellular vesicles (EVs) that were compatible in size with exosomes. Their ability to produce exosomes was also suggested by transmission electron microscopy pictures which revealed both EVs and intracellular structures that could be interpreted as multivesicular bodies. The fact that these cells were able to adapt to the PLLA scaffold, together with our previous results, which demonstrated that brain capillary endothelial cells can grow and differentiate on the same scaffold, could support the future use of 3D brain cell co-culture systems.

A galvanic method to deposit chitosan coatings on stainless steel substrate is reported. Deposition of suitable coatings is desired to improve biocompatibility and corrosion resistance of metallic medical devices to be implanted in human body. In the present work, a thin hydrogel layer of chitosan was deposited on 304SS by a galvanic displacement reaction, which is advantageous first as it does not require external power supply. 304SS was immersed into an aqueous solution of chitosan/lactic acid and electrochemically coupled with magnesium acting as a sacrificial anode. SEM images showed the formation of a uniform layer of chitosan with a thickness controlled by deposition time. Corrosion tests in simulating body fluid showed that chitosan coatings shift the corrosion potential of 304 substrates toward nobler values. Finally, the cytotoxicity of the coating was investigated through cell viability assays with osteoblastic cell MC3T3-E1. The results revealed highly satisfying biocompatibility of the coating.

Microbiota-derived acetate coordinates innate immune responses during intestinal Clostridium difficile infection through its cognate receptor FFAR2. Acetate accelerates early neutrophil recruitment and increases ILC3 expression of the IL-1 receptor, boosting ILC3 production of IL-22 in response to neutrophil-derived IL-1β., Antibiotic-induced dysbiosis is a key predisposing factor for Clostridium difficile infections (CDIs), which cause intestinal disease ranging from mild diarrhea to pseudomembranous colitis. Here, we examined the impact of a microbiota-derived metabolite, short-chain fatty acid acetate, on an acute mouse model of CDI. We found that administration of acetate is remarkably beneficial in ameliorating disease. Mechanistically, we show that acetate enhances innate immune responses by acting on both neutrophils and ILC3s through its cognate receptor free fatty acid receptor 2 (FFAR2). In neutrophils, acetate-FFAR2 signaling accelerates their recruitment to the inflammatory sites, facilitates inflammasome activation, and promotes the release of IL-1β; in ILC3s, acetate-FFAR2 augments expression of the IL-1 receptor, which boosts IL-22 secretion in response to IL-1β. We conclude that microbiota-derived acetate promotes host innate responses to C. difficile through coordinate action on neutrophils and ILC3s., Graphical Abstract

Up until the first half of the 20th century, silver found significant employment in medical applications, particularly in the healing of open wounds, thanks to its antibacterial and antifungal properties. Wound repair is a complex and dynamic biological process regulated by several pathways that cooperate to restore tissue integrity and homeostasis. To facilitate healing, injuries need to be promptly treated. Recently, the interest in alternatives to antibiotics has been raised given the widespread phenomenon of antibiotic resistance. Among these alternatives, the use of silver appears to be a valid option, so a resurgence in its use has been recently observed. In particular, in contrast to ionic silver, colloidal silver, a suspension of metallic silver particles, shows antibacterial activity displaying less or no toxicity. However, the human health risks associated with exposure to silver nanoparticles (NP) appear to be conflicted, and some studies have suggested that it could be toxic in different cellular contexts. These potentially harmful effects of silver NP depend on various parameters including NP size, which commonly range from 1 to 100 nm. In this study, we analyzed the effect of a colloidal silver preparation composed of very small and homogeneous nanoparticles of 0.62 nm size, smaller than those previously tested. We found no adverse effect on the cell proliferation of HaCaT cells, even at high NP concentration. Time-lapse microscopy and indirect immunofluorescence experiments demonstrated that this preparation of colloidal silver strongly increased cell migration, re-modeled the cytoskeleton, and caused recruitment of E-cadherin at cell-cell junctions of human cultured keratinocytes.

One of the most used thermal treatments in potatoes to inactivate enzymes and prevent their oxidation is the boiling process. This treatment significantly decreases the taste of the potato and causes “off-odours” during storage, whatsoever, represents a big problem for the production of potato-based foodstuffs. This study focused on evaluating the sensory profile of potato slices subjected to a boiling process of three Mexican potato varieties (Alpha, Chica and Gallo) and on off-odours detection in potato produced during storage. According to the examined parameters through PanelCheck, the trained panel had a good performance, resulting 8 of the 12 attributes evaluated were significant. The formation of “cardboard-like off-odour” was detected in the Alpha and Chica varieties at the 24 and 33 h of storage, respectively. Chica potato presented this off-odours with at level significantly lower than Alpha potato (about 30% lower). With respect of Gallo variety, this presented different oxidation olfactory perceptions described by the assessors as “burnt note”, detected after 5 h of refrigerated storage. An adequate election of the variety of potato according to processing will allow an effective utilization of this vegetable and the obtention of potato-based foodstuffs much more stable.

Plankton food web dynamics were studied during a complete production season in a semi-intensive land-based facility for rearing of turbot (Scophthalmus maximus) larvae. The production season was divided into three production cycles of 3–5 weeks. Phytoplankton biomass (using chlorophyll a as biomass proxy) peaked in each production cycle. However, the maximum biomass decreased from spring (18 μg chlorophyll a L−1) to fall (ca. 7 μg chlorophyll a L−1), simultaneous with a decline in the concentration of dissolved nitrogen in the inoculating water. During the three production cycles, we observed decreasing copepod nauplii concentration from spring to fall in the rearing tanks. The decreasing nitrogen gave increasing carbon to chlorophyll a ratio in the seston (from 23 in spring to 73 in fall). The pool of free amino acids in seston was constant. We suggest that the decreasing nitrogen input in the inoculating water reduces the quality of the phytoplankton and thus the growth potential of the prey for fish larvae, copepods.

The use of copepods as live feed has shown good potential, and in Taiwan copepods are harvested specifically as live feed for fin-fish production. The calanoid copepod Pseudodiaptomus annandalei is a species found typically in Taiwanese aquaculture and in the rest of the Indo-Pacific region. The copepods, as well as seston, were sampled from outdoor large-scale aquaculture ponds in southern Taiwan during a three week period in the summer, and their somatic biomass, fatty acid and amino acid profiles were examined. The resulting fatty acid profiles of the copepods and pond seston were compared. The analyses reveal high contents of fatty acids in the adult females (approx. 16% of dry weight) with moderate content in the nauplii (approx. 5% of dry weight). Relative abundance of HUFAs was also high. The ratio of fatty acids C22:6 n − 3 (DHA) and C20:5 n − 3 (EPA) stayed above 1.4 with the lowest combined relative abundance of 21.8% of total fatty acid content. The fatty acid C20:4 n − 6 (ARA) was present in adult females and late stage nauplii. Overall, P. annandalei demonstrated good trophic transfer capabilities of HUFAs. Discrepancies between adult female and seston fatty acid profiles indicate possible fatty acid chain alteration mechanisms and/or alternative dietary input. Frequent addition of different types of meal and manure by the farmers, in order to stimulate productivity in the ponds, may provide adults with additional fatty acids that are not found in the pond seston. Also, amino acid compositions in adult females and late stage nauplii reveal high abundances of lysine, arginine and histidine, which is a further indication of an intake of alternative particles to phytoplankton. Overall, the amino acid profile of P. annandalei reveals an abundance of essential amino acids above 53.8 ± 1.2%, combined with an estimated protein content of 57% of dry weight for adult females. Both the fatty and amino acid profiles show favourable nutritional values towards fish larvae rearing. Further investigation into P. annandalei's potential biosynthetic capabilities and intake of particles other than pelagic seston could pave the way for further manipulation of its nutritional value to suit a range of species of fish larvae.

The food industry often utilizes flavor-enriched, semifinished food products as ingredients in more complex preparations. To the best of our knowledge, there are no methods to produce minimally processed food items to which flavorings have been added. In this investigation, apple sticks were enriched with a green apple aroma using different techniques. In particular, vacuum impregnation (VI), ultrasound technology (USI), and the combination of these two techniques (VUSI) were compared with atmospheric pressure impregnation (AI). An isotonic solution of fructose containing ascorbic acid and green apple flavoring was used for impregnation of apple sticks. Different treatment times (2.5, 5.0, and 12.5 min) were investigated, and the relative amount of the major compounds of impregnation flavoring was recorded. Significant differences between treatments were detected: VI and VUSI gave the highest aroma enrichment at 5.0 min of treatment. Different impregnation behaviors were recorded for alcohols and esters: the former increased even after 5.0 min of treatment, and the other components increased until 5.0 min and then decreased, mainly when ultrasound was applied (USI and VUSI). Some possible explanations of these results are proposed, although additional studies are needed to explain the mechanisms involved.

We evaluated dehydrofreezing in strawberries in terms of retention of healthy compounds (i.e. polyphenolics) and sensory qualities for direct consumption in substitution of fresh fruit. Different osmodehydration (OD at 30 °C and 5 °C), vacuum osmodehydration (VOD at 30 °C) and immersion chilling freezing (ICF) processes were applied in sucrose syrup. Samples were analyzed for dry matter, soluble solids, pH, titratable acidity, mass transfers, polyphenolic content by HPLC-DAD/MSD, volatile profile by SPME-GC/MSD and consumer acceptance. The results of sensory evaluation, in particular, confirmed the cryoprotective effects of osmotic processes of fruits with respect to untreated frozen control samples. The OD samples at 5 °C presented a water loss to solid gain ratio comparable to OD at 30 °C and VOD samples. Moreover, while osmo-dehydrofreezing at relatively high temperatures caused a slight depletion of phenolic compounds, the samples osmodehydrated at 5 °C showed higher polyphenolic retention. Data on aromatic compounds showed that some compounds increased (e.g. ethanol and acetaldehyde), while others did not appear to be affected by the pre-treatments.

Anthocyanins, the major colourants of strawberries, are polar pigments that are positively charged at low pH. Herein, we have assessed a new analytical method for the separation of anthocyanins using CZE. Acidic buffer solutions (pH a2) were employed in order to maintain pigments in the cation flavylium form and achieve high molar absorptivity at 510 nm. These spectral properties enabled us to identify strawberry anthocyanins in a preliminary stage by detection in the visible range, although the method was optimised at 280 nm to obtain the best S/N. The effects of buffer composition highlighted the necessity of adding an organic modifier to the running buffer to obtain a suitable separation. The electrophoretic method permitted the separation of the three main anthocyanins of strawberry extracts, namely pelargonidin 3-glucoside (Pg-glu), pelargonidin 3-rutinoside and cyanidin 3-glucoside. The electrophoretic results, expressed as retention time and separation efficiency of the major anthocyanin (Pg-glu), were compared to those achieved in HPLC, the analytical technique traditionally used for the investigation of anthocyanins in vegetable matrix. The content of Pg-glu in strawberries (cv. Camarosa), calculated with HPCE and HPLC methods, resulted respectively in 11.41 mg/L and 11.37 mg/L.

A matrix-type silicone elastomer vaginal ring providing 28-day continuous release of dapivirine (DPV) ⿿ a lead candidate human immunodeficiency virus type 1 (HIV-1) microbicide compound ⿿ has recently demonstrated moderate levels of protection in two Phase III clinical studies. Here, next-generation matrix and reservoir-type silicone elastomer vaginal rings are reported for the first time offering simultaneous and continuous in vitro release of DPV and the contraceptive progestin levonorgestrel (LNG) over a period of between 60 and 180 days. For matrix-type vaginal rings comprising initial drug loadings of 100, 150 or 200 mg DPV and 0, 16 or 32 mg LNG, Day 1 daily DPV release values were between 4132 and 6113 μg while Day 60 values ranged from 284 to 454 μg. Daily LNG release ranged from 129 to 684 μg on Day 1 and 2⿿91 μg on Day 60. Core-type rings comprising one or two drug-loaded cores provided extended duration of in vitro release out to 180 days, and maintained daily drug release rates within much narrower windows (either 75⿿131 μg/day or 37⿿66 μg/day for DPV, and either 96⿿150 μg/day or 37⿿57 μg/day for LNG, depending on core ring configuration and ignoring initial lag release effect for LNG) compared with matrix-type rings. The data support the continued development of these devices as multi-purpose prevention technologies (MPTs) for HIV prevention and long-acting contraception. yes

The cone and 1,2,3 alternate isomers of calix[6]arene bis-crown-4 were investigated computationally. Structural optimizations, energies, bond distances, and Mulliken charges were calculated by the application of the B3LYP/6-31g(d) method/basis, followed by NMR calculations via both B3LYP/6-31g(d) and HF/6-31g(d). Calculations were completed at three different levels of imposed symmetry, and two calculations investigated the chloroform solvent effects. Better NMR results were obtained from HF/6-31g(d) calculations that did not impose molecular symmetry constraints. Consideration of solvent effects improved ground state energies, but other improvements were minimal and not significant enough to justify the added computational expense of solvent calculations. Overall results are consistent with known experimental assignments and were valuable for assigning previously unknown NMR peaks. Net charges, electrostatic forces, and local dipoles – but not bond lengths – are strongly correlated to spectroscopic manifestations of steric compression. Copyright © 2009 John Wiley & Sons, Ltd.

The firmness of green prickly pear fruits (Opuntia ficus indica) impregnated with a sucrose isotonic solution (IS) was evaluated. Whole fresh-peeled prickly pears were processed under different combinations of vacuum pressure (pv), vacuum application time (tv) and relaxation time (tr). Puncture test was applied to impregnated and fresh whole prickly pears. The maximum force (Fmax), average force (Fav) and the work (Wp) required to puncture 3 cm in the fruits were measured. Second order models provided good fits to the experimental data of Fmax (R2 = 0.754), Fav (R2 = 0.788) and Wp (R2 = 0.792). Impregnation factors pv, tr, tv–tr significantly affected firmness parameters (P ≤ 0.05). Firmness parameters of fresh-peeled prickly pear were Fmax = 10.934 ± 1.571 N, Fav = 2.152 ± 0.270 N and Wp = 5.930 × 10−2 ± 0.0054 Nm. Firmness reduction of impregnated fruits was linked to the IS impregnation levels and deformation-relaxation phenomena. PRACTICAL APPLICATIONS The aim of this study was to assess the influence of impregnation conditions on firmness of whole peeled prickly pear, as excessive softening is the main factor limiting consumer acceptability. This study helps to identify the better impregnation conditions for maintaining firmness. This information could be useful for the application of vacuum impregnation in the development of fruits and vegetables products, in which the impregnating solution is used as a carrier of active agents. To date, very limited studies have been conducted in whole fruits involving only peeling and impregnation operations.

A number of libraries were produced to explore the potential of 2,4-diaminopyridine lead 1. The resulting diaminopyridines proved to be potent and selective delta-opioid receptor agonists. Several rounds of lead optimisation using library chemistry identified compound 17 which went on to show efficacy in an electromyography model of neuropathic pain. The structure-activity relationship of the series against the hERG ion channel proved to be a key selectivity hurdle for the series.

The synthesis of a range of novel amine-containing structures and their primary potency as inhibitors of HIV-1 fusion via blocking of the CCR5 receptor is described. The development of the medicinal chemistry strategy and SAR's which led to the identification of the piperidine amide compounds 33 and 36 as excellent leads for further evaluation is described, along with key physicochemical data which highlighted their lead potential.

The discovery of maraviroc 17 is described with particular reference to the generation of high selectivity over affinity for the HERG potassium channel. This was achieved through the use of a high throughput binding assay for the HERG channel that is known to show an excellent correlation with functional effects.

An inherently chiral calix[6]arene possessing a C 2 -symmetric A–B–H substitution pattern was synthesized via a two step process starting from the parent hexa- t -butylcalix[6]arene. The racemic, inherently chiral compound exists as a single isomer with the 1,4-alternate conformation. The inherent chirality was confirmed by treatment of the racemic compound with Pirkle’s reagent to form diastereomeric complexes in solution.

Ring-opening metathesis polymerization (ROMP) of bicyclo[2,2,1]hept-2-ene (norbornene) has been effected in supercritical carbon dioxide (SC CO2) with two types of metal carbene catalysts. It has been found that the polynorbornenes prepared in SC CO2 are similar in molecular weight, molecular weight distribution and thermal stability to their counterparts prepared in tetrahydrofuran (THF). More important, the trans/cis ratio of the resulting polymers could be adjusted by varying the amount of cosolvent THF or metal carbene catalysts. However, neither the reaction temperature nor pressure significantly influenced the trans/cis ratio of the polymer. Copyright © 2005 John Wiley & Sons, Ltd.

The present study focused on the development of a sensory evaluation system, using a quantitative descriptive analysis (QDA) scheme, to define the sensory attributes of boiled potato slices. A HS-SPME–GC–MS technique for a rapid determination of volatile components in boiled potatoes was also investigated. In addition to the mechanism of generation of off-odours and off-flavours in boiled potatoes (POF), the effects of the use of food additives after cooking were examined. POF formation, analysed by both sensory evaluation and HS-SPME, demonstrated an oscillating mechanism of formation of volatile compounds, probably related to enzymatic lipid oxidation and hydroperoxide generation. In particular, POF were strongly correlated with the presence of 2-pentenal, 2-hexenal, 2-heptenal, 2-pentylfuran and 2-decenal. In all, about 50 compounds were detected by HS-SPME technique. Treatment with ascorbate or citrate, after cooking and before storage, did not prevent the formation of off-flavours, in contrast to sodium pyrophosphate. Potassium meta-bisulphite prevented POF formation, but caused the creation of other off-flavours detected by a trained panel.

A series of translucent interpenetrating polymer networks (IPNs) made of a reactive elastomer [linear (D) and branched (T) with varying molecular weights] (Jeffamine™), a commercially available epoxy (D.E.R. 331), and an unsaturated polyester (15:85 wt %) were prepared. DSC data indicated complete cure after 8 h at 90°C. DMTA data showed a single glass-transition temperature (Tg) for all elastomer-containing IPNs, an indication of homogeneity. As expected, all IPNs showed a decrease in Tg with incorporation of elastomer, from 16 to 114°C or lower, the largest decrease being with T-5000. Izod impact strengths were increased by 28–44%, but with no apparent pattern among structure and molecular weight variations. In several cases the standard deviation of impact data increased significantly. Flexural data were measured using a three-point bend test. The highest flexural modulus obtained was that which incorporated linear D-2000 with a decrease of only 22% upon incorporation of the elastomer, whereas other compositions dropped up to 55% in flexural modulus. The strongest material obtained was that using D-2000 with a flexural strength increase of 65% upon incorporation of the elastomer. Two of the three branched elastomer components showed flexural strength increases of about 53%, but one was only equal to the base polyester resin. TGA data were recorded for all IPNs and values compared well to that of the pure polyester resin, with the exception of T-403, which showed a 20°C decrease, and D-2000 with a 10°C decrease. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2283–2286, 2002

Alkenyl-substituted six- and seven-membered cyclic enol ethers, which are potential building blocks for the synthesis of marine polyether natural products, can be prepared in high yield (70–97%) from alkynyl ethers by ruthenium-catalysed ring-closing enyne metathesis. The carbene-bearing ruthenium complex 9 is generally the most efficient catalyst for the reaction.

A previously known imidazole-initiated intramolecular ester migration was modified by replacing the imidazole with Cs2CO3 to effect the efficient conversion of 25, 27-bis-p-methoxy-, 25,27-bis-p-fluoro and 25, 27-bisbenzoyloxycalix[4]arene in the flattened cone conformation to the corresponding 25,26-benzoyloxy compounds in the 1,2-alt. The rearrangement was highly efficient for the unsubstituted and methoxy-substituted esters; the 1,2-alternate isomers were isolated in 80–88% yield, but less efficient for the fluoro-substituted ester (isolated yield 58%). The p-methoxy- and p-fluoroesters were further functionalized in subsequent alkylation reactions with methyl p-toluenesulfonate and pentaethyleneglycol-di-p-tosylate to produce dimethoxy- and calixcrown-ester derivatives in the 1,2-alt. in moderate to good yields. The high yields of the 1,2-alt. are attributed to a π-metal template effect involving the soft cesium ion from the base, two aryl rings and the two phenolate oxygens of the deprotonated calixarene.

The phenolic fraction modification was evaluated in untreated vacuum impregnated frozen apple slices from two varieties (Granny Smith and Stark Delicious) a few days after freezing and after 12 months of frozen storage. After 12 months the phenolic content of both fresh and vacuum impregnated apple slices varied greatly. The most important change was the increase of many polymeric flavan-3-ols, which may be due to hydrolysis of polymeric procyanidins. Furthermore, there was significant correlation (r2 = 0.52, P < 0.05) between the increase in flavan-3-ols and the decrease in pH. In fact, control Stark slices presented the highest pH, and had no statistically significant increase in favan-3-ols. Other classes of phenolic compounds were decreased in apple slices following frozen storage.

Nectarines (Prunus persica L. cv. Maria Laura) were manually selected, cut in slices and divided into four groups: fresh, untreated frozen, soaked in osmotic solution and subsequently frozen, and vacuum impregnated (VI) and subsequently frozen. This investigation was focused on evaluation of consumer acceptance with respect to treated versus untreated frozen nectarine slices. In a preliminary acceptance test of untreated frozen nectarine slices, fruits were generally rejected on the basis of a darkened appearance and ‘‘oxidized’’ taste. These negative attributes were probably linked to the activity of polyphenol oxidase (PPO) and depletion of phenols due to cell rupture during freeze–thaw procedures. For these reasons, in order to evaluate the tendency of fruit to oxidation, several analyses were performed: the antioxidant capacity of phenolic fraction and the o-diphenol content were estimated by spectrophotometric assays, whereas the hydroxycinnamic acid (chlorogenic and neochlorogenic acids) composition was evaluated by high performance liquid chromatography (HPLC). Phenolic content and antioxidant capacity were found to correlate well with the acceptance level of frozen nectarine slices. In this regard a higher phenolic content associated with a higher acceptance level of nectarine samples.

ABTS•+ test, o-diphenols (spectrophotometric) and HPLC-DAD phenolic content in vacuum impregnated apple slices from Stark Delicious and Granny Smith cvv. were studied. Vacuum impregnation (VI) was carried out in a pilot plant using an aqueous solution containing 37.9% dextrose, 15.2% sucrose, 1.0% ascorbic acid, 0.25% calcium chloride and 0.25% sodium chloride. The impregnation time was 30 min and the vacuum pressure was 100 mbar; the temperature was 25 C during all processing steps and the solution/fruit ratio was 11:1. At the end of VI, samples were left 5 min in syrup. They were then rinsed with water, drained in a vibrating screen and quickly frozen. A significant decrease (p < 0.05) of the o-diphenol content was seen (17.84 and 12.32% of the initial content in Stark and Granny varieties, respectively). The same trend was confirmed by HPLC-DAD where reductions in total phenols were 21.57 and 26.86% in Stark and Granny, respectively. Individual phenolic compounds showed different rates of depletion, although in some cases there was no reduction. The ABTS•+ test was strongly affected by the presence of ascorbic acid (AA), which was much higher in treated samples. Sensory evaluation showed higher values of hardness, crispness, juiciness and sourness in VI Granny Smith than VI Stark delicious, with a higher retention of texture parameters in the former. Finally, sweetness was slightly higher in VI Stark.

A rapid method for the screening of metal binding selectivities of host compounds in mixtures is presented. This method involves the separation of mixtures of hosts by HPLC, followed by postcolumn complexation with one or more metals, then analysis by mass spectrometry. The intensities of the host-guest complexes in the mass spectra correlate with the binding selectivities of the hosts. The method was applied to a series of lariat ethers that were synthesized as ion-selective reagents for ion-selective electrodes. The compounds most selective for Na+ vs Li+ and K+ were identified. Additionally, a mixture of substituted calixarenes was screened for alkali-metal-binding selectivity. These compounds were determined to be selective for Cs+ over Rb+, K+, and Na+.

Cone and 1,2,3-alternate stereochemical isomers of 37,40-diallyloxy-(38,42),(39,41)-bis-crown-4 calix[6]arene, 3 and 4 were isolated in moderate yields by bridging the dialkylated calix[6]arene 2 with triethylene glycol di-p-tosylate. The alkali metal complex stoichiometries, association constants, and ion selectivities of 3 and 4 were studied by 1H NMR titration experiments, liquid−liquid extraction, electrospray ionization mass spectroscopy, and X-ray crystallography. Good agreement between the gas-phase and solution-phase studies regarding these metal binding properties was observed. Both conformers formed 1:1 complexes with all alkali metal ions but were structurally preorganized such that each exhibited a strong preference for the larger cesium ion as evidenced by the “deep-cavity” cesium complex of host 4, wherein π-metal interactions helped to stabilize the complex. The Cs+/Na+ selectivity factor for 4 was found to be 1500, while that of 3 was only 140.

Calix[4]arene molecules containing two and four silicon atoms appended to the upper rim of the cone conformation were synthesized via hydrosilation of the corresponding di- and tetra-p-allyl calixarene ethers. The p-allyl calixarene ethers were prepared via the well known Claisen rearrangement which transferred the allyl groups originally on the lower rim of the cone to the upper rim. The silated calix[4]arenes were designed to function as ditopic receptor molecules that will bind cations through the oxygen atoms at the lower rim and anions through the silicon atoms on the upper rim. The hydrosilation reaction provided an easy method for introducing different functionality on the silicon atoms in order to attenuate their relative stability and Lewis acidity.

Three new copolymers containing pendant calix[4]arene units have been synthesized via radical initiated reactions involving a vinylic calix[4]arene monomer with methylacrylate, acrylonitrile, and styrene. The calix[4]arene monomer was locked into tie cone conformation by appending four ethoxyethyl groups to its lower rim. The upper rim of the calix[4]arene monomer, which was the site of polymerization, was monofunctionalized with a modified acrylate ester moiety. A seven atom spacer group was incorporated between the bulky calixarene core and the acrylate moiety in order to minimize steric interactions which proved to impede the polymerization. The copolymers were designed to take advantage of the well-established binding interactions of calixarenes with neutral molecules and ions. The ultimate goal of this project is to develop materials that are suitable for incorporation into chemical sensor devices such as ion-specific electrodes, semipermeable membranes and quartz microbalances.

The de novo synthesis of the novel potent building blocks phenyl ( R )-3-acetoxymethyl-3,6-dihydro-2 H -pyridine-1-carboxylate (−)- 7 and phenyl ( S )-3-butyryl-oxymethyl-3,6-dihydro-2 H -pyridine-1-carboxylate (+)- 8 starting from commercially available methyl-1-benzyl-4-oxo-3-piperidinecarboxylate is described. The key steps are the enantioselective esterification of the racemic alcohol 6 and the enantioselective hydrolysis of the racemic acetate 5 , respectively, using lipase P from Pseudomonas caepacia .

A practical synthesis of N-p-anisyl-N-methyl-amino-3-(9-anthryl)-propane from 9-anthraldehyde is described. All the intermediates in this simple five step sequence are crystalline and simple re-crystallisation after each step allows the preparation of this exciplex fluorescence ‘thermometer’ molecule on a preparative scale without resort to chromatography.

Intramolecular [Pd2(dba)3]/tri(2‐furyl)phosphine‐catalysed (dba = dibenzylideneacetone, PhCH=CHCOCH=CHPh) cyclisations of olefinic propargylic carbonates I provided alk‐1‐enyl‐(3‐aza)bicyclo[3.1.0]‐hexanes VIII in good yields. A palladium cascade sequence I → II → III → IV → VII → VIII is proposed. Furthermore, chiral propargylic carbonates such as 23, 24 and 25 allowed diastereoselective formation of bicyclo[3.1.0]hexanes 29, 30 and 31, respectively. The first diastereoselective synthesis of the monoterpene, (−)‐α‐thujone 40 illustrates the potential of the method.

The initial synthesis of UK-427,857 (Maraviroc) is described including the preparation of 4,4-difluorocyclohexanoic acid and amide coupling utilizing a polymer supported reagent.

A practical synthesis of N-p-anisyl-N-methyl-amino-3-(9-anthryl)-propane from 9-anthraldehyde is described. All the intermediates in this simple five step sequence are crystalline and simple re-crystallisation after each step allows the preparation of this exciplex fluorescence ‘thermometer’ molecule on a preparative scale without resort to chromatography.

The de novo synthesis of the novel potent building blocks phenyl ( R )-3-acetoxymethyl-3,6-dihydro-2 H -pyridine-1-carboxylate (−)- 7 and phenyl ( S )-3-butyryl-oxymethyl-3,6-dihydro-2 H -pyridine-1-carboxylate (+)- 8 starting from commercially available methyl-1-benzyl-4-oxo-3-piperidinecarboxylate is described. The key steps are the enantioselective esterification of the racemic alcohol 6 and the enantioselective hydrolysis of the racemic acetate 5 , respectively, using lipase P from Pseudomonas caepacia .

The Lewis acidic calix[4]arene with four covalently attached diphenylmonochlorotin(IV) centers was synthesized and its stannate complex with chloride was studied by 119Sn NMR.