Enantiomeric Fraction Determination of 2‐Arylpropionic Acids in a Package Plant Membrane Bioreactor

Enantiomeric compositions of three 2‐arylpropionic acid (2‐APA) drugs, ibuprofen, naproxen, and ketoprofen, were monitored in a membrane bioreactor (MBR) treating municipal effluent in a small rural town in Australia. Specific enantiomers were determined as amide diastereomers using the chiral derivatizing reagent, (R)‐1‐phenylethylamine (PEA), followed by gas chromatography–tandem mass spectrometry (GC‐MS/MS). The six individual enantiomers were quantified by isotope dilution and the enantiomeric fractions (EFs) were determined. Over four separate sampling events, ibuprofen EF ranged from 0.88 to 0.94 (median 0.93) in the influent and 0.38 to 0.40 (median 0.39) in the effluent. However, no significant change in ketoprofen EF was observed, with influent EFs of 0.56–0.60 (median 0.58) and effluent EFs 0.54–0.68 (median 0.56). This is the first report of enantiospecific analysis of ketoprofen in municipal wastewater and it is not yet clear why such different behavior was observed compared to ibuprofen. Naproxen EF was consistently measured at 0.99 in the influent and ranged from 0.86 to 0.94 (median 0.91) in the effluent. This study demonstrates that EF is a relatively stable parameter and does not fluctuate according to concentration or other short‐term variables introduced by sampling limitations. The enantiospecific analysis of chiral chemicals presents a promising approach to elucidate a more thorough understanding of biological treatment processes and a potential tool for monitoring the performance of key biological pathways. Chirality 25:301–307, 2013. © 2013 Wiley Periodicals, Inc.     

UVB radiation and 17‐hydroxygeranyllinalool diterpene glycosides provide durable resistance against mirid (Tupiocoris notatus) attack in field‐grown Nicotiana attenuata plants

Depending on geographical location, plants are exposed to variable amounts of UVB radiation and herbivore attack. Because the role(s) of UVB in the priming and/or accumulation of plant defence metabolites against herbivores are not well understood, we used field‐grown Nicotiana attenuata plants to explore the effects of UVB on herbivore performance. Consistent with previous reports, UVB‐exposed plants accumulated higher levels of ultraviolet (UV)‐absorbing compounds (rutin, chlorogenic acid, crypto‐chlorogenic acid and dicaffeoylspermidine). Furthermore, UVB increased the accumulation of jasmonic acid, jasmonoyl‐L‐isoleucine and abscisic acid, all phytohormones which regulate plant defence against biotic and abiotic stress. In herbivore bioassays, N. attenuata plants experimentally protected from UVB were more infested by mirids in three consecutive field seasons. Among defence metabolites measured, 17‐hydroxygeranyllinalool diterpene glycosides (HGL‐DTGs) showed strongly altered accumulation patterns. While constitutive HGL‐DTGs levels were higher under UVB, N. attenuata plants exposed to mirid bugs (Tupiocoris notatus) had still more HGL‐DTGs under UVB, and mirids preferred to feed on HGL‐DTGs‐silenced plants when other UVB protecting factors were eliminated by UVB filters. We conclude that UVB exposure not only stimulates UV protective screens but also affects plant defence mechanisms, such as HGL‐DTGs accumulation, and modulates ecological interactions of N. attenuata with its herbivores in nature.     

Cone–shell Raman spectroscopy (CSRS) for depth‐sensitive measurements in layered tissue

We report the development of a depth‐sensitive Raman spectroscopy system using the configuration of cone–shell excitation and cone detection. The system uses a 785 nm diode laser and three identical axicons for Raman excitation of the target sample in the form of a hollow conic section. The Raman scattered light from the sample, passed through the same (but solid) conic section, is collected for detection. Apart from its ability of probing larger depths (? few mm), an important attraction of the system is that the probing depths can be varied by simply varying the separation between axicons in the excitation arm. Furthermore, no adjustment is required in the sample arm, which is a significant advantage for noncontact, depth‐sensitive measurement. Evaluation of the performance of the developed setup on nonbiological phantom and biological tissue sample demonstrated its ability to recover Raman spectra of layers located at depths of ?2–3 mm beneath the surface.

     

Essential‐Oil Composition of Helichrysum italicum (Roth) G.Don ssp. italicum from Elba Island (Tuscany,Italy)

The composition of 21 essential‐oil samples isolated from Helichrysum italicum collected in seven locations of Elba Island (Tuscany, Italy), characterized by different soil types, during three different periods (January, May, and October 2010) was determined by GC‐FID and GC/EI‐MS analyses. In total, 115 components were identified, representing 96.8–99.8% of the oil composition. The oils were characterized by a high content of oxygenated monoterpenes (38.6–62.7%), while monoterpene and sesquiterpene hydrocarbons accounted for 2.3–41.9 and 5.1–20.1% of the identified constituents, respectively. The main oxygenated derivatives were nerol (2.8–12.8%) and its ester derivative neryl acetate (5.6–45.9%). To compare the chemical variability of the species within Elba Island and between the island and other localities within the Mediterranean area, studied previously, multivariate statistical analysis was performed. The results obtained showed a difference in the composition of the essential oils of H. italicum from Elba Island, mainly due to the environment where the plant grows, and, in particular, to the soil type. These hypotheses were further confirmed by the comparison of these oils with essential oils obtained from H. italicum collected on other islands of the Tuscan archipelago.     

Analysis of fexofenadine in pharmaceutical formulations using tris(1,10‐phenanthroline)–ruthenium(II) peroxydisulphate chemiluminescence system in a multichip device

A simple, rapid and sensitive method has been developed for the analysis of fexofenadine (FEX) in pharmaceutical formulations, using a tris(1,10‐phenanthroline)–ruthenium(II) [Ru(phen)₃²⁺] peroxydisulphate chemiluminescence (CL) system in a multichip device. Various parameters that influence the CL signal intensity were optimized. These included pH, flow rates and concentration of reagents used. Under optimum conditions, a linear calibration curve in the range 0.05–5.0 µg/mL was obtained. The detection limit was found to be 0.001 µg/mL. The procedure was applied to the analysis of FEX in pharmaceutical products and was found to be free from interference from concomitants usually present in these preparations. Copyright © 2011 John Wiley & Sons, Ltd.     

Dual effects of [Tyr6]‐γ2‐MSH(6–12) on pain perception and in vivo hyperalgesic activity of its analogues

[Tyr⁶]‐γ2‐MSH(6–12) with a short effecting time of about 20 min is one of the most potent rMrgC receptor agonists. To possibly increase its potency and metabolic stability, a series of analogues were prepared by replacing the Tyr⁶ residue with the non‐canonical amino acids 3‐(1‐naphtyl)‐L ‐alanine, 4‐fluoro‐L ‐phenylalanine, 4‐methoxy‐L ‐phenylalanine and 3‐nitro‐L ‐tyrosine. Dose‐dependent nociceptive assays performed in conscious rats by intrathecal injection of the MSH peptides showed [Tyr⁶]‐γ2‐MSH(6–12) hyperalgesic effects at low doses (5–20 nmol) and analgesia at high doses (100–200 nmol). This analgesic activity is fully reversed by the kyotorphin receptor‐specific antagonist Leu–Arg. For the two analogues containing in position 6, 4‐fluoro‐L ‐phenylalanine and 3‐nitro‐L ‐tyrosine, a hyperalgesic activity was not observed, while the 3‐(1‐naphtyl)‐L ‐alanine analogue at 10 nmol dose was found to induce hyperalgesia at a potency very similar to γ2‐MSH(6–12), but with longer duration of the effect. Finally, the 4‐methoxy‐L ‐phenylalanine analogue (0.5 nmol) showed greatly improved hyperalgesic activity and prolonged effects compared to the parent [Tyr⁶]‐γ2‐MSH(6–12) compound. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.     

Epicardium‐derived cells (EPDCs) in development,cardiac disease and repair of ischemia

The proepicardial-derived epicardium covers the myocardium and after a process of epithelial–mesenchymal transition (EMT) forms epicardium-derived cells (EPDCs). These cells migrate into the myocardium and show an essential role in the induction of the ventricular compact myocardium and the differentiation of the Purkinje fibres. EPDCs are furthermore the source of the interstitial fibroblast, the coronary smooth muscle cell and the adventitial fibroblast. The possible differentiation into cardiomyocytes, endothelial cells and the recently described telocyte and other cells in the cardiac stem cell niche needs further investigation. Surgically or genetically disturbed epicardial and EPDC differentiation leads to a spectrum of abnormalities varying from thin undifferentiated myocardium, which can be embryonic lethal, to a diminished coronary vascular bed with even absent main coronary arteries. The embryonic potential of EPDCs has been translated to both structural and functional congenital malformations and adult cardiac disease, like development of Ebstein’s malformation, arrhythmia and cardiomyopathies. Furthermore, the use of adult EPDCs as a stem cell source has been explored, showing in an animal model of myocardial ischemia the recapitulation of the embryonic program with improved function, angiogenesis and less adverse remodeling. Combining EPDCs and adult cardiomyocyte progenitor cells synergistically improved these results. The contribution of injected EPDCs was instructive rather than constructive. The finding of reactivation of the endogenous epicardium in ischemia with re-expression of developmental genes and renewed EMT marks the onset of a novel therapeutic focus.     

Binding Pockets and Permeation Channels for Dioxygen through Cofactorless 3‐Hydroxy‐2‐methylquinolin‐4‐one 2,4‐Dioxygenase in Association with Its Natural Substrate, 3‐Hydroxy‐2‐methylquinolin‐4(1H)‐one. A Perspective from Molecular Dynamics Simulations

This work describes an investigation of pathways and binging pockets (BPs) for dioxygen (O₂) through the cofactorless oxygenase 3‐hydroxy‐2‐methylquinolin‐4‐one 2,4‐dioxygenase in complex with its natural substrate, 3‐hydroxy‐2‐methylquinolin‐4(1H)‐one, in aqueous solution. The investigation tool was random‐acceleration molecular dynamics (RAMD), whereby a tiny, randomly oriented external force is applied to O₂ in order to accelerate its movements. In doing that, care was taken that the external force only continues, if O₂ moves along a direction for a given period of time, otherwise the force changed direction randomly. Gates for expulsion of O₂ from the protein, which can also be taken as gates for O₂ uptake, were found throughout almost the whole external surface of the protein, alongside a variety of BPs for O₂. The most exploited gates and BPs were not found to correspond to the single gate and BP proposed previously from the examination of the static model from X‐ray diffraction analysis of this system. Therefore, experimental investigations of this system that go beyond the static model are urgently needed.     

Comparative Chemical and Molecular Variability of Cananga odorata (Lam.) Hook.f. & Thomson forma genuina (Ylang‐Ylang) in the Western Indian Ocean Islands: Implication for Valorization

Cananga odorata (Lam.) Hook .f. & Thomson forma genuina (Annonaceae) is a tropical tree, grown for the production of ylang‐ylang essential oil, which is extracted from its fresh and mature flowers. Despite its economic and social importance, very little information is available on its variability and the possible factors causing it. Therefore, the relationship between the genetic structure, revealed by amplified fragment length polymorphism (AFLP), and the essential oil chemical composition, determined by GC/MS analysis, of ylang‐ylang grown in semi‐managed systems in three Indian Ocean islands (Grande Comore, Mayotte, and Madagascar) was investigated. Our results revealed a low genetic variation within plantations and contrasted situations between islands. Variations of the chemical composition could be observed within plantations and between islands. The genetic differentiation pattern did not match the observed pattern of chemical variability. Hence, the chemical variation could not be attributed to a genetic control. As Grande Comore, Madagascar, and Mayotte present different environmental and agronomic conditions, it can be concluded that the influence of these conditions on the ylang‐ylang essential oil composition is consistent with the patterns observed. Finally, several strategies were proposed to valorize the chemical composition variations.     

Determination of thiram in natural waters using flow‐injection with cerium(IV)–quinine chemiluminescence system

A simple and rapid flow‐injection chemiluminescence method has been developed for the determination of dithiocarbamate fungicide thiram based on the chemiluminescence reaction of thiram with ceric sulfate and quinine in aqueous sulfuric acid. The present method allowed the determination of thiram in the concentration range of 7.5–2500 ng/mL and the detection limit (signal‐to‐noise ratio = 3) was 7.5 ng/mL with sample throughput of 120/h. The relative standard deviation was 2.5% for 10 replicate analyses of 500 ng/mL thiram. The effects of foreign species including various anions and cations present in water at environmentally relevant concentrations and some pesticides were also investigated. The proposed method was applied to determine thiram in spiked natural waters using octadecyl bonded phase silica (C₁₈) cartridges for solid‐phase extraction. The recoveries were in the range 99 ± 1 to 104 ± 1%. Copyright © 2009 John Wiley & Sons, Ltd.