Analysis of the volatiles in the headspace above the plasmodium and sporangia of the slime mould (Physarum polycephalum) by SPME-GCMS

Solid phase micro-extraction (SPME) coupled with Gas Chromatography Mass Spectrometry (GC-MS) was used to extract and analyse the volatiles in the headspace above the plasmodial and sporulating stages of the slime mould Physarum Polycephalum. In total 115 compounds were identified from across a broad range of chemical classes. Although more (87) volatile organic compounds (VOCs) were identified when using a higher incubation temperature of 75oC, a large number of compounds (79) were still identified at the lower extraction temperature of 30oC and where the plasmodial stage was living. Far fewer compounds were extracted after sporulation at the two extraction temperatures. There were some marked differences between the VOCs identified in the plasmodial stage and after sporulation. In particular the nitrogen containing compounds acetonitrile, pyrrole, 2, 5-dimethyl-pyrazine and trimethyl pyrazine seemed to be associated with the sporulating stage. There were many compounds associated predominantly with the plasmodial stage including a number of furans and alkanes. Interestingly, a number of known fungal metabolites were identified including 1-octen-3-ol, 3-octanone, 1-octen-3 one, 3-octanol. In addition known metabolites of cyanobacteria and actinobacteria in particular geosmin was identified in the headspace. Volatile metabolites that had previously been identified as having a positive chemotactic response to the plasmodial stage of P. polycephalum were also identified including {\beta} farnesene, {\beta}-myrcene, limonene and 3-octanone. This study constitutes the first comprehensive analysis of the headspace volatiles emitted from Physarum Polycephalum. Further work to understand the origin and function of the volatiles identified is required

Complementary products and drug interactions: screening for the potential to cause pharmacokinetic interactions

The use of complementary products has increased dramatically over the last few decades. These products are not subjected to the same safety and toxicity testing that we demand of our conventional medicines, yet they are consumed without medical supervision or advice. The concurrent use of these products with conventional medicines raises the potential for drug interactions to occur. We investigated the potential for complementary products to interact with three key pharmacokinetic parameters. The displacement of drugs bound to plasma proteins; inhibition of the transporter p-glycoprotein; and inhibition of the quantitative most important class of drug metabolising enzymes, the cytochrome P450s. Complementary products selected for investigation are likely to be concurrently used with a therapeutic drug for which, if an interaction was to occur, the outcome could be life threatening. This is based on the properties of the drug and the reported traditional therapeutic indication. Site-specific fluorescent probes were employed for albumin and alpha-1-acid glycoprotein to determine the binding and displacement of previously bound compounds. Of the 5 products investigated significant binding (K d < 1mg/ml) occurred at site I on human serum albumin for 1 extract (the methanolic extract of Goldenseal). A greater level of significant binding was seen at site II with 1 aqueous extract (CoEnzyme Q10) and 4 methanolic extracts (CoEnzyme Q10, Danshen, Ginkgo Biloba, Goldenseal) all binding with a dissociation constant less than 1 mg/ml. Investigations into binding to alpha-1-acid glycoprotein revealed that 1 product bund with significance (the methanolic extract of Echinacea). Inhibition of the transcellular membrane pump p-glycoprotein was investigated with 5 products utilizing a rapid fluorescent assay and the data confirmed with the enzyme based ATPase assay. Significant inhibition (IC 50 <100 μg/ml) was seen for 4 extracts (the aqueous extract of Cordyceps, the methanolic extract of Milk Thistle and both aqueous and methanolic extracts for Slippery Elm). The inhibition of cytochrome P450 was determined for 9 isoforms of the enzyme. Two methods were used; HPLC analysis combined with fluorometry with single substrates and their metabolites, and the N-in-one cocktail, which allows for the simultaneous monitoring of the 9 enzymes in a single incubation. The N-in-one assay was a more reliable assay with these complex products. Of the ten investigated products, Valerian was the most widely inhibitory as it inhibited all 9 of the isoenzymes to some degree. The inhibition of CYP3A4 by the methanolic extract was the most significant finding (IC 50 3.5µg/ml). Reliable extrapolation of in vitro findings to in vivo situation is still an unsurmountable challenge. Due to the large number of complementary products available, their variability in chemical composition and the requirement of ongoing monitoring, we have utilised assays that can provide rapid, cost-effective and reliable information with regards to the potential of these products to cause drug interaction. We have demonstrated the ability for rapid, accurate and reproducible assays to provide information on the potential for complementary products to cause drug interactions and presented a rationale basis for screening these products

Gas-Phase Formation of Environmentally Persistent Free Radicals from Thermal Degradation of Catechol, Hydroquinone, Phenols and Tobacco

Catechol, hydroquinone and Phenol are major constituents of the mainstream tobacco smoke. The toxicity of tobacco has been attributed to the ability of catechol and hydroquinone to undergo endogenous or exogenous redox cycling to form semiquinone type radicals responsible of Reactive Oxygen Species (ROS) formation. ROS such as hydroxyl radicals can cause severe oxidative stress on biological tissues and can provoke severe signaling pathways leading to cardiovascular and pulmonary dysfunctions and carcinogenesis. Given that semiquinone type radicals are organic radicals, characterized by their high instability and reactivity; it is somewhat surprising that they can live long enough mostly when associated with atmospheric fine particles to induce the biological damages reported in the literature. Thus identification of the exact nature of the free radicals, their origin, the reason for their stability and persistency, and their health impacts appear to be an increasing environmental issue. Consequently, we have performed studies of the thermal degradation of catechol, hydroquinone and phenol and structurally similar derivatives that have been proposed as progenitors of semiquinone type radicals. Tobacco pyrolysis has also been investigated. We have employed in conjunction with the Electron Paramagnetic Resonance (EPR), the technique of Low Temperature Matrix Isolation in which catechol, hydroquinone, phenols and Tobacco were pyrolyzed in both low and atmospheric pressures reactor that was directly connected to a liquid nitrogen-cooled cold finger located in the EPR cavity of a Bruker EPR spectrometer. Comprehensive potentially persistent free radicals identification associating additional experimental and mathematical tools has led to the acquisition of the EPR spectra of p- Semiquinone, o-Semiquinone, cyclopentadienyl and phenoxy radicals. The hydroxycyclohexadienyl radical, one of the unexpected radicals according to the decomposition mechanism developed earlier, was found during the atmospheric pyrolysis of phenol. The supposedly very labile radical identified was the hydroxycyclopentadienyl. The methylperoxide type radicals were found when trace of oxygen was used during the pyrolysis experiments. The precursors pyrolysis product analysis employing GC-MS revealed the formation of naphthalene, indenol, indene, benzofuran-2-methyl, indenone, fluorene, and acenaphthylene, thus giving additional evidence of the formation of both labile and potentially persistent free radicals

Electrokinetic treatment of environmental matrices. Contaminants removal and phosphorus recovery

There is a need to develop viable techniques for removal and recovery organic and inorganic compounds from environmental matrices, due to their ecotoxicity, regulatory obligations or potential supplies as secondary materials. In this dissertation, electro –removal and –recovery techniques were applied to five different contaminated environmental matrices aiming phosphorus (P) recovery and/or contaminants removal. In a first phase, the electrokinetic process (EK) was carried out in soils for (i) metalloids and (ii) organic contaminants (OCs) removal. In the case of As and Sb mine contaminated soil, the EK process was additionally coupled with phytotechnologies. In a second phase, the electrodialytic process (ED) was applied to wastes aiming P recovery and simultaneous removal of (iii) toxins from membrane concentrate, (iv) heavy metals from sewage sludge ash (SSA), and (v) OCs from sewage sludge (SS). EK enhanced phytoremediation showed to be viable for the remediation of soils contaminated with metalloids, as although remediation was low, it combines advantages of both technologies while allowing site management. EK also proved to be an effective remediation technology for the removal and degradation of emerging OCs from two types of soil. Aiming P recovery and contaminants removal, different ED cell set-ups were tested. For the membrane concentrates, the best P recovery was achieved in a three compartment (3c) cell, but the highest toxin removal was obtained in a two compartment (2c) cell, placing the matrix in the cathode end. In the case of SSA the best approach for simultaneous P recovery and heavy metals removal was to use a 2c-cell placing the matrix in the anode end. However, for simultaneous P recovery and OCs removal, SS should be placed in the cathode end, in a 2c-cell. Overall, the data support that the selection of the cell design should be done case-by-case

Study on herb-drug interactions

Herbal medicines, such as St John's wort, garlic, gingko, and ginseng, are commonly used complementary therapies. The human CYP enzymes are a superfamily which consists of at least 57 functional CYP genes. Among them, CYP1A2, 2C9, 2C19, 2D6 and 3A4/5 are the most important enzymes responsible for the Phase I metabolism of therapeutic drugs. When different compounds (e.g., a drug and herbal compound) are co-administered, they may compete at the same active site of CYPs, resulting in potential inhibition. We hypothesize that the atom-atom interactions between the ligands and the residues at the active site of CYPs determine the substrate and inhibitor specificity of individual CYPs. To test our hypothesis, we conducted a series of experiments including in vitro assays to determine inhibitory actions of a variety of natural compounds on human CYPs, pharmacokinetic-based predication of in vivo situation using the in vitro data; and in silico studies to explore the ligand-CYP interactions using docking and pharmacophore modeling methods. We first determined the inhibitory effects (IC50) of 56 herbal compounds on activities of five human drug metabolising CYPs (CYP1A2, 2C9, 2C19, 2D6 and 3A4) in vitro using a high throughput approach. The tested herbal components included a variety of structurally distinct compounds such as triterpenoids of danshen (Salvia miltiorrhiza), flavonoids and their glycoside derivatives, saponine, other glucosides, lactones, alkaloids, and acids. A small number of them are found to significantly inhibit human CYP1A2, 2C9, 2C19, 2D6 and 3A4 with differential potency, including tanshinone I, tanshinone IIA, cryptotanshinone, baicalein, quercetin, silybin, osthole and ч-schisandrin. Based on the in vitro data obtained, we predicted metabolic herb-drug interactions of these compounds in vivo with the application of appropriate pharmacokinetic principles. Some predicting results were consistent with published clinical reports. For example, the prediction of S. miltiorrhiza increasing the AUC value of warfarin is consistent with the results from clinical case reports. However, a marked disparity has been observed when some predictions are compared with results from clinical studies. For example, the prediction of S. mariani (containing silybin) increasing the AUC of indinavir (a CYP3A4 substrate) is not in agreement with the result of a clinical report where the plasma concentration of indinavir was not altered by co-administered silymarin in healthy volunteers. Finally, we studied the interactions of a series of ligands including substrates and inhibitors with CYP1A2 using docking and pharmacophore modeling approaches. We have identified 6 residues at the active site of CYP1A2 which are essential for ligand recognition. Furthermore, the relative potency of potential inhibitors could be predicted through analysis of hydrophobic interactions between the ligand and the 6 essential residues at the active site of CYP1A2. Moreover, we developed a pharmacophore model on the basis of the common features of known CYP1A2 inhibitors. In combination with the docking results, the established pharmacophore model could be applied for screening novel CYP1A2 inhibitors

Recent Developments in Identification of Genuine Odor- and Taste-Active Compounds in Foods

Both aroma and taste are important quality criteria for food products, and they have a great influence on our consumption behaviours. In recent years, a significant increase in the number of studies related to the identification of the characteristic odor- and taste-active compounds of particular foods has been observed.In this book, you can find nine valuable scientific contributions, which deal with the more recent analytical developments for the identification of some compounds responsible for odor and taste in foods such as ham, beer, strawberry, Amontillado sherry wine and others, in order to authenticate them or evaluate the effect of different techniques or making stages on their aroma and taste

Studies into the insecticidal activity and mode of action of monoterpenoid constituents of essential oils against the human louse, Pediculus humanus.

The incidence of head lice, Pediculus humanus capitis, in the West is increasing, with insecticide resistance the likely cause. Previous studies have explored the utility of essential oils, and some of their constituent monoterpenoids, in the treatment of head lice. This investigation examines the relative short-term toxicity of a range of different monoterpenoid structures on adult clothing lice, Pediculus humanus cmporis, and their eggs; a structure-activity series was generated for the adults, and partially for eggs. The most effective monoterpenoid against adult lice was (+)-terpinen-4-ol, with monocyclic compounds containing a single 0-atom having the highest activities. Furthermore, there appear to be important differences between the relative potencies of monoterpenoids on lice and eggs, as nerolidol was particularly effective against eggs but completely ineffective against adult lice. To investigate the insecticidal mechanism of action of monterpenoids, various pediculicidal structures were screened for activity on an insect ionotropic GABA receptor, composed of the Drosophila melanogaster subunit RDLac, expressed in Xenopus oocytes. Thymol, eugenol and carvacrol potentiated GABA responses at this receptor, and possessed agonist activity at high concentrations. This is the first documentation of monoterpenoid bioactivity at an isolated insect receptor known to be representative of an in vivo insecticidal target. Thymol also had potentiating and agonist effects on human al(33y2s GABAA receptors expressed in Xenopus oocytes, and 50 (AM thymol induced a leftwards shift of the GABA dose-response curve. Further work on this receptor examined the interaction of thymol with previously characterised modulator binding sites. The results of functional studies suggest that thymol does not share a binding site with benzodiazepines, barbiturates, steroids, propofo1,13-carbolines or loreclezole. The direct involvement of insect GABA receptors in monoterpenoid insecticidal activity remains to be confirmed, as does the location of the thymol binding site on insect and mammalian ionotropic GABA receptors

Utilisation Possibilities of By-Products from Coffee Production in Food Industry

Often referred to as worlds’ second most valuable commodity, coffee is produced in fifty countries and subsequently consumed worldwide generating a great amount of waste. Among their many other applications, this paper provides a survey of coffee by-products utilization in food industry. Coffee pulp is used to obtain volatile compounds and acetic acid by microbial activity. It can also be a source of anthocyanins, acting as natural colorants and bioactive ingredient. Recently, coffee pulp flour with high fiber (18%) and mineral (8%) content has been developed for application in confectionery and baked products. Various food additives (pectins, antioxidants and colors) can be obtained from mucilage, and even coffee honey was extracted from it. Husk is a source of citric acid and natural flavour. Silver skin has been used in combination with other ingredients in producing innovative coffee blends, bread, and biscuits, which had improved sensory and nutritional composition and reduced amount of hydroxymethylfurfural and acrylamide. Spent coffee grounds (SCG) has been used for obtaining a distilled beverage with coffee aroma and bioactive extract enriched in caffeine. Due to melanoidins content, it also exhibits an antimicrobial effect on some pathogens, such as S. aureus and E. coli. Being rich in dietary antioxidant fiber, SCG is incorporated in diverse food formulations with low glycemic and energetic value. A mixture of all coffee industry by-products is used as substrates for edible mushroom cultivation. Therefore, coffee waste, as an abundant natural material with low value, has a great potential of transferring into beneficial food products

PHYSICAL AND CHEMICAL CHARACTERISTICS OF THS IN RELATION TO STANDARD CIGARETTE

In order to reduce the harmful effects of cigarette smoke on the health of active and passive smokers, a new tobacco product - Tobacco heating system (THS) has been developed. Heating, rather than burning tobacco reduces the level of harmful and potentially harmful ingredients in the aerosol. New products are compared to cigarettes, because cigarettes are the most represented and most tested tobacco product on the market. This study aimed to compare the new THS product - IQOS (HEETS cartridges) and the Marlboro cigarette from the same manufacturer, which were available on the Serbian market. The physical characteristics of both products, the chemical characteristics of the aerosols and the amount of heavy metals in the aerosol were analyzed using standardized methods. Measurements were made in three replicates. The physical characteristics of the product showed that HEETS was 2.2 times shorter than a cigarette, 1.95 mm smaller in diameter and 25% less in weight than a cigarette. The content of total particulate phase (TPM) was reduced by 72.19%, nicotine by 30.99%, and the amount of TAR by 98.85% in HEETS condensate in relation to cigarette. Aerosol chemical analysis results indicate that the new THS product offers a lower health risk compared to traditional cigarettes consumption