Understanding the Risks of Diffusion of Cyanobacteria Toxins in Rivers, Lakes, and Potable Water.

Blue-green algae, or cyanobacteria, may be prevalent in our rivers and tap water. These minuscule bacteria can grow swiftly and form blooms in warm, nutrient-rich water. Toxins produced by cyanobacteria can pollute rivers and streams and harm the liver and nervous system in humans. This review highlights the properties of 25 toxin types produced by 12 different cyanobacteria genera. The review also covered strategies for reducing and controlling cyanobacteria issues. These include using physical or chemical treatments, cutting back on fertilizer input, algal lawn scrubbers, and antagonistic microorganisms for biocontrol. Micro-, nano- and ultrafiltration techniques could be used for the removal of internal and extracellular cyanotoxins, in addition to powdered or granular activated carbon, ozonation, sedimentation, ultraviolet radiation, potassium permanganate, free chlorine, and pre-treatment oxidation techniques. The efficiency of treatment techniques for removing intracellular and extracellular cyanotoxins is also demonstrated. These approaches aim to lessen the risks of cyanobacterial blooms and associated toxins. Effective management of cyanobacteria in water systems depends on early detection and quick action. Cyanobacteria cells and their toxins can be detected using microscopy, molecular methods, chromatography, and spectroscopy. Understanding the causes of blooms and the many ways for their detection and elimination will help the management of this crucial environmental issue.

Development and Validation of a Reversed-Phase HPLC Method with UV Detection for the Determination of L-Dopa in Vicia faba L. Broad Beans.

L-Dopa (LD), a substance used medically in the treatment of Parkinson's disease, is found in several natural products, such as Vicia faba L., also known as broad beans. Due to its low chemical stability, LD analysis in plant matrices requires an appropriate optimization of the chosen analytical method to obtain reliable results. This work proposes an HPLC-UV method, validated according to EURACHEM guidelines as regards linearity, limits of detection and quantification, precision, accuracy, and matrix effect. The LD extraction was studied by evaluating its aqueous stability over 3 months. The best chromatographic conditions were found by systematically testing several C18 stationary phases and acidic mobile phases. In addition, the assessment of the best storage treatment of Vicia faba L. broad beans able to preserve a high LD content was performed. The best LD determination conditions include sun-drying storage, extraction in HCl 0.1 M, chromatographic separation with a Discovery C18 column, 250 × 4.6 mm, 5 µm particle size, and 99% formic acid 0.2% v/v and 1% methanol as the mobile phase. The optimized method proposed here overcomes the problems linked to LD stability and separation, thus contributing to the improvement of its analytical determination.

Solanaceae glycoalkaloids: α-solanine and α-chaconine modify the cardioinhibitory activity of verapamil.

CONTEXT: Solanaceae glycoalkaloids (SGAs) possess cardiomodulatory activity. OBJECTIVE: This study investigated the potential interaction between verapamil and glycoalkaloids. MATERIAL AND METHODS: The cardioactivity of verapamil and glycoalkaloids (α-solanine and α-chaconine) was tested in adult beetle (Tenebrio molitor) myocardium in vitro using microdensitometric methods. The myocardium was treated with pure substances and mixtures of verapamil and glycoalkaloids for 9 min with saline as a control. Two experimental variants were used: simultaneous application of verapamil and glycoalkaloids or preincubation of the myocardium with one of the compounds followed by perfusion with a verapamil solution. We used 9 × 10-6-5 × 10-5 M and 10-9-10-5 M concentration for verapamil and glycoalkaloids, respectively. RESULTS: Verapamil, α-solanine and α-chaconine showed cardioinhibitory activity with IC50 values equal to 1.69 × 10-5, 1.88 × 10-7 and 7.48 × 10-7 M, respectively. When the glycoalkaloids were applied simultaneously with verapamil, an antagonistic effect was observed with a decrease in the maximal inhibitory effect and prolongation of t50 and the recovery time characteristic of verapamil. We also confirmed the expression of two transcript forms of the gene that encodes the α1 subunit of L-type calcium channels in the myocardium and brain with equal transcription levels of both forms in the myocardium and significant domination of the shorter form in the brain of the insect species tested. DISCUSSION AND CONCLUSIONS: The results show that attention to the composition of the daily diet during therapy with various drugs is particularly important. In subsequent studies, the nature of interaction between verapamil and SGAs on the molecular level should be checked, and whether this interaction decreases the efficiency of cardiovascular therapy with verapamil in humans.

Solanum nigrum Extract and Solasonine Affected Hemolymph Metabolites and Ultrastructure of the Fat Body and the Midgut in Galleria mellonella.

Glycoalkaloids, secondary metabolites abundant in plants belonging to the Solanaceae family, may affect the physiology of insect pests. This paper presents original results dealing with the influence of a crude extract obtained from Solanum nigrum unripe berries and its main constituent, solasonine, on the physiology of Galleria mellonella (Lepidoptera) that can be used as an alternative bioinsecticide. G. mellonella IV instar larvae were treated with S. nigrum extract and solasonine at different concentrations. The effects of extract and solasonine were evaluated analyzing changes in carbohydrate and amino acid composition in hemolymph by RP-HPLC and in the ultrastructure of the fat body cells by TEM. Both extract and solasonine changed the level of hemolymph metabolites and the ultrastructure of the fat body and the midgut cells. In particular, the extract increased the erythritol level in the hemolymph compared to control, enlarged the intracellular space in fat body cells, and decreased cytoplasm and lipid droplets electron density. The solasonine, tested with three concentrations, caused the decrease of cytoplasm electron density in both fat body and midgut cells. Obtained results highlighted the disturbance of the midgut and the fat body due to glycoalkaloids and the potential role of hemolymph ingredients in its detoxification. These findings suggest a possible application of glycoalkaloids as a natural insecticide in the pest control of G. mellonella larvae.

Cannabis: A Toxin-Producing Plant with Potential Therapeutic Uses.

For thousands of years, Cannabis sativa has been utilized as a medicine and for recreational and spiritual purposes. Phytocannabinoids are a family of compounds that are found in the cannabis plant, which is known for its psychotogenic and euphoric effects; the main psychotropic constituent of cannabis is Δ9-tetrahydrocannabinol (Δ9-THC). The pharmacological effects of cannabinoids are a result of interactions between those compounds and cannabinoid receptors, CB1 and CB2, located in many parts of the human body. Cannabis is used as a therapeutic agent for treating pain and emesis. Some cannabinoids are clinically applied for treating chronic pain, particularly cancer and multiple sclerosis-associated pain, for appetite stimulation and anti-emesis in HIV/AIDS and cancer patients, and for spasticity treatment in multiple sclerosis and epilepsy patients. Medical cannabis varies from recreational cannabis in the chemical content of THC and cannabidiol (CBD), modes of administration, and safety. Despite the therapeutic effects of cannabis, exposure to high concentrations of THC, the main compound that is responsible for most of the intoxicating effects experienced by users, could lead to psychological events and adverse effects that affect almost all body systems, such as neurological (dizziness, drowsiness, seizures, coma, and others), ophthalmological (mydriasis and conjunctival hyperemia), cardiovascular (tachycardia and arterial hypertension), and gastrointestinal (nausea, vomiting, and thirst), mainly associated with recreational use. Cannabis toxicity in children is more concerning and can cause serious adverse effects such as acute neurological symptoms (stupor), lethargy, seizures, and even coma. More countries are legalizing the commercial production and sale of cannabis for medicinal use, and some for recreational use as well. Liberalization of cannabis laws has led to increased incidence of toxicity, hyperemesis syndrome, lung disease cardiovascular disease, reduced fertility, tolerance, and dependence with chronic prolonged use. This review focuses on the potential therapeutic effects of cannabis and cannabinoids, as well as the acute and chronic toxic effects of cannabis use on various body systems.

Rearing substrate impacts growth and macronutrient composition of Hermetia illucens (L.) (Diptera: Stratiomyidae) larvae produced at an industrial scale.

Organic waste is a rapidly increasing problem due to the growth of the agricultural production needed to meet global food demands. Development of sustainable waste management solutions is essential. Black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae) (BSF), larvae are voracious consumers of a wide range of organic materials ranging from fruits and vegetables to animal remains, and manure. Thanks to this ability and considering the larval high protein and lipid content, BSF larvae are a useful additive in animal feeds and biodiesel production. Unfortunately, the feasibility of using the black soldier fly as a tool for waste valorization and feed production has primarily been investigated at the benchtop scale. Thus, mobilization of current practices to an industrial scale is challenging because scaling up from small laboratory studies to large industrial studies is not necessarily linear. The goal of this study was to demonstrate the ability of the BSF to recycle organic waste at an industrial scale. To accomplish this goal, three organic waste streams were used (e.g., apples, bananas, and spent grain from a brewery) to test six diet treatments (1) apple, (2) banana, (3) spent grain, (4) apple and banana, (5) apple and spent grain, and (6) banana and spent grain. Working at scale of 10,000 BSF larvae life history traits, waste valorization, protein and lipid profiles were measured for each diet treatment. Differences were recorded across all variables, except substrate conversion, for larvae fed on fruit and spent grain (alone or with fruit). Growth rate significantly differed across treatments; larvae reared on spent grain grew twice as fast as those fed apples alone, but those reared on the apple and spent grain mixture produced twice as much insect biomass. However, it should be noted that larvae resulting from the apple diet contained 50% more fat than larvae fed the fruit and spent grain mixtures. Commonly-available organic wastes were successfully used at an industrial scale to produce BSF larvae that have the potential to substitute other sources of protein and lipids in different industrial applications. Industrialization efforts are encouraged to assess these impacts when integrating diverse ingredients into larval diets as a means to more precisely predict output, such as larval development time and final larval biomass.

Validation of an Analytical Method for Nitrite and Nitrate Determination in Meat Foods for Infants by Ion Chromatography with Conductivity Detection.

Nitrate and nitrite as sodium or potassium salts are usually added to meat products to develop the characteristic flavor, to inhibit the growth of microorganisms (particularly Clostridium botulinum), and effectively control rancidity by inhibiting lipid oxidation. However, both nitrate and nitrite ions need to be monitored for ensuring the quality and safety of cured meats. In this work, for the first time the content of nitrite and nitrate ions in homogenized meat samples of baby foods was determined by a validated method based on ion chromatography (IC) coupled with conductivity detection. Recoveries of nitrate and nitrite ions in meat samples were not lower than 84 ± 6%. The detection limits of nitrate and nitrite were 0.08 mg L-1 and 0.13 mg L-1, respectively. Five commercial samples of homogenized meat, namely lamb, rabbit, chicken, veal, and beef, for infant feeding were investigated; while nitrite content was below the detection limit, nitrate ranged from 10.7 to 21.0 mg kg-1. The results indicated that nitrate contents were below the European (EU) fixed value of 200 mg kg-1, and an acceptable daily intake of 3.7 mg kg-1 was estimated.

Corrigendum: Chemical Ecology of Capnodis tenebrionis (L.) (Coleoptera: Buprestidae): Behavioral and Biochemical Strategies for Intraspecific and Host Interactions.

[This corrects the article DOI: 10.3389/fphys.2019.00604.].

Biological Activities of Alkaloids: From Toxicology to Pharmacology.

Plants produce many secondary metabolites, which reveal biological activity [...].

Profiling of quercetin glycosides and acyl glycosides in sun-dried peperoni di Senise peppers (Capsicum annuum L.) by a combination of LC-ESI(-)-MS/MS and polarity prediction in reversed-phase separations.

Interest in targeted profiling of quercetin glycoconjugates occurring in edible foodstuffs continues to expand because of their recognized beneficial health effects. Quercetin derivatives encompass several thousands of chemically distinguishable compounds, among which there are several compounds with different glycosylations and acylations. Since reference standards and dedicated databases are not available, the mass spectrometric identification of quercetin glycoconjugates is challenging. A targeted liquid chromatography (LC) coupled with tandem mass spectrometry (MS/MS) was applied for screening quercetin glycoconjugates in edible peperoni di Senise peppers (Capsicum annuum L.), protected by the European Union with the mark PGI (i.e., Protected Geographical Indication), and cultivated in Basilicata (Southern Italy). Chromatographic separation was accomplished by reversed-phase liquid chromatography (RPLC) using water/acetonitrile as the mobile phase and detection was performed on a linear ion trap mass spectrometer fitted with an electrospray ionization (ESI) source operating in negative ion mode. A correlation between experimental RP chromatographic retention time and those predicted by partition coefficients (log P) along with MS/MS data and an in-house developed database (named QUEdb) provided deep coverage for sixteen quercetin glycoconjugates. Among them, eleven quercetin glycoconjugates were already described in the literature and five were reported for the first time. These last acyl glycosidic quercetin derivatives were tentatively identified as quercetin-(galloyl-rhamnoside)-hexoside, [C34H33O20]- at m/z 761.1; quercetin-(sinapoyl-hexoside)-rhamnoside, [C38H39O20]- at m/z 815.4; quercetin-(galloyl-caffeoyl-hexoside)-rhamnoside, [C43H39O23]- at m/z 923.0; quercetin-(feruloyl-hexoside)-rhamnoside, [C37H37O19]- at m/z 785.1; and quercetin-(succinyl-rhamnoside)-rhamnoside, [C31H33O18]- at m/z 693.1. Graphical abstract.

Validation of a liquid chromatography coupled with tandem mass spectrometry method for the determination of drugs in wastewater using a three-phase solvent system.

Pharmaceuticals constitute one of the most important emerging classes of environmental pollutants. A three-phase solvent system of water, water containing 0.1% of formic acid and acetonitrile was successfully used to separate, by liquid chromatography with mass spectrometry (LC-MS), polarity-matched pharmaceuticals, that is, carbamazepine, clarithromycin, and erythromycin, as well as amoxicillin and metformin. Despite of polarity similarities, these pharmaceuticals were completely resolved in the analytical run time of 15 min. The optimized three-phase solvent system based-method was validated for the simultaneous analysis of six matched-polarity pharmaceuticals in wastewater samples. Good linearity (coefficient of determination more than 0.993) and precision (relative standard deviation less than 15.66%) were achieved. Recovery of analytes from the wastewater was between 0.70 and 1.18. Limits of detections ranged from 0.0001 to 0.5114 µg/L. No significant matrix effect, evaluated by post extraction addition, was observed in the electrospray ionization (ESI) source. Then, this methodology has been successfully applied to environmental study of pharmaceutical residues occurring in influent and effluent wastewater samples, from the main wastewater treatment plant in Potenza (Basilicata, Southern Italy).

Study of the Regulatory Role of N-Acyl Homoserine Lactones Mediated Quorum Sensing in the Biological Activity of Burkholderia gladioli pv. agaricicola Causing Soft Rot of Agaricus spp.

Many Burkholderia spp. produce in vitro secondary metabolites with relevant biological activities and potential practical applications. Burkholderia gladioli pv. agaricicola (Bga) possess promising biological activities regulated by N-Acyl homoserine lactones (N.AHLs) based quorum sensing (QS) mechanism. In the current study, N.AHLs-deficient (ICMP11096glad-I) and N.AHLs-complemented (ICMP11096glad-IR) mutants were constructed in which the gene coding for AHL synthase was inactivated by allelic exchange in glad I mutant strain. The aims of this research were to (i) assess the antagonistic activity of the wild type (WT) and the glad-I mutant of Bga against Bacillus megaterium (G+ve) and Escherichia coli (G-ve), (ii) screen their hydrolytic enzymes and hemolytic substances, (iii) monitor the pathogenic effect against Agaricus bisporus, and finally (iv) analyze the bioactive secondary metabolites produced by WT and mutant strain using high performance liquid chromatography (HPLC). Results showed that N.AHLs-deficient mutant exhibited high reduction of antagonistic activity against the tested microorganisms and notable reduction of chitinolytic, proteolytic and glucanolytic activities and complete absence of hemolytic activity, and the glad-IR complemented mutant was able to regain the major part of these activities. Furthermore, N.AHLs-deficient mutant strain was unable to degrade flesh cubes pseudo-tissues of A. bisporus. On the other hand, the virulence effect of complemented mutant was like to the parental WT strain. HPLC analysis revealed that some of the single components produced by WT strain were absent in N.AHLs-deficient mutant and others were highly reduced. The out-findings of the current research gave a spot into the regulatory role of N.AHLs and QS phenomenon in the biological activity of Bga bacterium.

The Biological Activity of Natural Alkaloids against Herbivores, Cancerous Cells and Pathogens.

The growing incidence of microorganisms that resist antimicrobials is a constant concern for the scientific community, while the development of new antimicrobials from new chemical entities has become more and more expensive, time-consuming, and exacerbated by emerging drug-resistant strains. In this regard, many scientists are conducting research on plants aiming to discover possible antimicrobial compounds. The secondary metabolites contained in plants are a source of chemical entities having pharmacological activities and intended to be used for the treatment of different diseases. These chemical entities have the potential to be used as an effective antioxidant, antimutagenic, anticarcinogenic and antimicrobial agents. Among these pharmacologically active entities are the alkaloids which are classified into a number of classes, including pyrrolizidines, pyrrolidines, quinolizidines, indoles, tropanes, piperidines, purines, imidazoles, and isoquinolines. Alkaloids that have antioxidant properties are capable of preventing a variety of degenerative diseases through capturing free radicals, or through binding to catalysts involved indifferent oxidation processes occurring within the human body. Furthermore, these entities are capable of inhibiting the activity of bacteria, fungi, protozoan and etc. The unique properties of these secondary metabolites are the main reason for their utilization by the pharmaceutical companies for the treatment of different diseases. Generally, these alkaloids are extracted from plants, animals and fungi. Penicillin is the most famous natural drug discovery deriving from fungus. Similarly, marines have been used as a source for thousands of bioactive marine natural products. In this review, we cover the medical use of natural alkaloids isolated from a variety of plants and utilized by humans as antibacterial, antiviral, antifungal and anticancer agents. An example for such alkaloids is berberine, an isoquinoline alkaloid, found in roots and stem-bark of Berberis asculin P. Renault plant and used to kill a variety of microorganisms.

Aphidius ervi Teratocytes Release Enolase and Fatty Acid Binding Protein Through Exosomal Vesicles.

The molecular bases of the host-parasitoid interactions in the biological system Acyrthosiphon pisum (Harris) (Homoptera, Aphididae) and Aphidius ervi (Haliday) (Hymenoptera, Braconidae) have been elucidated allowing the identification of a gamma-glutamyl transpeptidase, the active component of maternal venom secretion, and teratocytes, the embryonic parasitic factors responsible for host physiology regulation after parasitization. Teratocytes, cells deriving from the dissociation of the serosa, the parasitoid embryonic membrane, are responsible for extra-oral digestion of host tissues in order to provide a suitable nutritional environment for the development of parasitoid larvae. Teratocytes rapidly grow in size without undergoing any cell division, synthesize, and release in the host hemolymph two proteins: a fatty acid binding protein (Ae-FABP) and an enolase (Ae-ENO). Ae-FABP is involved in transport of fatty acids deriving from host tissues to the parasitoid larva. Ae-ENO is an extracellular glycolytic enzyme that functions as a plasminogen like receptor inducing its activation to plasmin. Both Ae-FABP and Ae-ENO lack their signal peptides, and they are released in the extracellular environment through an unknown secretion pathway. Here, we investigated the unconventional mechanism by which teratocytes release Ae-FABP and Ae-ENO in the extracellular space. Our results, obtained using immunogold staining coupled with TEM and western blot analyses, show that these two proteins are localized in vesicles released by teratocytes. The specific dimension of these vesicles and the immunodetection of ALIX and HSP70, two exosome markers, strongly support the hypothesis that these vesicles are exosomes.

Chemical Ecology of Capnodis tenebrionis (L.) (Coleoptera: Buprestidae): Behavioral and Biochemical Strategies for Intraspecific and Host Interactions.

This study focuses on several aspects of communication strategies adopted by adults of the Mediterranean flat-headed root-borer Capnodis tenebrionis (Coleoptera: Buprestidae). Morphological studies on the structures involved in mate recognition and acceptance revealed the presence of porous areas in the pronota in both sexes. These areas were variable in shape and size, but proportionally larger in males. The presence of chaetic, basiconic, and coeloconic sensilla in the antennae of both males and females was verified. Bioassays revealed stereotyped rituals in males and the involvement of female pronotal secretions in mate recognition and acceptance. During the mating assays, the female's pronotum was covered by a biologically inert polymeric resin (DenFilTM), which prevented males from detecting the secretions and from completing the copulation ritual. The use of the resin allowed for the collection of chemical compounds. GC-MS analysis of the resin suggested it may be used to retain compounds from insect body surfaces and revealed sex-specific chemical profiles in the cuticles. Since adult C. tenebrionis may use volatile organic compounds (VOCs) emitted from leaves or shoots, the VOC emission profiles of apricot trees were characterized. Several volatiles related to plant-insect interactions involving fruit tree species of the Rosaceae family and buprestid beetles were identified. To improve understanding of how VOCs are perceived, candidate soluble olfactory proteins involved in chemoreception (odorant-binding proteins and chemosensory proteins) were identified using tissue and sex-specific RNA-seq data. The implications for chemical identification, physiological and ecological functions in intraspecific communication and insect-host interactions are discussed and potential applications for monitoring presented.

Differentiated Effects of Secondary Metabolites from Solanaceae and Brassicaceae Plant Families on the Heartbeat of Tenebrio molitor Pupae.

The usage of insects as model organisms is becoming more and more common in toxicological, pharmacological, genetic and biomedical research. Insects, such as fruit flies (Drosophila melanogaster), locusts (Locusta migratoria), stick insects (Baculum extradentatum) or beetles (Tenebrio molitor) are used to assess the effect of different active compounds, as well as to analyse the background and course of certain diseases, including heart disorders. The goal of this study was to assess the influence of secondary metabolites extracted from Solanaceae and Brassicaceae plants: Potato (Solanum tuberosum), tomato (Solanum lycopersicum), black nightshade (Solanum nigrum) and horseradish (Armoracia rusticana), on T. molitor beetle heart contractility in comparison with pure alkaloids. During the in vivo bioassays, the plants glycoalkaloid extracts and pure substances were injected at the concentration 10-5 M into T. molitor pupa and evoked changes in heart activity. Pure glycoalkaloids caused mainly positive chronotropic effects, dependant on heart activity phase during a 24-h period of recording. Moreover, the substances affected the duration of the heart activity phases. Similarly, to the pure glycoalkaloids, the tested extracts also mainly accelerated the heart rhythm, however S. tuberosum and S. lycopersicum extracts slightly decreased the heart contractions frequency in the last 6 h of the recording. Cardioacceleratory activity of only S. lycopersicum extract was higher than single alkaloids whereas S. tubersoum and S. nigrum extracts were less active when compared to pure alkaloids. The most cardioactive substance was chaconine which strongly stimulated heart action during the whole recording after injection. A. rusticana extract which is composed mainly of glucosinolates did not significantly affect the heart contractions. Obtained results showed that glycoalkaloids were much more active than glucosinolates. However, the extracts depending on the plant species might be more or less active than pure substances.

Beetles as Model Organisms in Physiological, Biomedical and Environmental Studies - A Review.

Model organisms are often used in biological, medical and environmental research. Among insects, Drosophila melanogaster, Galleria mellonella, Apis mellifera, Bombyx mori, Periplaneta americana, and Locusta migratoria are often used. However, new model organisms still appear. In recent years, an increasing number of insect species has been suggested as model organisms in life sciences research due to their worldwide distribution and environmental significance, the possibility of extrapolating research studies to vertebrates and the relatively low cost of rearing. Beetles are the largest insect order, with their representative - Tribolium castaneum - being the first species with a completely sequenced genome, and seem to be emerging as new potential candidates for model organisms in various studies. Apart from T. castaneum, additional species representing various Coleoptera families, such as Nicrophorus vespilloides, Leptinotarsa decemlineata, Coccinella septempunctata, Poecilus cupreus, Tenebrio molitor and many others, have been used. They are increasingly often included in two major research aspects: biomedical and environmental studies. Biomedical studies focus mainly on unraveling mechanisms of basic life processes, such as feeding, neurotransmission or activity of the immune system, as well as on elucidating the mechanism of different diseases (neurodegenerative, cardiovascular, metabolic, or immunological) using beetles as models. Furthermore, pharmacological bioassays for testing novel biologically active substances in beetles have also been developed. It should be emphasized that beetles are a source of compounds with potential antimicrobial and anticancer activity. Environmental-based studies focus mainly on the development and testing of new potential pesticides of both chemical and natural origin. Additionally, beetles are used as food or for their valuable supplements. Different beetle families are also used as bioindicators. Another important research area using beetles as models is behavioral ecology studies, for instance, parental care. In this paper, we review the current knowledge regarding beetles as model organisms and their practical application in various fields of life science.

Bitterless guaifenesin prodrugs-design, synthesis, characterization, in vitro kinetics, and bitterness studies.

A respected number of drugs suffer from bitter taste which results in patient incompliance. With the aim of solving the bitterness of guaifenesin, dimethyl maleate, maleate, glutarate, succinate, and dimethyl succinate prodrugs were designed and synthesized. Molecular orbital methods were utilized for the design of the ester prodrugs. The density functional theory (DFT) calculations revealed that the hydrolysis efficiency of the synthesized prodrugs is significantly sensitive to the pattern of substitution on C=C bond and distance between the nucleophile and the electrophile. The hydrolysis of the prodrugs was largely affected by the pH of the medium. The experimental t1/2 for the hydrolysis of guaifenesin dimaleate ester prodrugs in 1N HCl was the least and for guaifenesin dimethyl succinate was the highest. Functional heterologous expression of TAS2R14, a broadly tuned bitter taste receptor responding to guaifenesin, and experiments using these prodrugs revealed that, while some of the prodrugs still activated the receptor similarly or even stronger than the parent substance, succinate derivatization resulted in the complete loss of receptor responses. The predicted binding modes of guaifenesin and its prodrugs to the TAS2R14 homology model suggest that the decreased activity of the succinate derivatives may be caused by a clash with Phe247.

Photodegradation using TiO2-activated borosilicate tubes.

This study examines the photocatalytic activity of titanium dioxide (TiO2) semiconductor supported on borosilicate tubes (cut-off 290 nm) towards removal of a mix of persistent organic pollutants (POPs) from water. For this purpose, two widely used analgesic and anti-inflammatory drugs (NSAIDs), ibuprofen (IBU) and mefenamic acid, along with MCPA sodium monohydrate, which is a common herbicide frequently used in the agricultural activities, were selected as a case study. Borosilicate tubes were coated with titanium oxide through two different approaches: sol-gel dip-coating and a hybrid nanoparticle dip-coating and plasma-enhanced chemical vapour deposition (PECVD) process. The photochemical reactor that hosts the titania-coated tubes was designed to permit continuous throughput of liquid feed stream. The photodegradation experiments were performed in laboratory conditions under artificial irradiation simulating solar light. The efficiency of direct photolysis and heterogeneous photocatalysis (TiO2) was investigated, and the performance of each coating method was evaluated. Kinetic studies for each experiment were accomplished, the overall results showed poor efficiency and insufficient removal for NSAIDs through direct photolysis, whereas applying heterogeneous photacatalysis with TiO2 coated on borosilicate tubes was found to accelerate their degradation rate with complete decomposition. Concomitantly, kinetic experimental results showed a critical difference of performance for the two coating methods used; in particular, the degradation rates of pollutants by the sol-gel-coated tubes were much faster than the degradation by the nanoparticle/PECVD-coated tubes. Using TiO2 supported on borosilicate tubes appears to be a promising alternative to conventional TiO2 suspension and avoid post-separation stages. The results achieved in this study can be used to optimise large-scale applications, and expanding the study to cover a wide range of pollutants will lead to achieve more representative results.

Novel Factors of Viral Origin Inhibit TOR Pathway Gene Expression.

Polydnaviruses (PDVs) are obligate symbionts of endoparasitoid wasps, which exclusively attack the larval stages of their lepidopteran hosts. The Polydnavirus is injected by the parasitoid female during oviposition to selectively infect host tissues by the expression of viral genes without undergoing replication. Toxoneuron nigriceps bracovirus (TnBV) is associated with Toxoneuron nigriceps (Hymenoptera: Braconidae) wasp, an endoparasitoid of the tobacco budworm larval stages, Heliothis virescens (Lepidoptera: Noctuidae). Previous studies showed that TnBV is responsible for alterations in host physiology. The arrest of ecdysteroidogenesis is the main alteration which occurs in last (fifth) instar larvae and, as a consequence, prevents pupation. TnBV induces the functional inactivation of H. virescens prothoracic glands (PGs), resulting in decreased protein synthesis and phosphorylation. Previous work showed the involvement of the PI3K/Akt/TOR pathway in H. virescens PG ecdysteroidogenesis. Here, we demonstrate that this cellular signaling is one of the targets of TnBV infection. Western blot analysis and enzyme immunoassay (EIA) showed that parasitism inhibits ecdysteroidogenesis and the phosphorylation of the two targets of TOR (4E-BP and S6K), despite the stimulation of PTTH contained in the brain extract. Using a transcriptomic approach, we identified viral genes selectively expressed in last instar H. virescens PGs, 48 h after parasitization, and evaluated expression levels of PI3K/Akt/TOR pathway genes in these tissues. The relative expression of selected genes belonging to the TOR pathway (tor, 4e-bp, and s6k) in PGs of parasitized larvae was further confirmed by qRT-PCR. The down-regulation of these genes in PGs of parasitized larvae supports the hypothesis of TnBV involvement in blocking ecdysteroidogenesis, through alterations of the PI3K/Akt/TOR pathway at the transcriptional level.