Carvone and less volatile analogues as repellent and deterrent antifeedants against the pine weevil, Hylobius abietis

Abstract:  The monoterpenoid carvone ( 1 ) has been shown to have strong antifeedant effects on Hylobius spp. However, because of the high volatility of carvone, long-time protection of conifer seedlings in the field using this compound has not been possible. We demonstrate, in several bioassay steps, that less-volatile, heavier analogues retain their pre-ingestive feeding inhibition activity in the large pine weevil, Hylobius abietis (L.) for a longer time. The first step in the evaluation of the biological activity of 12 carvone analogues was a micro-assay, a choice test lasting 4 h. Compounds active at 100 nmol/cm² were further dose–response tested to give the effective dose needed to inhibit feeding by 50% (ED50). Of the 14 compounds tested, including both carvone enantiomers, seven heavier analogues were active at low doses (had low ED50 values). As expected from their lower vapour pressure compared with carvone, the heavier analogues proved more resistant to evaporation before testing. Thus, whereas the effect of 8-hydroxy- p -menth-en-6-one 4 declined after 2 days, some of the compounds with high molar masses, such as the alkylhydroxymenthenones 6 and 8 , retained a stable activity for 4 days. The retained activity at 4 days was strongly correlated to molecular mass and boiling point. When tested on natural material (host Pinus sylvestris L. twig sections for 48 h), the heavier analogues showed a rather low activity. Probably, the activity of the more volatile compound carvone ( 1 ) is due to a repellent effect (olfactory mode) rather than the deterrent effects (gustatory mode) of the heavier compounds. In agreement with the relatively low activity on twigs in the laboratory, the hydroxymenthenone 4 was not active in the field when tested for 2 months as a 1 : 9 mixture with a polar wax.     

Evolution of risk assessment strategies for food and feed uses of stacked GM events

Data requirements are not harmonized globally for the regulation of food and feed derived from stacked genetically modified (GM) events, produced by combining individual GM events through conventional breeding. The data required by some regulatory agencies have increased despite the absence of substantiated adverse effects to animals or humans from the consumption of GM crops. Data from studies conducted over a 15‐year period for several stacked GM event maize (Zea mays L.) products (Bt11 ×  GA21, Bt11 ×  MIR604, MIR604 ×  GA21, Bt11 ×  MIR604 ×  GA21, Bt11 ×  MIR162 ×  GA21 and Bt11 ×  MIR604 ×  MIR162 ×  GA21), together with their component single events, are presented. These data provide evidence that no substantial changes in composition, protein expression or insert stability have occurred after combining the single events through conventional breeding. An alternative food and feed risk assessment strategy for stacked GM events is suggested based on a problem formulation approach that utilizes (i) the outcome of the single event risk assessments, and (ii) the potential for interactions in the stack, based on an understanding of the mode of action of the transgenes and their products.     

Characterizing monoclonal antibody formulations in arginine glutamate solutions using 1H NMR spectroscopy

Assessing how excipients affect the self-association of monoclonal antibodies (mAbs) requires informative and direct in situ measurements for highly concentrated solutions, without sample dilution or perturbation. This study explores the application of solution nuclear magnetic resonance (NMR) spectroscopy for characterization of typical mAb behavior in formulations containing arginine glutamate. The data show that the analysis of signal intensities in 1D ¹H NMR spectra, when compensated for changes in buffer viscosity, is invaluable for identifying conditions where protein-protein interactions are minimized. NMR-derived molecular translational diffusion rates for concentrated solutions are less useful than transverse relaxation rates as parameters defining optimal formulation. Furthermore, NMR reports on the solution viscosity and mAb aggregation during accelerated stability study assessment, generating data consistent with that acquired by size-exclusion chromatography. The methodology developed here offers NMR spectroscopy as a new tool providing complementary information useful to formulation development of mAbs and other large therapeutic proteins.     

Management of a German cockroach population with a juvenoid bait formulation: an experiment in residential buildings

Baits including 0.1% of ethyl 2-(4-((1,4-dioxaspiro [4.5]dec-6-yl) methyl) phenoxy) ethylcarbamate were applied in two buildings containing 46 apartments with various degrees of infestation of the German cockroach, Blattella germanica (L.). During a yearly experiment, generally 8 baits were placed in each apartment and replenished monthly at which time cockroach population density, demographic structure, and percentage of morphologically deformed adults were determined from specimens captured by stickytrap sampling. Initial growth of the cockroach population observed during the first two months after deposition of the baits was followed by an asymptotical decrease. Only 2.5% of the initial population remained at the end of the experiment. Although adults with twisted wings (sterile) constituted only 70% of the total adult catches, the decrease of the nymph/adult ratio from 2.9 to 0.7 indicated a far more profound inhibitory effect on cockroach reproduction. This study shows that baits might be an efficient alternative to juvenoid formulations currently in use for control of the German cockroach.     

Chronopharmacology of Oral Nitrates in Healthy Subjects

The pharmacokinetics and the hemodynamic effects (blood pressure, heart rate) of oral organic nitrates have been investigated in healthy subjects after oral single-dose application either in the morning or in the evening. Isosorbide-5-monitrate (IS-5-MN, 60 mg) was administered as an immediate-release tablet or as a slow-release formulation. Isosorbide dinitrate (ISDN, 20 mg) was ingested as an immediate-release tablet. After administration of IS-5-MN as an immediate-release tablet, the drug was more rapidly absorbed in the morning (t_max of 0.9 h) than in the evening (t_max of 2.1 h). The rapid absorption led to more pronounced effects in the morning, at which time maximum drug concentrations occurred at the same time as peak effects were observed. After evening administration, however, peak effects were in advance of the maximum drug concentrations. No chrono-kinetics were observed after application of the slow-release formulation of IS-5-MN. In accordance with the results of the immediate-release formulation, peak effects of the slow-release preparation occurred significantly earlier than peak drug concentrations after evening than after morning dosing. ISDN bioavailability was higher after morning than after evening administration and hemodynamic effects were more pronounced in the evening than in the morning. These results show that daily variations in pharmacokinetics and/or hemodynamic effects can be observed with oral nitrates. In addition, galenic formulation can influence the time-specified pharmacokinetics of IS-5-MN.     

The use of bacterial alginates to prepare biocontrol formulations

Summary Formulations which are economical and which can deliver a viable organism are critical to developing successful biocontrol products for plant pathogens. In the present study, alginates derived from commercial kelp and produced byAzotobacter vinelandii isolates ATCC 9104 and 12 837 were compared in their ability to form stable, biodegradable granular formulations of the biocontrol fungiTalaromyces flavus andGliocladium virens. Bacteria were grown in shake flask cultures (180 rpm) at 32°C for 104 h. The cultures were monitored for pH, dissolved oxygen, glucose concentration, dry cell weight, and alginate dry weight. Aqueous solutions of the bacterial alginates, as well as the kelp-derived alginate products, gelled readily in 0.25 M calcium chloride. Mannuronate (M) and guluronate (G) compositions of the alginate samples were determined by circular dichroism. M/G ratios for cultures of isolate 12837 averaged 0.98±0.18; for isolate 9104, 1.59±0.12; and for kelp, 1.54±0.39. The viability ofT. flavus in the kelp and bacterial alginate formulations were similar over 84 days. An exploratory experiment indicated good viability ofG. virens using the same bacterial alginates. This study demonstrated a practical use for bacterial alginate as a potentially less costly substitute for kelp alginate in the preparation of biocontrol agent formulations.     

Novel PARP-1 inhibitors based on a 2-propanoyl-3H-quinazolin-4-one scaffold

Poly(ADP-ribose)polymerase-I (PARP-1) enzyme is involved in maintaining DNA integrity and programmed cell death. A virtual screening of commercial libraries led to the identification of five novel scaffolds with inhibitory profile in the low nanomolar range. A hit-to-lead optimization led to the identification of a group of new potent PARP-1 inhibitors, acyl-piperazinylamides of 3-(4-oxo-3,4-dihydro-quinazolin-2-yl)-propionic acid. Molecular modeling studies highlighted the preponderant role of the propanoyl side chain.     

Glucosylglycerol and glucosylglycerate as enzyme stabilizers

Compatible solutes constitute a diverse class of low-molecular-mass organic molecules that are accumulated in high intracellular concentrations in response to the external stress of hyperosmolality or high temperature. Many of these compounds like α, α-trehalose are well known for their stabilizing effect on protein structure and could lead to development of more stable protein formulations. Negatively charged solutes like mannosylglycerate (R-2-O-α-D -mannopyranosyl-glycerate) are widespread among (hyper)thermophilic microorganisms and are thought to be exceptionally potent stabilizers of proteins under high-temperature denaturation conditions. To further inquire into the role of compound charge for protective function, we have compared two naturally occurring and structurally related solutes, glucosylglycerol (2-O-α-D -glucopyranosyl-sn-glycerol) and glucosylglycerate (R-2-O-α-D -glucopyranosyl-glycerate), as stabilizers of different enzymes undergoing inactivation through elevated temperature or freeze drying, and benchmarked their effects against that of α,α-trehalose. Glucosylglycerate in concentrations of ≥0.1 M was the most effective in preventing thermally induced loss of enzyme activity of lactate dehydrogenase, mannitol dehydrogenase, starch phosphorylase, and xylose reductase. α,α-Trehalose could usually be replaced by glucosylglycerol without compromising enzyme stability. Glucosylglycerol and glucosylglycerate afforded substantial (eightfold) protection to mannitol dehydrogenase during freeze drying.