5.5 Pesticide and Metabolites Residues in Honeybees: A 2014-2017 Greek Compendium

In the period between 2014 mid-2017, more than 200 samples of honeybees were sent by authorities and individuals in Benaki Phytopathological Institute after incidents of unexpected deaths of bees in various parts of Greece. The samples were analyzed for pesticides and breakdown products, by two multi-residue methods based on an expanded HPLC-ESI-MS/MS and a newly developed GC-MS/MS method. Sample preparation was optimized and based on modified QuEChERS using for clean-up C18 and PSA. Until mid-2017, 293 detections were registered in a total of 205 honeybee samples, resulting in a 76% percent of positive samples, to at least one active substance. Concentrations’ range varied from 1 to 160000 ng/g bee body weight . In some cases, these levels surpassed LD50 values indicating intoxication events. Predominant substances were clothianidin, coumaphos, imidacloprid, acetamiprid and dimethoate. In less extent, other acaricides such as amitraz (mostly its breakdown products DMF, DMPF), tau-fluvalinate and certain pyrethroids exemplified by cyhalothrin, cypermethrin and deltamethrin were also recorded. In several samples, more than one active substance was detected.Overall, this work aspires to provide valuable insight to pesticides and metabolites occurrence in honeybees in Greece between 2014-2017 and in parallel assist research community and apiculturists in this pivotal Mediterranean region that bee health and pollination services have prolific importance.In the period between 2014 mid-2017, more than 200 samples of honeybees were sent by authorities and individuals in Benaki Phytopathological Institute after incidents of unexpected deaths of bees in various parts of Greece. The samples were analyzed for pesticides and breakdown products, by two multi-residue methods based on an expanded HPLC-ESI-MS/MS and a newly developed GC-MS/MS method. Sample preparation was optimized and based on modified QuEChERS using for clean-up C18 and PSA. Until mid-2017, 293 detections were registered in a total of 205 honeybee samples, resulting in a 76% percent of positive samples, to at least one active substance. Concentrations’ range varied from 1 to 160000 ng/g bee body weight . In some cases, these levels surpassed LD50 values indicating intoxication events. Predominant substances were clothianidin, coumaphos, imidacloprid, acetamiprid and dimethoate. In less extent, other acaricides such as amitraz (mostly its breakdown products DMF, DMPF), tau-fluvalinate and certain pyrethroids exemplified by cyhalothrin, cypermethrin and deltamethrin were also recorded. In several samples, more than one active substance was detected.Overall, this work aspires to provide valuable insight to pesticides and metabolites occurrence in honeybees in Greece between 2014-2017 and in parallel assist research community and apiculturists in this pivotal Mediterranean region that bee health and pollination services have prolific importance

Pyrazoles as potential anti-angiogenesis agents: a contemporary overview

Angiogenesis is a mulit-step process by which new blood vessels are formed from preexisting vasculature. It is a key rate limiting factor in tumor growth since new blood vessels are necessary to increase tumor size. In this context it has been shown that anti-angiogenic factors can be used in cancer therapy. Among the plethora of heterocyclic compounds administered as anti-angiogenesis agents, pyrazoles constitute one of the bottlenecks of this category. Currently several pyrazole based compounds are administered or are in Phase II and III trials and new targets emerge. It is highly possible that the advent of the next two decades will lead to the discovery and use of additional pyrazoles whose anti-angiogenic profile will position them in the forefront of the battle of various malignancies. The present review is an attempt to focus on those pyrazoles that arise as anti-angiogenesis agents commenting both on the chemistry and bioactivity that these exhibit aiming to contribute to the perspectives that they hold for future research

A Dieldrin Case Study: Another Evidence of an Obsolete Substance in the European Soil Environment

Soil constitutes a central environmental compartment that, due to natural and anthropogenic activities, is a recipient of several contaminants. Among them, organochlorine pesticides are of major concern, even though they have been banned decades ago in the European Union, due to their persistence and the health effects they can elicit. In the presented work, a gas chromatographic tandem mass spectrometric (GC-MS/MS) developed method was applied to soil samples after the suspected and potential use of formulations containing organochlorine active substance. One soil sample was positive to dieldrin at 0.018 mg kg−1. Predicted environmental concentration in soil (PECsoil) considering a single application of this active substance potentially attributed the finding in its past use. The subsequent health risk assessment showed negligible non-carcinogenic risk and tolerable carcinogenic risk. The latter signifies that repetitive and prolonged sampling can unveil the pragmatic projection of persistent chemicals’ residues in the soil

Novel pyrazole derivatives: synthesis and evaluation of anti-angiogenic activity

The synthesis of a series of novel trisubstituted pyrazole derivatives and their PIFA-mediated conversion to molecules bearing the fused pyrazolo[4,3-c]quinoline ring system is reported. The anti-angiogenic activity of these compounds was evaluated by using in vitro assays for endothelial cell proliferation and migration, and in the chicken chorioallantoic membrane (CAM) assay. Compounds containing the fused pyrazolo[4,3-c]quinoline motifs emerged as potent anti-angiogenic compounds, which also had the ability to inhibit the growth of human breast (MCF-7) and cervical (Hela) carcinoma cells in vitro.status: publishe

Synthesis of (R)-Dihydropyridones as Key Intermediates for an Efficient Access to Piperidine Alkaloids

Abstract: The efficient transformation of D-glucal to (2R)-hydroxymethyldihydropyridinone 5 in seven steps and 35 % overall yield is reported. Dihydropyridone 5 constitutes a versatile chiral building block for the synthesis of various piperidine alkaloids. In this regard, 5 was converted to piperidinol 13 and piperidinone 15, that may be further elaborated for the syntheses of (+)-desoxoprosophylline (1) and deoxymannojirimycin (3) or D-mannolactam (4), respectively

Pesticide Residues and Metabolites in Greek Honey and Pollen: Bees and Human Health Risk Assessment

Background: Bees encounter a plethora of environmental contaminants during nectar and pollen collection from plants. Consequently, after their entrance into the beehives, the transfer of numerous pollutants to apicultural products is inevitable. Methods: In this context, during the period of 2015–2020, 109 samples of honey, pollen, and beebread were sampled and analyzed for the determination of pesticides and their metabolites. More than 130 analytes were investigated in each sample by applying two validated multiresidue methods (HPLC-ESI-MS/MS and GC-MS/MS). Results: Until the end of 2020, 40 determinations were reported in honey, resulting in a 26% positive to at least one active substance. The concentrations of pesticides ranged from 1.3 ng/g to 785 ng/g honey. For seven active substances in honey and pollen, maximum residue limits (MRLs) exceedances were observed. Coumaphos, imidacloprid, acetamiprid, amitraz metabolites (DMF and DMPF), and tau-fluvalinate were the predominant compounds detected in honey, while several pyrethroids such as λ-cyhalothrin, cypermethrin, and cyfluthrin were also found. Pollen and beebread, as expected, accumulated a higher number of active substances and metabolites (32 in total), exhibiting almost double the number of detections. Conclusions: Although the above findings verify the occurrence of numerous pesticide and metabolite residues in both honey and pollen, the human risk assessment in the majority of the cases does not raise any concerns, and the same applies to bee risk assessment

Nematicidal Activity of Stevia rebaudiana (Bertoni) Assisted by Phytochemical Analysis

To date, there has been great demand for ecofriendly nematicides with beneficial properties to the nematode hosting plants. Great efforts are made towards the chemical characterization of botanical extracts exhibiting nematicidal activity against Meloidogyne spp., but only a small percentage of these data are actually used by the chemical industry in order to develop new formulates. On the other hand, the ready to use farmer produced water extracts based on edible plants could be a sustainable and economic solution for low income countries. Herein, we evaluate the nematicidal potential of Stevia rebaudiana grown in Greece against Meloidogyne incognita and Meloidogyne javanica, two most notorious phytoparasitic nematode species causing great losses in tomato cultivation worldwide. In an effort to recycle the plant’s remnants, after leaves selection for commercial use, we use both leaves and wooden stems to test for activity. In vitro tests demonstrate significant paralysis activity of both plant parts’ water extracts against the second-stage juvenile (J2) of the parasites; while, in vivo bioassays demonstrated the substantial efficacy of leaves’ powder (95% at 1 g kg−1) followed by stems. Interestingly, the incorporation of up to 50 g powder/kg of soil is not phytotoxic, which demonstrates the ability to elevate the applied concentration of the nematicidal stevia powder under high inoculum level. Last but not least, the chemical composition analyses using cutting edge analytical methodologies, demonstrated amongst components molecules of already proven nematicidal activity, was exemplified by several flavonoids and essential oil components. Interestingly, and to our knowledge, for the flavonoids, morin and robinin, the anthocyanidin, keracyanin, and a napthalen-2-ol derivative is their first report in Stevia species

Novel pyrazole and indazole derivatives: synthesis and evaluation of their anti-proliferative and anti-angiogenic activities

The synthesis of several new pyrazole and indazole derivatives from acetophenone and tetralone substrates is reported. The bioactivities of the new compounds were evaluated through in vitro assays for endothelial cell proliferation and tube formation. Results herein indicate that the easily prepared compounds containing the indazole structural framework exhibit potent cytostatic properties against all cell lines tested, with compounds 13 and 14 being the most active displaying IC(50) values of 1.5 ± 0.4 µM and 5.6 ± 2.5 µM, respectively, against MCF-7 cells. In addition, the indazole derivative 16 was assessed as a competent inhibitor of endothelial tube formation at 30 µM.status: publishe