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The phenolic compounds in the leaves of 12 species of birch trees of the subgenera Neurobetula, Betulenta, and Betula were biochemically profiled using HPTLC. The duration of the vegetation period was found to be significantly related to the content of total phenols (r = 0.74) and flavonoids in leaves (r = 0.65). The correlations for Neurobetula plants were 0.86 and 0.91, respectively. The relationship between the duration of the growing season and the concentration of phenolic compounds in Betula plants was inverse (r = −0.84). A cluster analysis of phytochemical profiles revealed that the studied birch species form groups that coincide with the subgenera proposed by De Jong due to an affinity with the qualitative composition of phenolic compounds. A multiple correlation analysis confirmed the relationship between the qualitative composition of phenolic compounds and the morphological characteristics of the leaves. The results of phytochemical profiling revealed that the qualitative composition of polyphenols in the leaves of 12 birch species is quite specific, allowing the use of individual compounds as additional differential biochemical characters in identifying species and hybrids and studying their potential role in plant adaptation to habitat conditions. [ABSTRACT FROM AUTHOR]

Honey intake is advantageous to human health due to its antioxidant, anticancer, anti-inflammatory, and antimicrobial properties, all of which are attributed to the rich bioactive compound contents. Moreover, hepatoprotective, wound healing, and gastrointestinal protective properties have been documented. Honey's nutritional value is significantly affected by its chemical composition, which varies depending on botanical and geographical origin. In particular, after Manuka honey, Sidr honey from the Ziziphus species is the most popular. The chemical compositions, physicochemical properties, bioactive compounds, and sensory characteristics of two Sidr honey samples from Egypt and Saudi Arabia were investigated in the current study. Moisture content, electrical conductivity (EC), pH, free acidity (FA), total acidity, lactone hydroxymethylfurfural (HMF) content, and diastase (α-amylase) activity were measured. By using high-performance liquid chromatography (HPLC), mass spectrometry (LC-MS/MS), nuclear magnetic resonance (1HNMR), and solid-phase micro-extraction (SPME) coupled with gas chromatography (GC-MS) analyses, the sugar profile, non-volatile, and volatile compounds were also identified. The physicochemical analysis revealed the following results for Sidr honey from Saudi Arabia and Egypt, respectively: a moisture content of 18.03 ± 0.05% and 19.03 ± 0.06%, EC values of 1.18 ± 0.05 and 1.16 ± 0.01 mS/cm, pH values of 4.87 ± 0.08 and 5.10 ± 0.01, FA of 37.50 ± 0.05 and 36.50 ± 0.05 meq/kg, total acidity of 41.06 ± 0.05 and 37.50 ± 0.05 meq/kg, lactone of 3.49 ± 0.005 and 1 ± 0.0 meq/kg, HMF of 20.92 ± 0.02 and 11.33 ± 0.01 mg/kg, and diastase of 59.97 ± 0.05 and 8.64 ± 0.06g/100 g. Honey from Saudi Arabia and Egypt displayed 22.51 ± 0.05 and 26.62 ± 0.16 % glucose, 40.33 ± 0.06 and 35.28 ± 0.01% fructose, 8.94 ± 0.17, and 8.87 ± 0.01% sucrose, and 8.22 ± 0.006 and 8.13 ± 0.01% maltose, respectively. According to the International Honey Commission (IHC) and GCC Standardization Organization (GSO) regulations, the levels of glucose, fructose, sucrose, and maltose were near the standard levels. Flavonoids, sugars, vitamins, and nitrogen contents were additionally measured using LC-MS/MS, whereas GC-MS was employed to identify aldehydes, ketones, phenols, acids, esters, anthraquinone, hydrocarbons, and nitrogenous compounds. The results of a study on the effect of honey's geographic origin on its broad quality are summarized. As a result, knowing its optimal chemical and physical characteristics served as the criterion and indicator of the honey's quality. [ABSTRACT FROM AUTHOR]

Honeybee losses have been attributed to multiple stressors and factors including the neonicotinoid insecticides (NIs). Much of the study of hive contamination has been focused upon temperate regions such as Europe, Canada and the United States. This study looks for the first time at honey, pollen and bees collected from across the Nile Delta in Egypt in both the spring and summer planting season of 2013. There is limited information upon the frequency of use of NIs in Egypt but the ratio of positive identification and concentrations of NIs are comparable to other regions. Metabolites of NIs were also monitored but given the low detection frequency, no link between matrices was possible in the study. Using a simple hazard assessment based upon published LD50 values for individual neonicotinoids upon the foraging and brood workers it was found that there was a potential risk to brood workers if the lowest reported LD50 was compared to the sum of the maximum NI concentrations. For non-lethal exposure there was significant risk at the worst case to brood bees but actual exposure effects are dependant upon the genetics and conditions of the Egyptian honeybee subspecies that remain to be determined. [ABSTRACT FROM AUTHOR]

Dramatic losses of pollinating insects have become of global concern, as they threaten their ecosystem services as well as human food production. Recent research provided evidence that interactions between ecological stressors are drivers of declining pollinator health and responsible for observed population collapses. We used the honeybee Apis mellifera and conducted a series of experiments to test for long-term effects of a single short exposure to the agricultural pesticide flupyradifurone to a second environmental stressor later in life. To do this, we exposed individuals during their larval development or early adulthood to sublethal levels of flupyradifurone, either pure or as part of an agricultural formulation (Sivanto). We afterwards exposed bees to a second environmental stressor, infecting them with the fungal gut parasite Nosema ceranae. We found that pesticide exposures significantly reduced survival of bees and altered the expression of several immune and detoxification genes. The ability of bees to respond to these latter effects differed significantly between colonies, offering opportunities to breed bees with elevated levels of pesticide tolerance in the future. We conclude that short episodes of sublethal pesticide exposures during development are sufficient to trigger long-lasting effects that could contribute to the widespread declines in bee health. [ABSTRACT FROM AUTHOR]