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Jerkovic I.,University of Split | Suste M.,Marko Marulic Polytechnic of Knin | Males Z.,University of Zagreb | Pilepicc K.H.,University of Zagreb
Natural Product Communications

The essential oils from the aerial parts of Prasium majus L., collected during two years in Croatia, were analysed by GC and GC/MS. Fifty-two compounds were identified, representing 90.3-91.8% of the total oils. The major constituents in both samples were fatty acids (particularly hexadecanoic acid and (Z)-octadec-9-enoic acid), lower aliphatic alcohols, aldehydes and acids (major ones oct-1-en-3-ol and (E,E)-hepta-2,4-dienal) and phenylpropane derivatives (e.g. eugenol). β-Caryophyllene was the most abundant terpene and (E)-β-ionone was the major norisoprenoid. Source

Jerkovic I.,University of Split | Marijanovic Z.,Marko Marulic Polytechnic of Knin | Ljubicic I.,Marko Marulic Polytechnic of Knin | Gugic M.,Marko Marulic Polytechnic of Knin
Chemistry and Biodiversity

This research is focused on the immediate contribution of the bees and combs to honey volatiles in order to exclude these compounds as botanical-origin biomarkers for honey authentification. Therefore, the bees were closed in a hive containing empty combs under controlled food-flow conditions (saccharose solution). The obtained 'saccharose honey' probe samples were subjected to ultrasonic solvent extraction (USE), followed by gas chromatography and mass spectrometry analyses (GC and GC/MS). A total of 66 compounds were identified. Higher alcohols made up ca. 50% of the total volatiles, mainly (Z)-octadec-9-en-1-ol, hexadecan-1-ol, and octadecan-1-ol, with minor percentages of undecan-1-ol, dodecan-1-ol, tetradecan-1-ol, pentadecan-1-ol, and heptadecan-1-ol. Other abundant compounds were saturated long-chain linear hydrocarbons, C10-C25, C27, and C28, particularly C23, C25, and C27). Identified chemical structures were related to the composition of combs and cuticular waxes, and less to the bee pheromones. In addition, the impact of two-hour heat treatment at 80° and one-year storage at room temperature on the same probe was investigated in order to identify thermal and storage artefacts. These findings can be considered as blank-trial probe (no plant source) for honey chemical profiling and identification of reliable botanical origin biomarkers. © 2010 Verlag Helvetica Chimica Acta AG. Source

Crkvencic M.,University of Zagreb | Dudas S.,Polytechnic of Rijeka | Jerkovic I.,University of Split | Marijanovic Z.,Marko Marulic Polytechnic of Knin | And 2 more authors.
Chemistry and Biodiversity

The chemical composition of the essential oils obtained by hydrodistillation from the aerial parts of Globularia cordifolia L., G. meridionalis (Podp.) O.Schwarz, and G. punctata Lapeyr. was characterized by GC-FID and GC/MS analyses. Among the 33 identified compounds, the most abundant present in all investigated samples were oct-1-en-3-ol (2.9-47.0%), 6-(1,5-dimethylhex-4-enyl)-3-methylcyclohex-2-enone (8.2-40.9%), and fukinanolid (7.4-31.6%). Multivariate statistical analyses (PCA and HCA) of the hitherto studied Globularia volatile compounds confirmed to some extent the assumed phylogenetic relationships of the Globularia species studied, including the close relationship between the morphologically similar species G. cordifolia and G. meridionalis, but also evidenced several discrepancies in the current classification of Globularia species. Copyright © 2016 Verlag Helvetica Chimica Acta AG. Source

Costa C.,Italian Agricultural Research Council | Panasiuk B.,Research Institute of Horticulture | Meixner M.,Bee Institute | Kryger P.,University of Aarhus | And 14 more authors.
Journal of Apicultural Research

Honey bee colonies exhibit a wide range of variation in their behaviour, depending on their genetic origin and environmental factors. The COLOSS Genotype-Environment Interactions Experiment gave us the opportunity to investigate the phenotypic expression of the swarming, defensive and hygienic behaviour of 16 genotypes from five different honey bee subspecies in various environmental conditions. In 2010 and 2011, a total of 621 colonies were monitored and tested according to a standard protocol for estimation of expression of these three behavioural traits. The factors: year, genotype, location, origin (local vs. non-local) and season (only for hygienic behaviour) were considered in statistical analyses to estimate their effect on expression of these behaviours. The general outcome of our study is that genotype and location have a significant effect on the analysed traits. For all characters, the variability among locations was higher than the variability among genotypes. We also detected significant variability between the genotypes from different subspecies, generally confirming their known characteristics, although great variability within subspecies was noticed. Defensive and swarming behaviour were each positively correlated across the two years, confirming genetic control of these characters. Defensive behaviour was lower in colonies of local origin, and was negatively correlated with hygienic behaviour. Hygienic behaviour was strongly influenced by the season in which the test was performed. The results from our study demonstrate that there is great behavioural variation among different subspecies and strains. Sustainable protection of local genotypes can be promoted by combining conservation efforts with selection and breeding to improve the appreciation by beekeepers of native stock. © IBRA 2014. Source

Jerkovic I.,University of Split | Marasovic M.,University of Split | Marijanovic Z.,Marko Marulic Polytechnic of Knin | Pilepic K.H.,University of Zagreb | And 2 more authors.
Natural Product Communications

The aerial parts of Hypericum richeri Vill. subsp. grisebachii (Boiss.) Nyman were collected from two different locations in Croatia and subjected to hydrodistillation. GC/FID and GC/MS analysis of the isolated essential oils revealed 64 compounds representing 94.7% and 98.2% of the total oils. Predominant constituents in both samples were: germacrene D (10.9%; 6.0%), bicyclogermacrene (4.7%; 3.5%), α-pinene (6.8%; 6.9%), β-pinene (8.1%; 5.1%), decanoic acid (4.5%; 6.8%), β-caryophyllene (3.3%; 7.5%), δ-cadinene (7.0%; 4.4%), spathulenol (6.0%; 9.5%) and tetracosane (3.1%; 5.8%). Comparison of both samples revealed similarity in the chemical composition with minor fluctuations of constituent percentages. The chemical profile of Croatian oils was in general similar to those reported for other geographic areas regarding major mono- and sesquiterpene constituents. However, spathulenol, δ-cadinene and bicyclogermacrene were more abundant in Croatian oils. The presence of decanoic acid (4.5%; 6.8%) in Croatian oils was the major difference between acids and fatty acids derivatives. Higher abundance of alkanes (particularly tetracosane and docosane) was also noticed. Source

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