Quantitative analysis of pungent and anti-inflammatory phenolic compounds in olive oil by capillary electrophoresis

The first CE procedure for the quantitative determination of pharmacologically relevant secoiridoids in olive oil, oleocanthal and oleacein, is described. Together with their precursors tyrosol and hydroxytyrosol they could be baseline separated in less than 15 min using a borax buffer with pH 9.5, at 25 kV and 30 °C. Method validation confirmed that the procedure is selective, accurate (recovery rates from 94.0 to 104.6%), reproducible (σmax ≤ 6.8%) and precise (inter-day precision ≤ 6.4%), and that the compounds do not degrade quickly if non-aqueous acetonitrile is used as solvent. Quantitative results indicated a low occurrence of oleocanthal (0.004-0.021%) and oleacein (0.002-0.048%) in olive oil samples, which is in agreement to published HPLC data. The CE method impresses with its simple instrumental and methodological design, combined with reproducible and valid quantitative results. © 2014 Elsevier Ltd. All rights reserved

Recent advances and new strategies in the NMR-based identification of natural products

Nature comprises an untapped pool of unique compounds with high structural uniqueness and exceptional properties. At the core of natural products (NPs) discovery is the identification procedure and NMR remains the most efficient method. Technical improvements such as miniaturized and crycogenic NMR probes along with hyphenation capabilities and computational support are at the center of evolution. Concepts such as dereplication and metabolomics are increasingly adopted in NPs using the power of databases, currently fragmented. The introduction and utilization of these technical and computational implements could lead NPs research to more comprehensive structure identification and new holistic perspectives. © 2013 Elsevier Ltd

The application of highly centrifuged honey as an improved diet for experimentally caged honey bees

Whilst sucrose syrup appears to be the most commonly used diet applied during honey bee cage experiments, dead honey bees may occur within the first week of feeding. However, sucrose syrup remains the dominant food supplement for cage experiments since past research has proved that all alternative hydrocarbon diets, including honey, decrease the lifespan of honey bees when compared to syrup. In this study we tested feeding caged honey bees with honey from which all pollen grains and possibly all pathogenic spores were removed through high speed centrifugation. This preparation significantly extended the lifespan of honey bees in cages compared with sucrose syrup and honey. The analysis of the glycoside content of centrifuged honey and of the honey from which it was produced showed that the two products were identical. The 1H NMR spectra of the two samples displayed an identical resonance pattern. This refers to the qualitative content, as well as the ratio of the constituent sugars of the two samples. This study showed that highly centrifuged honey could be applied as an improved reliable diet for experimentally caged honey bees. © IBRA 2013

Evaluation of estrogenic/antiestrogenic activity of Onobrychis ebenoides extract - Interaction with estrogen receptor subtypes ERα and ERβ

A protective effect of plant extract from Onobrychis ebenoides on ovariectomy-induced bone loss in rats has been shown. To investigate the molecular mechanisms that underly the beneficial effect of O. ebenoides (Onb) on bone loss, we studied its potential to activate ER subtypes (ERα and ERβ) on transiently transfected HeLa cells with HO-hERα or pSG5-hERβ and 3×ERE-TATA-Luc expression vectors. Its impact to stimulate differentiation and mineralization of osteoblasts (KS483 cell line) by Alizarin Red-S staining was also examined. Furthermore we sought to induce for its potential the IGFBP3, a known estrogen-dependent marker in MCF7 breast cancer cells. 17β-Estradiol and the pure antiestrogen ICI182780 were included to serve as control samples of the estrogenic and antiestrogenic activity respectively. Our data revealed: (1) Onb extract displayed a significant estrogenic activity on both ERα and ERβ subtypes. (2) It exhibited direct action on osteoblasts by inducing mineralization. (3) It showed estrogenic activity in MCF7 cells. These findings suggest that the beneficial effect of Onb extract on bone loss is mediated through an estrogen-like action via activation of ERα-ERE and ERβ-ERE pathways and via direct action on the mineralization process of osteoblasts. © 2006 Elsevier Ltd. All rights reserved

Ion tree-based structure elucidation of acetophenone dimers (AtA) from Acronychia pedunculata and their identification in extracts by liquid chromatography electrospray ionization LTQ-Orbitrap mass spectrometry

Acronychia-type acetophenones (AtA) is a chemical group of compounds of important structural and biological interest, abundant in Acronychia species. However, there are no data available for their characterization using mass spectrometry. In the current work, AtA have been investigated by multistage high resolution mass spectrometry and both electrospray ionization and atmospheric pressure chemical ionization, in positive and negative mode, were utilized for their structure elucidation and identification. The analysis of AtA using a linear ion trap-Orbitrap analyzer enabled the structural determination of key fragment ions and cleavages, which can be used for the structural characterization thereof. A systematic nomenclature based on protonated and deprotonated fragment ions under collision-induced dissociation conditions and decision trees for the structural determination of AtA are proposed. Furthermore, taking advantage of the characteristic fragmentation patterns, a selective Ultra High Performance Liquid Chromatography Electrospray Ionization multistage Mass Spectrometry (UHPLC-ESI(-)-MSn) method was developed and successfully applied for the dereplication of known AtA and the identification of potentially new ones in Acronychia extracts. Despite the structure similarity and the presence of isomers, accurate characterization of known and unknown AtA derivatives was possible. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd