Direct determination of phenolic secoiridoids in olive oil by ultra-high performance liquid chromatography-triple quadruple mass spectrometry analysis

In recent years, a large number of biological properties and an important role in the organoleptic characteristics of olive oil have been attributed to phenolic secoiridoids, such as oleacein, oleocanthal, oleuropein aglycone and ligstroside aglycone. Consequently, quantifying them is of great interest for the olive oil sector. Currently, there is no consensus in which analytical method must be use to accurately determine these compounds in olive oil, mainly owing to the lack of reference standards for calibration. In this work, analytical standards of phenolic secoiridoids have been used to develop a quantitative and rapid analytical method by UHPLC-MS/MS, in which sample extraction is not carried out. Simple dilutions of the sample with dry tetrahydrofuran and dry acetonitrile were performed before analysing them. It is worth noting that under these conditions the generation of artefacts such as acetals and hemiacetals of the aldehydic forms is highly reduced. The detection and quantification was performed with a Xevo TQS tandem quadrupole mass spectrometer. The method was validated at four concentration levels and finally applied to six samples of extra virgin olive oil

Terpenoides de abies marocana :transformaciones químicas

La tesis doctoral presenta los resultados obtenidos en el estudio de la composición química del extracto hexanico de las hojas y de la madera de la especie botánica abies marocana trabut, como parte de la investigación sobre abetos de Andalucía y norte de África que se desarrolla en el Dto. de Química Orgánica de esta universidad. El estudio de esta especie presenta interés desde el punto de vista fitoquimico, ecológico e industrial. los resultados descritos en la presente memoria ponen de manifiesto la presencia, en esta especie de sesquiterpenoides, diterpenoides y triterpenoides, algunos con potencial utilidad como insecticidas ecológicos. La tesis doctoral también describe transformaciones químicas (deshidrataciones, reordenamientos, hidrogenaciones cataliticas, om-dm) de los productos naturales encontrados con mayor utilidad industrial.Tesis Universidad de Granada. Departamento de Química Orgánic

First synthesis of antitumoral dasyscyphin B

The first synthesis of dasyscyphin B, an antitumoral metabolite obtained from the ascomycete Dasyscyphus niveus, has been achieved starting from commercial abietic acid. The key steps of the synthetic sequence are the diastereoselective α-methylation of a ketoaldehyde, followed by an intramolecular aldol condensation and the further Diels–Alder cycloaddition of a dienol ester. The procedure reported will allow the synthesis of related metabolites functionalized in the A ring.The authors thank the Spanish Ministry of Science and Innovation (project CTQ2009-09932) and the Regional Government of Andalucia (project P11-CTS-7651 and assistance to the FQM-348 group) for financial support. A.F. thanks the Spanish Ministry of Science and Innovation for the predoctoral grant provided

Lipid analogs reveal features critical for hemolysis and diminish granadaene mediated Group B Streptococcus infection.

Although certain microbial lipids are toxins, the structural features important for cytotoxicity remain unknown. Increased functional understanding is essential for developing therapeutics against toxic microbial lipids. Group B Streptococci (GBS) are bacteria associated with preterm births, stillbirths, and severe infections in neonates and adults. GBS produce a pigmented, cytotoxic lipid, known as granadaene. Despite its importance to all manifestations of GBS disease, studies towards understanding granadaene's toxic activity are hindered by its instability and insolubility in purified form. Here, we report the synthesis and screening of lipid derivatives inspired by granadaene, which reveal features central to toxin function, namely the polyene chain length. Furthermore, we show that vaccination with a non-toxic synthetic analog confers the production of antibodies that inhibit granadaene-mediated hemolysis ex vivo and diminish GBS infection in vivo. This work provides unique structural and functional insight into granadaene and a strategy to mitigate GBS infection, which will be relevant to other toxic lipids encoded by human pathogens