Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016.

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Labdane diterpenes protect against anoxia/reperfusion injury in cardiomyocytes: involvement of AKT activation

Several labdane diterpenes exert anti-inflammatory and cytoprotective actions; therefore, we have investigated whether these molecules protect cardiomyocytes in an anoxia/reperfusion (A/R) model, establishing the molecular mechanisms involved in the process. The cardioprotective activity of three diterpenes (T1, T2 and T3) was studied in the H9c2 cell line and in isolated rat cardiomyocyte subjected to A/R injury. In both cases, treatment with diterpenes T1 and T2 protected from A/R-induced apoptosis, as deduced by a decrease in the percentage of apoptotic and caspase-3 active positive cells, a decrease in the Bcl-2/Bax ratio and an increase in the expression of antiapoptotic proteins. Analysis of cell survival signaling pathways showed that diterpenes T1 and T2 added after A/R increased phospho-AKT and phospho-ERK 1/2 levels. These cardioprotective effects were lost when AKT activity was pharmacologically inhibited. Moreover, the labdane-induced cardioprotection involves activation of AMPK, suggesting a role for energy homeostasis in their mechanism of action. Labdane diterpenes (T1 and T2) also exerted cardioprotective effects against A/R-induced injury in isolated cardiomyocytes and the mechanisms involved activation of specific survival signals (PI3K/AKT pathways, ERK1/2 and AMPK) and inhibition of apoptosis

Chemical analysis of Greek pollen - Antioxidant, antimicrobial and proteasome activation properties

<p>Abstract</p> <p>Background</p> <p>Pollen is a bee-product known for its medical properties from ancient times. In our days is increasingly used as health food supplement and especially as a tonic primarily with appeal to the elderly to ameliorate the effects of ageing. In order to evaluate the chemical composition and the biological activity of Greek pollen which has never been studied before, one sample with identified botanical origin from sixteen different common plant taxa of Greece has been evaluated.</p> <p>Results</p> <p>Three different extracts of the studied sample of Greek pollen, have been tested, in whether could induce proteasome activities in human fibroblasts. The water extract was found to induce a highly proteasome activity, showing interesting antioxidant properties. Due to this activity the aqueous extract was further subjected to chemical analysis and seven flavonoids have been isolated and identified by modern spectral means. From the methanolic extract, sugars, lipid acids, phenolic acids and their esters have been also identified, which mainly participate to the biosynthetic pathway of pollen phenolics. The total phenolics were estimated with the Folin-Ciocalteau reagent and the total antioxidant activity was determined by the DPPH method while the extracts and the isolated compounds were also tested for their antimicrobial activity by the dilution technique.</p> <p>Conclusions</p> <p>The Greek pollen is rich in flavonoids and phenolic acids which indicate the observed free radical scavenging activity, the effects of pollen on human fibroblasts and the interesting antimicrobial profile.</p

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Natural and synthetic 2,2-dimethylpyranocoumarins with antibacterial activity

A new efficient synthetic approach to the natural coumarins 5-hydroxyseselin (5), 5-methoxyseselin (3), and (±) cis-grandmarin (9) is described as well as the synthesis of some new derivatives in the 5-methoxyseselin series (10-15). The natural coumarins 7-hydroxyalloxanthyletin (6), alloxanthoxyletin (8), and dipetalolactone (7) have also been obtained as secondary products. The type of fusion of the pyrano ring in all cases has been established by 2D NMR spectroscopy. The compounds have been studied for their in vitro antibacterial activity, which has been compared with that of some previously synthesized seselin derivatives. The most active compounds were 3, 7, 8, 11, and 14. Some structure-activity relationships are discussed

Triterpenic derivatives of Achillea alexandri-regis Bornm. & Rudski

Investigation of the aerial parts of Achillea alexandri-regis led to the identification of 19 chemical constituents: twelve 3-O-fatty acid esters of triterpene alcohols arnidiol (1-4), maniladiol (5-8) and 16beta-hydroxy-lupeol (9-12), alpha-amyrin, beta-amyrin, beta-sitosterol, 3,4-O-dicaffeoyl quinic acid, cinnamic acid, pinoresinol-beta-D-glucoside and rutin. Among them, compounds 3, 4, 8, 11 and 12 are new natural products. The structures of all compounds have been elucidated on the basis of their spectral and chemical data

Chemical composition of the essential oils and headspace samples of two helichrysum species occurring in Spain

The oils obtained by hydrodistillation and the headspace volatiles from the aerial parts of Helichrysum italicum ssp. serotinum (Boiss) and H. stoechas ssp. stoechas (Moench) were analyzed by means of GC and GC/MS. Both oils were found to be dominated by non-oxygenated monoterpenes. A total of 68 compounds were identified. The major components of H. italicum ssp. serotinum were guaiol (8.9%), nerol (7.0%) and β-caryophyllene (6.0%), while those of H. stoechas ssp. stoechas were: α-pinene (28.3%), epi-α-bisabolol (21.9%) and β-caryophyllene (5.5%). Furthermore, the bacteriostatic activity of the oils against two Gram-positive and four Gram-negative bacteria was evaluated. © 1999, Taylor &amp; Francis Group, LLC. All rights reserved

Chemical composition and antimicrobial activity of the essential oils of Pistacia lentiscus var. chia

The chemical composition of the three essential oils obtained by steam distillation of the mastic gum, leaves and twigs of Pistacia lentiscus var. chia, was studied by GC/MS. Sixty nine constituents were identified from the oils. α-Pinene, myrcene, trans-caryophyllene and germacrene D were found to be the major components. The in vitro antimicrobial activity of the three essential oils and of the resin (total, acid and neutral fraction) against six bacteria and three fungi is reported

Biologically active triterpenoids from Cephalaria ambrosioides

The roots of Cephalaria ambrosioides yielded a new triterpene, 6α-hydroxyhederagenic acid (1), in addition to the known triterpene hederagenic acid (2) and four corresponding saponins, leontoside A (or akeboside Stb) (3), kalopanax saponin A (or α-hederin) (4), saponin PG (or sapindoside B) (5), and dipsacoside B (6). Their structures have been elucidated on the basis of their spectral data (MS, 1 D and 2 D NMR) and by some chemical transformations. The extract and all isolated compounds were evaluated for their antimicrobial, molluscicidal and in vitro cytotoxic activities. All compounds showed strong antimicrobial activity (MIC values 1.80-2.50 μg/mL), with 5 and 6 exhibiting activities comparable to those of standard antibiotics. Moreover, compounds 3-5 were active against all assayed cancer cell lines, whereas compounds 3 and 4 exhibited higher activities against Biomphalaria glabrata snails, with minimum inhibitory concentrations of 5.4 and 6.2 μg/mL, respectively. © Georg Thieme Verlag KG Stuttgart