Thermophilic bacteria of four genera in contrast to the commonly used production strains such as Bacillus subtilis, produce homologs other than menaquinone (MK) with seven isoprene units. The number of isoprene units and the configuration of double bonds are essential factors for their biological activity. The goal was to obtain a strain of bacteria that produces a wide range of MK homologs and only all-trans geometrical isomers, which was the strain G. kaustophilus. Using off-line two-dimensional LC-tandem MS in columns with the RP18 phase and the COSMOSIL cholester phase (separation according to the geometric configuration of double bonds) it was shown that thermophilic bacteria grown at different temperatures produce only all-trans isomers of menaquinones from MK-5 (menaquinone with five isoprenyl units) to MK-15 (fifteen isoprenyl units). Therefore, G. kaustophilus appears to be a biotechnologically important strain produces only trans isomers and additionally homologs from 5 to 15 isoprene units.

• Klíčová slova
• Cis/trans isomers, LC/ESI–tandem MS, Menaquinones, Shotgun mass spectrometry, Thermophilic bacteria,
• MeSH
• Bacteria * MeSH
• butadieny * MeSH
• hmotnostní spektrometrie MeSH
• vitamin K 2 chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• butadieny * MeSH
• isoprene MeSH Prohlížeč
• vitamin K 2 MeSH

Microbial infections and nosocomial diseases associated with biomaterial have become a major problem of public health and largely lead to revision surgery, which is painful and quite expensive for patients. These infections are caused by formation of biofilm, which present a difficulty of treatment with conventional antibiotics. The aim of our study is to investigate the theoretical adhesion of Staphylococcus aureus and Pseudomonas aeruginosa on four 3-dimensional printing filament materials used in the manufacture of medical equipment. Thus, the physicochemical properties of these microorganisms and all filament materials were determined using the contact angle measurements. Our results indicated that bacterial surfaces were hydrophilic, strongly electron donating and weakly electron accepting. In contrast, nylon, acrylonitrile butadiene-styrene, polyethylene terephthalate, and polylactic acid surfaces were hydrophobic and more electron-donor than electron-acceptor. In addition, according to the values of total free interaction energy ΔGTotal, Staphylococcus aureus was found unable to adhere to the filament materials except polyethylene terephthalate surface. However, Pseudomonas aeruginosa showed adhesion capacity only for acrylonitrile butadiene-styrene and polyethylene terephthalate surfaces. These findings imply that the usage of these 3D printed materials in the medical area necessitates more research into enhancing their resistance to bacterial adherence.

• Klíčová slova
• 3D printing, Bacterial adhesion, Pseudomonas aeruginosa, Staphylococcus aureus,
• MeSH
• akrylonitril * MeSH
• bakteriální adheze MeSH
• biofilmy MeSH
• butadieny farmakologie   MeSH
• infekce spojené se zdravotní péčí * MeSH
• lidé MeSH
• polyethylentereftaláty chemie   MeSH
• Pseudomonas aeruginosa MeSH
• stafylokokové infekce * MeSH
• Staphylococcus aureus MeSH
• styreny MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 1,3-butadiene MeSH Prohlížeč
• akrylonitril * MeSH
• butadieny MeSH
• polyethylentereftaláty MeSH
• styreny MeSH

Engineering cyanobacteria for the production of isoprene and other terpenoids has gained increasing attention in the field of biotechnology. Several studies have addressed optimization of isoprene synthesis in cyanobacteria via enzyme and pathway engineering. However, only little attention has been paid to the optimization of cultivation conditions. In this study, an isoprene-producing strain of Synechocystis sp. PCC 6803 and two control strains were grown under a variety of cultivation conditions. Isoprene production, as quantified by modified membrane inlet mass spectrometer (MIMS) and interpreted using Flux Balance Analysis (FBA), increased under violet light and at elevated temperature. Increase of thermotolerance in the isoprene producer was attributed to the physical presence of isoprene, similar to plants. The results demonstrate a beneficial effect of isoprene on cell survival at higher temperatures. This increased thermotolerance opens new possibilities for sustainable bio-production of isoprene and other products.

• Klíčová slova
• Biofuels, Cultivation conditions, Flux Balance Analysis, Optimization, Thermotolerance,
• MeSH
• butadieny metabolismus   MeSH
• hemiterpeny metabolismus   MeSH
• Synechocystis * metabolismus   MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• butadieny MeSH
• hemiterpeny MeSH
• isoprene MeSH Prohlížeč

The case of spoilage of flavoured and sweetened soft drink occurred in the Czech Republic in 2019. After drinking it, the consumer was admitted to a hospital with sickness. The spoilage was caused by mould and an odorous substance, 1,3-pentadiene. The mechanism of food spoilage, with the formation of 1,3-pentadiene arising from the decarboxylation of sorbic acid and mould growth, is described. This could be the second case history reported worldwide of an allergic reaction to penicillin explaining how penicillin might get into the beverage. We hypothesise three possible causes of the health problem experienced with allergic reaction to penicillin or other mycotoxin produced by Penicillium mould as the most probable one.

• Klíčová slova
• 1, 3-pentadiene, allergy, mould, penicillin, soft drink,
• MeSH
• alkadieny * MeSH
• houby MeSH
• kyselina sorbová * MeSH
• lidé MeSH
• pentany MeSH
• sycené nápoje MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 1,3-pentadiene MeSH Prohlížeč
• alkadieny * MeSH
• kyselina sorbová * MeSH
• pentany MeSH

Carotenoids are conjugated linear molecules built from the repetition of terpene units, which display a large structural diversity in nature. They may, in particular, contain several types of side or end groups, which tune their functional properties, such as absorption position and photochemistry. We report here a detailed experimental study of the absorption and vibrational properties of allene-containing carotenoids, together with an extensive modeling of these experimental data. Our calculations can satisfactorily explain the electronic properties of vaucheriaxanthin, where the allene group introduces the equivalent of one C═C double bond into the conjugated C═C chain. The position of the electronic absorption of fucoxanthin and butanoyloxyfucoxanthin requires long-range corrections to be found correctly on the red side of that of vaucheriaxanthin; however, these corrections tend to overestimate the effect of the conjugated and nonconjugated C═O groups in these molecules. We show that the resonance Raman spectra of these carotenoids are largely perturbed by the presence of the allene group, with the two major Raman contributions split into two components. These perturbations are satisfactorily explained by modeling, through a gain in the Raman intensity of the C═C antisymmetric stretching mode, induced by the presence of the allene group in the carotenoid C═C chain.

• MeSH
• alkadieny * MeSH
• elektronika MeSH
• karotenoidy * chemie   MeSH
• Ramanova spektroskopie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alkadieny * MeSH
• karotenoidy * MeSH
• propadiene MeSH Prohlížeč

A set of new substituted dienes were synthesized from betulinic acid by its oxidation to 30-oxobetulinic acid followed by the Wittig reaction. Cytotoxicity of all compounds was tested in vitro in eight cancer cell lines and two noncancer fibroblasts. Almost all dienes were more cytotoxic than betulinic acid. Compounds 4.22, 4.30, 4.33, 4.39 had IC50 below 5 μmol/L; 4.22 and 4.39 were selected for studies of the mechanism of action. Cell cycle analysis revealed an increase in the number of apoptotic cells at 5 × IC50 concentration, where activation of irreversible changes leading to cell death can be expected. Both 4.22 and 4.39 led to the accumulation of cells in the G0/G1 phase with partial inhibition of DNA/RNA synthesis at 1 × IC50 and almost complete inhibition at 5 × IC50. Interestingly, compound 4.39 at 5 × IC50 caused the accumulation of cells in the S phase. Higher concentrations of tested drugs probably inhibit more off-targets than lower concentrations. Mechanisms disrupting cellular metabolism can induce the accumulation of cells in the S phase. Both compounds 4.22 and 4.39 trigger selective apoptosis in cancer cells via intrinsic pathway, which we have demonstrated by changes in the expression of the crucial apoptosis-related protein. Pharmacological parameters of derivative 4.22 were superior to 4.39, therefore 4.22 was the finally selected candidate for the development of anticancer drug.

• Klíčová slova
• Apoptosis, Betulinic acid, Cancer, Cell cycle, Cytotoxicity, Mechanism of action, Selectivity, Triterpene, Wittig reaction,
• MeSH
• alkadieny chemická syntéza   chemie   farmakologie   MeSH
• antitumorózní látky chemická syntéza   chemie   farmakologie   MeSH
• apoptóza účinky léků   MeSH
• buněčný cyklus účinky léků   MeSH
• kultivované buňky MeSH
• kyselina betulinová MeSH
• léky antitumorózní - screeningové testy MeSH
• lidé MeSH
• molekulární struktura MeSH
• pentacyklické triterpeny chemie   farmakologie   MeSH
• proliferace buněk účinky léků   MeSH
• psi MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• psi MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alkadieny MeSH
• antitumorózní látky MeSH
• kyselina betulinová MeSH
• pentacyklické triterpeny MeSH

Volatile breath metabolites serve as potential disease biomarkers. Online mass spectrometry (MS) presents real-time quantification of breath volatile organic compounds (VOCs). The study aims to assess the relationship between two online analytical mass spectrometry techniques in the quantification of target breath metabolites: selected ion flow tube mass spectrometry (SIFT-MS) and proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS). The two following techniques were employed: (i) direct injection with bag sampling using SIFT-MS and PTR-ToF-MS and (ii) direct injection and thermal desorption (TD) tube comparison using PTR-ToF-MS. The concentration of abundant breath metabolites, acetone and isoprene, demonstrated a strong positive linear correlation between both mass spectrometry techniques (r = 0.97, r = 0.89, respectively; p < 0.001) and between direct injection and TD tube (r = 0.97, r = 0.92, respectively; p < 0.001) breath sampling techniques. This was reflected for the majority of short chain fatty acids and alcohols tested (r > 0.80, p < 0.001). Analyte concentrations were notably higher with the direct injection of a sampling bag compared to the TD method. All metabolites produced a high degree of agreement in the detection range of VOCs between SIFT-MS and PTR-ToF-MS, with the majority of compounds falling within 95% of the limits of agreement with Bland-Altman analysis. The cross platform analysis of exhaled breath demonstrates strong positive correlation coefficients, linear regression, and agreement in target metabolite detection rates between both breath sampling techniques. The study demonstrates the transferability of using data outputs between SIFT-MS and PTR-ToF-MS. It supports the implementation of a TD platform in multi-site studies for breath biomarker research in order to facilitate sample transport between clinics and the laboratory.

• Klíčová slova
• SIFT-MS, breath analysis, direct injection, thermal desorption: PTR-ToF-MS, volatile organic compound,
• MeSH
• aceton analýza   MeSH
• butadieny analýza   MeSH
• dechové testy přístrojové vybavení   metody   MeSH
• dospělí MeSH
• hemiterpeny analýza   MeSH
• hmotnostní spektrometrie přístrojové vybavení   metody   MeSH
• lidé MeSH
• těkavé organické sloučeniny analýza   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aceton MeSH
• butadieny MeSH
• hemiterpeny MeSH
• isoprene MeSH Prohlížeč
• těkavé organické sloučeniny MeSH

Systematic scrutiny is carried out of the ability of multicentre bond indices and the NOEL-based similarity index dAB to serve as excited-state aromaticity criteria. These indices were calculated using state-optimized complete active-space self-consistent field wavefunctions for several low-lying singlet and triplet states of the paradigmatic molecules of benzene and square cyclobutadiene and the inorganic ring S2N2. The comparison of the excited-state indices with aromaticity trends for individual excited states suggested by the values of magnetic aromaticity criteria show that whereas the indices work well for aromaticity reversals between the ground singlet and first triplet electronic states, addressed by Baird's rule, there are no straightforward parallels between the two sets of data for singlet excited states. The problems experienced while applying multicentre bond indices and dAB to singlet excited states are explained by the loss of the information inherently present in wavefunctions and/or pair densities when calculating the first-order density matrix.

• Klíčová slova
• excited-state aromaticity reversals, magnetic properties of excited states, molecular similarity, multicentre bond indices,
• MeSH
• benzen chemie   MeSH
• butadieny chemie   MeSH
• elektrony MeSH
• kvantová teorie MeSH
• molekulární modely MeSH
• molekulární struktura * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 1,3-butadiene MeSH Prohlížeč
• benzen MeSH
• butadieny MeSH

Tuberous sclerosis complex (TSC) is an autosomal dominantly inherited neurocutaneous disorder caused by inactivating mutations in TSC1 or TSC2, key regulators of the mechanistic target of rapamycin complex 1 (mTORC1) pathway. In the CNS, TSC is characterized by cortical tubers, subependymal nodules and subependymal giant cell astrocytomas (SEGAs). SEGAs may lead to impaired circulation of CSF resulting in hydrocephalus and raised intracranial pressure in patients with TSC. Currently, surgical resection and mTORC1 inhibitors are the recommended treatment options for patients with SEGA. In the present study, high-throughput RNA-sequencing (SEGAs n = 19, periventricular control n = 8) was used in combination with computational approaches to unravel the complexity of SEGA development. We identified 9400 mRNAs and 94 microRNAs differentially expressed in SEGAs compared to control tissue. The SEGA transcriptome profile was enriched for the mitogen-activated protein kinase (MAPK) pathway, a major regulator of cell proliferation and survival. Analysis at the protein level confirmed that extracellular signal-regulated kinase (ERK) is activated in SEGAs. Subsequently, the inhibition of ERK independently of mTORC1 blockade decreased efficiently the proliferation of primary patient-derived SEGA cultures. Furthermore, we found that LAMTOR1, LAMTOR2, LAMTOR3, LAMTOR4 and LAMTOR5 were overexpressed at both gene and protein levels in SEGA compared to control tissue. Taken together LAMTOR1-5 can form a complex, known as the 'Ragulator' complex, which is known to activate both mTORC1 and MAPK/ERK pathways. Overall, this study shows that the MAPK/ERK pathway could be used as a target for treatment independent of, or in combination with mTORC1 inhibitors for TSC patients. Moreover, our study provides initial evidence of a possible link between the constitutive activated mTORC1 pathway and a secondary driver pathway of tumour growth.

• Klíčová slova
• SEGA, TSC, low grade glioma, sequencing,
• MeSH
• adaptorové proteiny signální transdukční genetika   metabolismus   MeSH
• astrocytom etiologie   genetika   metabolismus   MeSH
• astrocyty účinky léků   metabolismus   MeSH
• butadieny farmakologie   MeSH
• dítě MeSH
• dospělí MeSH
• extracelulárním signálem regulované MAP kinasy antagonisté a inhibitory   genetika   metabolismus   MeSH
• hamartin genetika   MeSH
• inhibitory enzymů farmakologie   MeSH
• intracelulární signální peptidy a proteiny genetika   metabolismus   MeSH
• kojenec MeSH
• lidé MeSH
• MAP kinasový signální systém genetika   MeSH
• mechanistické cílové místo rapamycinového komplexu 1 MeSH
• messenger RNA metabolismus   MeSH
• mikro RNA metabolismus   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• nádorové buňky kultivované MeSH
• nádory mozku komplikace   genetika   metabolismus   MeSH
• nitrily farmakologie   MeSH
• předškolní dítě MeSH
• sekvenční analýza RNA MeSH
• sekvenování transkriptomu MeSH
• stanovení celkové genové exprese MeSH
• tuberin genetika   MeSH
• tuberózní skleróza komplikace   genetika   MeSH
• výměnné faktory guaninnukleotidů genetika   metabolismus   MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• butadieny MeSH
• extracelulárním signálem regulované MAP kinasy MeSH
• hamartin MeSH
• inhibitory enzymů MeSH
• intracelulární signální peptidy a proteiny MeSH
• LAMTOR1 protein, human MeSH Prohlížeč
• LAMTOR2 protein, human MeSH Prohlížeč
• LAMTOR3 protein, human MeSH Prohlížeč
• LAMTOR4 protein, human MeSH Prohlížeč
• LAMTOR5 protein, human MeSH Prohlížeč
• mechanistické cílové místo rapamycinového komplexu 1 MeSH
• messenger RNA MeSH
• mikro RNA MeSH
• nitrily MeSH
• TSC1 protein, human MeSH Prohlížeč
• TSC2 protein, human MeSH Prohlížeč
• tuberin MeSH
• U 0126 MeSH Prohlížeč
• výměnné faktory guaninnukleotidů MeSH

The prediction of vegetation responses to climate requires a knowledge of how climate-sensitive plant traits mediate not only the responses of individual plants, but also shifts in the species and functional compositions of whole communities. The emission of isoprene gas - a trait shared by one-third of tree species - is known to protect leaf biochemistry under climatic stress. Here, we test the hypothesis that isoprene emission shapes tree species compositions in tropical forests by enhancing the tolerance of emitting trees to heat and drought. Using forest inventory data, we estimated the proportional abundance of isoprene-emitting trees (pIE) at 103 lowland tropical sites. We also quantified the temporal composition shifts in three tropical forests - two natural and one artificial - subjected to either anomalous warming or drought. Across the landscape, pIE increased with site mean annual temperature, but decreased with dry season length. Through time, pIE strongly increased under high temperatures, and moderately increased following drought. Our analysis shows that isoprene emission is a key plant trait determining species responses to climate. For species adapted to seasonal dry periods, isoprene emission may tradeoff with alternative strategies, such as leaf deciduousness. Community selection for isoprene-emitting species is a potential mechanism for enhanced forest resilience to climatic change.

• Klíčová slova
• climate feedback, drought, plant functional traits, plant secondary metabolism, thermotolerance, tree physiology, tropical forest, volatile organic compounds,
• MeSH
• butadieny analýza   MeSH
• časové faktory MeSH
• fylogeneze * MeSH
• hemiterpeny analýza   MeSH
• klimatické změny * MeSH
• lesy MeSH
• stromy fyziologie   MeSH
• tropické klima * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Názvy látek
• butadieny MeSH
• hemiterpeny MeSH
• isoprene MeSH Prohlížeč