The use of salicylaldehyde derivatives as a nitrogen source for antibiotic production by Streptomyces hygroscopicus CH-7

In the present work, four derivatives of salicylaldehyde (salicylaldehyde-hydrazone, phenylhydrazone, semicarbazone and thiosemicarbazone) were synthesized using both conventional (95% ethanol) and green (crude glycerol from biodiesel production) solvents. The obtained compounds were identified by elemental microanalysis, as well as FTIR, UV/Vis and H-1-NMR spectroscopic methods. Yields of 93-98% of the compounds in crude glycerol were achieved within 10-25 min. The derivatives of salicylaldehyde and crude glycerol were used as a nitrogen and carbon source, respectively, in the medium for antibiotic (hexaene H-85 and azalomycine B) production by Streptomyces hygroscopicus CH-7. The highest concentrations of hexaene H-85 and azalomycine B were achieved in the medium containing salicylaldehyde-thiosemicarbazone (198 and 69 mu g/cm(3), respectively). Derivatives of salicylaldehyde also impacted the strain morphology. In the media with salicylaldehyde- phenylhydrazone and salicylaldehyde-thiosemicarbazone, S. hygroscopicus CH-7 grew like large dispersive pellets with long twisted filaments that produced the highest yield of the antibiotics

Analysis of Epitopes on Dengue Virus Envelope Protein Recognized by Monoclonal Antibodies and Polyclonal Human Sera by a High Throughput Assay

Dengue virus is the leading cause of arboviral diseases worldwide. The envelope protein is the major target of neutralizing antibodies and vaccine development. While previous studies have reported several epitopes on envelope protein, the possibility of interdomain epitopes and the relationship of epitopes to neutralizing potency remain unexplored. We developed a high throughput dot blot assay by using 67 alanine mutants of surface-exposed envelope residues as a systematic approach to identify epitopes recognized by mouse monoclonal antibodies and polyclonal human sera. Our results suggested the presence of interdomain epitopes more frequent than previously appreciated. Compared with monoclonal antibodies generated by traditional protocol, the potent neutralizing monoclonal antibodies generated by a new protocol showed several unique features of their epitopes. Moreover, the predominant epitopes of antibodies against envelope protein in polyclonal sera can be identified by this assay. These findings have implications for future development of epitope-specific diagnostics and epitope-based dengue vaccine, and add to our understanding of humoral immune responses to dengue virus at the epitope level

Current challenges facing the assessment of the allergenic capacity of food allergens in animal models

Food allergy is a major health problem of increasing concern. The insufficiency of protein sources for human nutrition in a world with a growing population is also a significant problem. The introduction of new protein sources into the diet, such as newly developed innovative foods or foods produced using new technologies and production processes, insects, algae, duckweed, or agricultural products from third countries, creates the opportunity for development of new food allergies, and this in turn has driven the need to develop test methods capable of characterizing the allergenic potential of novel food proteins. There is no doubt that robust and reliable animal models for the identification and characterization of food allergens would be valuable tools for safety assessment. However, although various animal models have been proposed for this purpose, to date, none have been formally validated as predictive and none are currently suitable to test the allergenic potential of new foods. Here, the design of various animal models are reviewed, including among others considerations of species and strain, diet, route of administration, dose and formulation of the test protein, relevant controls and endpoints measured

Agricultural Academy

abstract CVETANOVIC, B. and D. ZLATKOVIC, 2013. Evaluation of whole-body vibration risk in agricultural tractor drivers. Bulg. J. Agric. Sci., 19: 1155-1160 During their work, agricultural tractor drivers are exposed to various negative influences, among which vibrations are especially harmful. It is about vibrations generated in engine while the tractor is working, which are then transmitted to the driver's body through the seat, the frame and the controls. Exposure to these vibrations over a longer period can lead to serious health issues. Therefore, measuring and evaluating of vibrations are critical from the aspect of developing safety measures. A measurement of vibrations in older models of IMT tractors shows that more than one-hour work with these models regularly causes a risk of intense daily vibration exposure, with the values much higher than those allowed by law. In these cases, the employer is obliged to take safety and organizational measures to reduce the vibration values to acceptable level

REDUKCIJA5-ACETIL-1,6-DIMETIL-4-FENIL-3,4-DIHIDROPIRIMIDIN-2(1H)-ONA LITIJUM-ALUMINIJUM-HIDRIDOM

In this paper, we investigated the LiAlH4-reduction of 5-acetyl-1,6-dimethyl-4-phenyl-3,4-dihydropyrimidin-2(1H)-one (N-methylated Biginelli compound). Following the reduction and SiO2-promoted dehydration, (Z)-5-ethylidene-1-methyl-6-methylene-4-phenyltetrahydropyrimidin-2(1H)-one was isolated as the major product (33% yield). Chromatographic separation of the reaction products also allowed us to isolate (yield in parentheses) and fully spectrally characterize: 1,6-dimethyl-4-phenyl-5-vinyl-3,4-dihydropyrimidin-2(1H)-one (20%), 5-ethyl-1,6-dimethyl-4-phenyl-3,4-dihydro-pyrimidin-2(1H)-one (9%), 5-(1-hydroxyethyl)-1,6-dimethyl-4-phenyl-3,4-dihydropyrimidin-2(1H)-one (5%). A possible mechanism explaining the formation of these products is proposed.U ovom radu ispitana je redukcija 5-acetil-1,6-dimetil-4-fenil-3,4-dihidropirimidin-2(1H)-ona (N-metilovanog Biđinelijevog proizvoda) litijum-aluminijum-hidridom. Kao najzastupljeniji proizvod reakcije, nakon redukcije I dehidratacije na silica gelu, izolovan je (Z)-5-etiliden-1-metil-6-metilen-4-feniltetrahidropirimidin-2(1H)-on u prinosu od 33%. Hromatografskim razdvajanjem prečišćeni su I ostali proizvodi:4-fenil-1,6-dimetil-5-vinil-3,4-dihidropirimidin-2(1H)-on (prinos: 20%), 5-etil-1,6-dimetil-4-fenil-3,4-dihidropirimidin-2(1H)-on (9%) i5-(1-hidroksietil)-1,6-dimetil-4-fenil-3,4-dihidropirimidin-2(1H)-on (5%). Predložen je mogući mehanizam koji objašnjava nastajanje ovih proizvoda

Comparison of lung diffusing capacity in young elite athletes and their counterparts

Background: The influence of exercise on the pulmonary function is controverse, some studies have reported no sports influence, while the others have found positive correlation. Aim: To evaluate and compare the sports influence on pulmonary function: spirometry (VC, FVC, FEV1, FEV1/FVC), lung diffusing capacity (DLCO) and coefficient of the CO gas transfer (KCO) in two elite athletes groups and healthy sedentary controls. Method: Equally divided into aerobic and anaerobic group, 60 elite athletes were recruited, as well as 43 age-matched, healthy sedentary controls. All of the participants performed basic anthropometric measurements, spirometry, DLCO and KCO at rest. Kruskal–Wallis one way ANOVA test was used to determine differences between groups; Mann–Whitney U test was used for inter-groups differences and Pearson coefficient for pulmonary variables and anthropometric parameters correlation. Statistical analyses were performed using the SPSS computer statistic program, version 20. Results: No differences were found in pulmonary characteristics (spirometric function values, DLCO and KCO) in athletes and non-athletes at rest, as well as between aerobics and anaerobics. There were no correlations between the anthropometric parameters and the investigated respiratory function tests. DLCO (%) correlated positively with height in athletes playing anaerobic type of sport (karate and taekwondo) (p = 0.036; r = 0.544), and negatively in sedentary control group (p = 0.030; r = −0.560). Regarding KCO, no differences were found. Conclusion: Spirometry indices and DLCO are not influenced either by aerobic or anaerobic training type, so benefits of sports on pulmonary indices or DLCO was not confirmed. Keywords: Athletes, Diffusing capacity, Transfer coefficien

Cytotoxic effect of Reseda lutea L.: A case of forgotten remedy

Ethnopharmacological relevance: Reseda lutea L (Resedaceae) or Wild Mignonette is a widely distributed plant species. Pliny the Elder (AD 23-AD 79), a Roman scholar and naturalist, reported the use of R. lutea for reducing tumors in his Historia naturalis. Accounts of the beneficial effects of R. lutea in tumor treatment could also be found in the works of later authors, such as Etienne Francois Geoffroy (1672-1731) and Samuel Frederick Gray (1766-1828). However, to date no in vivo or in vitro evidence exists in support of the alleged tumor healing properties of R. lutea. Materials and methods: The composition of autolysates obtained from different organs (root, flower and fruit) of R. lutea was investigated by GC and GC-MS analyses and IR, 1D and 2D NMR spectroscopy. These analyses led to the discovery of a new compound isolated in pure form from the flower autolysate. Autolysates and their major constituents were submitted to MU-dye reduction cytotoxic assay on human A375 (melanoma) and MRC5 (fibroblast) cell lines. Mechanism of the cytotoxic effects was studied by cell cycle analysis and Annexin V assay. Results: Benzyl isothiocyanate and 2-(alpha-L-rhamnopyranosyloxy)benzyl isothiocyanate were identified as the major constituents of the root and flower autolysates, respectively (the later represents a new natural product). These compounds showed significant antiproliferative effects against both cell lines, which could also explain the observed high cytotoxic activity of the tested autolysates. Cell cycle analysis revealed apoptosis as the probable mechanism of cell death. Conclusions: Tumor healing properties attributed to R. lutea in the pre-modern texts were substantiated by the herein obtained results. Two isothiocyanates were found to be the major carriers of the observed activity. Although there was a relatively low differential effect of the plant metabolites on transformed and non-transformed cell lines, one can argue that the noted strong cytotoxicity provides first evidence that could explain the long forgotten use of this particular species. (C) 2014 Elsevier Ireland Ltd. All rights reserved