Chlorophyll fluorescence instrumentation for a rapid, in situ measurement of algal density

In the project reported, we are developing an instrument for measuring algal density based on the detection of chlorophyll fluorescence. Following the adjustment of several parameters defined during preliminary analyses, measurements were made on different concentrations of model green and blue algal cultures. Fluorescent signal intensities measured by the prototypes of the fluorometer module were compared to values determined by other, widely used methods for estimation of algal density (i.e. Bürker chamber cell counting, optical density measurement and chlorophyll-a measurement with ethanol extraction method). Fluorometer results correlated well with the other methods, resulting high correlation coefficients (R2>0.9%). Limits of detection and limits of quantification showed a decreasing trend during the development phases resulting in a highly sensitive instrument

Application of an induced fluorometry-based method in algal growth inhibition tests

Aquatic ecosystems are strongly exposed to various micropollutants from agricultural origin. The harmful effect can be expressed directly on aquatic organisms and indirectly through the food chain. The use of ecotoxicity assays mainly in aquatic environments, and corresponding water quality assessment are undoubtedly important. Project Aquafluosense was designed to develop instrument prototypes of a fluorescence-based setup for in situ measurement of algal biomass and for application of flurescence in ecotoxicity assays. Fluorescence-based determination of algal density was validated by conventional methods and signals obtained by the fluorometer correlated well with the conventional methods for algal density determination. The applicability of the fluorometer developed was demonstrated in ecotoxicity assays using the herbicide active ingredient isoxaflutole in neat and formulated forms

Telített 1,3-heterociklusok gyűrű-lánc tautomériája - szubsztituenshatások vizsgálata, szintetikus alkalmazás = Ring-chain tautomerism of saturated 1,3-heterocycles - substituent effects, synthetic applications

Megállapítottuk, hogy az aminoalkil-naftolok és az aminoalkil-kinolinolok három komponensű, egylombikos Mannich-reakcióval történő előállításában az ammónium-karbamát és az ammónium-hidrogénkarbonát hatékony ammónia¬forrásként használható. Módosított Mannich reakciók során 1- és 2-naftolból illetve heterociklusos analógjaikból kiindulva számos új heterociklust állítottunk elő. Aminometilnaftolból dihidroizokinolinokkal, új pentaciklusos oxazinokat nyertünk. E közleményünket a Synfact folyóirat méltatta: http://www.thieme-connect.com/ejournals/toc/synfacts. Bizonyítottuk, hogy irodalmi adatokkal ellentétben a 2-amino-feniletanol és a 2-amino-fenilpropanol aromás aldehidekkel oldatfázisban háromkomponensű tautomer elegyet alkot. Új, környezetbarát eljárást fejlesztettünk ki spiropiperidinek előállítására. Megállapítottuk, hogy a 2-aminokarbohidrazidok és az 1-benzil-4-piperidon ciklizációja katalizátor nélkül, vízben is lezajlik, és az oldatból nagy tisztaságú termék kristályosodik ki. Nagyszámú 2,2-diszubsztituált kinazolin-4-on egyszerű, könnyen végrehajt¬ható szintézisét oldottuk meg „zöld” körülmények között vízben, vagy oldószer nélkül, 2-amino-karboxamidok ketonokkal történő gyűrűzárásával. Gyűrű-lánc tautomériát mutató közti terméken keresztül lezajlódó dominó reakcióval új típusú laktámok szintézisét oldottuk meg kiváló diasztereoszelektivitással. A kutatások során nemzetközi folyóiratokban összesen 23 közlemény jelent meg, melyek összimpakt faktora 47,6. | Ammonium carbamate and ammonium hydrogencarbonate were found to be very effective, solid sources of ammonia in the preparation of various aminoalkylnaphthols and aminoalkylquinolinols via one-pot Mannich reaction. By using a modified Mannich reaction, a great number of new heterocycles were prepared starting from 1- and 2-naphthol or their heterocyclic analogs. By reactions of aminomethylnaphthol and dihydroisoquinolines, new pentacyclic oxazines were formed. It was proved that in spite of the literature data, the condensation products of 2-aminophenylethanol or 2-aminophenylpropanol with aromatic aldehydes, participate in three-component tautomeric equilibria in solution. A new, environment-friendly process has been developed for the synthesis of spiropiperidines. The spirocyclizations of 2-aminocarbohydrazides and 1-benzyl-4-piperidone took place even in water under catalyst-free conditions, and the products crystallized out of the reaction mixture in pure form. An easy and green synthetic protocol has been developed for the preparation of 2,2-disubstituted quinazolin-4-one derivatives via ring-closures of 2-aminocarboxamides with ketones using water as solvent or solvent-free conditions. By the domino reactions of the corresponding ring-chain tautomeric intermediates, novel lactams were prepared with excellent diastereoselectivities. In frame of the research project, 23 publications (cumulative impact factor: 47.6) has been published in international scientific journals

Integrated evolutionary analysis reveals antimicrobial peptides with limited resistance

Antimicrobial peptides (AMPs) are promising antimicrobials, however, the potential of bacterial resistance is a major concern. Here we systematically study the evolution of resistance to 14 chemically diverse AMPs and 12 antibiotics in Escherichia coli. Our work indicates that evolution of resistance against certain AMPs, such as tachyplesin II and cecropin P1, is limited. Resistance level provided by point mutations and gene amplification is very low and antibiotic-resistant bacteria display no cross-resistance to these AMPs. Moreover, genomic fragments derived from a wide range of soil bacteria confer no detectable resistance against these AMPs when introduced into native host bacteria on plasmids. We have found that simple physicochemical features dictate bacterial propensity to evolve resistance against AMPs. Our work could serve as a promising source for the development of new AMP-based therapeutics less prone to resistance, a feature necessary to avoid any possible interference with our innate immune system