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Recently, there has been increased interest in the use of microorganisms in the production of pharmaceuticals, nutraceuticals and energy supply products, which is due to their rapid growth rate and ability to biosynthesize fine chemicals or biotransform specific xenobiotics. To achieve the desired scale of production and optimization of microbial cultures, it is necessary to design bioreactors that enable process automation, control of working parameters, reduction of microbial and chemical contaminations, and culture independence of climate conditions. In response to this need, an original, modular airlift-type photobioreactor system was designed and manufactured. This novel semitechnical system, with a total volume of 1000 dm3, was operated via computer control, which enabled the creation of time profiles of red, blue and white LED illumination and of carbon dioxide and air dosing. The quality and usefulness of the developed system was demonstrated via the case study, namely two-stage cultivation of the microalgae Haematococcus pluvialis—a species commonly used in the production of natural astaxanthin. The experimentally developed procedure ensures a repeatable and efficient biomass multiplication process and the maintenance of a light- and chemical-mediated effective stress mechanism that allows the production of up to 3.2% natural astaxanthin in terms of dry biomass.

Aminophosphonates are an important group of building blocks in medicinal and pharmaceutical chemistry. Novel representatives of this class of compounds containing nontypical side chains are still needed. The aza-Michael-type addition of amines to phosphonodehydroalanine derivatives provides a simple and effective approach for synthesizing N′-substituted α,β-diaminoethylphosphonates and thus affords general access to aminophosphonates bearing structurally diverse side chains. Thermodynamic analysis of the chosen aminophosphonates at physiological pH proves that they serve as potent chelators for copper(II) ions and moderate chelators for nickel(II) ions.

Background: Dehydropeptides are analogs of peptides containing at least one conjugate double bond between α,β-carbon atoms. Its presence provides unique structural properties and reaction centre for chemical modification. In this study, the series of new class of dipeptides containing S-substituted dehydrocysteine with variety of heterocyclic moieties was prepared. The compounds were designed as the building blocks for the construction of artificial metalloenzymes (artzymes). Therefore, the complexing properties of representative compounds were also evaluated. Furthermore, the acknowledged biological activity of natural dehydropeptides was the reason to extend the study for antiproliferative action of against several cancer cell lines. Methods: The synthetic strategy involves glycyl and phenylalanyl-(Z)-β-bromodehydroalanine as a substrate in one pot addition/elimination reaction of thiols. After deprotection of N-terminal amino group the compounds with triazole ring were tested as complexones for copper(II) ions using potentiometric titration and spectroscopic techniques (UV-Vis, CD, EPR). Finally, the antiproliferative activity was evaluated by sulforhodamine B assay. Results and Conclusions: A simple and efficient procedure for preparation of dipeptides containing S-substituded dehydrocysteine was provided. The peptides containing triazole appeared to be strong complexones of copper(II) ions. Some of the peptides exhibited promising antiproliferative activities against number of cancer cell lines, including cell lines resistant to widely used anticancer agent.

The aim of the following paper was to gather current scientific information about the analytical protocols dedicated to measuring the content level of short-chain chlorinated paraffins (SCCPs) in various types of environmental samples. Moreover, the data about the basic validation parameters of applied procedures for SCCPs determination are listed. The main issue which is highlighted in the paper is the possibility of the application of green analytical chemistry (GAC) principals in the SCCPs measuring process to reduce the environmental impact of the applied methodology. Analytical methods dedicated to SCCPs determination contain a significant number of steps and require advanced analytical equipment during the quantitative and qualitative analysis. In addition, there is a substantial issue associated with the reliability of the obtained results, especially in the case of the quantification of individual SCCPs in the studied samples. Due to this fact, the paper attempts to discuss the various stages of the analytical procedure, in which appropriate changes in the formula or equipment solutions might be introduced to ensure a better quality of the analytical results, as well as to meet the requirements of the philosophy of green analytical chemistry. The most important case which concerns this subject is finding an optimal consensus between the economic and logistic aspects and the quality and “greenness” of the analytical procedure employed in SCCPs determination process.

The hydrogenation of N-substituted vinylphosphonates using rhodium complexes derived from P–OP ligands L1, ent-L1, or (R,R)-Me-DuPHOS as catalysts has been successfully accomplished, achieving very high levels of stereoselectivity (up to 99% ee or de). The described synthetic strategy allowed for the efficient preparation of α-aminophosphonic acid derivatives and phosphonopeptides, which are valuable building blocks for the preparation of biologically relevant molecules.

Although information about the ability of some filamentous fungi to biodegrade organophosphonates is available, the knowledge about accompanying changes in fungal metabolism is very limited. The aim of our study was to determine the utilization of the chosen, structurally diverse aminophosphonates by Aspergillus terreus (Thom), in the context of the behaviour of this fungus while growing in unfavourable conditions, namely the lack of easily available phosphates. We found that all the studied compounds were utilized by fungus as nutritive sources of phosphorus, however, their effect on the production of fungal biomass depended on their structure. We also observed an interesting change in the metabolism of A. terreus; namely the overproduction of 2,4-di-tert-butylphenol (2,4-DTBP), which is known to possess fungistatic activity. In the case of our study, the biosynthesis of this compound was induced by phosphorus starvation, caused either by the lack of that element in the medium, or the poor degradation of phosphonate.

The procedures for the synthesis of esters of dehydropeptides containing C-terminal (Z)-dehydrophenylalanine and dehydroalanine have been elaborated. These esters appeared to be moderate or weak inhibitors of cathepsin C, with some of them exhibiting slow-binding behavior. As shown by molecular modeling, they are rather bound at the surface of the enzyme and are not submersed in its binding cavities. Electronic supplementary material The online version of this article (doi:10.1007/s00044-015-1366-0) contains supplementary material, which is available to authorized users.

In the crystal structure of the de­hydro­dipeptide (Boc-Phe-ΔAla-OiPr), the mol­ecule has a trans configuration of the N-methyl­amide group. Its geometry is different from saturated peptides but is in excellent agreement with other de­hydro­alanine compounds. In the crystal, an N—H⋯O hydrogen bond links the mol­ecules in a herringbone packing arrangement., In the title compound, the de­hydro­dipeptide (Boc–Phe–ΔAla–OiPr, C20H28N2O5), the mol­ecule has a trans conformation of the N-methyl­amide group. The geometry of the de­hydro­alanine moiety is to some extent different from those usually found in simple peptides, indicating conjugation between the H2C=C group and the peptide bond. The bond angles around de­hydro­alanine have unusually high values due to the steric hindrance, the same inter­action influencing the slight distortion from planarity of the de­hydro­alanine. The mol­ecule is stabilized by intra­molecular inter­actions between the isopropyl group and the N atoms of the peptide main chain. In the crystal, an N—H⋯O hydrogen bond links the mol­ecules into ribbons, giving a herringbone head-to-head packing arrangement extending along the [100] direction. In the stacks, the mol­ecules are linked by weak C—H⋯O hydrogen-bonding associations.

Addition of thiols to double bond of glycyl-dehydroalanine and phenyl-dehydroalanine esters provided micromolar inhibitors of cathepsin C. The structure-activity studies indicated that dipeptides containing N-terminal phenylalanine exhibit higher affinity towards the enzyme. A series of C-terminal S-substituted cysteines are responsible for varying interaction with S1 binding pocket of cathepsin C. Depending on diastereomer these compounds most likely act as slowly reacting substrates or competitive inhibitors. This was proved by TLC analysis of the medium in which interaction of methyl (S)-phenylalanyl-(R,S)-(S-adamantyl)cysteinate (7i) with the enzyme was studied. Molecular modeling enabled to establish their mode of binding showed that S2 pocket is long and narrow and accommodates phenyl group of phenylalanine while significantly spacious sites located at the surface of the enzyme (one of them being S1 pocket) bind the adamantly moiety oriented in different direction for each stereoisomer. Finally replacement of carboxymethyl moitey of methyl (S)-phenylalanyl-(R,S)-(S-phenyl)cysteinate (7c) with nitrile group provided about 650-times more potent inhibitor of cathepsin C indicating that the studied C-terminal S-substituted cysteines are good activity probes for S1 binding pocket of this enzyme.

Electrophilic addition of amines, thiols and bromide to the double bonds of model dehydrodipeptides and dehydrophosphonodipeptide was studied. The double bond in these two classes of peptides reacted similarly and gave the same products. These results indicate that dehydropeptides are very good candidates as substrates for modifications of peptide side-chains.

In a de­hydro­amino acid with a C=C bond between the α- and β-C atoms, the amino acid residues are linked trans to each other and there are no strong intra­molecular hydrogen bonds. The torsion angles indicate a non-helical conformation of the mol­ecule., The title compound, C11H17BrN2O5, is a de­hydro­amino acid with a C=C bond between the α- and β-C atoms. The amino acid residues are linked trans to each other and there are no strong intra­molecular hydrogen bonds. The torsion angles indicate a non-helical conformation of the mol­ecule. The dipeptide folding is influenced by an inter­molecular N—H⋯O hydrogen bond and also minimizes steric repulsion. In the crystal, mol­ecules are linked by strong N—H⋯O hydrogen bonds, generating (001) sheets. The sheets are linked by weak C—H⋯O and C—H⋯Br bonds and short Br⋯Br [3.4149 (3) Å] inter­actions.