Biological Activity of Hydrophilic Extract of Chlorella vulgaris Grown on Post-Fermentation Leachate from a Biogas Plant Supplied with Stillage and Maize Silage

Algae are employed commonly in cosmetics, food and pharmaceuticals, as well as in feed production and biorefinery processes. In this study, post-fermentation leachate from a biogas plant which exploits stillage and maize silage was utilized as a culture medium forChlorella vulgaris. The content of polyphenols in hydrophilic extracts of the Chlorella vulgaris biomass was determined, and the extracts were evaluated for their antioxidant activity (DPPH assay), antibacterial activity (against Escherichia coli, Lactobacillus plantarum, Staphylococcus aureus, Staphylococcus epidermidis) and antifungal activity (against Aspergillus niger, Candida albicans, Saccharomyces cerevisiae). The use of the post-fermentation leachate was not found to affect the biological activity of the microalgae. The aqueous extract of Chlorella vulgaris biomass was also observed to exhibit activity against nematodes. The results of this study suggest that Chlorella vulgaris biomass cultured on post-fermentation leachate from a biogas plant can be successfully employed as a source of natural antioxidants, food supplements, feed, natural antibacterial and antifungal compounds, as well as in natural methods of plant protection

<i>N</i>-Lipidated Amino Acids and Peptides Immobilized on Cellulose Able to Split Amide Bonds

N-lipidated short peptides and amino acids immobilized on the cellulose were used as catalysts cleaved amide bonds under biomimetic conditions. In order to select catalytically most active derivatives a library of 156 N-lipidated amino acids, dipeptides and tripeptides immobilized on cellulose was obtained. The library was synthesized from serine, histidine and glutamic acid peptides N-acylated with heptanoic, octanoic, hexadecanoic and (E)-octadec-9-enoic acids. Catalytic efficiency was monitored by spectrophotometric determination of p-nitroaniline formed by the hydrolysis of a 0.1 M solution of Z-Leu-NP. The most active 8 structures contained tripeptide fragment with 1-3 serine residues. It has been found that incorporation of metal ions into catalytic pockets increase the activity of the synzymes. The structures of the 17 most active catalysts selected from the library of complexes obtained with Cu2+ ion varied from 16 derivatives complexed with Zn2+ ion. For all of them, a very high reaction rate during the preliminary phase of measurements was followed by a substantial slowdown after 1 h. The catalytic activity gradually diminished after subsequent re-use. HPLC analysis of amide bond splitting confirmed that substrate consumption proceeded in two stages. In the preliminary stage 24&#8315;40% of the substrate was rapidly hydrolysed followed by the substantially lower reaction rate. Nevertheless, using the most competent synzymes product of hydrolysis was formed with a yield of 60&#8315;83% after 48h under mild and strictly biomimetic conditions

1,3-OXAZOLIDIN-5-ONES DERIVED FROM PROLINE AS CHIRAL COMPONENTS IN THE SYNTHESIS OF PREDICTIVE ENANTIOSELECTIVE COUPLING REAGENTS

1,3-Oxazolidin-5-ones derived from both enantiomers of proline and trichloroacetaldehyde were prepared and applied as amine component in the synthesis of chiral predictive triazine based coupling reagents. The usefulness of these reagents in the condensations yielding enantiomerically enriched products from racemic substrates was presented

Orthogonal Functionalization of Nanodiamond Particles after Laser Modification and Treatment with Aromatic Amine Derivatives

A laser system with a wavelength of 1064 nm was used to generate sp2 carbon on the surfaces of nanodiamond particles (NDPs). The modified by microplasma NDPs were analysed using FT-IR and Raman spectroscopy. Raman spectra confirmed that graphitization had occurred on the surfaces of the NDPs. The extent of graphitization depended on the average power used in the laser treatment process. FT-IR analysis revealed that the presence of C=C bonds in all spectra of the laser-modified powder. The characteristic peaks for olefinic bonds were much more intense than in the case of untreated powder and grew in intensity as the average laser power increased. The olefinized nanodiamond powder was further functionalized using aromatic amines via in situ generated diazonium salts. It was also found that isokinetic mixtures of structurally diverse aromatic amines containing different functional groups (acid, amine) could be used to functionalize the surfaces of the laser-modified nanoparticles leading to an amphiphilic carbon nanomaterial. This enables one-step orthogonal functionalization and opens the possibility of selectively incorporating molecules with diverse biological activities on the surfaces of NDPs. Modified NDPs with amphiphilic properties resulting from the presence carboxyl and amine groups were used to incorporate simultaneously folic acid (FA-CONH-(CH2)5-COOH) and 5(6)-carboxyfluorescein (FL-CONH-(CH2)2-NH2) derivatives on the surface of material under biocompatible procedures

Conjugates of Chitosan and Calcium Alginate with Oligoproline and Oligohydroxyproline Derivatives for Potential Use in Regenerative Medicine

New materials that are as similar as possible in terms of structure and biology to the extracellular matrix (external environment) of cells are of great interest for regenerative medicine. Oligoproline and oligohydroxyproline derivatives (peptides 2&ndash;5) are potential mimetics of collagen fragments. Peptides 2&ndash;5 have been shown to be similar to the model collagen fragment (H-Gly-Hyp-Pro-Ala-Hyp-Pro-OH, 1) in terms of both their spatial structure and biological activity. In this study, peptides 2&ndash;5 were covalently bound to nonwovens based on chitosan and calcium alginate. Incorporation of the peptides was confirmed by Fourier transform -infrared (FT-IR) and zeta potential measurements. Biological studies (cell metabolic activity by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test and Live/Dead assay) proved that the obtained peptide-polysaccharide conjugates were not toxic to the endothelial cell line EA.hy 926. In many cases, the conjugates had a highly affirmative influence on cell proliferation. The results of this study show that conjugates of chitosan and calcium alginate with oligoproline and oligohydroxyproline derivatives have potential for use in regenerative medicine

Molecular Fingerprints of Thyroid Cancer Cells by Using Library of Molecular Receptors Formed by N-Lipidated Peptides Immobilized on Cellulose

A novel diagnostic method based on recognition of qualitative and quantitative composition of healthy and tumor tissue samples by library of molecular receptors was presented. Molecular receptors were formed by self-organization of N-lipidated peptides attached in the regular fashion via aminophenylamino-1,3,5-triazine linker to the surface of cellulose plate. For samples testing, the library was cloned into multiple, identical copies and for each experiment the new clone was used. The binding process was monitored by staining the discs with Brilliant Black and quantitative color measurement was performed in 256 grade gray scale. Substantial differences in the composition of healthy and tumor samples were observed in most cases. The highly individual chemical fingerprints were found to be reliant on the cancer type. For malignant papillary thyroid cancer statistical analysis identified two receptors most useful for diagnostic purposes

Bimetallic Pd-Au/SiO2 Catalysts for Reduction of Furfural in Water

Catalytic systems based on bimetallic Pd-Au particles deposited on SiO2 were prepared by ultrasonically assisted water impregnation and used in the hydrogenation of furfural obtained by the acidic hydrolysis of waste biomass (brewery&rsquo;s spent grain) in aqueous phase. Pd-Au/SiO2 catalysts containing 50 g of Pd and 2&ndash;100 g of Au per 1 kg of catalyst were characterized by high activity in the studied process and, depending on the Pd/Au ratio, selectivity to 2-methyloxolan-2-ol. The modification of 5%Pd/SiO2 by Au leads to the formation of dispersed Au-Pd solid solution phases, which was confirmed by XRD, XPS, ToF-SIMS, SEM-EDS, and H2-TPR techniques. The effect of dilution of surface palladium by gold atoms is probably crucial for modification of the reaction mechanism and formation of 2-methyloxolan-2-ol as the main product

Search for New Aggregable Fragments of Human Insulin

In this study, three independent methods were used to identify short fragment of both chains of human insulin which are prone for aggregation. In addition, circular dichroism (CD) research was conducted to understand the progress of aggregation over time. The insulin fragments (deca- and pepta-peptides) were obtained by solid-phase synthesis using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium toluene-4-sulfonate (DMT/NMM/TosO-) as a coupling reagent. Systematic studies allowed identification of the new fragments, expected to be engaged in triggering aggregation of the entire structure of human insulin under physiological conditions. It was found that the aggregation process occurs through various structural conformers and may favor the formation of a fibrous structure of aggregate

Butanol Synthesis Routes for Biofuel Production: Trends and Perspectives

Butanol has similar characteristics to gasoline, and could provide an alternative oxygenate to ethanol in blended fuels. Butanol can be produced either via the biotechnological route, using microorganisms such as clostridia, or by the chemical route, using petroleum. Recently, interest has grown in the possibility of catalytic coupling of bioethanol into butanol over various heterogenic systems. This reaction has great potential, and could be a step towards overcoming the disadvantages of bioethanol as a sustainable transportation fuel. This paper summarizes the latest research on butanol synthesis for the production of biofuels in different biotechnological and chemical ways; it also compares potentialities and limitations of these strategies