The fresh bulbs of Stenomesson miniatum, a plant belonging to Amaryllidaceae family with a poorly investigated phytochemical profile, were traditionally employed by Andean healers to treat tumors and abscesses. The aims of this study were to characterize the alkaloid extract from the bulbs of S. miniatum and test its cytotoxic and antibacterial potential. The alkaloid extract was characterized by dereplication using various techniques (CPC, NMR, UPLC-HRMS) and referring to in-home or online databases for spectroscopic data matching. Cytotoxic activities were evaluated on A431 human epidermoid carcinoma cells through a metabolic assay, and on Jurkat human acute T-leukemia cells through a cell-impermeant fluorescent nuclear probe. Antibacterial assays were carried out against Staphylococcus aureus, Staphylococcus epidermidis and Streptococcus pyogenes by using a standardized microdilution broth method 96-well plate. Eleven known Amaryllidaceae alkaloids were identified together with another compound determined as being an extraction artefact. The alkaloid extract showed good cytotoxic activity against both the tumor cell lines, reaching an IC50 of 3.3 µg/mL against A431 cells and of 10.9 µg/mL against Jurkat cells. The analysis of the fractions allowed the activity to be attributed to the presence of pretazettine and haemathamine. Conversely, no antibacterial activities were recorded for any of the samples.

RNA polymerase III (RNAP III) holoenzyme activity and its products processing have been linked to several metabolic dysfunction in lower and in higher eukaryotes. Alterations in the activity of RNAP III driven synthesis of non-coding RNA, causes extensive changes in the glucose metabo-lism. Increased RNAP III activity in S.cerevisiae maf1Δ strain, manifests with lethality when grown on non-fermentable carbon source. This lethal phenotype is suppressed by reducing tRNA syn-thesis. The cause for the lack of growth neither the underlying molecular mechanism has not been deciphered and has been awaiting a scientific explanation for a decade. Our previous proteomics data suggested mitochondrial dysfunction of the strain. Using model mutant strains maf1Δ (with increased tRNA abundance) and rpc128-1007 (with reduced tRNA abundance) we collected data showing major changes in TCA cycle metabolism of the mutants that explain the phenotypic ob-servations. The present study, based on 13C flux data and analysis of TCA enzymes activities, identifies the flux constraints in the mitochondrial metabolic network. The lack of growth is associated with the de-crease in TCA cycle activity and downregulation of the flux towards glutamate, aspartate and phosphoenolopyruvate (PEP), the metabolic intermediate feeding gluconeogenic pathway. rpc128-1007, the strain that is unable to increase tRNA synthesis due to a mutation in C128 subunit, has increased activity of TCA cycle under non-fermentable conditions. To summarize, cells with non-optimal activity of RNAP III, undergo substantial adaptation to a new metabolic state, that make them vulnerable under specific growth conditions. Our results strongly suggest that balanced, non-coding RNA synthesis that is coupled to glucose signaling is a fundamental requirement to sustain cell’s intracellular homeostasis and flexibility under changing growth conditions. Presented results provide insight into the possible role of RNAP III in mito-chondrial metabolism of other cell types.

This article has been studied the synthesis of a new derivative of the known alkaloid cytisine contained in the seeds of plants of Cytisus laburnum L. and Thermopsis lanceolata R.Br., both of the Lugiminosae family. The new compound has been obtained from two biologically active compounds such as isoxazole and cytisine. It has been demonstrated that the reaction led to the single-stage method under very mild conditions to obtain some 4-[(3,5-dimethyl-1,2-oxazole-4-yl)sulfonyl]amides. This class of compounds is promising to obtain the new biologically active compounds. This article has examined in detail a structure with using the 1H and 13C NMR and two-dimensional NMR spectroscopy of COSY (1H-1H), HMQC (1H-13C) and NMVS (1H-13C). As a result, the homo- and heteronuclear spin-spin couplings should be established. The X-ray diffraction analysis has determined the spatial structure of a new derivative based on cytisine alkaloid. Thus, its hemorheological activity has been studied.

Novel cultivation technologies demand the adaptation of existing analytical concepts. Metabolic flux analysis (MFA) requires stable-isotope labeling of biomass-bound protein as the primary information source. Obtaining the required protein in cultivation set-ups where biomass is scarce or inaccessible due to low cell densities and cell immobilization is difficult to date. We developed a non-disruptive analytical concept for 13C-based metabolic flux analysis based on secreted protein as an information carrier for isotope mapping in the protein-bound amino acids. This "metabolic flux probe" (MFP) concept was investigated in different cultivation set-ups with a recombinant, protein-secreting yeast strain. The obtained results grant insight into intracellular protein turnover dynamics. Experiments under metabolic but isotopically nonstationary conditions in continuous glucose-limited chemostats at high dilution rates demonstrated faster incorporation of isotope information from labeled glucose into the recombinant reporter protein than in biomass-bound protein. Our results suggest that the reporter protein was polymerized from intracellular amino acid pools with higher turnover rates than biomass-bound protein. The latter aspect might be vital for 13C-flux analyses under isotopically nonstationary conditions for analyzing fast metabolic dynamics.