Aggregation induced nucleic acids recognition by homodimeric asymmetric monomethyne cyanine fluorochromes in mesenchymal stem cells.

In the light of recent retrovirus pandemics, the issue of discovering new and diverse RNA-specific fluorochromes for research and diagnostics became of acute importance. The great majority of nucleic acid-specific probes either do not stain RNA or cannot distinguish between DNA and RNA. The versatility of polymethine dyes makes them suitable as stains for visualization, analysis, and detection of nucleic acids, proteins, and other biomolecules.

Micellar Form of a Ferrocene-Containing Camphor Sulfonamide with Improved Aqueous Solubility and Tumor Curing Potential.

The discovery of new anticancer drugs with а higher, more specific activity and diminished side effects than the conventional chemotherapeutic agents is a tremendous challenge to contemporary medical research and development. To achieve a pronounced efficacy, the design of antitumor agents can combine various biologically active subunits in one molecule, which can affect different regulatory pathways in cancer cells. We recently demonstrated that a newly synthesized organometallic compound, a ferrocene-containing camphor sulfonamide (DK164), possesses promising antiproliferative activity against breast and lung cancer cells.

Selective Cytotoxicity and Changes in Protein Expression of T24 Bladder Carcinoma Permanent Cell Line after Treatment with Hemocyanins.

Background: Some molluscan hemocyanins (Hcs) have significant immunological and antitumor potential, enabling their application in oncology. The antitumor activity of Hcs from marine snails Rapana venosa (RvH), giant keyhole limpet Megathura crenulata (KLH) and garden snails Helix lucorum (HlH), as well as their different derivatives, were studied in vitro on a permanent T24 cell line of bladder cancer and normal urothelial cell line HL 10/29 compared to doxorubicin.

Methods: The antiproliferative activity of the tested Hcs was determined using the WST-1 assay and BrdU ELISA assay.

In Vitro Anticancer Activity of Two Ferrocene-Containing Camphor Sulfonamides as Promising Agents against Lung Cancer Cells.

The successful design of antitumour drugs often combines in one molecule different biologically active subunits that can affect various regulatory pathways in the cell and thus achieve higher efficacy. Two ferrocene derivatives, DK-164 and CC-78, with different residues were tested for cytotoxic potential on non-small lung cancer cell lines, A549 and H1299, and non-cancerous MRC5. DK-164 demonstrated remarkable selectivity toward cancer cells and more pronounced cytotoxicity against A549.

Essential Oil Composition of Five Thymus Species from Bulgaria.

In this study, the essential oil composition of five Thymus species, belonging to Sect. Hyphodromi (A. Kerner) Halácsy - Thymus atticus Čelak.

Biotechnologically-Produced Myconoside and Calceolarioside E Induce Nrf2 Expression in Neutrophils.

The pathological manifestation of various diseases can be suppressed by the activation of nuclear factor erythroid 2 p45-related factor 2 (Nrf2), a transcriptional regulator of the cellular redox balance. Friv. is a resurrection plant species endemic for Bulgaria, containing biologically active phenylethanoid glycosides that might possess antioxidant or redox activity.

Thiol-ene coupling reaction achievement and monitoring by "" UV irradiation NMR spectroscopy.

In this study, the possibilities of a new "" LED UV illumination NMR spectroscopic technique for performing an initiator-free thiol-ene "click" coupling reaction of an allyl-functionalized poly(allyl glycidyl ether) (PAGE) prepolymer with a number of mono- and di-oligo polyethylene glycol (PEG) thiols is demonstrated. The state-of-the-art setup constructed with LEDs as UV light sources that illuminate through optical fibers directly into an NMR testing tube at a fixed wavelength of 365 nm is appropriate for various polymeric materials and biologically active substances. The selected experimental protocol uses a series of periods of irradiation and dark periods, thus providing opportunities to conduct an effective thiol-ene "click" reaction and simultaneously study the kinetics of the photochemical reaction with the exposure time, as well as macromolecular association directly in a solution applying the whole types of NMR methods: from conventional H or C NMR to diffusion NMR spectroscopy (DOSY).

Prooxidant and antimicrobic effects of iron and titanium oxide nanoparticles and thalicarpine.

The aim is to evaluate the prooxidant and antimicrobial effects of FeO and TiO nanoparticles and thalicarpine by luminescent and standard microbiological assays. Their effect on the kinetics of free-radical oxidation reactions (at pH 7.4 and pH 8.

Caffeoylquinic Acids, Cytotoxic, Antioxidant, Acetylcholinesterase and Tyrosinase Enzyme Inhibitory Activities of Six Inula Species from Bulgaria.

Chlorogenic (5-CQA), 1,5-, 3,5-, 4,5- and 3,4-dicaffeoylquinic (DCQA) acids were identified and quantified in the methanol extracts of Inula oculus-christi L., I. bifrons L.

New benzimidazole-aldehyde hybrids as neuroprotectors with hypochlorite and superoxide radical-scavenging activity.

Background: Many neurodegenerative disorders include oxidative stress-mediated pathology. Melatonin and its metabolites act as endogenous reactive oxygen species (ROS) scavengers and antioxidants. N,N'-Disubstituted benzimidazole-2-thiones with extended side chains could exert antioxidant and neuroprotective properties due to structural similarities to melatonin.

Tautomerism of Inosine in Water: Is It Possible?

Syn- and anti-conformers of four tautomer structures of inosine were studied in the gas phase and in solvent water to investigate the possibility of hydrogen bonding and tautomeric conversion. It was found that in the gas phase and in water solution the most stable is the syn-conformer of the 6-keto tautomer followed by its anti-conformer and syn-conformer of the 6-enol form. In the gas phase, the percent content of syn- and anti-conformers is 83.

Photodynamic opening of blood-brain barrier.

Photodynamic treatment (PDT) causes a significant increase in the permeability of the blood-brain barrier (BBB) in healthy mice. Using different doses of laser radiation (635 nm, 10-40 J/cm) and photosensitizer (5-aminolevulinic acid - 5-ALA, 20 and 80 mg/kg, i.v.

Pd(II) complexes of acetylcholinesterase reactivator obidoxime.

The ability of the acetylcholinesterase reactivator obidoxime (H2L(2+)) to bind palladium(II) cations was evaluated spectrophotometrically at different reaction conditions (pH, reaction time, metal-to-ligand molar ratio). The results showed that immediately after mixing the reagents, pH 7.4, complex species of composition [PdHL](3+) existed predominantly with a value of conditional stability constant lgβ'=6.

Water Structure Recovery in Chaotropic Anion Recognition: High-Affinity Binding of Dodecaborate Clusters to γ-Cyclodextrin.

Dodecaborate anions of the type B12X12(2-) and B12X11Y(2-) (X=H, Cl, Br, I and Y=OH, SH, NH3(+), NR3(+)) form strong (K(a) up to 10(6) L mol(-1), for B12Br12(2-)) inclusion complexes with γ-cyclodextrin (γ-CD). The micromolar affinities reached are the highest known for this native CD. The complexation exhibits highly negative enthalpies (up to -25 kcal mol(-1)) and entropies (TΔS up to -18.

Analytical studies of the Alexandrovo Thracian tomb wall paintings.

A profound study of samples obtained from Thracian tomb wall paintings at Alexandrovo, Bulgaria (dating back to the fourth century BC) were carried out by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and Attenuated Total Reflectance Fourier transform infrared spectroscopy (ATR FTIR), high-resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray spectroscopy (EDS). The current work provides a glimpse of the ingenious construction and painting techniques used in Thracian tomb at Alexandrovo. The results suggest that beeswax was used as a paint binder and also revealed presence of various nano-materials.

Inhibition of the DHT-induced PSA secretion by Verbascum xanthophoeniceum and Serenoa repens extracts in human LNCaP prostate epithelial cells.

Ethnopharmacological Relevance: Verbascum xanthophoeniceum is a mullein plant, typical of Balkan region and some parts of Turkey, traditionally used as phytotherapeutic agent due to its anti-inflammatory properties. It is rich in phenylethanoid and iridoid metabolites whose anti-inflammatory properties are under characterization.

Materials And Methods: The role of Verbascum xanthophoeniceum crude methanolic extract and its isolated phenylethanoid glycoside verbascoside have been evaluated, in comparison to a saw palmetto extract, on a human in vitro model of androgen-regulated prostate epithelium, the LNCaP cell line.

Antimycobacterial activity of chiral aminoalcohols with camphane scaffold.

A series of aminoalcohols were synthesized by reaction of aminolysis of camphor derived oxiranes with chosen amines. The compounds were evaluated for their in vitro activity against Mycobacterium tuberculosis H37Rv. Ten of the new structures show much higher activity than the classical anti-TB drug ethambutol.

Phenoloxidase activity of intact and chemically modified functional unit RvH1: a from molluscan Rapana venosa hemocyanin.

o-Diphenol oxidase activities (o-diPO) of chemically modified functional unit RvH1-a of molluscan hemocyanin Rapana venosa were studied using L-Dopa and dopamine as substrates. With L-Dopa as substrate the native FU RvH1-a did not show any o-diPO activity. Therefore the native FU RvH1-a was converted to enzymatic active form, after treatment with SDS, trypsin, urea and different values of pH when its o-diPO activity was studied.

Resolution and quantification of isomeric fatty acids by silver ion HPLC: fatty acid composition of aniseed oil (Pimpinella anisum, Apiaceae).

A silver ion HPLC procedure is described that is suitable to determine the fatty acid composition of plant seed oils. After conversion of fatty acids to p-methoxyphenacyl derivatives, it was possible to achieve baseline resolution of all fatty acid components with 0 to 3 double bonds, including the positionally isomeric 18:1 fatty acids oleic acid (cis 9-18:1), petroselinic acid (cis 6-18:1), and cis-vaccenic acid (cis 11-18:1), in aniseed oil (Pimpinella anisum, Apiaceae) by a single gradient run on a single cation exchange column laboratory converted to the silver ion form. The UV detector response (280 nm) was linearly related to the fatty acid concentration in the range 0.

Quantitative analysis of sesquiterpene lactones in extract of Arnica montana L. by 1H NMR spectroscopy.

(1)H NMR spectroscopy was used as a method for quantitative analysis of sesquiterpene lactones present in a crude lactone fraction isolated from Arnica montana. Eight main components - tigloyl-, methacryloyl-, isobutyryl- and 2-methylbutyryl-esters of helenalin (H) and 11α,13-dihydrohelenalin (DH) were identified in the studied sample. The method allows the determination of the total amount of sesquiterpene lactones and the quantity of both type helenalin and 11α,13-dihydrohelenalin esters separately.

Composition and properties of biologically active pectic polysaccharides from leek (Allium porrum).

Background: Leek (Allium porrum) is very commonly used vegetable in Bulgaria and is distinctive with high content of bioactive components. Previously we obtained five crude pectic polysaccharides from leek through consecutive extraction. Some of them appeared to be good stimulators of the immune system.

Purification and characterization of tyrosinases from Streptomyces albus.

The bacterium Streptomyces albus has so far never been investigated for tyrosinase activity. The studies presented in this communication show that this bacterium may be a future source for larger production of tyrosinase. The enzyme was purified starting with 5,600 ml of culture filtrate.

Screening of some saponins and phenolic components of Tribulus terrestris and Smilax excelsa as MDR modulators.

Background: Cytotoxic activity of saponins and phenolic compounds have been described in the literature, but no reports were found on their multidrug resistance (MDR)-modulating effects on human mdr1 gene-transfected mouse lymphoma cell line.

Materials And Methods: Methylprototribestin, structurally related compounds and a mixture of 3 acetylated isomers of methylprotodioscin were investigated for antiproliferative effect and modulation of drug accumulation.

Results: The growth inhibitory dose (ID50) of the compounds ranged from 12.

Do N-terminal nucleophile hydrolases indeed have a single amino acid catalytic center?

A new set of experimental kinetic data on the hydrolysis of a series of phenylacetyl p-substituted anilides catalyzed by penicillin G acylase from Escherichia coli (PGA) is presented in this article. The Hammett plot of log(k(cat,R)/k(cat,H)) versus sigma(p) (-) has three linear segments, which distinguishes the enzyme from the other N-terminal nucleophile hydrolases for which data are available. Three amino acids in the vicinity of the catalytic SerB1 (AsnB241, AlaB69, and GlnB23) were included in the quantum mechanical model.

Immunological potential of Helix vulgaris and Rapana venosa hemocyanins.

A new hemocyanin was isolated from the hemolymph of garden snails Helix vulgaris, composed of two isoforms, HvH1 and HvH2 separated on an ion exchange column DEAE-Sepharose 6CL. Structural and immunological properties of Helix vulgaris hemocyanin were studied in comparison with molluscan Hcs Rapana venosa and Megathura crenulata. The possibility of using HvH and RvH as carriers of small molecules (haptens) in immunizing protocols was studied in comparison with KLH, which is a widely used, highly immunogenic carrier protein.