Partial purification, and some properties and reactivities of cetraxate benzyl ester hydrochloride-hydrolyzing enzyme

Debenzylating enzyme from Aspergillus niger enzyme (commercial crude cellulase) catalyzes the hydrolysis of cetraxate benzyl ester hydrochloride (2), a precursor of the antiulcer agent (1). The enzyme was highly purified by three kinds of chromatographies (hydrophobic, ion exchange, gel filtration) with a recovery of 36%. The content of the debenzylating enzyme was about 0.1% in the crude cellulase, but the enzyme showed no cellulase activity. The purified enzyme was inactivated by Hg2+, and diisopropyl phosphorofluoridate (DFP). It was a monomer with a molecular weight of about 35,000, and its isoelectric point was estimated to be 5.3. It showed a debenzylating activity for the phenylpropionic acid benzyl ester moiety of various benzyl ester derivatives, and the benzyl ester of phenylalanine or that of tyrosine was also well hydrolyzed.     

Behavioural response of Triatoma infestans (Klug) (Hemiptera: Reduviidae) to quinazolines

The behavioural responses of the haematophagous bug Triatoma infestans towards some previously identified components of its faeces: 4-methylquinazoline, 2,4- dimethylquinazoline and their mixtures were evaluated using a video tracking system. Fifth instar nymphs and females but not males were significantly attracted to polyethylene glycol formulations of 4-methyl + 2,4-dimethylquinazoline (50 microg each). Fifth instar nymphs were also attracted to 4-methylquinazoline alone (50 microg) but females were only attracted by the mixture of both methyl quinazolines (50 microg each). Syntheses of both methyl quinazolines were carried out starting from 2-aminoacetophenone by modifying the conditions of reported procedures.     

Partial purification and properties of putrescine oxidase from Candida guilliermondii

Putrescine oxidase ([PO]; E.C. 1.4.3.4), which catalyzes the oxidative deamination of putrescine into γ-aminobutyraldehyde, has been partially purified from Candida guilliermondii. Among the substrates tested, putrescine has the highest reaction rate, followed by spermidine and cadaverine. The K _IN values for putrescine, spermidine, and cadaverine were 20, 200, and 1.1 mM, respectively. The optimum pH and the temperature for PO were 8.0 and 37°C, respectively. Growth of Candida species on putrescine as the solenitrogen source induced the synthesis of PO that converts putrescine into Δ¹-pyrroline and γ-aminobutyric acid. These two products were detected and identified from the culture medium. The enzyme was not activated by divalent cations. Among the species of Candida tested, the highest enzyme activity was found in cell-free extracts of C. guilliermondii. The pathway of putrescine degradation was identified by substrate analysis to be along the nonacetylated pathway in C. guilliermondii.     

Identification of lectin activity in the hemolymph ofCastnia licus Drury,a sugar-cane giant borer (Lepidoptera-Castniidae)

Castnia licus Drury, in the larvae stage, is a major pest in the sugarcane industry of Northeastern Brazil (giant borer). A natural hemagglutination activity was detected in the larvae hemolymph of this insect and the activity have not been inhibited by tested carbohydrates. Fractionation with ammonium sulfate showed that the supernatant of the 15–30% fraction (S15-30%) had the lectin’s highest specific activity. Acidic and basic lectin activities were separated by chromatography on CM-cellulose; the fractionated molecular forms showed distinct electrophoresis mobilities.     

Isolation,purification, and some physicochemical properties of glucose isomerase from Streptomyces atratus

A highly purified glucose isomerase with a specific activity 23.5 times greater than that of a homogenate of the mycelium has been obtained fromStreptomyces atratus by methods of homogenization from the freeze-dried biomass, heat treatment (70°C, 10 min), ion-exchange chromatography, and gel filtration. The yield of enzyme on the initial biomass was 51.8%. The molecular mass of the enzyme has been determined by various methods as 160 kDa but in the presence of sodium dodecyl sulfate in thin-layer PAG it amounts to 40 kDa.Institute of Microbiology, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 524–528, July–August, 1990.     

Purification, biochemical characterization, and bioactive properties of a lectin purified from the seeds of white tepary bean (phaseolus acutifolius variety latifolius)

The present work shows the characterization of Phaseolus acutifolius variety latifolius, on which little research has been published, and provides detailed information on the corresponding lectin. This protein was purified from a semi-domesticated line of white tepary beans from Sonora, Mexico, by precipitation of the aqueous extract with ammonium sulfate, followed by affinity chromatography on an immobilized fetuin matrix. MALDI TOF analysis of Phaseolus acutifolius agglutinin (PAA) showed that this lectin is composed of monomers with molecular weights ranging between 28 and 31 kDa. At high salt concentrations, PAA forms a dimer of 63 kDa, but at low salt concentrations, the subunits form a tetramer. Analysis of PAA on 2D-PAGE showed that there are mainly three types of subunits with isoelectric points of 4.2, 4.4, and 4.5. The partial sequence obtained by LC/MS/MS of tryptic fragments from the PAA subunits showed 90-100% identity with subunits from genus Phaseolus lectins in previous reports. The tepary bean lectin showed lower hemagglutination activity than Phaseolus vulgaris hemagglutinin (PHA-E) toward trypsinized human A and O type erythrocytes. The hemagglutination activity was inhibited by N-glycans from glycoproteins. Affinity chromatography with the immobilized PAA showed a high affinity to glycopeptides from thyroglobulin, which also has N-glycans with a high content of N-acetylglucosamine. PAA showed less mitogenic activity toward human lymphocytes than PHA-L and Con A. The cytotoxicity of PAA was determined by employing three clones of the 3T3 cell line, demonstrating variability among the clones as follows: T4 (DI?? 51.5 μg/mL); J20 (DI?? 275 μg/mL), and N5 (DI?? 72.5 μg/mL).     

Formation, isolation, spectroscopic properties, and calculated properties of some isomers of C(60)H(36)

Isomers of C(60)H(36) and He@C(60)H(36) have been synthesized by the Birch or dihydroanthracene reduction of C(60) and isolated by preparative high-pressure liquid chromatography. (3)He, (13)C, and (1)H NMR spectroscopic properties were then determined. A comparison of experimental chemical shifts against those computed using density functional theory (B3LYP) with polarized triple- and double-zeta basis sets for He and C,H, respectively, allowed provisional assignment of structure for several isomers to be made. Theoretical calculations have also been carried out to identify low-energy structures. The transfer hydrogenation method using dihydroanthracene gives a major C(60)H(36) isomer and a minor C(60)H(36) isomer with C(3) symmetry as determined by the (13)C NMR spectrum of C(60)H(36) and the (3)He NMR spectrum of the corresponding sample of (3)He@C(60)H(36). In view of the HPLC retention times and the (3)He chemical shifts observed for the Birch and dihydroanthracene reduction products, the two isomers generated by the latter procedure can be only minor isomers of the Birch reduction. A significant energy barrier apparently exists in the dihydroanthracene reduction of C(60) for the conversion of the C(3) and C(1) symmetry isomers of C(60)H(36) to the T symmetry isomer previously predicted by many calculations to be among the most stable C(60)H(36) isomers. Many of the (1)H NMR signals exhibited by C(60)H(36) (and C(60)H(18), previously reported) are unusually deshielded compared to "ordinary" organic compounds, presumably because the unusual structures of C(60)H(36) and C(60)H(18) result in chemical shift tensors with one or more unusual principal values. Calculations clearly show a relationship between exceptionally deshielded protons beta to a benzene ring in C(60)H(18) and C(60)H(36) and relatively long C-C bonds associated with these protons. The additional information obtained from 1D and 2D (1)H NMR spectra obtained at ultrahigh field strengths (up to 900 MHz) will serve as a critical test of chemical shifts to be obtained from future calculations on different C(60)H(36) isomers.     

Zuccagnia punctata Cav. Essential Oil into Poly(ε-caprolactone) Matrices as a Sustainable and Environmentally Friendly Strategy Biorepellent against Triatoma infestans (Klug) (Hemiptera,Reduviidae)

The main strategies against Triatoma infestans (primary vector responsible for the Chagas disease transmission) are the elimination or reduction of its abundance in homes through the application of insecticides or repellents with residual power, and environmental management through the improvement of housing. The use of plant-derived compounds as a source of therapeutic agents (i.e., essential oils from aromatic plants and their components) is a valuable alternative to conventional insecticides and repellents. Essential oil-based insect repellents are environmentally friendly and provide reliable personal protection against the bites of mosquitoes and other blood-sucking insects. This study investigates, for the first time to our knowledge, the potential repellent activity of Zuccagnia punctata essential oil (ZEO) and poly(ε-caprolactone) matrices loaded with ZEO (ZEOP) prepared by solvent casting. The analysis of its essential oil from aerial parts by GC–FID and GC-MS, MS allowed the identification of 25 constituents representing 99.5% of the composition. The main components of the oil were identified as (−)-5,6-dehydrocamphor (62.4%), alpha-pinene (9.1%), thuja-2, 4 (10)-diene (4.6%) and dihydroeugenol (4.5%). ZEOP matrices were homogeneous and opaque, with thickness of 800 ± 140 µm and encapsulation efficiency values above 98%. ZEO and ZEOP at the lowest dose (0.5% wt./wt., 96 h) showed a repellency of 33 and 73% respectively, while at the highest dose (1% wt./wt., 96 h) exhibited a repellent activity of 40 and 66 %, respectively. On the other hand, until 72 h, ZEO showed a strong repellent activity against T. infestans (88% repellency average; Class V) to both concentrations, compared with positive control N-N diethyl-3-methylbenzamide (DEET). The essential oils from the Andean flora have shown an excellent repellent activity, highlighting the repellent activity of Zuccagnia punctata. The effectiveness of ZEO was extended by its incorporation in polymeric systems and could have a potential home or peridomiciliary use, which might help prevent, or at least reduce, Chagas’ disease transmission.     

Isolation, purification, and study of some properties of the lysl-, phenylalanyl-, and aspartyl-tRNA synthetases from the fungus Verticillium dahliae

Conclusions Relatively highly purified preparations of lysyl-, phenylalanyl- and aspartyl-tRNA synthetases have been isolated from the 12-day mycelium of a strongly virulent form of the fungusV. dahliae and some of their physicochemical properties have been studied.Institute of Biochemistry, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 229–233, March–April, 1974.     

Partial purification of neutron-activation 99Mo from cross-contaminant radionuclides onto potassium nickel hexacyanoferrate(II) column

Potassium nickel hexacyanoferrate(II) matrix was prepared and characterized. Purification of neutron-activation ⁹⁹Mo–molybdate(VI) solutes from some residual cross-contaminant radionuclides including ¹³⁴Cs, ⁸⁶Rb, ¹²⁴Sb, ⁶⁰Co and ⁵¹Cr was carried out onto small chromatographic columns of the matrix (each of 1.0 g). Gamma-ray spectrometric analysis data showed that the purification process was not affected by either Mo(VI) concentrations (0.13 and 0.02 M Mo) in the feeding solution of 3.5 M NaNO₃ at pH 9.5 or flow rates (0.2 and 5.0 mL/min) at room temperature. Molybdenum(VI) average loss onto the column matrix did not exceed 7.7 × 10^?2 mmol Mo. Except for ⁵¹Cr, the matrix has very high selectivity for ¹³⁴Cs, ⁸⁶Rb and ¹²⁴Sb with ~50% ⁶⁰Co elimination. The obtained data were briefly discussed.     

Analysis, purification and properties of a 50,000-dalton membrane-associated phosphoprotein from human platelets

Recently, the development of a monospecific antiserum against a 46,000/50,000-dalton membrane protein from human platelets which was stoichiometrically and reversibly phosphorylated in intact human platelets in response to vasodilators was reported. Using this antiserum, the subcellular distribution and the purification of this vasodilator-stimulated phosphoprotein (VASP) from human platelets has now been analysed. The VASP of human platelets is primarily a membrane-associated protein and can be purified to apparent homogeneity by salt extraction and sequential ion-exchange and dye-ligand chromatography with a purification factor of 1200 and a yield of 13%. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis under reducing and non-reducing conditions indicated that purified monomers of this VASP are linked by interchain disulphide bonding.     

Synthesis, characterization and some properties of amide-linked porphyrin-ruthenium(II) tris(bipyridine) complexes

A new molecular dyad, comprised of a zinc-porphyrin and a ruthenium(II) tris(bipyridine) complex linked through an amide bond has been synthesized and characterized by ¹H, ¹³C NMR, UV-vis, mass-spectrometry and elemental analysis. The electrochemistry as well as the steady-state emission properties were investigated. The redox behavior of the dyad exhibits a favorable reversible characteristic. Substantial quenching of porphyrin emission was found when the Q band of 5 and 5-Zn was selectively photoexcited. This observation suggests a quenching mechanism with possible intramolecular electron transfer or energy transfer between the Ru(bpy)₃ moiety and the porphyrin free-base or Zn porphyrin moieties.     

Synthesis,structural, photophysical and thermal properties of some praseodymium(III) complexes

Some carboxylato-bridged praseodymium(III) complexes (1–5) having tp [hydrotris(pyrazol-1-yl)borate] and sodium p-X-benzoate (where X =?H, F, Cl, NO₂) have been synthesized and characterized by different techniques including X-ray crystallography. The X-ray studies demonstrated that 1, 3 and 5 crystallized in triclinic space group P 1 with cell dimensions a =?11.761(13) Å, b =?12.536(13) Å, c =?17.726(19) Å for 1, a =?9.309(8) Å, b =?12.667(11) Å, c =?14.421(12) Å for 3, a =?11.5688(9) Å, b =?12.0055(9) Å, c =?12.3005(10) Å for 5. In 1–4 the coordination number of praseodymium is seven, whereas in 5 it is eight. IR suggested that the benzoate groups in 1–5 are bidentate bridging. The photophysical properties of these complexes have been studied in solution at room temperature. Thermogravimetric analysis showed that these complexes undergo complete decomposition with formation of praseodymium oxide.     

Synthesis, spectral and thermal properties of some transition metal(II) complexes with a novel ligand derived from thiobarbituric acid

Four novel metal(II) complexes, Ni(L)₂, Co(L)₂, Cu(L)₂, and Zn(L)₂ (L = 5-(2-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)hydrazono)-1,3-diethyl-2-thioxo-dihydropyrimidine-4,6(1H,5H)-dione), were synthesized using the procedure of diazotization, coupling and metallization. Their structures were identified by elemental analyses, ¹H NMR, ESI-MS and FT-IR spectra. The effect of different central metal(II) ions on absorption bands of the metal(II) complexes was researched. The thermal properties of the metal(II) complexes were investigated by thermogravimetry (TG) and differential scanning calorimetry (DSC). Furthermore, the thermodynamic parameters, such as activation energy (E*), enthalpy (?H*), entropy (?S*) and free energy of the decomposition (?G*) are calculated from the TG curves applying Coats–Redfern method. The results show that the metal(II) complexes have suitable electronic absorption spectra with blue-violet light absorption at about 350–450 nm, high thermal stability with sharp thermal decomposition thresholds.