Effect of intravenous nitroglycerin therapy on erythrocyte antioxidant enzymes

Intravenous nitroglycerin (GTN) has been used as an anti-ischemic agent for the therapy of unstable and post-infarction angina. Nitric oxide (^?NO) and S-nitrosothiols constitute the biologically active species formed via nitroglycerin bioactivation. Increased levels of reactive oxygen species can diminish the therapeutic action of organic nitrates by scavenging donated ^?NO and oxidizing tissue thiols important in nitrate biotransformation. Studies reported here show that the red cell activity of antioxidant enzymes, catalase and glutathione peroxidase, are significantly decreased after intravenous nitroglycerin treatment. Catalase activity decreased to and after 1 and 24?hr GTN infusion, respectively. Similarly, glutathione peroxidase activity decreased to and after 1 and 24?hr GTN infusion, respectively. The reported decrease in antioxidant enzyme activities can lead to an oxidant milieu and contribute to the generation of nitrate tolerance.     

Lipolysis by Intracellular Lipase of Streptococcus lactis against Its Neutral Lipids Obtained by Growth at Low Temperature

Lipolytic activities of intracellular lipase obtained from Streptococcus lactis 527 cells grown at 30°C were determined using bacterial neutral lipids extracted from cells grown at 10 and 30°C. The amounts of free fatty acids liberated from lipids by lipase were in the order: 30°C neutral lipid > 10°C neutral lipid > triolein > intracellular membrane fraction. Glycerides hydrolyzed partially by lipase were detected on thin-layer plates and were composed of 1,3- and 1,2-diglycerides, fatty acids and unhydrolyzed triglycerides. Fatty acids liberated from neutral lipids by lipase were determined by gas chromatography. It was found that the major acid was cy-C₁₀ and the minor among the acids liberated from 10°C neutral lipid, whereas the major acid was and the minors and cy-C₁₀ from 30°C lipid.     

Determination of CGTase from Bacillus ohbensis and Its Optimum pH Using HPLC

Glucose is widely known to be required during superoxide generation in phagocytic cells. However, when an specific chemiluminescence probe with the Cypridina luciferin analog 2-methyl-6-(p-methoxyphenyl)-3, 7 -dihydroimidazo[ 1,2-a]pyrazin-3-one (MCLA) was used, about 60% of the chemiluminescence remained in stimulated macrophages in the presence of the glycolytic inhibitor 2-deoxyglucose. -nonspecific luminol-dependent chemiluminescence disappeared when the same drug was added. These results clearly demonstrate that the generation of by macrophages is not completely glucose-dependent, and strongly suggest that macrophages have both glucoseindependent NADPH-supplying pathway(s) and glucose dependent pathway(s) which generate reactive oxygen species other than .     

Kinetics of Carbon Dioxide Evolution in Agitation System

Kinetics of carbon dioxide evolution was investigated in agitation system. Reaction steps of carbon dioxide evolution in submerged fermentations may consist of three steps; the first, hydration of carbon dioxide liberated from living cells, the second, dehydration of bicarbonate ions and the third, formation of carbon dioxide bubbles. Taking into account the equilibrium between hydration of carbon dioxide and dehydration of bicarbonate ions at physiological pH value, the fallowings may be rate-limiting steps in mass transfer of carbon dioxide in submerged fermentations, dehydration of bicarbonate ions and the bubble formation. The overall velocity constant of these two reaction steps was determined in the agitation vessel This reaction obeyed good first-order kinetics and the term of was introduced as a velocity constant. This value was influenced by agitation speed, temperature, viscosity of the fluid and carbonic anhydrase. The value of carbon dioxide coefficient (Kd)_CO2 was higher than the oxygen absorption coefficient Kd. The driving force of mass transfer for carbon dioxide, DCO₂—pCO₂, therefore, was lower than that for oxygen, P_B—P_L. The relationship between the overall coefficient of oxygen transfer across gas-liquid interface K_La and the overall velocity constant of carbon dioxide evolution was expressed in the formula      

Trophic state and nutrient limitation in Lake Baringo,Kenya

The trophic state of Lake Baringo and factors that could be limiting the development of algal biomass in it were investigated during one wet/dry hydrological cycle in 2014–2015. Water samples were analysed for dissolved inorganic nutrients, including , and , total phosphorus and Chlorophyll a. Light attenuation was estimated using Secchi depth. The trophic state was determined using Carlson trophic state indices (CTSI). Deviations in CTSI, nutrient ratios and ambient nutrient concentrations were used to identify factors limiting phytoplankton growth. The mean values measured for Secchi depth, nitrate, total phosphorus and Chlorophyll a showed significant seasonal variation (p < 0.05). Based on the Carlson trophic state index, the results show that Lake Baringo is eutrophic. However, the lake is also experiencing phosphorus limitation and poor light penetration, because of high turbidity, which is more pronounced during the wet season.     

Changes in Amino Acid Composition during Germination of Soybean

Malonogalactan, a malonylated polysaccharide (—74° (c=1.6, H₂O)) produced by Penicillium citrinum, consisted of d-galactose and malonic acid in the approximate molar ratio of 3:1. Molecular weight of the demalonylated galactan (-99° (c=4.6, H₂O)) was about 40,000. From the data regarding optical rotation, nuclear magnetic resonance spectrum, infrared spectrum, glycosidase susceptibility, periodate oxidation, Smith degradation, methylation and acid hydrolysis, the possible structure of the Penicillium malonogalactan is deduced as follows: A galactan, 1,5-β-galactofuranoside polymer esterified with malonic acid at the position of 2 or 3.     

Red Algae (Eucheuma muricatum) Mucilage- Complex Formation and Mechanism

Eucheuma muricatum mucilage which was extracted and purified after irradiation of the seaweed with γ-ray of ⁶⁰Co formed a complex with , and exhibited a new absorption band at 555 nm. The absorbancy observed at that time depended on the concentration of urea and on the temperature. The curves representing relations between absorbancy at 555 nm and the above factors have two inflection points. The fact that their inflection points shift toward the lower temperature side with the increase in urea concentration suggests that the coloring phenomenon may relate closely to the transition of the mucilage. It was also found that the absorbancy at 555 nm depended on the content of pyruvic acid residue in the same mucilages, the absorbancy decreased with the increase pyruvic acid residues, and that the steric hindrance caused by a sugar residue of large demension affected the stable from containing viscous polysaccharide.     

Structure-activity relationships for a class of selective inhibitors of the major cysteine protease from Trypanosoma cruzi

Chagas' disease is a parasitic infection widely distributed throughout Latin America, with devastating consequences in terms of human morbidity and mortality. Cruzain, the major cysteine protease from Trypanosoma cruzi, is an attractive target for antitrypanosomal chemotherapy. In the present work, classical two-dimensional quantitative structure-activity relationships (2D QSAR) and hologram QSAR (HQSAR) studies were performed on a training set of 45 thiosemicarbazone and semicarbazone derivatives as inhibitors of T. cruzi cruzain. Significant statistical models (HQSAR, q² = 0.75 and r² = 0.96; classical QSAR, q² = 0.72 and r² = 0.83) were obtained, indicating their consistency for untested compounds. The models were then used to evaluate an external test set containing 10 compounds which were not included in the training set, and the predicted values were in good agreement with the experimental results (HQSAR, = 0.95; classical QSAR, = 0.91), indicating the existence of complementary between the two ligand-based drug design techniques.     

Particular interaction between pyrimethamine derivatives and quadruple mutant type dihydrofolate reductase of Plasmodium falciparum: CoMFA and quantum chemical calculations studies

Comparative molecular field analysis (CoMFA) was performed on twenty-three pyrimethamine (pyr) derivatives active against quadruple mutant type (Asn51Ile, Cys59Arg, Ser108Asn, Ile164Leu) dihydrofolate reductase of Plasmodium falcipaarum (PfDHFR). The represented CoMFA models were evaluated based on the various three different probe atoms, C_sp3 (+1), O_sp3 ( ? 1) and H (+1), resulting in the best model with combined three types of probe atoms. The statistical results were = 0.702, S_press = 0.608, = 0.980, s = 0.156, and = 0.698 which can explain steric contribution of about 50%. In addition, an understanding of particular interaction energy between inhibitor and surrounding residues in the binding pocket was performed by using MP2/6-31G(d,p) quantum chemical calculations. The obtained results clearly demonstrate that Asn108 is the cause of pyr resistance with the highest repulsive interaction energy. Therefore, CoMFA and particular interaction energy analyses can be useful for identifying the structural features of potent pyr derivatives active against quadruple mutant type PfDHFR.     

Antitumor Active Fucoidan from the Brown Seaweed,Umitoranoo (Sargassum thunbergii)

Neutral and acidic polysaccharides and their protein complexes were fractionated and purified from the brown seaweed umitoranoo (Sargassum thunbergii) by fractional extraction, iron-exchange chromatography, and gel filtration. Thirty-one polysaccharide fractions were obtained and tested for antitumor activity in mice with Ehrlich carcinoma transplanted i.p. Two of the fractions, GIV-A ( – 127° and mol. wt., 19,000) and GIV-B ( – 110° and mol. wt., 13,500) had such activity. On the basis of chemical and spectral analyses, these compounds were found to be a fucoidan or L-fucan containing approx. 30% sulfate ester groups per fucose residue, about 10% uronic acid, and less than 2% protein.     

Studies on Bacterial Protease

A crystalline alkaline protease was prepared from B. amylosacchariticus, which was isolated as a strain of saccharogenic α-amylase-producing Bacillus subtilis. The enzyme was most active at pH values between 10.3 and 10.7 towards casein and was stable at pH values from 6 to 11 on twenty hour incubation at 30°C. Calcium ions were effective to stabilize the enzyme especially at higher temperatures. The enzyme was markedly inactivated by DFP as well as protease inhibitor from potato and slightly by surface active agents, but not affected by sulfhydryl reagents and divalent metal ions except Hg⁺⁺ .Hemoglobin was the best substrate for the enzyme and more than 20% of the peptide bonds were hydrolyzed. Of numerous synthetic peptides tested, only the two compounds, and , were found to be hydrolyzed. A cyclic peptide, gramicidin S, was split by the enzyme only at the peptide bond of -l-valyl-l-ornithyl-. Methyl n-butyrate and tributyrin were also good substrates for the alkaline protease obtained here.     

Conformation depends on 4D-QSAR analysis using EC–GA method: pharmacophore identification and bioactivity prediction of TIBOs as non-nucleoside reverse transcriptase inhibitors

The electron conformational and genetic algorithm methods (EC–GA) were integrated for the identification of the pharmacophore group and predicting the anti HIV-1 activity of tetrahydroimidazo[4,5,1-jk][1,4]benzodiazepinone (TIBO) derivatives. To reveal the pharmacophore group, each conformation of all compounds was arranged by electron conformational matrices of congruity. Multiple comparisons of these matrices, within given tolerances for high active and low active TIBO derivatives, allow the identification of the pharmacophore group that refers to the electron conformational submatrix of activity. The effects of conformations, internal and external validation were investigated by four different models based on an ensemble of conformers and a single conformer, both with and without a test set. Model 1 using an ensemble of conformers for the training (39 compounds) and test sets (13 compounds), obtained by the optimum seven parameters, gave satisfactory results ( = 0.878, = 0.910, q² = 0.840, = 0.926 and = 0.900).     

Aromatic Amino Acid Residues in Japanese-radish Peroxidase a and Apoenzyme†

The nature of aromatic amino acid residues in Japanese-radish peroxidase a and the apoprotein was investigated by means of spectrophotometry and fluorospectrophotometry. The tyrosine residues in the holoenzyme were masked in the alkali-titration, giving an abnormally high value of 12.6, while they were exposed in the apoenzyme, exhibiting a value of 10.8. The difference spectra in the ultraviolet region between the holo-and apo-enzyme showed characteristic bands of tryptophan and phenylalanine as well as tyrosine. The perturbation of the aromatic amino acid residues by 50% ethyleneglycol was observed in the apoenzyme but not in the holoenzyme. The fluorophotometric experiments also revealed that the aromatic amino acid residues were in different environments in the holo- and apoenzyme. The difference between the conformation of peroxidase and that of the apoprotein was discussed.     

Isosclerone,a New Metabolite of Sclerotinia sclerotiorum (Lib.) De Bary

Isosclerone, mp 74~76°C, , a new metabolite of Sclerotinia sclerotiorum, was isolated and its absolute structure was determined as (4S)-3,4-dihydro-4,8-dihydroxy-1(2H)-naphthalenone. It stimulated the root elongation of rice seedlings by ca. 30% at concentrations of 1~10 ppm, and inhibited the growth of shoots and roots at high concentrations above 50 ppm.     

Antitumor Protein-containing Polysaccharides from a Chinese Mushroom Fengweigu or Houbitake,Pleurotus sajor-caju (Fr.) Sings

Protein-containing polysaccharides extracted from fruiting bodies of a Chinese fungus named Feng Wei Gu, were fractionated and purified, and their antitumor activities were tested, out of which the following active fractions were obtained.

FI_o-a: A protein-containing xyloglucan, MW 280,000, polysaccharide: protein=76: 24 (w/w), polysaccharide consisting of Man: Gal: Xyl: Glc = 2: 12: 42: 42 (molar ratio). + 25.3°.

FA-2: A protein-containing mannogalactan, MW 120,000, polysaccharide: protein = 76 : 16 (w/w), consisting of Xyl : Man: Gal = 9 : 35 : 56 (molar ratio), + 98.5°.

FII-1: A Protein-containing xylan (62: 21 w/w). MW 200,000, +8.7°.

FIII-1a: A protein-containing glucoxylan (15: 71 w/w), +30.7°, MW 90,000, consisting of Glc : Xyl = 40 : 44 (molar ratio).

FIII-2a: A protein-containing xyloglucan, MW 70,000, polysaccharide: protein = 69: 3 (w /w), polysaccharide consisting of Xyl: Glc = 36 : 62 (molar ratio). + 38.6°.     

Isolation and Physicochemical Properties of a Soluble Glycoprotein Fraction of Milk Fat Globule Membrane

A soluble apoprotein fraction was prepared from milk fat globule membrane lipoproteins by delipidation with a chloroform-methanol mixture and was fractionated into three fractions by gel filtration on Bio-Gel A–5m.

The major fraction, Fraction II, contained about 30% of carbohydrate, i.e. 13.9% of hexoses, 8.1% of hexosamines, 8.0% of sialic acid and 0.8% of fucose, and was therefore designated a soluble glycoprotein fraction. The fraction was apparently homogeneous on sedimentation velocity analysis and DEAE-Sephadex chromatography, and had 6.1, 3.79, 0.719, f/f⁰ 2.16 and molecular weight 139,000 daltons. However, the diffused pattern on disc electrophoresis and the occurrence of plural N-terminal amino acid residues suggest that the protein of this fraction is likely to be formed by intermolecular association of heterogeneous polypeptide chains.     

Cell-wall Polysaccharides of Immature Barley Plants. II. Characterization of a Xyloglucan

A xyloglucan occurring in the hemicellulose II fraction of cell walls of immature barley plants was characterized by methylation and fragmentation analyses. The results indicated that the xyloglucan was mainly composed of the following repeating units:      

Radiation Chemistry of Foods

When 10^?3m cysteine solution was irradiated in the presence of glucose at the concentration of ten-fold of cysteine, the G-values of products produced from cysteine were similar to those from 10^?3m cysteine solution. On the other hand, the yield of carbonyl compound from glucose was suppressed completely by interaction between cysteine and radicals which are secondarily produced from glucose.

Methionine could not suppress the yield of carbonyl compound from glucose, and, G-values of products from methionine varied in comparison with those from solution containing methionine only.

From the results using scavenger, it was concluded that oxidation to methionine sulfoxide and cleavage to α-aminobutyric acid was caused by OH and attack, respectively.     

Studies on Some New Azoxy Glycosides of Cycas revoluta Thunb.

The isolation of a new glycoside, named here as neocycasin A, with use of carbon chromatography, is described. It is one of a series of aliphatic azoxy glycosides, found in the seeds of Japanese cycad together with cycasin which is β-glucosyloxyazoxymethane as reported previously. The glycoside monohydrate gives m.p. 162° ~ 163° (decomp.), ? 35.1°; its heptaacetylate, m.p. 142° ~ 143°, ? 55.5°, from which octaacetyl-β-laminaribiose is isolated. On the basis of examination of the products obtained from partial or complete hydrolysis, and spectroscopic measurements, neocycasin A is concluded to be β-laminaribiosyloxyazoxymethane, i.e. 3-O-β-d-glucopyranosylcycasin.     

The Initial Attack Sites of a Streptomyces Alkalophilic Proteinase on Oxidized Insulin B-Chain

The sites on oxidized insulin B-chain substrate initially attacked by an alkalophilic proteinase from a Streptomyces sp., were investigated under incubation conditions employing one part enzyme to one thousand parts of substrate at 0°C.

Analysis of the peptides produced after 10 to 40 seconds of incubation revealed that the enzyme, which has an optimum pH of around 13, first attacks two peptide linkages “-Leu (15)Tyr (16)-Leu (17)-” of the oxidized insulin B-chain with equal efficiency.