bluuebunny/crossref_metadata_2025_split huggingface dataset:
Azo Bridges from Azines, XXI. Carbonyl and Enol Functionalities in Parallel Positions to Azo Groups
Authors: Brand Owe , Hünig Siegfried 
Published: June 2010

AbstractThe synthesis of compounds of type A3, carrying both, a silylenol and an azo group in parallel rigid positions, and the syntheses of ketone and diketone of type B and C, respectively, are reported. The crucial precursors, the mono‐ and dihydroxy acetals 2 and 3, both obtained from 1, are transformed by the already reported route to azo compounds 4 and 5. The latter compound is also prepared by dihydroxylation of the olefinic bridge in 7. Swern oxidation of alcohols 4, 6, and 5 yields ketones 12, 13, and 14. Enol silyl ether 15 (type A3) is obtained from 12 via its enolate 17 together with small amounts of diazetidine 16 which may arise from the equilibrium 17 18 19. By contrast, cyano ketone 20 yields the enol silyl ether 21 quantitatively.
Azo Bridges from Azines, XXII. [2 + 2] Photocycloaddition and 1,5‐Laticyclic Conjugation Between Parallel Azo Groups and π‐Systems The Symmetry Criterion in Azo‐Carbonyl Interactions
Authors: Brand Uwe , Hünig Siegfried , Martin Hans‐Dieter , Mayer Bernhard 
Published: June 2010

AbstractThe known 1,5‐lacticyclic interaction between parallel CC/ NN bridges in 1 in expressed by a bathochromic shift of the azo n‐π* transition of +7–10 nm. A CCCN bridge (2, 6) increases the bathochromic shift slightly, whereas a CC–OSiR3 bridge (3) cases a hypsochromic shift of −6 nm. In a R3SiO–C = C–CN bridge (4) the effect of the two substituents cancel each other. All these compounds (1–6, 13) undergo quantitative [2 + 2] photocycloaddition by n‐π* excitation. A novel transannular interaction between azo and carbonyl (20, 21: +8 nm) and 1,2‐dicarbonyl groups (24: ca. +20 nm) is observed. From photoelectron spectra and MO calculations neighboring group effects on the orbital energies in 20, 21, and 24 are assessed and discussed.
Glycosyl Imidates, 75. Synthesis of the Hexasaccharide Moiety of Globo H (Human Breast Cancer) Antigen
Authors: Lassaletta José M. , Schmidt Richard R. 
Published: June 2010

AbstractThe hexasaccharide moiety1cof the globo H antigen1awas synthesized based on a highly efficient strategy. To this end galactosyl trichloroacetimidate2was employed for the glycosylation of azidogalactose derivative3as acceptor to afford β(1→3)‐linked disaccharide7in high yield. Deacetylation and regioselective benzoylation and then fucosylation with trichloroacetimidate5gave trisaccharide10which was readily transformed into trichloroacetimidate12as glycosyl donor. Thus, with galactose derivatives4a, bas acceptors tetrasaccharides13a, bwere obtained in overall seven steps in high yields. Transformation of13into a glycosyl donor was best performed with13bvia 2‐O‐benzylation, 1‐O‐deallylation and then transformation into trichloroacetimidates20α,β. With6as acceptor the desired hexasaccharide21was obtained which could be fully structurally assigned. Hydrogenolytic debenzylation, debenzylidenation, and azido group reduction in one step and then acetylation concluded the synthesis of hexasaccharide1c.
Electrochemically Initiated Hydrocyanomethylation of N‐Heteroaryl‐Substituted Azomethines
Authors: Windeck Anne‐Kathrin , Hess Ulrich , Steckhan Eberhard , Reck Günter 
Published: June 2010

AbstractThe acetonitrile anion (1‐), generated by electrochemical initiation and chemical regeneration, may be used as cyanomethylation reagent for C,N double bond structures, e.g. for hydrocyanomethylation of π‐deficient N‐heteroaryl‐substituted Schiff bases (2–12) yielding the β‐aminonitriles (2a–12a). The synthesis is initiated by deprotonation of acetonitrile (1) to 1− by cathodically generated azomethine radical anions (2−·–12−·) followed by nucleophilic reaction of 1− with 2–12 up to its complete consumption, in a cyclic self‐reproducing process of 1−. Besides 2a–12a, 3,4‐heteroaryl‐substituted 4‐amino‐3‐butenonitriles and 1,3‐heteroaryl‐substituted 1,3‐diaminoisobutyronitiles are formed in the course of a nearly currentless reaction.
Anti‐histone H1 IgGs from blood serum of systemic lupus erythematosus patients are capable of hydrolyzing histone H1 and myelin basic protein
Authors: Magorivska Irina B. , Bilyy Rostyslav O. , Havrylyuk Anna M. , Chop'yak Valentyna V. , Stoika Rostyslav S. , Kit Yury Y. 
Published: June 2010

AbstractNovel hydrolytic activity of the anti‐histone H1 antibodies (Ab) toward histone H1 and myelin basic protein (MBP) was shown. Blood serum of ten patients with clinically diagnosed systemic lupus erythematosus (SLE), and nine healthy donors (control) were screened for the anti‐histone H1 antibody‐ and anti‐MBP antibody‐mediated specific proteolytic activity. IgGs were isolated by chromatography on Protein G‐Sepharose, and four of ten SLE patients appeared to possess IgGs that were capable of cleaving both histone H1 and MBP. Such activity was confirmed to be an intrinsic property of the IgG molecule, since it was preserved at gel filtration at alkaline and acidic pH. At the same time, proteolytic activity was absent in the sera‐derived Ab of all healthy donors under control. Anti‐histone IgGs were purified by the affinity chromatography on histone H1‐Sepharose. Their cross‐reactivity toward cationic proteins (histones, lysozyme, and MBP) and their capability of hydrolyzing histone H1 and MBP were detected. However, these IgGs were not cleaving core histones, lysozyme, or albumin. Capability of cleaving histone H1 and MBP was preserved after additional purification of anti‐histone H1 IgGs by the HPLC gel filtration. The protease activity of anti‐histone H1 IgG Ab was inhibited by serine protease inhibitors. Copyright © 2010 John Wiley & Sons, Ltd.
Growth and cell division of Escherichia coli 173‐25 in the presence of some analogues of diaminopimelic acid
Authors: Chaloupka J. , Strnadová M. , Čáslavská J. , Vereš K. 
Published: June 2010

AbstractThe dap‐dependent mutant of Escherichia coli could grow in the presence of several analogues of diaminopimelic acid (dap). The multiplication proceeded without any apparent difference for several hours when dap was replaced with 2,6‐diamino‐4‐fluoro‐pimelic acid or lanthionine. Only growth without accompanying division could be detected in the presence of 2,6‐diamino‐4‐hydroxypimelic acid (hydroxy‐dap). 3H‐hydroxy‐dap was incorporated into the TCA precipitable material under these conditions. 2,4,6‐triaminopimelic acid, probably also 2,6‐diamino‐5‐oxo‐pimelic acid could not substitute dap in the synthesis of murein. The synthesis of DNA measured by the incorporation of 3H‐thymidine was not inhibited by hydroxy‐dap but the formation of the cross wall was impaired. The rods were longer, formed bulges in the central part of the cell and ultimately lyzed. Selenium‐lanththionine was more toxic but even in its presence some growth occurred and DNA synthesis took place. The replacement of dap with hydroxy‐dap stimulated the degradation of the wall mucopeptide during the growth.
Heterotrophic growth of the nitrogen fixing blue‐green alga Nostoc muscorum
Authors: El‐Refai A. H. , Nashat M. A. , Salem H. M. 
Published: June 2010

AbstractNostoc muscorum could grow heterotrophically and successfully utilized a number of different sugars. Glucose proved to be the best sugar tested for growth and nitrogen fixation. However, citrate was outstanding among the different organic acids tried in allowing a substantial algal growth and consequently a high amounts of fixed nitrogen. The chemical analysis of the algal cells as well as the culture filtrate revealed the presence of various amino acids as well as auxine like substances.
Septation sporogener und asporogener Bacillus megaterium‐Zellen während des Übergangs zu Stickstoff‐ und Kohlenstoff‐hunger
Authors: Kretschmer S. , Fiedler G. 
Published: June 2010

AbstractFirst, the kinetics and frequency of sporulation of two Bacillus megaterium strains were determined after transition to nitrogen starvation. As the formation of the spore septum started at 1 hour after the shift, the initiation of sporogenesis was similar to that observed earlier in carbohydrate limited cultures. But later processes of sporulation were retarded and partly inhibited.From these strains two sporulation defective mutants were isolated. In ammonia‐, resp. glucose‐ or arabinose‐limited cultures cell division of the sporogenic and asporogenic strains was studied electronmicroscopically. Samples were taken from 2 generations before the transition to the stationary growth phase (t0) through 3 hours after the shift.Three types of division behaviour were observed during the transition to nitrogen‐(N) or carbon‐(C)‐starvation:

The initiation of division was inhibited already 1 ‐ 2 generations before cessation of net growth. In average, about 70% of all visibly initiated division septa were completed by t0 or shortly after that time. This type was expressed in all sp+‐cultures and in the N‐limited sp−‐populations.
Initiation of septum formation was stimulated 1 ‐ 2 generations before t0 in sp−‐strains under C‐limitation. About 80% of all initiated septa were completed, if citrate was absent.
The completion of the division septum was completely blocked independent of whether initiation was stimulated or inhibited. This inhibition of late division processes occurred with sp−‐strains under C‐ or N‐limitation in glucose‐citrate medium.
From these results it is concluded that the metabolism of sp+‐ and sp−‐strains differs already 1 ‐ 2 generations before t0. Concerning factors controlling division early sporulating cells resemble N‐starved cells, independent of the composition of the medium. Initiation of division is at least influenced by the ratio of catabolic to anabolic reactions in a cell. Initiation and completion of the septum are separately controlled steps of the division process, but probably not of the spore septum formation.
Detoxication of carboxin
Authors: Lyr H. , Ritter G. , Banasiak L. 
Published: June 2010

AbstractCarboxin (= vitavax = DCMO) is rapidly oxidized by hydrogen peroxide or H2O2 generating systems as riboflavin, flavin enzymes with or without substrate, to the more water soluble nontoxic sulfoxid (DCMOS). Illumination enhances the inactivation. Peroxidase is without effect. Isolated mitochondria from sensitive as well as from insensitive fungal species have the ability to oxidize DCMO, which leads to a leakage of the compounds mainly in form of DCMOS from the mitochondria. Among several fungal species investigated only Ustilago maydis in vivo oxidizes DCMO to a higher degree. The further oxidation of DCMOS to the corresponding dioxid (DCMOD = plantvax) occurs only under certain conditions to a limited extent. Proteases are unable to attack the ‐ CONH‐bounding. It is assumed that in vivo mainly flavin enzymes are responsible for the rapid oxidative inactivation of DCMO (vitavax).
Stimulation des Wachstums von Torulopsis utilis (Candida utilis) in Saccharose‐haltiger Nährlösung durch verschiedene Vitamin‐ und Wuchsstoffquellen
Authors: Leopold H. , Španêlová M. 
Published: June 2010

AbstractIf Torulopsis utilis is grown in mineral solutions containing 2.5 and 5% sugar the yields of yeast dry matter are only 80% and 26%, respectively, relative to the theoretical value if an economical coefficient of 50% is used. In the presence of 30% of waste liquor of the citric acid fermentation (CAF‐waste liquor) the yields attain 70‐85%. The effects of corn‐steep, group B vitamins or of biotin are much lower. Theoretical and higher yields of biomass are obtained by the combination of the CAF‐waste liquor with corn‐steep. The stimulation of yeast growth by wet or dry mycelium of the mould Aspergillus niger was similar to that of the CAF‐waste liquor, both when acting alone and in combination with other carriers of vitamins or growth factors. A good effect was observed with a mixture of the CAF‐waste liquor and the mould mycelium, both products of the citric acid fermentation. Mineral salt solutions containing 7% sugar may be fermented with theoretical yields by adding larger quantities of CAF‐waste liquor and mould mycelium. An attempt is made to interpret some of the findings according to the hypothesis of overflow metabolism.
Untersuchungen über Phagenlysozym. II. Isolierung und Charakterisierung von kälteempfindlichen Mutanten im Lysozymgen des Phagen T4
Authors: Liebscher D.‐H. , Dauberschmidt R. , Rosenthal H. A. 
Published: June 2010

AbstractWith the help of bromouracil mutagenesis and selection of haloless plaques after chloroform treatment 15 haloless mutants of phage T4 were isolated.The mutant cse BU56 proved to be cold‐sensitive due to a base substitution in the lysozyme gene according to the following criteria:

At 20 °C no plaques were formed; they appeared, however, after a temperature shift‐up.
The energy of activation of the lysozyme reaction was significantly increased as compared to that of the wild type.
This proves that an increased energy of activation of an essential enzyme‐catalyzed reaction is one of the causes for cold sensitivity in microorganisms.
Abbau von Tryptophan durch Candida guilliermondii, Stamm H17
Authors: Teuscher Gisela , Karczewski P. , Weide H. 
Published: June 2010

AbstractIn replacementexperiments L‐tryptophan was rapidly metabolized by Candida guilliermondii, strain H17, cultivated before in a medium containing n‐alkanes as sole carbon sources. After growth in a medium containing glucose tryptophan utilization was suppressed. Thin layer chromatography showed tryptophol as main metabolite. Kynurenine, anthranilic acid, and other substances of the aromatic pathway of tryptophan metabolism could not be detected. Feeding experiments showed a significant degradation of anthranilic acid, tryptamine, indolylpyruvic acid, and indolylacetic acid. As a metabolite of tryptamine utilization tryptophol has been identified. Degradation of formyl kynurenine and formyl anthranilic acid was within limits of error. Transamination and decarboxylation are discussed to be the primary reactions in the degradation of L‐tryptophan under the conditions used in this study.
Steroidtransformation with immobilized microorganisms VI. The reverse reaction of steroid‐1‐dehydrogenases from different micoorganisms in immobilized state
Authors: Atrat P. , Groh H. 
Published: June 2010

AbstractWhole cells of Nocardia erythropolis, N. opaca and Mycobacterium phlei containing 4‐en‐3‐oxosteroid: (acceptor)‐l‐en‐oxidoreductase activities were immobilized by adsorption on DEAE cellulose and silica and by entrapment in polyacrylamide gel. The obtained biocatalysts were used in an anaerobic continuous column process to transform l,4‐dien‐3‐oxo‐steroids into 4‐en‐3‐oxo‐steroids. The half life of steroid‐1(2)‐reductase activity of the N. erythropolis was found to be up to 15 days. The DEAE‐cellulose‐adsorbed cells showed a slighthly higher relative activity than free cells. The influence of substrate concentration and the action of dimethylformamide were also investigated.
Purification and characterization of an extracellular β‐glucanase from Bacillus IMET B 376
Authors: Borriss R. 
Published: June 2010

Abstractβ‐1.3‐1.4‐glucanase (E.C.3.2.1.73) was obtained in highly purified form from the culture fluid of Bacillus IMET B 376 by precipitation with ammonium sulfate, adsorption on CM‐cellulose and then affinity chromatography on lichenan‐Sepharose 4B. The purified enzyme was active on lichenan and barley glucan but not on laminarin and on CM‐cellulose. The molecular weight of the enzyme was estimated to be 26,000 daltons. The Km values for lichenan and barley glucan were determined to be 1.43 and 1.15 mg/ml, respectively. The β‐glucanase has a broad pH optimum between 6 to 8, and was particularly thermostable in presence of Ca++.
Vergleichende physiologische Untersuchungen zwischen Candida spec. H und der Mutante H 13 unter Stickstoffmangelbedingungen
Authors: Brückner B. , Tröger R. 
Published: June 2010

AbstractWith Candida spec. H and the mutant H13 during nitrogen starvation we studied the changes occurring in the macromolecular cell composition. In the absence of nitrogen, but in the presence of n‐alkanes as carbon source, both the nucleic acid and protein levels of the dried yeasts rapidly decreased. At the same time carbohydrates and lipids were accumulated. Candida spec. H predominately increased carbohydrate content, whereas the mutant accumulated significantly higher amounts of lipids. The main components of the cellular carbohydrates and the fatty acid content were analyzed, and the results were discussed.
Synthese Poly(A)‐haltiger RNA in auswachsenden Sporen von Bacillus subtilis
Authors: Hecker M. , Prösch S. , Mach H. , Mach F. 
Published: June 2010

AbstractThe synthesis of poly (A) ‐containing RNA in outgrowing spores of Bacillus subtilis was studied. A significant amount of RNA puls‐labelled with 3H‐uridine is polyadenylated. With the beginning of RNA synthesis in outgrowing spores labelled poly(A)‐containing RNA was detected. The amount of poly(A)‐RNA during the outgrowth and first cell division remains constant. Besides poly(A)‐RNA the synthesis of tRNA and rRNA occurs. These results indicate a simultaneous activation of synthesis of tRNA, rRNA as well as of poly(A)‐contaning RNA during outgrowth of B. subtilis spores.
An experimental approach to energy balance in a microbial process using the dichromate oxidation method
Authors: Nikolajewski H. E. , Meineke L. , Wettig Gudrun 
Published: June 2010

AbstractThe dichromate oxidation method was used to determine the number of reduction equivalents of organic substrates, cell mass and extracellular products in aerobical batch cultivations of Bordetella pertussis.The reduction equivalents obtained by this method were transformed into caloric values based on the fact that heat of reaction per equivalent oxygen consumed by oxidation of different organic substances is relatively constant. According to the law of conservation of energy a complete energy balance associated with an aerobical microbial process was developed using the caloric values mentioned above.
Effects of chloramphenicol on the thermal profile of Saccharomyces cerevisiae
Authors: Madeira‐Lopes A. , van Uden N. 
Published: June 2010

AbstractChloramphenicol decreased the maximum temperature for growth of a petite mutant of Saccharomyces cerevisiae, shifted the Arrhenius plot of thermal death to lower temperatures and shortened correspondingly, the Arrhenius plot of growth, while an associative thermal profile was maintained. At saturating concentrations (about 5 mg per ml) of chloramphenicol in liquid mineral medium with vitamins and glucose the final maximum temperature for growth was depressed from about 40°C to about 37°C. The results suggested that chloramphenicol acted in the mutant on targets other than mitochondrial ribosomes and that these targets are identical or associated with the death and Tmax sites of the yeast.
A direct selection method for isolating antimutators of Escherichia coli
Authors: Quinones A. , Piechocki R. 
Published: June 2010

AbstractA screening procedure based on the formation of lactose‐fermenting papillae on lactose‐nonfermenting bacterial colonies has been described. Due to supplementation of 50 μg/ml 2‐aminopurine in EMB plates the frequency of papillae rose to an average number of 28 papillae per colony. Of 150,000 mutagenized colonies inspected 16 colonies were detected with drastically reduced or no papillae per colony.
Gewinnung und Charakterisierung kohlenhydratspezifischer Antikörper aus anti‐Candida utilis Serum
Authors: Rademacher K.‐H. 
Published: June 2010

AbstractMannan of Candida utilis was hydrolyzed in oligosaccharides of different chain lenghts. Mannohexaose and mannopentaose were shown to be the immunodominant group of this mannan. The oligosaccharides obtained were bound to sepharose by way of β‐(p‐aminophenyl) ethylamine. Immunoglobulins against mannohexaose down to mannodiose were obtained using affinity chromatography of the anti‐C. utilis serum. The affinity columns were filled with sepharose‐oligosaccharide gels. The serological activity was proved by agglutination and precipitation.
Effect of microtubule inhibitors on the tubulin system of Dictyostelium discoideum
Authors: Rubino S. , Unger E. , Fogu G. , Cappuccinelli P. 
Published: June 2010

AbstractIndirect immunofluorescence with antibodies to microtubular proteins has been used to investigate the microtubule system of Dictyostelium discoideum vegetative amoebae and the action of several compounds that interfere with that system. All the inhibitors tested show an antimicrotubular effect.Colchicine, vinblastine, nocodazole, thiabendazole, and isopropyl‐N‐phenyl‐carbamate (IPC) seem to act mainly by destroying microtubules leaving the appearance of nuclei associated organelles (NAOs) undisturbed. On the other hand griseofulvin also affects NAOs which disappear in treated cells.
Wirkung von Pentachlornitrobenzol (PCNB) auf die Ultrastruktur von Mucor mucedo und Phytophthora cactorum
Authors: Casperson G. , Lyr H. 
Published: June 2010

AbstractThe effect of PCNB in various concentrations on the ultrastructure of Mucor mucedo and Phytophthora cactorum was analyzed after an incubation period of 2 hours. The most striking effect in both fungi was a diffuse lysis of the internal structure of the mitochondria which differs markedly from the lysis induced by etridiazol (terrazol). Moreover an enlargement of the perinuclear space and an increased formation of vacuoles was observed.In Mucor mucedo, but not in Phytophthora cactorum a pathological thickening of the cell wall was observed. Although after 2 hours incubation with PCNB Phytophthora gave similar ultrastructural reactions in the mitochondria as Mucor, in growth experiments on agar dishes this species was 5–10 times less sensitive to PCNB compared to Mucor.
Anomalous cell wall synthesis in Mucor mucedo (L.) FRES. induced by some fungicides and other compounds related to the problem of dimorphism
Authors: Lyr H. , Casperson G. 
Published: June 2010

AbstractAn anomalous cell wall thickening in Mucor mucedo is induced already within 60–120 min by some fungicides (etridiazol, chloroneb, pentachloronitrobenzene, dicloran, drazoxolon, biphenyl) as well as with a N2‐atmosphere or high concentrations of glucose, but not with 2,4‐dinitrophenol, chlorinated phenols, dichlofluanid and antimycin A. This effect seems to be identical to the change from the mycelial (M‐) to the yeast (Y‐) form in dimorphic fungi, which can be achieved by culture conditions as well as by addition of chemicals. The cause seems to be a specific, complex change in the metabolic state. A scheme of regulation is presented which explains most of the experimental results described till now.
Phosphate release in turimycin fermentations
Authors: Müller P. J. , Hilliger H. , Menner M. , Forberg W. 
Published: June 2010

AbstractThe important effect of release of soluble phosphate from complex media constituents during the turimycin fermentation is demonstrated by investigation of process kinetic and phosphate balance. The observed changes in physiological parameters and the diauxic growth are discussed in connection with extracellular enzymes formation hydrolyzing phosphate‐containing complex media constituents.
Effects of different factors on the sporulation of Pithophora oedogonia (MONT.) WITTROCK
Authors: Agrawal S. C. , Sarma Y. S. R. K. 
Published: June 2010

AbstractThe present study emphasizes the effects of different qualities of visible light, intensities of white light, temperature and pH on the sporulation in the green alga Pithophora oedogonia (MONT.) WITTROCK. Of the different qualities of light used, green light was found to delay the initiation of sporulation. Percentage of sporulation was greatly decreased in yellow light followed by red light. Delay in time taken for initiation of sporulation and decrease in percentage sporulation were observed at 0.25 and 0.5 K lux intensity of white light. Sporulation upto the extent of its natural population was achieved with white light between 2 to 3.5 K lux, temperature between 20 to 30 °C and pH between 4–9.