Volume 38, Issue 7-8

Single crystal electron diffraction data from an odd-chain triglyceride, glycerol triheptadecanoate, are compared with the known structure of the even-chain homo-acid triglycerides. Both class­es of triglycerides are found to resemble one another in chain packing: they both have the same chain tilt (61 °) for the β-polymorph and, further, the orientation of the T ∥ subcell in the crystal structure is identical. The existence of the T ∥ subcell is quantitatively verified for the first time with the diffraction intensities from suitably tilted crystals. Given these similarities in β-poly­morph structure, the major difference between triglycerides with even or odd chains (indicated by published long spacing and melting point alternation) must be due to the methyl end group pack­ing - i.e., the end group packing volume for the odd-chain glycerides must be larger than found for the even-chain materials.

The methylethers 4-O,8-O-dimethyl-(1S, 2E, 4R, 6E, 8S, 11E)-2,6,11-cembratriene-4,8-diol (9), 4-O-methyl-(1S, 2E, 4R, 7E, 11E)-2,7,11-cembratriene-4,6-diol (4) und 4-O,6-O-methyl-(1S, 2E, 4R, 7E, 11E)-2,7,11-cembratriene-4,6-diol (8) were identified as new natural products from tobacco. They were isolated from processed tobacco as well as from leaf surface gum of fresh tobacco. The spectral data of all six methylethers of (1S, 2E, 4S, 6R, 7E, 11E)- and (1S, 2E, 4R, 6R, 7E, 11E)-2,7,11-cembratrienen-4,6-diol are given.

3,7,11,15-Cembratetraene-6-ol (1) was isolated from tobacco and identified as a new natural product by spectral data and chemical degradation. 1-H-NMR, 13-C-NMR and MS data are given.

Cell-free extracts from oak (Quercus robur) leaves were found to contain at least two β-glucogallin-dependent galloyltransferases. One enzyme catalyzed a rapid exchange of the galloylmoiety of β-glucogallin with free glucose. A second enzyme fraction was shown to form digalloylglucose, utilizing β-glucogallin both as acyl-donor and acceptor molecule; in addition, evidence for the synthesis of trigalloylglucose was obtained. Both enzyme-systems had their pH-optimum at pH 6.0-6.5. It is assumed that these newly described galloyltransferases are involved in the biosynthesis of gallotannins.

Organic acids from wheat (Triticum aestivum), rye (Secale cereale), and barley (Hordeum vulgare, var. “Gerbel” and “Igri”) were analysed by gas chromatography-mass spectrometry. Two carboxylic acid fractions were obtained by chromatography on Sephadex LH 20: frac­tion A contained mainly aliphatic acids, fraction B contained mainly aromatic acids. The identified compounds (50 aliphatic and 32 aromatic acids) are listed in Tables I and II. Quanti­tative analysis was achieved by calibration of the gas chromatogram with authentic compounds or - if not available - with closely related compounds. The possibility to identify the origin of cereal food-stuff by analysis of the organic acids is discussed.

Two isoforms of glutamine synthetase. GS 1 and GS 2 , have been separated from Chlamydomonas reinhardii cells grown autotrophically with nitrate. The intracellular level of GS 2 was higher than that of GS 1 . In cells under darkness, the GS 1 peak increased markedly, whereas that of GS 2 became negligible. The two isoenzymes were purified to electrophoretic homogeneity by a method which included: a) DE-52 cellulose chromatography; b) ammonium sulphate fractionation: and c) affinity chromatography on ADP-sepharose. The specific activity was 114 and 63 U/mg for GS 1 and GS 2 respectively, and both enzymes (M r = 380 000 and 373 000) are oligomeric proteins composed by 8 subunits of similar size (M r = 48 000 in GS 1 , and 46 000 in GS 2 ). The basic differences between GS 1 and GS 2 are: a) the effect of light on their intracellular level: b) their K m for ammonium (83 and 244 μᴍ, respectively). Both isoenzymes were inhibited in a similar extent by ʟ-alanine, ʟ-glycine and ʟ-arginine.

Transformation of phenazines in Pseudomonas aureofaciens were investigated with deuterated phenazine-1-carboxylic acid, 2-hydroxyphenazine-1-carboxylic acid, phenazine-1,6-dicarboxylic acid, methyl phenazine-1-carboxylate, dimethyl phenazine-1,6-dicarboxylate, and its mono methyl derivative. It was shown that hydroxylation and decarboxylation of phenazine-1-carboxylic acid gave rise to the variety of phenazines isolated from this strain.

Two isovitexin glycosides have been found in the cotyledons and foliage leaves of Sitene pratensis plants that are unable to glycosylate isovitexin in their petals (genotype gg glgl fgfg). The glycosides (isovitexin 7-O-galactoside and isovitexin 7-O-galactose 2″-O-arabinoside) were present only in the lower leaves: leaves produced later in the development of the flower stem accumulated only the aglycon isovitexin. The transition in the flavone composition during the ontogeny of the plants could be influenced by light intensity. In plants grown at low light intensity, glycoside production continued until a higher leaf pair number than in plants grown at higher light intensities. However, the effect of light intensity is indirect: the transition in the flavone composition is correlated with the transition from rosette leaves to stem leaves. The presence of the 7-O-galactosides in cotyledons and rosette leaves suggests that in addition to the g, gl and fg loci, there are further glycosylating loci which are not expressed in stem leaves and petals.

Enzyme activity responsible for the biosynthesis of isovitexin-7-O-galactoside from isovitexin and UDP-galactose can be demonstrated in protein extracts of cotyledons and rosette leaves from Silene pratensis plants. This galactosyltransferase activity is absent in stem leaves and petals. “True Km” values of 0.0025 mᴍ for isovitexin and of 8.2 mᴍ for UDP-galactose were found. At infinite concentration of both substrates the “true V max ” value was 0.11 mᴍ/min/mg protein. The galactosyltransferase activity was optimal at pH 7.0; the divalent ions Zn and Hg were inhibitory, whereas Ca, Co, Mg, Mn and EDTA were not inhibitory.

The activity of five enzymes concerning anthocyanin biosynthesis as well as the anthocyanin accumulation were studied during the development of buds and flowers of Matthiola incana. The investigations included the first three enzymes in the anthocyanin pathway, chalcone synthase, chalcone isomerase and flavanone 3-hydroxylase, and the flavonoid-modifying enzymes, flavonoid 3'-hydroxylase and flavonoid 3-O-glucosyltransferase. The bud and flower development was subdivided into eight stages with respect to morphological criteria. On a fresh weight basis, a substantial correlation between anthocyanin content and the activities of all of the five enzymes were found in the various developmental stages. Furthermore, the anthocyanins formed are obviously not or only less subject to degradation. Although all maxima of activity proved to be in buds, clear differences were observed between the five enzymes with regard to increase and stage of maximum activity. The isolation of other enzymes involved in flavonoid biosynthesis is likely to be most successful in the bud stages.

Herbicides like norflurazon, oxadiazon, or oxyfluorfen affect the pigment apparatus of green algae. Their influence on variable (F maK - F 0 ) and initial fluorescence (F 0 ) as well as on the state of chlorophylls were investigated. Two main modes of action of these herbicides on the photo­synthetic apparatus during growth have been found: First: Scenedesmus cells grown with norflurazon. a carotene-biosynthesis inhibitor, show chlorophyll bleaching concurrently with decrease or inactivation of photosystem-II reaction centers, with small changes in fluorescence spectra. Further, electron transport is blocked at the acceptor side of photosystem II. Disappearance or inactivation of photosystem-II reaction centers after a 50% loss of chlorophyll is accompanied by a sharp increase of the F 0 yield, with small changes in the chlorophyll state. The slow-decay phase in fluorescence induction of these cells, enhanced by dithionite, is ascribed to a reversible photobleaching of chlorophyll during the measurement. Second: Oxadiazon and oxyfluorfen alter substantially the state of chlorophylls and cause strong bleaching, but reaction centers of photosystem II, although less than in control cells, are active even after an 80% disappearance of chlorophyll. The yields of F 0 and (F max - F 0 ) in treated cells are independent of the extent of chlorophyll bleaching. In contrast to norflurazon, the latter two herbicides do not inhibit carotenogenesis. Decrease of photosystem-II reaction centers may be due to non-specific pigment destruction (oxyfluorfen) or interference w'ith chlorophyll biosynthesis.

Glutamic-1-semialdehyde which is discussed to be involved in the early steps of chlorophyll biosynthesis, has been synthesized from glutamic acid by reduction of several N-protected carboxylic acid derivatives like the N-CBO-glutamic acid-1-dimethyl amide or methylanilide, the pyroglutamic acid imidazolide and the acid chlorides of N-phthaioyl-glutamic acid-5-methyl ester or 5-benzylester. The α-aminoaldehyde could only be generated in solution, where it is polymerized rapidly. Due to its instability, it is suggested thal glutamic semialdehyde plays no role as a free metabolite in green plants.

The O 2 - sensitivitiy of N 2 -fixation by the carotenoid forming strain Azospirillum brasilense Cd and the colourless strain Sp 7 is compared in the present communication. As no difference in the reaction is observed with both strains, it is concluded that carotenoids do not protect nitrogenase from damage by O 2 . Azospirillum spp. have also been shown to perform NO 3 - - dependent N 2 -fixation. The physiological properties of this reaction are described in more detail in the present communication. Evidence is presented that NO 3 - - dependent N 2 -fixation is a transitory reaction, proceeding only as long as the enzymes of assimilatory nitrate reduction are synthesized by the cells.

cAMP levels were monitored in soybean (Glycine max) infected with race 1 of Phytophthora megasperma f. sp. glycinea and in soybean cell suspension cultures treated with a glucan elicitor from P. megasperma. While cAMP could be readily detected in soybean hypocotyls using a radio ­ immunoassay, no correlation was observed between infection and cAMP levels. No cAMP was detected in suspension cultured soybean cells. These results suggest that cAMP does not play a significant role in the plant's response to fungal attack, or the response of suspension cultured cells to elicitor.

C -13 NMR data for linamarin and lotaustralin, obtained after feeding of either Zygaena Jilipendulae or Heliconius melpomone (Lepidoptera) with C-13 enriched valine and isoleucine respectively, indicate that intact units of amino acid with loss of the carboxyl group are incorporated during the biosynthesis of these cyanogenic glycosides.

The mechanism of plasma membrane proliferation was studied in the acellular slime mold Physarum polycephalum with the aid of light and electron microscopical techniques. Treatment of protoplasmic drops with a Tris-buffered 15 mᴍ caffeine solution causes surface blebbing and budding over periods of 5-90 min. The process of surface blebbing is coupled to a 5-10-fold increase of the surface area in conjunction with characteristic changes in cytoplasmic morphol­ogy. Successive constriction of blebs exhibiting different sizes and degree of hyalo-granuloptasmic separation leads to the formation of numerous spherical caffeine droplets. During the process of surface budding and droplet formation the total surface area of the original (genuine) protoplasmic drop is not reduced, but continues to grow. Freeze-etch studies show that caffeine concomitantly causes characteristic changes in the fine structure of the plasma membrane. During the initial phase of surface blebbing the original density of intramembranous particles (IMP) is reduced from 3676/μm 2 to 1669/μm 2 and the PF:EF ratio (IMP/μm 2 protoplasmic face: exoplasmic face) shifts from 2.4:1 to 2.8:1. When surface budding is completed the IMP-density in the plasma membrane of single caffeine droplets increases again to 2289/μm 2 and the PF:EF ratio changes to 1.5:1. Simultaneously, the isolated caffeine droplets produce numerous small hyaline membrane protrusions, which are pinched off and contain no IMP. Control experiments demonstrate that Tris-buffer without caffeine also shows a weak capacity to induce surface blebbing, to change the IMP-density and the PF:EF ratio (2443/μm 2 ; 1.5:1); but Tris-buffer fails to cause surface budding. On the other hand, different concentrations of sucrose (25-200 mᴍ) can supress to a certain degree both caffeine- and Tris-buffer-induced surface blebbing, but not caffeine-dependent surface budding. The caffeine-effect is reversible insofar as protoplasmic drops with blebbing and budding activity recover to normal morphology, fine structure and locomotion when transferred to physiological conditions. The mechanisms of successive changes in plasma membrane morphology as well as the mode of a participation of the actomyosin system in cell surface dynamics are discussed.

The complex anatomical structure of an intact leaf results in a distribution of photosynthetically active energy between photosynthetic pigments which is different from that observed in isolated chloroplasts. The variance is due mainly to scattering at the gas-liquid interface between cells and intercellular space which tends to increase light absorption by the long wavelength absorbing pigments through secondary fluorescence. Evidence is given in support of an active use of this feature by the higher plant to regulate energy flow at the photophysical level of light absorption.

1.In order to elucidate the significance of oxidative ATP production for the proliferation of Ehrlich ascites tumor cells, cell cycle progression, energy metabolism and macromolecular synthesis in the presence of oligomycin were studied. 2.In the presence of the inhibitor (20 μ/ml), lactate production and glucose uptake of the cells increased by about 30-35% as compared to controls; oxygen consumption was maximally inhibited by 30-45% and could not further be reduced by higher concentrations of the inhibitor. ATP/ADP ratios of the oligomycin treated cells and control cells were not significantly different. 3.In the first passage in the presence of oligomycin proliferation of the cells is reduced to about 50% that of controls; without severely affecting viability (dye exclusion test). In the second passage with oligomycin cell proliferation completely arrests. As was shown by flow cytometric analysis and BrdU-H33258 technique of flow cytometry, cells accumulate in the early S phase; division of cells which are in the S- and G 2 M compartment at the beginning of oligomycin treatment accounts for the increase of cell number in the first passage in the presence of oligomycin. On recultivation in the third passage in the absence of the inhibitor cells take up proliferation again; an increase of cell number of about 60% of controls was observed within 24 h. 4.In the presence of oligomycin incorporation of [2-l4C]thymidine is reduced to about 20% of the controls within 8 h. incorporation of [U-l4C]lysine begins to slow down immediately after treatment with the inhibitor, the same is true for the incorporation of [2-14C]uridine. Transport of α-aminoisobutyric acid into the cells is not severely affected. 5.It is suggested, that not lack of energy by inhibition of oxidative phosphorylation accounts for the arrest of cell cycle progression in the presence of oligomycin but rather the blockade of transport of cytoplasmatic (glycolytic) ATP into mitochondria, which is caused by the high potential built up across the mitochondrial membrane in the presence of this inhibitor.

The amino-acid sequences of all expressed hemoglobins of the pig embryo are given: Hemo­globin Gower I (ζ 2 /ε 2 ), Hemoblobin Gower II (α 2 /ε 2 ), Hemoglobin Heide I (ζ 2 /ϑ 2 ) and Hemo­globin Heide II (α 0 /ϑ 2 ). The ζ-, ε- and ϑ-chains were obtained with chromatography on CM-cellulose from isolated hemoglobin components. The primary structure was established by sequencing the tryptic peptides in the sequenator: they where isolated using HPLC. The ζ-chains from pig and human differ in 23, the ε-chains in 20 positions. The embryonic globin-gene which express the ϑ-chains, is a new one in mammals, of ε-type and up to now it could only be found in pigs: the amino-acid sequence differ in only 4 positions from the ε-chains. Because no γ-chains (fetal Hb) are expressed the sequences of all hemoglobins (5 hemoglobin chains forming 5 different hemo­globins) of ontogeny in pig are now described.

In Streptomyces hydrogenans, acidic amino acfds are taken up either as anions by a specific transport system or as zwitterions via a nonspecific one. Variations in the zwitterion concentration caused by changes in pH influence the uptake and exchange diffusion by the nonspecific system. Differences in pH-optima for ʟ-glutamate and ʟ-aspartate transport are due to the different pK 2 -­values of these amino acids. The anion transport by the specific system is accompanied by a short hyperpolarization of the membrane potential followed by a secondary influx of potassium ions into the cells.

The rigidity and stability of the tertiary structure of yeast tRNA Phe is related to a bond index obtained in an IEHT (iterative extended Hückel theory) calculation. The index permits a quantitative estimate of the electron density along the hydrogen bond, having thus an appealing physical meaning. The results indicate that Hoogsteen-type bonds have, as expected, greater electronic population than Watson-Crick type ones. Other non-Watson-Crick pairs, the wobble pair and G 15 -C 48 , exhibit high values of the index for the NH ... O bond. In the triples, the electron density of the hydrogen bridges does not weaken (compared with the one of the pairs involved). Contour density maps are shown and dipolar moments of pairs and triples are qualitatively discussed.

(2'-5')-oligoadenylates bearing a 5'-terminal triphosphate or a 5'GTP-group inhibit the activity of a dinucleoside triphosphatase in rat liver nuclei thereby protecting mRNA against 5'-exonucleolytic degradation. (2'-5')-oligoadenylates, on the other hand, were known to enhance the activity of an endoribonuclease, RNaseF. Thus a synergistic effect may be assumed in vivo, i.e. cellular metabolism seems to be protected twice in virus-infected cells.

In cultures of certain streptococcal strains, RNA added as a carrier for streptolysin S (SLS) was hardly degraded, owing to deficiency of extracellular RNase activity. Production of RNA-SLS into culture supernatant was markedly reduced in the RNase-deficient streptococci. Even in these RNase-less strains, guanylic-acid rich oligonucleotides, polyG or trypan blue effectively induced SLS production, as in RNase-positive cells. These results demonstrate involvement of the streptococcal nuclease in manifestation of SLS-inducing effect of exogenous RNA. Additional data indicated that cellular growth was promoted by supplementation of RNA, in the nuclease-producing streptococci.

The Na/K-ATPase-rich microsomal fraction and purified Na/K-ATPase membranes of the salt-stressed avian salt gland were studied at defined filipin/cholesterol molar ratios (F/C) using enzyme assay and electron microscopy including negative staining, thin sectioning and freeze frac­ turing. Comparative examinations of detergent-treated microsomal fractions and the use of elec­ tron microscopic tracers revealed that F/C up to 2 activated latent Na/K-ATPase in sealed right-side-out vesicles by increasing membrane permeability without disrupting the vesicular mem­ brane. Therefore, filipin offers an alternative to the detergents for the activation of latent vectorial membrane enzymes and a possible tool to examine their subcellular localization and sidedness in the membrane. The same F/C had no stimulatory effect on the microsomal anion-ATPase sug­gesting that the 2 ATPases are not located in the same membrane. Increasing F/C applied to the unfixed Na/K-ATPase membranes caused an increase in the number of structural F-C-complexes and a progressive lateral displacement of the enzyme par­ ticles which finally led to a separation of the areal distribution of these structures at F/C = 10. Such displacements did not occur in unfixed microsomes and were prevented by glutaraldehyde fixation of the purified membranes. F/C exceeding 2 progessively and temperature-dependently inhibited the Na/K-ATPase in its membrane-bound states, whereas the solubilized enzyme was rather insensitive. The structural and biochemical data suggest that inhibition results from the perturbation of the lipidic microen­ vironment of the enzyme caused by filipin-cholesterol complexation.

A pore from guinea pig heart mitochondria has been incorporated into BLM's (Black lipid membranes) in a highly oriented manner and its electrical properties studied. The pore shows multistate behaviour, the distribution of the pore between different conducting states being very sensitive to voltage. This has been proven by computation of single-pore experiments. Highest single pore conductance was 4.5 nSi in 1 ᴍ KCl, independent of voltage and with no detectable preference for cations or anions. The pore from guinea pig heart mitochondria reacts more sensitivly to voltage than pores of mitochondria from other tissues so far incorporated into BLM's.

Hymenoclea salsola (Asteraceae), a dominant shrub of the desert areas of California and Baja California, Mexico, secretes high amounts of resin on the leaf surface. Chemi­cal analysis of the resin revealed the presence of a complex mixture of flavonoid aglycones. Among the compounds identified is the rare 2',4',6'-OH chalcone, previously not known to occur in the Asteraceae.

The first 7,8,3',4'-oxygenated benzylisoquinoline, the probable precursor of the cularine alkaloids, has been isolated together with 2 new cularines and 10 other alkaloids from Corydalis claviculata.

During micronuclear metaphase, the decondensed chromosomes bear conical kinetochores connected by a single microtubule to the tapered ends of the spindle-shaped nucleus. Using Bernhard's procedure for the pre­ ferential staining of ribonucleo-protein-containing struc­ tures, the whole kinetochore cone retains its electron density. Chromosome separation at anaphase involves shortening of the kinetochore microtubule and elongation of the interpolar region.

The water boatmen Corixa dentipes and C. punctata produce an acoustic mounting signal when beginning to copulate. Automated recording of this signal over the entire life cycle of the anim als reveals that the main mating period of C. punctata occurs in autumn and that of C. dentipes, in the spring. In the case of C. punctata, mounting signals were routinely recorded even during the winter, at water temperatures below 4 °C.