Band 37, Heft 3-4

The chemical examination of Pterocarpusm arsupium root afforded pterosupin, a new C-glu-cosyl-β-hydroxydihydrochalcone along with pseudobaptigenin, liquiritigenin, isoliquiritigenin, garbanzol, 5-deoxy-kaempferol and p-hydroxybenzaldehyde.

From acetone extracts of fresh aerial parts o f Polypodium vulgare L. 9 phenolic compounds were isolated. Two of them, catechin 7-O-ᴅ-apioside and kaempferol 3-O-(4 or 5-rhamnosyl) arabinoside, were found for the first time in nature. Furthermore it was shown that polydine is catechin, 7-O-α-ʟ-arabinofuranoside. The other components were rutin, hyperin, kaempferol- 3-O-glucoside and -arabinoside-7-O-rhamnoside and the C-glycosides schaftoside and isoschaftoside.

By use of GC and GC-MS analysis more than 70 compounds, mainly mono- and sesquiterpenes, were structurally identified from the essential oil from blossoms of Artemisia vulgaris L. A distinct seasonal dependence of oil production was observed.

The source of nitrogen in the phenazine, iodinin 5, and in 2-aminophenoxazinone 7 in Brevi­ bacterium iodinum cultures is shown to be primarily from the amide nitrogen of glutamine in experiments with (S)-[CO 15 NH 2 ]glutamine, [ 15 N]ammonium sulphate, and (S)-[ 15 N]glutamic acid. The biosynthesis of 5 and 7 is closely related; biosynthesis o f 7 like that o f 5 diverts from the shikimic acid pathway at a stage prior to anthranilic acid 8.

A membrane-bound enzyme catalysing the cleavage of 13-hydroperoxy-(Z)-9,(E)-11-oc-tadecadienoic acid (13-LHPO) and 13-hydroperoxy-(Z)-9,(E)-11,(Z)-15-octadecadienoic acid (13-LnHPO) to C 6 -aldehydes was isolated and partially purified from apples and tomatoes. Attempts to employ Ultrogel AcA 34 and AcA 22 in a gel chromatographic purification step were partially frustrated by reaggregation phenomena. However, by using Sepharose CL-4 B an enzyme fraction (MW 200 000 Da) with lipoxygenase and fatty acid hydroperoxide cleaving activity could be separated from a high molecular-weight active eluate. By applying preparative isoelec­ tric focussing to the tomato protein we succeeded in separating the fatty acid cleaving activity from the lipoxygenase, because o f their different isoelectric points of pH 5.8 -6 .1 and pH 5.0, respectively, An 8.4-fold purification of the fatty acid cleaving activity was achieved. A pH-optimum of 5.5 and a K m -value of 2.6 × 10 -5 м/1 for the 13-hydroperoxide of linoleic acid were measured. p-Chloromercuribenzoic acid (1 mм) showed significant inhibitory effect on the fatty acid hydroperoxide cleaving enzyme, but no evidence o f inhibition was found with 1 mм H 2 O 2 , KCN, DABCO and EDTA or superoxide dismutase (270 U). The maximum amount of fatty acid hydroperoxide decomposition (C 6 -aldehyde formation) was determined to be 59%.

Using [ 14 C]tryptophan as a precursor, the intracellular localization of indole-3-acetic acid biosynthesis in spinach mesophyll cells was investigated. Chloroplasts as well as extraplastidic compartments were able to transform tryptophan into indole-3-acetic acid. The cofactor requirement of plastidic and extraplastidic indole-3-acetic acid synthesis is shown. Light and abscisic acid treatment inhibited preparations.

The verdin-type Chromophore of denatured C-phycocyanin (1) from Spirulina platensis is reduced to the corresponding rubin (2a) by sodium borohydride. The structure assigned is in agreement with the uv-vis spectroscopic properties of the product and was deduced from model studies with free bile pigments. Analogous model studies using sodium dithionite demonstrated a two-fold reactivity for this reagent, leading to products which are both o f the rubin spectral type under the conditions tested. True rubins (10,22-dihydrobilindions) are formed in low yield only if an excess of reagent is used in methanol/water mixtures. It is accompanied by polar addition product(s) of the same spectral type, which are generally formed exclusively. In particular, no bilirubin was formed under the reaction conditions previously applied for the chemical modification of phycobiliproteins and phytochrome. From this finding and from the strikingly different properties of the borohydride and dithionite products, of phycocyanin upon renaturation, the dithionite product is suggested to be a rubinoid addition product (2b) rather than a hydrogenation product. In contrast to the dithionite addition product 2b of phycocyanin, the chromophore of the true phycorubin (2a) remains stable upon renaturation. The uv-vis spectral properties of the chromophore are not markedly different whether the apoprotein is in its native or denatured state. The different electrophoretic mobilities of native (renatured) phycocyanin compared to the renatured borohydride product suggest that these two have different protein conformations. The preparation of these phycorubins renders the extensive techniques of bilirubin chemistry applicable in the study of biliproteins.

A cytochrome oxidase (EC 1.9.3.1) was solubilized from the membrane fraction of aerobically grown cells of Rhodopseudomonas capsulata by treatment with Triton X-100. The enzyme was purified 160 fold by chromatography on DEAE-Sepharose CL-6B and affinity chromatography on cytochrome c-thiol activated Sepharose 4B. The purified enzyme has a pH-optimum at 8.5 and a temperature optimum at 35 °C. The ap­ parent K m for reduced horse cytochrome c is 24 μм (at pH 8 and 30 °C). The purified cytochrome oxidase was 50% inhibited by 1.5 μм KCN and 10 μм NaN 3 . The purified enzyme contained one polypeptide of m r 65,000 and 6-type cytochrome.

Aerobically in the dark grown cells were incubated semiaerobically (30 min) and afterwards 180 min anaerobically in the light During phototrophic induction the bacteriochlorophyll concentra­ tion increased from 0.26 to 2.10 nmol/mg cell protein. In samples taken at different times after lowering of oxygen partial pressure the following tetrapyrrol derivatives were identified by fluorescence emission and excitation spectroscopy at 1.7 K: Mg-protoporphyrin EX-monomethylester, Mg-2,4-divinylphaeoporphyrin a 5 -monomethylester, 2-de-vinyl-2 -hydroxyethyl-chlorophyllide, 2 -devinyl-2 -hydroxyethyl-pheophorbide, chlorophyllide a, pheophorbide, bacteriopheophorbide, bacteriopheophytin, bacteriochlorophyllide and bacte­ riochlorophyll a in different pigment complexes. The highest relative concentrations of bacte­ riochlorophyll precursors normalized to the total amount o f bacteriochlorophyll a were found in cells during the first hour of adaptation at 0.5 μg Bchl/mg cell protein or less.

The cyanobacterium Anacystis nidulans is bleached when subjected to both light and O 2 to­ gether with suitable (pre)treatment o f the cells such as incubation at high (≧ 48 °C) or low (≦ 17 °C) temperatures, or in presence of metabolic inhibitors, or of substances forming com­ plexes with divalent cations. Concomitantly degradation o f the intracellular membranes is ob­ served (G. Schmetterer, G. A. Peschek, Biochem. Physiol. Pflanzen 176, 90-100 (1981)). The same three conditions cause formation of hydrocarbons, mostly ethane, a characteristic product of lipid peroxidation. Ethane production is unchanged and still light-sensitive even when no more pigments can be detected in the cells. In "white" cells light-dependent O 2 -uptake is also observed. The action spectrum of this process suggests that "completely" bleached cells retain very small amounts of residual chlorophyll, which must be unusually resistant to photooxidation.

The obligate halophilic member of Rhodospirillaceae, Rhodospirillum salexigens, does not contain lipopolysaccharide in its thin and delicate gram-negative type cell wall. Major constituents are protein (approximately 70% of dry weight) and peptidoglycan (murein).

The cyanobacterium Anabaena cylindrica grown in a nitrogen -free medium at + 25 °C was used for short-term 14 C-kinetics experiments under different conditions. During the dark/light transients the initial fixation products were mainly sugar monophosphates and 3-phosphoglyceric acid (Calvin cycle intermediates), aspartate (10% of total radioactivity) and glycine/serine. Io­ doacetamide (0.01 м) caused an inhibition o f photosynthetic 14 CO 2 fixation and a 14 C-in corpor­ation into aspartate, glutamate and 3-phosphoglyceric acid only. During dark 14 CO 2 assimilation labelling of these products could be measured, too. In a nitrogen atmosphere (N 2 + 0.04 vol. % CO 2 ) a strong labelling of sugar monophosphates mainly at the beginning o f photosynthetic period could be observed. In an oxygen atmosphere (100% O 2 ) an enhanced label of aspartate and glycerate and a decreased radioactivity in sugar monophosphates were found. Our results were discussed with reference to the operating of a phosphoenolpyruvate carboxylation reaction be­ sides the Calvin cycle and to the glycolate metabolism.

The aim of this investigation was to elucidate the rapid synthesis o f monogalactosyl mono­ glycerides and their role as intermediary acyl-acceptors in galactolipid synthesis of spinach chlo­ roplasts. The problem was attacked by studying the incorporation o f sn-[14C]glycerol-3-phosphate and [l-14C]acetate into the lipid fraction o f gently shocked and reconstituted preparations. The data revealed: 1 . a concurrent accumulation o f both monoglycerides and monogalactosyl monoglycerides under acidic incubation conditions, with C16-fatty acid species predominating, 2 . similarities in the fatty acid incorporation of both monoacyllipids, 3. the occurrence o f two isomeric forms viz. 1 -and 2-O-acyl-isomers o f these lipids. Thus, it appears that monogalactosyl monoglycerides are synthesized by galactosylation o f mo­ noglycerides rather than by galactolipase hydrolysis. Both monoacyllipids are likely to be derived from the corresponding lysophosphatidic acids by dephosphorylation. Their fatty acid incorporation pattern therefore may contribute to an under­ standing of the specific esterification o f different fatty acids at the Ct-and exp osition of the gly­ cerol moiety of galactolipids. Analysis o f the specific acylation o f monoglycerides and monogalac­ tosyl monoglycerides as well as the nature of the acyl donors involved in this fatty acid transfer yielded the following observations: 5. The position of the fatty acids within the monoacyllipids seems to depend on whether acyl-ACP or acyl-CoA is the primary acyl donor. 6 . The characteristics of the fatty acid incorporation into monoglycerides and their galactosylated derivatives support the notion that a successive acylation o f sn-glycerol-3-phosphate occurs first in the C2-and then in the Q-position. 7. In contrast, the chain length o f the fatty acids incorporated seems to be determined by such fac­ tors as pH and the concentration o f sn-glycerol-3-phosphate. This observation suggests that these parameters may act by controlling the elongation o f ACP-bound C16-fatty acids to their C18-species.

Murein, Models, Fourier Transforms Murein, the rigid layer of the cell walls of almost all bacteria can be regarded as derivative of chitin. Within the sterically allowed region its polysaccharide chain can perform conformations with two-to threefold screw axes. Two dimensional Fourier transforms calculated from different possible conformations have been compared with data of density measurements, X-ray and electron diffraction. The Fourier transform of murein with a chitin-like conformation of the poly­ saccharide chain and an elementary cell of 4.5 × 10.4 × 21.5 Å 3 provides the best agreement with the experimental results.

The maximal binding of antibodies against the subunits of the coupling factor o f photo­ phosphorylation onto the ultrasonic sediment and to stroma-freed chloroplasts of Antirrhinum majus was determined. Different surfaces o f the thylakoid membrane are accessible to antibodies in both chloroplast preparations. Stroma-freed chloroplasts bind antibodies only at the outer surface, which is directed towards the stroma in intact chloroplasts. In the ultrasonic sediment, which is the product of ultrasonication and centrifugation, as was demonstrated by electronmicroscopy, the major part of the surface directed towards the inside of the thylakoids is accessible. Both chloroplasts preparations are able to bind different amounts of antibodies to the five sub­ units of the coupling factor. While antigenic determinants of all five subunits are present on the surface directed to the outside, the δ-components seems to be lacking on the surface directed towards the inside. The α- and ε-component bind on both surfaces nearly the same amount of antibodies. Antigenic determinants of the β-subunit seem to exist in higher concentrations on the surface towards the outside and those of the γ-subunit on the surface towards the inside. From the serological investigations it follows that coupling factor molecules span the thylakoid membrane from the outside to the inside. They are not only present in those parts of the thylakoid membrane, exposed in intact chloroplasts to the stroma, but also in stacked thylakoids. The differences between the results of other authors and the present results are discussed.

Intact chloroplasts exposed to hypotonic assay conditions are capable of photophosphorylating exogenous ADP. The rate of phosphorylation by these unbroken plastids is increased by 10-50% upon the addition of low concentrations (<mм) of NH 3 or CH 3 NH 2 . Stimulation of phosphorylation is abolished by washing chloroplasts with MgCl 2 . Evidence is presented that washing removes a factor responsible for amine-induced increase of ATP production and that this factor is associated with the thylakoid membrane. Addition of CH 3 NH 2 increased the proton permeability of the thylakoid membrane of unbroken and washed chloroplasts during the light/dark transition. Hence, differences of the membrane permeability for protons between the two preparations seem not to be responsible for an increase of ATP production upon the addition of amines. Stimulation of photophosphorylation by methylamine is observed even at light itensities which do not saturate the proton motive force, which in turn is reduced upon the addition of the uncoupler. Apparently, phosphorylation can be stimulated, although the limiting driving force is diminished. It is concluded that phosphorylation by unbroken chloroplasts under low light illumination is limited kinetically, not energetically. Consequences of these findings for observation made with intact chloroplasts are discussed.

Completely dissolved lipids of a prolamellar body/primary thylakoid (PLB/PT) fraction from etiolated Avena sativa plastids were reaggregated in vitro. The analysis of the originating tubular structures showed a qualitative identity in their lipid content with that of the native PLB/PT fraction. Reaggregation experiments also showed that not all lipids constituting the PLB are necessary to build up the tubular structures. Only avenacosids A and B together with 3-β-hydroxy-sterols are the obligatory structural components.

An improved method for isolation of (photosystem II)-particles from Euglena gracilis, strain Z was established. PS II-particles isolated by ultrasonic treatment and following differential centrifugation show fluorescence emission and absorption spectra identical with in vivo properties of Euglena gracilis. These PS II-particles have only PS II-activity and contain CP a, the typical chlorophyll-protein-complex of PS II. No contamination of PS I-components are detectable.

With chlorophyll a-dipalmitoylphosphatidylcholine-liposomes, the absorption increases at 706 and 450 nm, and decreases at 660 and 420 nm, as the temperature is lowered. As the temperature is increased opposite changes are observed. A lipid phase change occurs at 34°. The pigment to lipid ratio is 1 to 5 in the liposome. With chlorophyll a-soy bean lecithin-liposomes the absorption increases at 706, 680 and 440 nm, and decreases at 650 and 430 nm, as the temperature is lowered. As the temperature is increased, opposite changes are observed. A lipid phase change occurs at 26-27 °C. The pigment to lipid ratio is 1 to 13. The spectral change at 706 nm is identified with aggregated chlorophyll. The concentration of chlorophyll aggregate increases as the temperature is lowered, and decreases as the temperature is raised. Fluorescence decay from chlorophyll a-soy bean lecithin-liposomes is biphasic. The lifetimes of freshly prepared liposomes are 121 ± 4 ps and 1400 ± 200 ps. The relative contribution of the fast and slow fluorescence components are modified by temperature. Heating results in an increase in both lifetimes, and an increase in fluorescence from the long lived component. These changes are interpreted as resulting from a decrease in energy transfer and concentration quenching. The origin of the biphasic fluorescence and spectral transformations in liposomes, and the possible relation between in vitro and in vivo picosecond fluorescence is discussed.

Diuron and bentazon are very strong inhibitors of the photosynthetic electron transport in isolated radish chloroplasts. The chlorosis producing herbicide SAN 6706 also inhibited the photosystem II dependent oxygen evolution. Aminotriazole had no effect. The inhibitor concentration for 50% inhibition of photosystem II activity was 10 -7 m for diuron and 10 -4 m for bentazon and SAN 6706 respectively. Diuron and bentazon quenched the chlorophyll a fluorescence transients in isolated radish chloroplasts drastically, while aminotriazole was not effective. It was of particular interest that the bleaching herbicide SAN 6706 inhibited photosystem II dependent oxygen evolution in a similar concentration as bentazon but had no effect on the chlorophyll a-fluorescence transients suggesting that SAN 6706 is not binding to the same site of the electron transport chain as diuron and bentazon. Apart from their direct influence on electron transport in isolated photosynthetically active chloroplasts the photosystem II and bleaching herbicides assayed also strongly affected photosynthesis in radish seedlings that were grown in the presence of the herbicides for a long time. As already obtained using isolated chloroplasts, photosystem II dependent oxygen evolution like the chlorophyll a fluorescence transients were strongly inhibited by the photosystem II herbicides diuron and bentazon. A reduction but no inhibition of photosystem II activity was observed in plants that were grown in the presence of aminotriazole. The pyridazinone SAN 6706 was behaving contradictory. In partly green plants photosystem II activity was still maintained and even higher than in untreated plants while in albinistic plants no photosynthetic activity was detected.

The effects of the aminotriazinone herbicides metribuzin [4-amino-6-tert-butyl-3-(methylthio)-1,2,4,-triazin-5(4H)one] and metamitron [4-amino-3-methyl-6-phenyl-1,2,4-triazin-5(4H)-one] on the metabolism of enzymatically isolated leaf cells of Abutilon theophrasti Medic, were examined. Photosynthesis, protein, ribonucleic acid (RNA), and lipid synthesis were assayed by the in­ corporation of radioactive substrates such as NaH 14 CO 3 , [ 14 C]leucine, [ 14 C]uracil, and [ 14 C]acetate, respectively, into the isolated cells. Photosynthesis was the most sensitive process inhibited by both herbicides, but metribuzin was a more potent inhibitor than metamitron. Protein synthesis was not affected by any herbicide. RNA synthesis was inhibited significantly by both herbicides and may be involved in their ultimate herbicidal action. Lipid synthesis was inhibited significantly only by the high concentrations of metribuzin, and it was not affected by any concentration of metamitron at any incubation time. Inhibition of lipid synthesis may be involved in the action of metribuzin as a herbicide.

The crystal structure of Trimethyl(4-oxopentyl)ammonium-chloride ([(CH 3 ) 3 N + -(CH 2 ) 3 COCH 3 ]Cl - ) (1) was determined by an X-ray structure analysis. 1 crystallizes in the orthorhombic space group P2 1 2 1 2 1 with a = 10.440 (3), b = 14.600 (9), c = 6.804 (9) Å and with four formula units per unit cell. The structure was solved by a Patterson and a successive Fourier synthesis. The least squares refinement yielded an R-value of 0.064 for 1077 observed reflections. The cation of 1 is derived from acetylcholine by replacement of the ester oxygen with a CH 2 group. It shows a potent nicotinic activity and a significant difference in conformation as compared with acetylcholine. In the crystal structure the anions are oriented stereospecifically with respect to the tetrahedron of the quaternary ammonium group. The geometry of two triangles formed by the quaternary nitrogen atom, the oxygen atom of the carbonyl group, and by either of the two anions nearest to the quaternary ammonium group is characteristic for the nicotinic activity of 1.

1. Delipidation of the Ca 2+ -ATPase of sarcoplasmic reticulum membranes by gel chromatography employing ionic detergents (cholate, deoxycholate and mixtures of both) in the presence of glycerol has been studied with respect to residual phospholipids and ATPase activities. 2. The extent of delipidation depends on the detergent chosen and on the ionic strength of the elution buffer. Increasing ionic strength favours a more effective removal of phospholipids, down to about 1 phospholipid molecule per ATPase molecule. 3. The residual ATPase activities of the delipidated preparations are negligibly low. Extensive restoration of the Ca 2+ -dependent ATPase activity has been achieved by oleic acid, a lysolecithin (myristoylglycerophosphocholine) and a lecithin (dimyristoylglycerophosphocholine). The per­ centage of reactivation by oleate depends linearly on the amount of residual phospholipids and on the detergent employed. 4. After gel filtration through an Ultrogel or Sepharose column containing 1% cholate in the elution buffer the delipidated ATPase is eluted as a reactivatable high molecular aggregate, whereas 1% deoxycholate favours the formation of completely lipid-free monomeric units which cannot be reactivated, however. A high molecular aggregate is also formed in deoxycholate, the ratio of monomer to polymer depending on the solubilizing and elution conditions. 5. The residual lipids are always composed of a mixture of all different lipid classes present in the native sarcoplasmic vesicles, even at high degrees of delipidation. Specific changes with varying extent of delipidation were not detected.

During the stepwise solubilization of sarcoplasmic reticulum vesicles with detergents, the following changes in the structural and enzymatic properties of the preparation are observed: 1. The viscosity of the vesicular suspension initially rises. This change is accompanied by the formation of elongated tubules. Subsequently the membranes are completely desintegrated, resulting in a considerable reduction of the viscosity. 2. A decrease in the activity of the Ca 2+ -dependent ATPase, which is restored after complete solubilization. 3. A decrease in the change of intrinsic tryptophan-fluorescence on removal of calcium ions, which is also restored after complete solubilization. 4. A decrease of the calcium affinity of the ATPase. 5. A decrease in the amount of phosphorylated protein formed by the incorporation of inorganic phosphate. On the other hand, the amount of phosphoprotein formed from ATP is not affected during solubilization. 6. The dependence of the initial rates of phosphoprotein formation from inorganic phosphate on either magnesium or inorganic phosphate at low concentrations of the respective ligand changes from an S-shape profile to a normal hyperbolic profile after solubilization.

Acetyl CoA Carboxylase, Protein Inhibitor, Rat Liver A high molecular weight protein (approximately 1.5-2 × 10 6 daltons) has been found in rat liv­ er cytosol to inhibit acetyl CoA carboxylase activity. The protein inhibitor was purified by am­ monium sulfate precipitation, DEAE-cellulose chromatography and gel filtration. The inacti­ vation of the carboxylase is not attributable to either phosphorylation of the enzyme or to action on substrates or cofactors of the reaction. The activity of the inhibitor is destroyed by heating to 55 °C for 5 min, by treatment with trypsin, or by increasing bovine serum albumin in the reaction mixture. Hence it appears that the inhibitor is a regulatory protein that acts directly on acetyl CoA carboxylase.

Phospholipase A 1 and A 2 , Lysolecithin-Acyltransferase, Macrophage, Subcellular Localization Analysis of the subcellular distribution of lipid-metabolizing enzymes was carried out in bone marrow-derived macrophages with special respect to a comparison of the subcellular localisation of phospholipase A 1 and A 2 and to acyl-CoA: 1-acylglycero-3-phosphorylcholine-0-acyltransferase. After cell disruption differential centrifugation was followed by additional sucrose gradient purification of three main fractions. Satisfactory enrichment factors were obtained by this method for the following marker enzymes. The plasma-membrane enzyme alkaline phosphodiesterase I was enriched up to 25-fold and the acyl-CoA:1-acylglycero-3-phosphorylcholine-0-acyltransferase was enriched up to 30-fold. The marker enzyme for the endoplasmic reticulum, NADPH-cytochrome c reductase showed a similar enrichment and distribution as the acyltransferase. Therefore it was concluded that the acyl-CoA:1-acylglycero-3-phosphorylcholine-O-acyltransferase of bone marrow-derived macrophages is mainly located in the endoplasmic reticulum. Phospholipase A 1 and A 2 occurred in a high proportion together with the lysosomal marker enzyme N-acetyl-β-glucosaminidase in the soluble supernatant and in the gradient fractions. In the endoplasmic reticulum phospholipase A 2 occurred only in trace activities whereas phospholipase A 1 was maximally enriched in this subcellular fraction. No subcellular fraction could be obtained where phospholipase A 2 was enriched exclusively. However, it can be concluded that the two enzymes which are responsible for the balance of fatty acid liberation and re-acylation are located in two different cellular compartments. Furthermore it can be claimed that in the cell there has to exist an exchange of substrates and products between these compartments to achieve a complete metabolic cycle of the de-and re-acylation reaction of phospholipids in bone marrow-derived macrophages.

The natural DNA sequence of bacteriophage, ΦX174, when analyzed as a "text" of dinucleo­ tides, is shown to display an easily detectable degree of non-randomness by the distribution of values of dinucleotide self-information along the sequence. Self-information corresponding to occurrences of dinucleotides separated by a single nucleotide is found to be somewhat higher than the values which preceed or follow it for every third nucleotide position along the sequence. Consequently autocorrelation coefficients of these values display a strong periodicity and harmonic analysis of the values shows a spike at a value of 3. Self-information autocorrelation periodicity is used as a test of the effect of randomizing portions of the sequence. Any one or two of the three nucleotides in each triplet of the sequence can be chosen at random without losing dinucleotide self-information periodicity except when both the 1st and 3rd nucleotide of all of the triplets in the major ΦX174 protein reading frame are randomized. Periodicity is also lost when sequences are generated by randomizing triplets. Autocorrelation and harmonic analysis also indicate other less marked periodic features of dinucleotide self-information values of the native sequence; non-random features are suggested at periods of 12,20 and 24 nucleotides.

The effects of deprivation of oxygen on proliferation kinetics of in vitro grown Ehrlich ascites tumor cells were studied by means of flow cytometry. The flow cytometric results obtained by applying the BUdR-H 33 258 technique showed that 6 -8 hours after establishment of anaerobiosis cells lose their capacity for proliferation and accumulate in the late G1-phase; during this time late S cells enter the G2 compartment but do not divide while cells, which are in G2+M at the beginning of anaerobiosis divide and enter G1. Cell cycle distribution remained constant up to about 20 hours, thereafter G1-cells enter the S-phase. Up to 24 hours of anaerobiosis cell number does not change and viability of the cells was not severely affected. Recultivation under aerobic conditions of 12 hours anaerobically treated cells revealed, that the cytokinetic properties of G1 cells were not impaired, while S-phase cells after reaeration did not enter G2 but began again to synthesize DNA forming cells with a DNA content greater than 4c. S-phase cells are most sensitive to deprivation of oxygen.

A novel C-methylated flavonoid has been isolated from the leaves of Dasylirion acrotrichum and Xanthorrhoea hastilis. It was identified by spectroscopic methods as 3-Omethyl, 8-C-methyl quercetin. The taxonomic and ecophysiological implications are discussed.

2′,6′,4-OH, 4′-OMe-chalcone (neosakuranetin) and 2′,6′,4-OH, 4′-OMe-dihydrochalcone (asebogenin) were found as major constituents of the frond exudate on one in­ dividual plant of Pityrogramma calomelanos. Galangin-5,7-dimethyl ether was isolated from the farina on fronds of a certain population of Pityrogramma triangularis as a novel natural flavonol.

Actinioerythrin has been isolated together with asta-xanthin-esters and β-carotene from different samples of Mullus barbatus for the first time.

We report on the chemical preparation of the NAD + analog P1, P2-(5′-β-nicotinamideribofuranosyl-3″-adeno-syl)-diphosphate (N3″AD + ) by applying the 1,1′-carbonyl-diimidazole activation method. The importance of how adenosine is linked to the nicotinamide mononucleotide phosphoriboride (NMNPR + ) moiety is discussed with re­ spect to the coenzyme activity in the lactate dehydrogenase catalyzed reaction.

The nuclear envelope of the larval fat body in the blow­ fly Calliphora vicina reveals a conspicuous nuclear lamina. It appears homogeneous, Fibrous or granular depending upon the fixing and staining methods. The best relative contrast for the nuclear lamina and the nuclear pore complex is obtained with a phosphotungstic acid staining procedure designed for proteins.

Workers of Formica polyctena Förster (Hymenoptera, Formicidae) follow artificial trails made with the contents of mandibular glands, poison glands, Dufour glands and rectal glands of their own species, as well as recruitment trails of Lasius fuliginosus (Latreille) or Myrmica ruginodis Nylander. Some specialized out-door workers prefer poison trails, as do workers irritated by a marking procedure. After withdrawal of sugared water the workers prefer rectal trails. Workers of hungry colonies also follow trails made with sugared water or faeces of tortricid larvae.