bluuebunny/crossref_metadata_2025 huggingface dataset:
Solution Conformations of Some Acyclo Nucleoside and Nucleotide Analogues of Antiviral Acyclonucleosides, and Their Substrate/Inhibitor Properties in Several Enzyme Systems
Authors: Stolarski Ryszard , Lassota Piotr , Kazimierczuk Zygmunt , Shugar David
Published: August 2018

Chemical and enzymatic procedures have been employed for the preparation of various phosphorylated derivatives of the acyclonucleoside 9-(1,3-dihydroxy-2-propoxymethyl)adenine, an analogue of the active antiviral agent 9-(1,3-dihydroxy-2-propoxymethyl)guanine (DHPG). In combination with the previously reported 2′,3′-seco nucleosides and their phosphates and cyclic phosphates (Stolarski et al., Z. Naturforsch. 41c, 758-770, 1986), this made available a broad class of acyclonucleosides and nucleotides, the acyclic moieties of which are capable of mimicing the ribose and 2′-deoxyribose rings.

The solution conformations of the foregoing were determined with the aid of 1H, 13C and 31P NMR, and compared with those of DHPG and 9-(hydroxyethoxymethyl)guanine (Acyclovir, ACV). Particular attention was devoted to conformations about C-O bonds in different acyclic fragments, which demonstrated well-defined differences between 2′,3′-seco derivatives on the one hand (conformational “rigidity”) and derivatives with DHP and AC acyclic chains on the other (rotation about the C(1′)-O(4′) bond). The overall results are in good general agreement with reported crystal structures, and are compared with those obtained by quantum mechanical calculations.

The conformational features of the various compounds are also discussed in relation to their substrate and/or inhibitor properties in a number of enzyme systems, including adenosine deaminase, phosphodiesterases, nuclease P1, 3′-nucleotidase and herpes virus type 1 thymidine kinase.
2′,5′-Dihydroxyflavone and its 5′-Acetate — Novel Compounds from the Farinose Exudate of Primula
Authors: Wollenweber Eckhard , Mann Karin , Iinuma Munekazu , Tanaka Toshiyuki , Mizuno Mizuo
Published: August 2018

2′,5′-Dihydroxyflavone and its 5′-acetate were isolated from the farinose exudate of Primula japonica and P. pulverulenta. Their structures were elucidated by spectroscopic methods and confirmed by synthesis. Both flavones are novel natural products.
On the Volatile Components of Heterotropa takaoi and Related Species (Aristolochiaceae)
Authors: Hayashi Nanao , Sugiyama Yasuharu , Yasuda Sigejiro , Komae Hisashi
Published: August 2018

The volatile components of the leaves of four species and five varieties of the section Bicornes of Heterotropa were examined by gas chromatography and gas chromatograph-mass spectrometry. The analytical results showed that the species of the section contain phenylpropanes, terpenes, and a paraffin as main components. The components have been used to construct phylogenetic trees of the section Bicornes. Despite some discrepancies, the phylogenetic tree obtained for the section seems to be relevant at the tribal revel. Among the species of the section, geographical variation of twelve localities of H. takaoi also were examined and three chemical types (myristicin, safrole, n-pentane-elemicin types) of H. takaoi are distinguished on the basis of their components.
Biosynthesis of Porphyrinogens in Etiolated Euglena gracilis Z. I. Isolation and Purification of an Endogenous Factor Stimulating the Formation of Porphyrinogens
Authors: Juknat A. A. , Dörnemann D. , Senger H.
Published: August 2018

A low molecular weight, heat-stable factor has been purified from Euglena gracilis supernatant fraction by employing gel filtration, cation and anion exchange and paper chromatography.

This endogenous compound stimulates porphobilinogenase (PBG-ase) (EC 4.3.1.8) activity, an enzyme of the porphyrin biosynthetic pathway.

10-7 ᴍ folic acid and 10-4 ᴍ 6-biopterin produced a significant activation, equivalent to 2-4 units of the purified factor.

Elution patterns from the columns and fluorescence and UV absorption peaks suggest that this compound is a pteridine. This conclusion is further supported by the fact that both, folic acid and 6-biopterin can replace the action of the isolated factor on PBG-ase. The mechanism of stimulation is discussed.
On the Role of Δ1-Piperideine and Tripiperideine in the Biosynthesis of Quinolizidine Alkaloids
Authors: Perrey Ralf , Wink Michael
Published: August 2018

Carbon 14-labelled cadaverine, Δ1-piperideine and α-tripiperideine were administered to leaf disks of Lupinuspolyphyllus in short term experiments of 12-20 h duration. Whereas cadaverine was readily incorporated into lupanine in good yields, a 7 to 60 times lower incorporation was observed for tripiperideine or Δ1-piperideine. In L. arboreus the incorporation of cadaverine into sparteine was 9 times better than that of Δ1-piperideine. These results indicate that Δ1-piperideine and tripiperideine are not direct intermediates of lupanine or of sparteine biosynthesis.
Ribosylierung mono- und bicyclischer Dicarbonsäureimide / Ribosylation of Mono- and Bicyclic Dicarboxylic Acid Imides
Authors: Raezke Kurt-Peter , Frister Hermann , Schlimme Eckhard
Published: August 2018

The N-trimethylsilyl compounds of the cyclic imides derived from cis-cyclohexan-1,2-dicarboxylic acid, cis-4-cyclohexen-1,2-dicarboxylic acid and phthalic acid were prepared. Reaction of the N-silylated cyclic imides 2 and 10 with 1,2,3,5-tetra-O-acetyl-β-ᴅ-ribofuranose in the presence of tin tetrachloride yielded the appropriate unusual ribonucleosides 4 and 12 whereas 14 led only to traces of the ribosylated derivative. The silylation and ribosylation sites in the aforementioned bicyclic imides were proved by 1H, 13C, and 29Si NMR spectroscopy and compared with data found for the monocyclic imides N-succinimide and N-maleinimide.
Cerulenin-Induced Modifications in the Fatty Acid Composition Affect Excitation Energy Transfer in Thylakoids of Petunia hybrida Leaves
Authors: Graf Josef A. , Witzan Karin , Strasser Reto J.
Published: August 2018

Cerulenin-induced modifications in the fatty acid composition have been used to investigate the influence of acyl lipids on excitation energy distribution in thylakoid membranes of Petunia hybrida by means of 77 K fluorescence spectroscopy. Although cerulenin has no effect on relative contents of chlorophyll and acyl lipids, changes in the fatty acid composition of all thylakoid acyl lipids have been observed. The main cerulenin effect seems to be an increase in linoleic acid at the expense of saturated and monounsaturated C16- and C18-fatty acids resulting most likely in an increase in acyl lipid species containing both linoleic and linolenic acid. Low temperature (77 K ) fluorescence kinetics reveal a remarkable decrease in the ratio of the variable divided by the maximal fluorescence of photosystem II (F2(v)/F2(M)), taken as indicator for cerulenin-induced changes in this photosystem. Calculations of the excitation energy distribution terms based on a grouped bipartite model of photosynthesis suggest that a decrease in this ratio is caused by changes in energy transfer probabilities responsible for both, photochemical trapping of photosystem II and energetic cooperativity (grouping) between different photosystem II-light harvesting complex-units. Moreover, changes in the conformation responsible for spillover energy transfer are most likely to occur. Correlations between cerulenin-induced modifications of fatty acid composition and energy distribution support the assumption that excitation energy transfer depends on the structural state of the lipid matrix.
Evidence for Photoreduction of NADP+ in a Suspension of Lysed Plastids from Etiolated Bean Leaves
Authors: Bertrand Martine , Bereza Barbara , Dujardin Esther
Published: August 2018

It has been investigated if photoreduction of NADP+ (detected by absorption spectroscopy) may take place in lysed plastids within minutes of exposure to light. This process was made possible by removal of oxidants from the reaction mixture. Lysed plastids were suspended in a medium containing NADP+ , catalase, glucose oxidase and glucose; exposure to light simultaneously to addition of ferredoxin and ferredoxin-NADP+ reductase, resulted in increased absorbance in the band around 340 n m , while addition of 3-phosphoglycerate resulted in the disappearance of this band. Ferredoxin and ferredoxin-NADP+ reductase are only effective when photoactivation takes place before their addition to the medium.
Novel Glucoalkaloids from Rauwolfia Cell Cultures – Acetylrauglucine and Related Glucosides
Authors: Ruyter Carl Michael , Schübel Helmut , Stöckigt Joachim
Published: August 2018

From cell suspension cultures of Rauwolfia serpentina grown in an optimized production medium for the glucoalkaloid raucaffricine, a novel glucoalkaloid was isolated and identified as 17-O-acetyl-21-O-β-ᴅ-glucopyranosyl-ajmaline (acetylrauglucine). This alkaloid is formed in very small amounts (< 5 × 10-4%). The biogenetically related Nα-demethylated base (acetyl-nor-rauglucine) and the deacetyl product rauglucine have also been detected in culture extracts. In addition 21(.R)-(β-D-glucopyranosyl)-hydroxy-sarpagan-17-al has been isolated and identified as an artifact which originates from raucaffricine.
Glycosilation of Terpenols and Aromatic Alcohols by Cell Suspension Cultures of Peppermint (Mentha piperita L.)
Authors: Berger R. G. , Drawert F.
Published: August 2018

Plant cell cultures effectively convert terpenoid and aromatic alcohols into glycosides. A quantitative comparison showed a culture of peppermint (Mentha piperita) to be the most active among four species examined. The synthesis of glycosides was affected by the concentration of substrate, incubation period, cell age and aggregation, and by light. Conversion rates of exogenous alcohols were greater than 70% under optimized conditions.
Biosynthesis of Lipids Containing Isoricinoleic (9-Hydroxy-cis-12-octadecenoic) Acid in Seeds of Wrightia Species
Authors: Ahmad Fasih , Mukherjee Kumar D.
Published: August 2018

Seeds of two Wrightia species, i.e. W. tinctoria and W. coccinea, synthesize triacylglycerols containing isoricinoleoyl (9-hydroxy-cis-12-octadecenoyl, 9-OH-Δ1218:1) moieties as the major lipid constituents. Seed maturation is accompanied by lipid accumulation and steep increase in the level of 9-OH-Δ1218:1 in the total lipids, while relative proportions of palmitic (16:0), oleic (18:1), and linoleic (18:2) acids decrease. 9-Hydroxy stearic acid (9-OH-18:0) is also detected in these seed lipids, and both 9-OH-Δ1218:1 and 9-OH-18:0 occur exclusively in the neutral lipids of mature and developing seeds. Developing seeds of both Wrightia species synthesize upon incubation with sodium [1-14C]acetate, besides common long-chain fatty acids, considerable proportions of 9-OH-Δ1218:1 and 9-OH-18:0, which are predominantly esterified in triacylglycerols. Substantial proportions of radiolabeled 9-OH-Δ1218:1 and 9-OH-18:0 are also formed upon anaerobic incubation of the developing seeds with the ammonium salts of [1-14C]18:2 and [1-14C]18:1, respectively. The data presented suggest that hydration of the Ay olefinic bond of 18:2 is a possible pathway of synthesis of 9-OH-Δ1218:1, however, hydration of the Δ9 olefinic bond of 18:1 followed by Δ12 desaturation of 9-OH-18:0 cannot be ruled out.
Hydroxylation of Chlorinated and Unchlorinated Chlorophylls in vitro
Authors: Senge M. , Struck A. , Dörnemann D. , Scheer H. , Senger H.
Published: August 2018

Chlorophyll a is hydroxylated quantitatively in the 132-position, when chromatographed on silica gel thin-layer plates. This was shown by using HPLC as a non-destructive method für analyzing photosynthetic pigments. The hydroxy-group of Chl RC I, a 132-hydroxy-20-chloro-chl a. described by Dörnemann and Senger (1986) and Scheer et al. (1986), is shown to be artificially introduced during the purification procedure by TLC.
Synthesis of Flavonoid Sulfates. II. The Use of Aryl Sulfatase in the Synthesis of Flavonol-3-sulfates
Authors: Barron Denis , Ibrahim Ragai K.
Published: August 2018

The rates of aryl sulfatase hydrolysis of several 7-, 4′- and 3-sulfated flavonoids were compared and found to follow the order 7 or 4′ >>> 3. The complete resistance of the 3-sulfate ester to enzyme hydrolysis provided a unique and convenient method for the synthesis of a number of naturally occurring flavonol-3-sulfates from the corresponding higher sulfated analogs in quantitative yield.
Mammalian Pheromone Studies, VII*. Identification of Thiazole Derivatives in the Preorbital Gland Secretions of the Grey Duiker, Sylvicapra grimmia, and the Red Duiker, Cephalophus natalensis
Authors: Burger B. V. , Pretorius P. J. , Stander Jonine , Grierson G. R.
Published: August 2018

2-Isobutyl-1 ,3-thiazole and its 4,5-dihydro derivative were identified in the preorbital gland secretions of the grey duiker, Sylvicapra grimmia, and the red duiker, Cephalophus natalensis, but are absent from the preorbital secretion of the blue duiker, C. monticola. These two compounds which are present in high, but varying concentrations in the secretions of male grey duikers, are present in low concentrations in the secretions of females. This seems to be the only consistent significant difference between the secretions of male and female grey duikers and together with the fact that only males mark out their territories, was construed as evidence in favour of these two compounds playing a significant role in the territorial behaviour of male grey duikers.
Effect of Preparative Procedures on Ghostcells from Bovine Erythrocytes
Authors: Pitterich Horst , Lawaczeck Rüdiger
Published: August 2018

Several methods for the preparation of “white ghosts” or “resealed ghosts” were described in the recent literature. This article compares three methods to prepare white, resealed ghosts from bovine erythrocytes based on the principle of hypotonic lysis. The methods described differ by the removal of hemoglobin from the empty cells. The main difference between the standard centrifugation, the gelfiltration and the hollow-fibre diafiltration is the mechanical stress on the leaky membranes after swelling in hypotonic media. Mean cellular volumes, rates of potassium-efflux and the access of impermeable dyes to cytoplasmatic proteins are criteria to differentiate between ghostcell-populations.
Sex Pheromone of Brinjal Shoot and Pod Borer Leucinodis orbonalis Guenèe (Lepidoptera: Pyralidae: Pyraustinae)
Authors: Attygalle Athula B. , Schwarz Jürgen , Gunawardena Neelakanthi E.
Published: August 2018

(E)-11-Hexadecenyl acetate is the major volatile component of the sex pheromone gland of female Leucinodis orbonalis collected from Sri Lanka. (E)-11-hexadecen-1-ol was also found in trace quantities.
Evidence of an Intracellular Dissipative Structure
Authors: Medina Miguel Angel , Núñez de Castro Ignacio
Published: August 2018

Data are presented showing the result of the functioning of the mitochondrial respiratory chain in Ehrlich ascites tumour cells incubated with glucose and glutamine.

The very different results obtained depending on the order of substrate addition suggest that the functioning of the respiratory chain in Ehrlich cells far-from-equilibrium maintains an intracellular dissipative structure.
Biosynthesis of Cytochalasans. XI. New Results on the Incorporation of Phenylalanine into Cytochalasin D by Zygosporium masonii [1]
Authors: Hädener Alfons , Roth Patricia , Tamm Christoph
Published: August 2018

Incorporation of L-[2-2H]phenyl-[2-2H]alanine and L-phenyl-[2-13C, 15N]alanine into cytochalasin D by Zygosporium masonii involved the complete loss of both the α-2H- and the α-15N-atom. Incorporation of a mixture of L-phenyl-[15N]alanine and L-[U-14C]phenylalanine into cytochalasin D and protein amino acids (phenylalanine, leucine, isoleucine) was accompanied by a substantial loss of 15N with respect to 14C. These effects are attributed to rapid exchange reactions taking place while L-phenylalanine is part of the intracellular pool of amino acids. In addition, the medium- and concentration-dependent incorporation of the carbon skeleton of exogeneous D-phenylalanine into cytochalasin D is reported. In a peptone-based complex medium, D-phenylalanine is poorly incorporated. Throughout the whole concentration range (0-250 mg/l), the incorporation rates are less than 10% of those of L-phenylalanine. In a minimal medium containing NH4NO3 as nitrogen source however, D-phenylalanine is preferred over the natural enantiomer by a factor of 1.28 up to 6.78, depending on the concentrations of exogeneous D - and L-phenylalanine. These effects are attributed to the medium-dependent activities of different amino acid transport systems responsible for the uptake of D - and L-phenylalanine in Z. masonii.
Inhibitors Influencing Plant Enzymes of the Polyamine Biosynthetic Pathway
Authors: Christ Marbeth , Felix Hansruedi , Harr Jost
Published: August 2018

Absract

Several enzymes involved in polyamine biosynthesis namely ornithine, arginine and S-adenosylmethionine decarboxylase as well as spermidine synthase, were analyzed in partially purified wheat extracts. For all enzymes effective inhibitors were found. Among them the most interesting was l-aminooxy-3-aminopropane, which inhibited all three decarboxylases. Classical polyamine biosynthesis inhibitors like difluoromethylornithine, difluoromethylarginine. methyl glyoxal bis- (guanylhydrazone) and cyclohexylamine were also inhibitory on plant enzymes.

A remarkable difference in the amount of arginine and ornithine decarboxylase existed in wheat. Arginine decarboxylase seems to be more important at least during the early stage of development. Influence of polyamine synthesis inhibitors on polyamine levels is more likely to come from arginine decarboxylase inhibitors.

As inhibitors of all essential enzymes involved in plant polyamine biosynthesis were found, the study of the importance of polyamines in plant physiology will be considerably facilitated.
Product Specificity in an Entire Series of (ω-6 Z, ω-9 Z)-C13~C20-Dienoic Acids and -Dienols for Soybean Lipoxygenase
Authors: Hatanaka Akikazu , Kajiwara Tadahiko , Matsui Kenji , Yamaguchi Masanori
Published: August 2018

Substrate specificity of soybean lipoxygenase-1 (EC 1.13.11.12) was studied using as synthetic substrate analogs an entire series of (ω-6 Z,ω-9 Z)-C13 ~ C20 (rdienoic acids and (ω-6 Z,ω-9 Z)- C12 ~ C20 (i-dienols. The relative activity of lipoxygenase-1 against linoleic acid (C18:2COOH) was the highest among the dienoic acids and that of (6Z.9Z)-pentadecadienol (C15:2OH) was the highest among the dienols. Soybean lipoxygenase-1 oxygenated almost at to- 6 position of the dienoic acids independently of the chain length. With the dienols as substrate, the position of oxygenation was much influenced by the chain length. Above all, C15:2OH was selectively oxygenated at ω-10 rather than at ω-6 . Kinetic analyses revealed that longer and more hydrophobic dienols had higher affinity but lower velocity of oxygenation reaction. But higher velocity was obtained when smaller Km value was observed for the dienoic acids.

To clucidate stereospecificity of the oxygenation to C15:2OH, optically active authentic samples were prepared via biological asymmetric reduction with baker’s yeast. The ω- 6 oxygenation to C15:2OH was found to be (S)-specific (R/S = 26/74) as is that to C18:2COOH. whereas the ω-10 oxygenation showed low enantioselectivity (R/S - 60/40).
Trace Elements in Propolis and in its Ethanolic Extract (EEP) as Determined by Neutron Activation Analysis
Authors: Scheller S. , Czauderna M. , Krol W. , Konecki J. , Czuba Z. , Gabrys J. , Glowacka M. , Shani J.
Published: August 2018

Propolis is a natural composite balsam, manufactured by honey bees, and active biochemically. Some of its biological effects are attributed to its ability to stimulate enzymatic systems, which in many instances involve trace elements. In the present study we assayed propolis and its ethanolic extract (EEP) for trace elements, and quantified them with the aid of neutron activation analysis. Four elements that have been detected in propolis and EEP for the first time are Na. Cr, Co (ppm) and Ag (ppb). The wide concentration range of the inorganic components in various batches of propolis and EEP is due to the difference in their extraction capacities, and to the variability in the environmental pollutants and the flora at the beehive sites.
The Formation of Singlet Oxygen during Oxidation of Catechol Amines as Detected by Infrared Chemiluminescence and Spectrophotometric Method
Authors: Kruk Irena , Lichszteld Krzysztof , Michalska Teresa , Wronska Joanna , Bounias Michel
Published: August 2018

1Δg → 3∑g
- near infrared chem iluminescence from the peroxidation reaction of dopa, dopamine, noradrenaline and adrenaline was measured. The spectrophotometric method based on the bleaching of p-nitrosodimethylaniline was applied to check the generation of singlet oxygen catecholamines.
Kaurane-Type Diterpenes from Fern Frond Exudates
Authors: Rüedi Peter , Wollenweber Eckhard , Marx Dieter , Scheele Cornelia
Published: August 2018

The viscid exudate found on fronds of the fern, Cheilanthes kaulfussii, consists of terpenoids in which flavonoid aglycones are dissolved. One of the terpenes is shown to be em-kaur-16-en-19-oic acid. The farinose frond exudate of Notholaena pallens contains this acid as the major constituent and its 3 R-hydroxy derivative, together with flavonoid aglycones as minor components. In N.incana, two of the diterpenes that form the farinose exudate along with flavonoid aglycones have been identified as 16R-ent-kauran-17-oic acid and 16R,17-dihydroxy-3-oxo-ent-kaurane (abbeo-kutone).
Isoflavonoids from the Root Bark of Piscidia erythrina and a Note on the Structure of Piscidone
Authors: Ingham John L. , Tahara Satoshi , Shibaki Seiji , Mizutani Junya
Published: August 2018

A methanolic extract of Piscidia erythrina root bark has been found to contain various isofla-vonoids including rotenone (rotenoid), lisetin (coum aronochrom one) and six known isoflavones (ichthynone, piscidone, piscerythrone, 2′-deoxypiscerythrone, 6′-prenylpiscerythrone and 3′,5′-diprenylgenistein). The extract additionally yielded three new 5-hydroxyisoflavones (piscery-thrinetin, 2′-hydroxypiscerythrinetin and isow ighteone) and a previously unreported coum arono­ chrom one (8-prenyl-lisetin). All four com pounds were identified using a com bination of spectro­ scopic (UV , MS, 1H NMR) and chemical methods. Although several other 5-hydroxyisoflavones were also isolated from the root bark extract, the quantities of each were sufficient only to permit their partial characterization. Structure 2 for piscidone has been confirmed by 1H NMR spectros­ copy.
The Occurrence of β-Carotene-5,6-epoxide in the Photosynthetic Apparatus of Higher Plants
Authors: Young Andrew , Barry Paul , Britton George
Published: August 2018

The occurrence of β-carotene-5,6-epoxide in higher plant photosynthetic tissue is described. The compound is found in isolated chloroplasts, thylakoids and other subchloroplast particles but can only be detected in intact leaves or cotyledons of higher plants when these are exposed to very high light intensities or to inhibitors such as monuron or paraquat. The distribution of the epoxide within the individual pigment-protein complexes is given. It is particularly associated with the PS I reaction centres (C P I and CP la) and less so with the PS II reaction centre (CPa).

Circular dichroism shows that the β-carotene-5,6-epoxide isolated from photosynthetic tissue is optically inactive. It is therefore not produced enzymically but is a product of photooxidative events in the photosynthetic apparatus. Its presence in photosynthetic tissue is a reliable indicator of photooxidative damage to the thylakoid membrane involving oxidation of β-carotene.
Growth Inhibition of Kirkman-Robbins Hepatoma by l-(l,3-Dihydroxy-2-propoxymethyl)-5,6-tetramethyIeneuraciI and Possible Mechanism of its Biological Activity
Authors: Greger Janusz , Dramiriski Marcin
Published: August 2018

Hepatoma, Acyclonucleoside Metabolism , dN and dTMP Kinases. dNTP Pool l-(l,3-D ihydroxy-2-propoxym ethyl)-5,6-tetram ethylene-uracil (DHPTU) is a newly synthe­ sized acyclonucleoside which shows cytostatic properties. It was tested in Syrian hamster 6 days after heterotransplantation of Kirkm an-Robbins hepatoma. A reduction of tumour weight by 61% was found 48 h after its intraperitoneal (i.p .) administration in doses of 20 mg per kg of body weight. Inhibition of tumour growth is accompanied by a reduction of dThd, dGuo and dTMP kinase activities in tumourcytosol (by 91% and 74% and 55% , respectively) and decrease in contents of dTTP, dGTP and dA TP (by 92% , 77% and 67% , respectively) in dNTP pool. DHPTU is not phosphorylated by any tumour dN kinases, but undergoes cleavage with TU release in reaction catalyzed by the tumour cell enzyme, com petitively inhibited by FA . After [14C]DHPTU or [14C]TU had been given i.p. to the animals with the tumour, 90% of the subcellu­lar fraction labelling fell into the nuclear fraction. How ever, if [l4C ]DHPTU was administered with FA and DCF, 27% of radioisotope was found in the nuclear fractions and 68% in cytosol. Since D C F which prevented FA deamination to FB (which is not an inhibitor of the mentioned enzyme) reduces DHPTU-induced changes in activity of dN kinases and dTMP kinase in hepato­ ma cells, the cytostatic activity of DHPTU seems to be connected to an enzyme which releases TU from DHPTU .
Two-Component Sexual Attractant for Male Batrachedra pinicolella (Zell.) (Lepidoptera: Batrachedridae)
Authors: Priesner Ernst
Published: August 2018

Contrary to an earlier report, male B. pinicolella are shown to respond to synergistic blends of (Z)-5-decenyl acetate with its corresponding alcohol analogue. Four other, decenyl or dodecenyl, com pounds are reported as potent trapping inhibitors. This pattern of pheromonal attraction and inhibition conforms with that found in some species groups of Coleophoridae, supporting the view of a close phylogenetic origin of the two families.
The Compositions of the Essential Root Oils from Pimpinella saxifraga s.l. and Chemotaxonomic Implications
Authors: Kubeczka K.-H. , Bohn I. , Schultze W.
Published: August 2018

The essential root oils of the Pim pinella saxifraga subspecies eusaxifraga, alpestris and nigra were investigated by means of capillary GC and spectroscopic m ethods. A total of 48 com ponents was identified.

Characteristic constituents of all oils are pseudoisoeugenol derivatives, sesquiterpenoids and trinor-sesquiterpene hydrocarbons, but the qualitative and quantitative patterns of the individual oils exhibit significant differences.

The results obtained were discussed in regard to a chemotaxonomic reliable delimitation of the 3 described subspecies of Pimpinella saxifraga L.
Low Concentrations of Phytoalexins Correlate with Resistance in Regenerated Plants from Meristem Cultures of Vicia faba L
Authors: Thynn M. , Wolff A. , Gorge E. , Werner D.
Published: August 2018

In tissue cultures from shoot apex meristems with leaf primordias of Vicia faba cv. TP667, addition of low concentration of auxins (0.01 mg ・1-1) induced regeneration of whole plants at high frequency (100%). The combination of NAA and kinetin or GA , also induced a high yield of plant regeneration. Regenerated plants from various cultivars on a medium with 2 ,4 D (0.01 mg ・1-1) were infected with Botrytis cinerea, Phytophthora megasperma and R hizoctonia solani. Accumulation of phytoalexins, ethylene production and the resistance to fungal diseases were studied. In general, production of phytoalexins occurred at a high level in all cultivars infected with B. cinerea. Ethylene production varied more in the seven cultivars studied than phytoalexin accumulation. No cultivar was resistant to B. cinerea. The highest resistance and the low est concentration of phytoalexin was found after infection by R. solani, and phytoalexin accumulation and resistance were interm ediate in plants infected by P. megasperma. The data suggest that only low to medium concentrations of phytoalexin in faba beans are correlated with resistance of regenerated plants.
Fluorescence Reaction of Chromatin by Curcumin
Authors: Stockert J. C. , Castillo P. Del , Gómez A. , Llorente A. R.
Published: August 2018

Treatment of cell smears, paraffin, and Epon tissue sec­tions with aqueous solutions of curcumin results in a green fluorescence reaction in chromatin under violet-blue exci­tation which is abolished after extraction procedures with DNase and TCA. The selective fluorescence characteris­ tics of curcumin support the possibility of employing this dye as a new fluorochrome.
Properties of 5′-AMP Deaminase and its Inhibitors with the Aid of a Continuous Fluorimetric Assay with Formycin-5′-phosphate as Substrate
Authors: Bzowska Agnieszka , Shugar David
Published: August 2018

A new continuous fluorimetric assay for AMP deaminase activity is described. The m ethod makes use of a fluorescent analog of 5′-AMP, formycin-5′-phosphate (5′-FM P), which undergoes deam ination to formycin B-5′-phosphate, not fluorescent at neutral pH. The pH -dependence for deamination of 5′-FMP is similar to that for 5′-AMP, but shifted about 0.2 units to more acidic pH. Deamination of 5′-FM P may also be followed spectrophotometrically at 306 nm, permitting better assays of crude extracts. Some kinetic results obtained by means of the new method for AMP deaminase from chick and rabbit skeletal muscle are presented. In particular it was found that the natural product of deamination, 5′-IMP exhibited allosteric inhibition of the chick enzyme with K, values 1.6mM , 1.2mM and 1.0mM at pH 5.8, 6.5 and 7.3, respectively. Activation by diadenosine tetraphosphate, Ap4A , reported for mouse muscle AMP deaminase, has not been noted for the chick enzyme. Inhibition by the transition state analogs, coformycin and 2′-deoxycoformycin, was observed for both rabbit and chick deaminases with Ki values ~ 1 μM and ~ 1.6 μM respectively. Kinetic data for coformycin-5′-phosphate show it to be a tight-binding inhibitor with K, < 0.6 × 10-9 M as compared to 1 × 10-9 m for 2′-deoxycoformycin-5′-phosphate.
Lipid Composition and Structural Studies on Lipids from the Land Snail Eobania vermiculata
Authors: Stavrakakis Helen J. , Mastronicolis Sofia K.
Published: August 2018

The total lipids of the commercial land snail Eobania vermiculata (Gastropoda, Pulm onata, Stylom m atophora) are found to constitute a small percentage (0.8% ) of the wet tissue, which is comparable to that reported for other gastropods. Polar lipid components comprise 61.4% of the total lipids. The individual lipid classes obtained by column chromatographic fractionation were purified by preparative TLC or by column chromatography and their structure was confirmed by a combination of chromatographic and analytical determinations before and after mild alkaline hydrolysis and/or (dry) acid methanolysis and by IR analysis. Neutral lipids represent 36.4% of total lipids, containing cholesterol, cholesterol esters and triglycerides as their major components (26.2% , 29.1% and 25.5% respectively). They contain also a significant amount (14%) of free glyceryl ethers, which are found in a mollusc for the first time. The overall composition of the polar lipids (mol/100 mol lipid-P) was found as follows: Cardiolipin, 2.9; phosphatidylethanolamine, 24.9 (of which 19.8% plasmalogen analog); phosphatidylcholine, 49.2 (of which 45.6% glycerylether analog); ceramide aminoethylphosphonate, 7.5 plus 0.01 (another three minor species); diglyceride-am noethylphosphonate, 6.3; Sphingoethanolamine 1.65 (for the first time found and structurally studied in a land gastropod); and phosphatidic acid 1.1. Unsaturated fatty acyl groups represent about 72.6 and 44.1 respectively in phosphatidylethanolamine and phosphatidylcholine. A significant amount (70.5% ) of unsaturated fatty acids is concentrated in neutral lipids.

The C16:0 alk-1-enyl chain was found to predominate (55.6% ) in the side chains of ethanolamine plasmalogen. Batyl alcohol was found as the main glycerylether bound to choline phosphate (97.5% ).

Saturated fatty acyl groups with 16 carbon atoms were main components (54%) of the major ceramide aminoethylphosphonate species.
Hormonal Modulation of the Rat Mammary Gland γ-Glutamyltranspeptidase
Authors: Ríos M. , Puente J.
Published: August 2018

1. The in vivo effect of estradiol and domperidone (a hypophysis stimulator of prolactin secretion) in immature ovariectomized-adrenalectomized and hypophysectomized rat mammary gland was studied.

2. γ-Glutamyltranspeptidase activity was used to evaluate the role of estradiol in the specific response of the gland to prolactin.

3. Our results suggest that the activity of γ-glutamyltranspeptidase, like casein and lactose synthetase, is part of the specific response of the gland to prolactin.
Minor Isoflavones from the Roots of Pueraria mirifica
Authors: Ingham John L. , Tahara Satoshi , Dziedzic Stanley Z.
Published: August 2018

The isoflavone aglycone kwakhurin hydrate, and the glycosides genistin (genistein-7-Oglucoside) and puerarin-6′′-monoacetate have been isolated from a methanolic extract of Pueraria mirifica roots.
Physiologische Bedeutung der „Stringent Control“ bei Escherichia coli unter extremen Hungerbedingungen / Stringent Control and Starvation Survival in Escherichia coli
Authors: Mach H. , Hecker M. , Hill I. , Schroeter A. , Mach F.
Published: August 2018

The viability of three isogenic relA+/relA strain pairs of Escherichia coli (CP78/CP79; NF 161/ NF162; CP 107/CP 143) was studied during prolonged starvation for amino acids, glucose or phosphate. After amino acid limitation we found a prolonged viability of all relA+ strains which synthesized ppGpp. We suggest that some ppGpp-mediated pleiotropic effects of the stringent response (e.g. glykogen accumulation, enhanced protein turnover) might be involved in this prolongation of survival. After glucose or phosphate starvation there was no difference in the relA+/relA strains either in the ppGpp content or in the survival.
A New Method for the Investigation of Cellular Dielectrophoresis
Authors: Zieliński Jerzy J. , Marszałek Piotr , Fikus Magdalena
Published: August 2018

A new method and a new type of measuring-microchamber for the investigation of cellular dielectrophoresis is presented. The method is based on the observation of the trajectory of a single cell in gravitational and electric fields being crossed and orientated perpendicularly to the observation direction. By means of this method the whole dielectrophoretic spectrum ranging from negative to positive dielectrophoresis may be easily and quickly obtained. The experiments carried out on different cell types showed that the dielectrophoretic spectra, as well as the dependence of the critical frequency upon medium conductivity and cell size agree well with the predictions of a new model of the dielectrophoretic mechanism proposed by Sauer.
Temperature-Dependent ESR Studies of Radical Pairs in Single Crystals of Barbituric Acid
Authors: Schupfner Robert , Müller Adolf
Published: August 2018

After irradiation of single crystals of barbituric acid with X-rays at 77 K different types of radical pairs are found, which are com posed of only one type of monoradical. The properties of radical pairs of the unpaired electrons are studied using frequency-variable ESR methods at various temperatures. In addition to the radical pairs AD and BC two further pairs A′D′ and XY were identified. Measurements of the fine structure parameter D showed a linear temperature dependence in some regions between 77 K and 290 K. At 240 K the radical pairs AD and A′D′ changed reversibly into A*D* and this pair remained stable up to 290 K.

A level anticrossing effect was observed with the pair AD. The exchange energy J between the singlet state and the triplet state was determined as -(15.1 ± 0.6) GHz at 77 K and its temperature coefficient as -(3.8 ± 0.8) × 10-3K-1.
Resonant Microwave Effect on Locally Fixed Yeast Microcolonies
Authors: Grundier W. , Keilmann F.
Published: August 2018

The microwave influence on the growth of yeast cells is studied in a novel experimental set-up designed to observe individual cells growing for several division cycles. The results are in accordance with resonant microwave-induced growth stimulation as observed in our earlier set-up where the turbidity of a stirred suspension of cells was used as the measure of growth. The new experimental set-up is suited to decide on the proposed triplet mechanism of resonant microwave biological effects.
Accumulation of Colorless Carotenes and Derivatives during Interaction of Bleaching Herbicides with Phytoene Desaturation
Authors: Sandmann Gerhard , Albrecht Manuela
Published: August 2018

Colorless carotenoids were accumulated, analyzed and quantified in heterotrophically- grown Scenedesmus cultures treated with the bleaching herbicide norflurazon. By optical, IR and mass spectroscopy 15-cis as well as all-trans phytofluene, 15-cis phytoenes and traces of its all-trans isomer were identified. Furthermore, a phytoene epoxyde and several hydroxyphy- toenes were assigned. Comparing the concentrations of these phytoene derivatives in hetero-trophic cultures grown in darkness with those in light-grown autotrophic cells, an exchange of phytoene derivatives was observed. Levels of phytoene were much higher in the dark whereas concentrations of hydroxyphytoenes dominated in the light. Other herbicides like fluridone, diflufenican, and difunon accumulate the same colorless carotenoids including phytoene epoxyde and various hydroxyphytoenes. For all herbicides an almost constant hydroxyphytoene to phytoene epoxyde ratio was observed indicating an interrelated formation of both oxygenated phytoene derivatives which can be influenced by light conditions of the cultures.
Molecular Characterization of Genes Coding for Wild-Type and Sulfonylurea-Resistant Acetolactate Synthase in the Cyanobacterium Synechococcus PC C7942
Authors: Friedberg D. , Seijffers J.
Published: August 2018

We present here the isolation and molecular characterization of acetolactate synthase (ALS) genes from the cyanobacterium Synechococcus PCC7942 which specify a sulfonylurea-sensitive enzyme and from the sulfonylurea-resistant mutant SM3/20, which specify resistance to sulfonylurea herbicides. The ALS gene was cloned and mapped by complementation of an Escherichia coli ilv auxotroph that requires branched-chain amino acids for growth and lacks ALS activity. The cyanobacterial gene is efficiently expressed in this heterologous host. The ALS gene codes for 612 amino acids and shows high sequence homology (46%) at the amino acid level with ALS III of E. coli and with the tobacco ALS. The resistant phenotype is a consequence of proline to serine substitution in residue 115 of the deduced amino acid sequence. Functional expression of the mutant gene in wild-type Synechococcus and in E. coli confirmed that this amino-acid substitution is responsible for the resistance. Yet the deduced amino-acid sequence as compared with othjer ALS proteins supports the notion that the amino-acid context of the substitution is important for the resistance.
Synergistic Activity of the Herbicide Safener Dichlormid with Herbicides Affecting Photosynthesis
Authors: Fedtke Carl , Strang Robert H.
Published: August 2018

Dichlormid, a safener for thiolcarbamate herbicides, was tank-mixed with several herbicidal inhibitors of photosystem II, or with the herbicide acifluorfen, and applied postemergence to Ipomoea hederacea plants. Dichlormid had no visible effects on the plants when applied alone, but interacted synergistically with the herbicides in the combination treatments. Dichlormid strongly decreased the ascorbic acid levels in the Ipomoea hederacea cotyledons. Ascorbate is known to protect plant tissue from photooxidative damage. The herbicides which interacted synergistically with dichlormid are believed to generate their phytotoxic action via the production of excess singlet oxygen. It is suggested that the decreased ascorbate levels in the Ipomoea hederacea cotyledons after dichlormid treatment result in an impaired singlet oxygen scavenging system and consequently lead to increased plant damage in the presence of singlet oxygen generating herbicides.
Morphology and Chemical Contents of Dufour Glands of Pseudomyrmex Ants (Hymenoptera: Formicidae)
Authors: Attygalle A. B. , Billen J. P. J. , Jackson B. D. , Morgan E. D.
Published: August 2018

The morphology and ultrastructure of the Dufour gland of a pseudomyrmecine ant is described. The gland has an unusually large volume but possesses a very thin epithelial lining. Its morphology does not constitute a specific subfamily character as in some ant subfamilies. Analysis by gas chromatography-mass spectrometry of the glands of three species showed them all to be rich in saturated linear hydrocarbons (C17:0 and C15:0 dominant) and isopropyl esters of the common fatty acids. Each species produces its own characteristic mixture of these substances. The most abundant ester in Pseudomyrmex ferruginea is isopropyl oleate and in P. sp. A it is isopropyl palmitate, in P.flavicornis there is only a trace of isopropyl palmitate. An alate female of P. ferruginea contained a very similar mixture to that of the workers.
Stilbene and Chalcone Synthases: Related Enzymes with Key Functions in Plant-Specific Pathways
Authors: Schröder Gudrun , Schröder Gudrun
Published: August 2018

Several years of extensive research using the new powerful techniques of molecular biology have enabled the direct comparison of functionally or evolutionarily related genes and their products at the nucleotide and aminoacid sequence levels. Two types of synthase with similar functions are discussed as an interesting example. Stilbene synthases, e.g. resveratrol synthase, produce the stilbene backbone as a key reaction in the biosynthesis of stilbene-type phytoalexins. Chalcone synthase is a key enzyme in the biosynthesis of flavonoids, including certain phytoalexins derived from a 6′-deoxychalcone which is synthesized by cooperation of chalcone synthase with a reductase. Resveratrol and chalcone synthases utilize the same substrates (4-coumaroyl-CoA and 3 molecules of malonyl-CoA ) and catalyze the same condensing type of enzyme reaction (resulting in sequential addition of acetate units via malonyl-CoA ), but the products differ in the newly formed ring systems (resveratrol and naringenin chalcone). A comparative analysis of cloned DNA sequences and of the reaction mechanisms indicates that the two enzymes are closely related. It seems likely that the proteins possess a common scaffold for substrate recognition and for the condensing reaction, and that the different folding of an enzyme-bound intermediate prior to closure of the new aromatic ring is responsible for the formation of the different products. The same type of condensing reaction is utilized by the 2-ketoacyl-ACP synthases of fatty-acid biosynthesis. How ever, the available data indicate that these enzymes share little overall homology with either resveratrol or chalcone synthase. One exception maybe a short aminoacid sequence which corresponds to the active center of the condensing reaction in 2-ketoacyl-ACP synthases.
Volatile Components of the Essential Oils of Four Chinese Species in the Genus Asarum (Aristolochiaceae)
Authors: Hayashi Nanao , Ding Jingkai , Chen Zonglian , Yi Yuanfen , Komae Hisashi
Published: August 2018

The volatile components of the essential oils of four Chinese species in the genus Asarum were investigated by means of GC-MS. Large amounts of elemicin, safrole, and 2-undecane to gether with several mono- and sesquiterpenes were identified in the essential oils. It was found that Chinese Asarum species is similar phytochemically to the genus Heterotropa in Japan.
Anzeichen sexueller Fortpflanzung bei dem plasmodialen Protisten Chlorarachnion reptans Geitler / Indications of Sexual Reproduction in the Plasmodial Protist Chlorarachnion reptans Geitler
Authors: Grell Karl G.
Published: August 2018

The algal protists Reticulosphaera socialis Grell and Chlorarachnion reptans Geitler are “meroplasmodia”: They consist of separate cell bodies and a comm on reticulopodial network by means of which they capture and digest food organisms, for instance diatoms. When food becomes exhausted, the meroplasmodium disintegrates sooner or later into single cells.

In Chlorarachnion reptans shortage of food may lead directly to globular resting cells with a distinct cell wall. In other cases disintegration is delayed. The plasmodial cells, still connected by reticulopodial strands, move about and join with single resting cells to form pairs. After pair formation they lose the reticulopodial connections, round off and form a cell wall of their own. The cells which rested from the beginning on start growing, whereas the cells which searched for them do not. It is probable that the nuclei of the latter are transferred into the growing cells so that synkarya are formed. If this the case, pair formation is a fertilization process and the growing cells are zygotes. A single zygote, isolated and transferred on a “lawn” of diatoms, gives rise to a plasmodium whose cells display both sexual types again.
Photosystem II Inhibition by 3-Acyl-5-(l-aminoalkylidene)-4-hydroxy- 2H -pyran-2,6(3H)-dione Derivatives
Authors: Yoneyama Koichi , Konnai Makoto , Asami Tadao , Takahashi Nobutaka , Yoshida Shigeo
Published: August 2018

3-Acyl-5-(1-aminoalkylidene)-4-hydroxy-2 H- pyran-2,6(3 H)-dione derivatives carrying lipophilic amino groups were found to be highly potent inhibitors of photosynthetic electron transport, and both the acyl and the aminoalkylidene groups on the pyran ring appeared to be indispensable for high activity. The structural features needed for activity in the 3-acyl-5- (l-am inoalkylidene)-4-hydroxy -2 H-pyran -2 ,6 (3 H)-dione derivatives were very similar to those for 3 -(l-aminoalkylidene)-2H-pyran-2,4(3H)-diones, except for the acyl group in the former compounds. Thermoluminescence measurements indicated that the 3-acyl-5- (1-aminoalkylidene)-4 -hydroxy -2H-pyran -2 ,6 (3 H )-dione derivatives bind to the D 1 protein in a manner similar to that of DCMU .
Studies on the Substrate Specificity of Soybean Lipoxygenase-1 Using an Entire Series of (ω3 Z,ω6 Z ,ω9 Z)-C12~ C22-Trienoic Acids and -Trienols
Authors: Hatanaka Akikazu , Kajiwara Tadahiko , Matsui Kenji , Ogura Miharu
Published: August 2018

Substrate recognition mechanism of soybean lipoxygenase-1 (L -1) was studied by using an entire series of (ω3Z,ω6Z,ω9Z)-C12~C22-trienoic acids and -trienols. The maximum activity of L-1 was obtained with C20-trienoic acid of all the substrates used. Among trienols, the maximum activity was obtained with C15-trienol. Analysis of the products obtained by the reaction of these substrates with L-1 revealed that trienoic acids were oxygenated mostly at ω6 position independently on the chain length. The hydroperoxy group at ω6 was introduced at (S)-configuration with over 98% enantioselectivity. Although the products formed from most trienols were also selectively oxygenated at ω6 position, only C15-trienol was oxygenated at both ω6 and ω10 positions in the ratio of ω6/ω10 = 48/52.
Simulations of a Fox-Rabies Epidemic on an Island Using Space-Time Finite Elements
Authors: Gardner Gwen A. , Gardner Leslie R. T.
Published: August 2018

Abstract The two-dimensional reaction diffusion equations for the spread of rabies in a logistically growing fox population are solved numerically. The method, based upon Galerkin’s approach, uses space-time finite elements. The numerical model is shown, quantitatively, to possess the essential features of earlier one and two-dimensional models and to reproduce the values of field data accurately. A more realistic illustration of the use of the model, a study of the spread of rabies over the Isle of Anglesey, is then discussed.