Volume 28, Issue 11-12

A novel flavonoid, the natural 3-acetyl-derivative of pinobanksin, has been isolated from the lipophilic bud excretion of poplar. The structure and spectral analysis (UV, IR, NMR, M S). The strated

Vaucheriaxanthin is 19'-0H and not 19-OH neoxanthin. This structural conclusion was borne out by mass, PMR and infrared (IR) spectra from the free pigment and its derivatives (vaucheria- xanthal, vaucheriaxanthal-diacetate, vaucheriaxanthal-diacetate-mono (trimethylsilyl) -ether, vaucheria- xanthintriacetate- and triacetate-monosilanate, vaucheriaxanthin-dimethylether) and by comparison of the characteristic lines of epoxi-xanthophylls at mje 181 and m/e 221 in the mass spectrum

Mass spectral fragmentation studies of dehydro-a-lapachone and dehydro-iso-a-lapadione, isolated from the heartwood of Tabebuia rosea, have been made. The fragmentation patterns in the case of two compounds are essentially similar and have been discussed

5-Methyltetrahydrofolic acid is prepared from folic acid by sodium borohydride reduction, reac­ tion with formaldehyde and reduction to the methyl derivative by sodium borohydride. The crude product is precipitated as barium salt which after having been converted to the sodium salt by ion exchange is adsorbed to QAE-Sephadex and eluted by different acetic acid gradients in subsequent chromatographies. This method allows to process gram quantities on reasonably small columns

In the side chain halogenated, especially fluorinated, alkoxyphenylureas are new herbicides with high activity. Methods for the synthesis of these compounds are reviewed

The preparation of substituted cis,cis-muconic acids by oxidative ring scission of simple o-di-phenols with peracetic acid is investigated. Scission of pyrocatechol (1) to cis,cis-muconic acid (2) gives optimal yields, if acetic acid or ethyl acetate is used as solvent and if the solution is 15-20% with respect to sulfuric acid free peracetic acid comprising a one molar excess of oxidant. Under similar conditions, 3-tosylamino-pyrocatechol yields with peracetic acid the hitherto unknown α-tosylamino-cis,cis-muconic caid (18). 18 may be converted to α-tosylamino-traras,trans-muconic acid (19) by means of iodine, UV light or heating. From protocatechuic acid (4) under similar conditions not β-carboxy-cis,cis-muconic acid (5) is obtained, but rather β-carboxy-mucono-lactone (6 b, γ-carboxymethyl-β-carboxy-Δα-butenolide). As yet, this lactone has been accessible only from an isomer of β-carboxy-cis,cis-muconic acid, the latter being obtainable by enzymatic scission of protocatechuic acid (4). Steric effects are responsible for both, the formation of the free cis,cis-muconic acids 2 and 18 from pyrocatechol (1) and α-tosylamino-pyrocatechol, and the formation of the γ-lactone 6 b instead of β -carboxy-cis,cis-muconic acid by scission of protocatechuic acid (4). The time course of the reactions shows that - compared to pyrocatechol (1) - a 3-tosylamino-group enhances the peracetic acid scission, whereas a 4-carboxygroup as in 4 slows it down

By cleavage of the aromatic ring of 6,7-dihydroxy-tetraline (1) with peracetic acid 1,2-bis-carboxymethylene- cyclohexane (3 a) is obtained. The addition of one mole of water to 3 a leads to 1-hydroxy-1-carboxymethyl-2-carboxymethylene-cyclohexane (4), which is readily converted to the lactone 1-hydroxy-2-carboxymethylene-cyclohexane-γ-lactone-aceticacid-(1) (5). By melting of compound 4 or 5 1,2-dihydroxy-cyclohexane-diaceticacid-1 (1,2) -di-γ-lactone (6) is obtained. 1,2-bis-carboxymethylene-cyclohexane (3 a) shows a molecular asymmetry which is of a type similar as found in atropisomeric compounds. On the basis of conformational considerations it is demonstrated that in the dilactone 6 the cyclohexane ring is stabilized in the boat form. Cleavage of the aromatic A-ring of 2-hydroxy-estradiol- (17β) -acetate (7) with peracetic acid occurs in a manner analogous to that of compound 1, giving rise to 2,3-seco-Δ 10(1) -estrenediol- (5ξ, 17β)-diacid-(2,3)-lactone-(2 → 5) -17-acetate (8 a). 8 a is converted to the methylester 9 and further to the corresponding estrone derivative 11 a. Estrone-[16- 14 C] was incubated with the 15 000 × g supernatant from rat liver homogenate in order to investigate the possibility if scission of the aromatic ring A of estrogens is a step in their katabolism. Substance 11 a was used as a carrier in these studies

Interactions of polyadenylic acid with the mercury electrode were followed by means of direct current (d.c.), alternating current (a.c.), and pulse polarography. It was ascertained that the electrode reaction of polyadenylic acid did not differ significantly from the reaction of its monomeric components. In contrary to the latter reaction, the polarographic reduction of poly­ adenylic acid takes place only in the adsorbed state. Desorption of polyadenylic acid from the surface of the mercury electrode at negative potentials inhibits the reduction current. Due to this inhibition the d.c. polarographic curves of polyadenylic acid can have the shape of a single maxi­ mum or of a "double-wave". A method was suggested for a rapid determination of diffusion coef­ ficients of single-stranded polyadenylic acid by means of d.c. polarography. A.c. polarographic measurements yielded data on the adsorption/desorption behaviour of polyadenylic acid, on the basis of which conclusions were made concerning the conformation of polyadenylic acid in solu­ tion. While relatively concentrated solutions of polyadenylic acid must be used in the d.c. and a.c. polarographic studies, a little as 10 -15 ng of polyadenylic acid can be determined by means of pulse polarography

A theory of the elasticity of lipid bilayers is proposed. Three types of strain, i. e. stretching, tilt and curvature, are distinguished and the associated stresses are identified. It is argued that in the case of vesicles (= closed bilayer films) the only elasticity controlling nonspherical shapes is that of curvature. Euler-Lagrange equations are derived for the shape in magnetic fields and under excess outside pressure. It is shown that magnetic fields can deform spherical vesicles into ellipsoids of revolution. Under excess outside pressure the spherical shape becomes unstable at a certain threshold pressure. Both effects can be influenced by a spontaneous curvature of the bilayer. Some possible experiments to determine the elastic properties are also discussed

Primary photosynthetic processes under pressures of up to 1300 atm were studied by means of chlorophyll fluorescence induction (Kautsky-effect) and compared to simultaneous oxygen exchange transients determined polarographically. Chlorophyll fluorescence induction was affected by increased hydrostatic pressure in three distinct ways: 1. At 400 atm loss of the first fluorescence drop (I-D transient), reflecting inhibition of PSI activity; 2. at 400 -1200 atm suppression of the fluores­ cence peak (D -P -S transient), indicating a block at the electron donor site of PS II; 3. at 800 -1200 atm flattening of the first fluorescence rise (O -I transient), suggesting a loss of ex­ citation energy within the pigment system. Pressure effects on oxygen exchange include inhibition of transient oxygen uptake and stimulation of the initial oxygen burst, which is paralleled by loss of the first transient fluorescence drop. Inhibition of the second oxygen burst is accompanied by the elimination of the transient fluorescence peak. The first burst only decreases with pressures exceeding 800 atm, as does the initial fluorescence rise. All pressure effects on fluorescence and oxygen exchange were reversible. Hydrostatic pressure appears to be a useful multilateral inhibitor in the study of primary photosynthetic reactions

The plastoquinone antagonist dibromothymoquinone interrupts the photosynthetic electron transport chain between photosystem II and I by inhibiting the oxidation of plastohydroquinone by photosystem I. The effect of phenylenediamines on NADP and ferricyanide photoreduction inhibited by dibromothymoquinone is studied in isolated chloroplasts. IV-substituted phenylene­ diamines fully restore NADPH and ATP formation as well as oxygen evolution in DBMIB inhibited NADP reduction, but are practically inactive in stimulating ferricyanide reduction by photo­ system II. On the other hand phenylenediamine and C-substituted phenylenediamines are only weakly active in restoring NADP reduction but are very active in stimulating ferricyanide reduc­ tion. The P/e 2 ratio in restoration of NADP reduction by phenylenediamines is close to 1, whereas the P/e 2 ratio in ferricyanide reduction is about 0.4 (the ratio is dependent on the DBMIB con­ centration). The reversal of the DBMIB inhibition in NADP reduction by phenylenediamines is attributed to a bypass of the inhibition site: Reduced phenylenediamines are electron donors for photosystem I after and oxidized phenylenediamines are electron acceptors for photosystem II be­ fore the DBMIB inhibition site. To explain the different rates and P/e 2 ratios in the various systems it is assumed that all phenylenediamines are reduced at the expense of water oxidation by photo­ system II but via plastoquinone and on the inside of the membrane. Therefore two energy con­ serving steps (i. e. two proton releasing sites on the inside of the membrane) are involved, N-sub­ stituted phenylenediamines like TMPD reduced by photosystem II inside remain inside the mem­ brane and are reoxidized inside by photosystem I. This way they connect photosystem II bade onto photosystem I, electron transport rates are high and the P/e 2 ratio is one in the restored NADP photoreduction. Phenylenediamine and C-substituted phenylenediamines on the other hand travel back to the outside through the membrane, and by doing so carry some of the protons released on the inside of the membrane by the energy conserving steps back to the outside. This way they are very active in stimulating the rate of ferricyanide photoreduction but the P/e 2 ratio is only about 0.4. These phenylenediamines being removed from the inside are less active in restoring the rate of NADP reduction

Photosynthetic cytochrome c reduction by isolated chloroplasts is mediated by substances with characteristics of a "Cytochrome c Reducing Substance" (CRS). A water soluble extract of ether treated, lyophilized chloroplasts (called Sʟ-eth), related to the primary acceptor complex of photo­ system I, has CRS-activity. It contains p-coumaroyl-meso-tartaric acid. By comparison with model substances, the CRS-activity in chloroplasts is attributed to the iron complex of this compound. A number of other iron complexes and numerous quinones with redox potentials from - 220 mV to + 300 mV are also shown to possess CRS-activity. The CRS preparation from the blue green alga Anabaena cylindrica, as first described by Fujita and Myers, contains Fe 3+ /EDTA, which has all the chemical and functional properties as reported for CRS

The proteins of mature potato tubers can be used for variety identification. Their pattern after electrophoresis or focusing are genetically determined. Various growth regulators applied during the season had no influence. Molecular weights of the protein subunits are uniform and decrease with age of the tuber, often due to depolymerization. Some subunits are linked by S -S-bridges. A proteid characteristic for immature tubers has been discovered. Part of the diversity in charge distribution is based on different degree of amidation; treatment at pH 10 changes the variety-dependent pattern to a picture similar in all varieties. The latter is also true for proteins from immature tubers. Focusing followed by SDS-incubation (with and without ME) and SDS-gelelectro-phoresis revealed that the main proteins which were different in charge had common MW and may derive from a parent protein. The tuber proteins and especially some of the peroxidases are quite resistant to SDS-attack. Only prolonged incubation (50 °C, 40 hours) with SDS brings about digestibility. A borate buffer, pH 7.9 has been used, making possible the electrophoresis of undiluted, unfractionated sap or other crude mixtures of proteins. Some new versions of two-dimensional techniques with PAA as a carrier are applied in order to differentiate between charge, shift of charge, and MW

Unter the permanent influence of lithium ions the circadian rhythm of movement of Kalanchoe petals is effectively lengthened but a pulse administered up to 12 hours has no influence. Lithium ions could also be demonstrated to similarly slow down the circadian activity rhythm of a small mammal (Meriones crassus). It is hypothesized that the therapeutic effect of lithium salts in endogenous depressions in human beings may result also from its acting on the human circadian system

High frequencies of fusion were induced between isolated tobacco leaf protoplasts when they were incubated at 37 °C in the presence of 0.05 M CaCl 2 in 0.4 ᴍ mannitol at pH 10.5. Subsequent to the fusion treatment the protoplasts were washed and cultured in a suitable medium and within two weeks, actively dividing cell colonies were observed. The fusion treatment had no irreversible, deleterious effects on the protoplasts

Acid and alkaline deoxyribonuclease (EC 3.1.4.6, EC 3.1.4.5) activities were demonstrated in the human seminal plasma. By means of a micro-disc-electrophoretic deoxyribonuclease test six different fractions are detectable. They were characterized with respect to their optimal substrate and optimal incubation conditions. The various enzyme activities were tested at pH 5.0 in 0.1 ᴍ Na-acetat buffer or at pH 7.4 in 0.1 ᴍ Tris-HCl buffer in the presence of different combinations of MgCl 2 , CaCl 2 , EDTA, NaSO 4 , NaF and mercaptoethanol with native or denatured herring sperm DNA as substrate

Different ways for studying DNA synthesis and DNA methylation were investigated. On the one hand the reactions were measured by incorporation of several specific precursors, taking into ac­ count that pool alterations might influence the results. The best way to avoid this is the direct conversion of DNA cytosine to DNA 5-methyl-cytosine by using [ 14 C]-cytidine. According to our results we propose to calculate the correct DNA methylation rate in term of the specific radio­ activity of the separated DNA bases

Two phase points (18 C.T. and 19 C.T.) in the subjective night of the Drosophila pseudoobscura circadian rhythm of eclosion, representing the end of the first half of the night and the beginning of the second half respectively, were exposed to blue (442 nm) light pulses of varying energies. The 18 C.T. phase was less sensitive relative to the 19 C.T. phase which is nearly 10-times as sensitive. This difference is not a feature restricted to the two phase points studied since similar differences could be traced to rhythm attenuating stimuli offered slightly earlier or later than the subjective midnight. It is suggested that the differences in sensitivity to light displayed by the two halves of the night are inherent to the oscillator driving the rhythm

The new mutation “dunkel” (d) of the mosquito Culex pipiens L. causes larvae darker than the wildtype. Especially head capsule and siphon are dark brown, almost black. The factor is inherited like a recessive autosomal one. It is linked with the eye color mutation “ruby” in the 2 nd coupling group and is characterised by 45 - 47% crossingover between these two mutations. Showing com­plete penetrance, the mutation is a good marker for the second chromosome. This mutation “dun­kel” is not identic with mel (melanotic larvae) or Bl (Blade larvae)

The increase of survival of ultraviolet irradiated Escherichia coli cells, due to the splitting of thymine dimers to monomers by photoreactivation, is inhibited by potassium nitrate. The possible mechanisms of the inhibition are discussed

Microbial degradation of both the isomers of the cyclodiene insecticide endosulfan (hexachloro-bicyclo [2,2,1] hept-5-en-2,3-bis-hydroyxmethylene-cyclic sulfit) by Pseudomonadaceae in water has been investigated. Strong resorption of the applied insecticide (90%) by the bacteria has been ob­ served. The main metabolite of both the isomers was identified by EC-gaschromatography as the endosulfan-alcohol. Additionally the /?-isomere yielded small amounts of the cyclic endosulfan-ether and isomerisation to the more stable a-endosulfan

By means of isoelectric focusing in polyacrylamid gels cell proteins of botton - respectively topfermenting yeasts (Saccharomyces cerevisiae), Pseudomonas ovalis and Achromobacter alcali-genes were separated into over 30 peaks with a good reproducibility. The distribution pattern of the proteins is a base for a classification

The presence of the rare free amino acid octopine in different plant material was tested in order to confirm its validity as a specific marker for the expression of bacterial genetic information in tumors produced by infection with A grobacteriu m tu m efaciens. This guanidine derivative is present in auxin-autotrophic fast growing callus cultures of C repis capillaris, and N icotiana tabacum var. ''White Burley", all transformed by infection with A grobacteriu m tum efaciens. In auxin-hetero-trophic callus cultures and in healthy plant material of the same species octopine could not be found. In all A . tum efaciens strains including the avirulent No. 55 tested this guanidine derivative was present. However, since octopine was found in fast growing "habituated" cultures of N . taba­ cum var. "White Burley" and, in small amounts in root tips of pea and bean seedlings and not in a slow growing "transformed" strain T5 of C repis, it cannot be considered as a specific marker for the expression of genetic material from the transforming bacteria

P. praecox (Sieb, et Zucc.) Nakai (Lauraceae), flowers and leaves, n-paraffins (C 17 to C 34 )

In den oberirdischen Teilen von Reseda luteola L. sind bisher an Flavonoiden Luteolin (1), Apigenin (2) und Luteolin-7-glucosid (3) aufgefunden wor­ den 1 . Als wir zu Vergleichszwecken 1 und 2 aus Reseda luteola isolierten, ist uns das Vorkommen weiterer Glykoside aufgefallen. Ähnliche Beobach­ tungen sind auch von anderer Seite gemacht wor­ den 2 . Es ist uns jetzt gelungen, zwei dieser Glyko­ side, Luteolin-S'-glucosid (4) und Luteolin-7.3 -di-glucosid (5), in reiner Form zu isolieren und deren Konstitution aufzuklären

Temperature dependence, uptake of hexoses, Chlorella

Circadian rhythms, leaf epidermis, light perception, Kalanchoe

3-Indol acetic acid, calcium, adenosin-3':5'-monophosphat (c-AMP), maize coleoptile sections

Cation transport, chloroplast envelope, thylacoid membrane

Spin-labeling of phosphorus compounds, cancer, EPR, 2,2,6,6-tetramethylpiperidine-1-oxyl

Dipteran flies, anatomy, ventral ganglion, giant fibers, dye injection

Glycoproteins, mouse leukemia virus