Band 42, Heft 11-12

A compound obtained from an early Iron-Age wood tar via “Kugelrohr”-distillation or extraction was identified as betulin by TLC. 1 H - and 13 C - NMR as well as by mass spectroscopy. This result validates the assumption that birch was used for the preparation of the archaeological wood tar found at the excavation in Stillfried a .d . March. Lower Austria.

The chemical com position and morphology of leaf surface waxes of Solanum tuberosum were analysed using FT - IR . GLC and MS studies. There is a predominance of saturated and long chained components resulting in a crystalline wax layer in the form of ribbons, n-alkanes are a major constituent with C 31 being p rominent. Wax esters and 5-alcohols form the other major components. Wax composition of five other solanaceous plants, viz., Solanum eleagnifolium, Lycopersicon esculentum, Nicotiana tabacum, Datura stromonium and Solanum nigrum were compared with those of potato using TLC techniques and do not show any qualitative differences.

Asymmetric reduction of 4(5)-oxocarboxylic acids (esters)by baker’s yeast and cyclizationin acidic media yield soptically active γ(δ)lactones. The evaluation of their chirality and optical purity was carried out by HPLC (HRGC)analysis of the corresponding 1,4(1.5)-diols via diastereomeric esters with(R)-Mosher acid(MTPA) and (S)-O-acyllactic acids respectively. By increasing the 4(5)alkyl side chain 4R(5R) configurated γ(δ)-lactones with high ee-values are generated.

The rigid layer and peptidoglycan fractions from two strains (ATCC 17100 and Rm 5) of the budding phototrophic Rhodomicrobium vannielii were isolated. Rigid layers of both strains contain protein in addition to peptidoglycan. They were free of polysaccharides and fatty acids. The respective peptidoglycan fractions contain glucosamine, muramic acid, ʟ-and ᴅ-alanine, ᴅ-glutamic and meso-diaminopimelic acid in approximately equimolar ratios except for a signifi­ cant lower relative ᴅ-alanine content. Analysis of partial acid hydrolysates revealed A 1 γ-type structure of Rhodomicrobium vannielii peptidoglycan (shown with strain ATCC 17100). An about 10-30% lack of N-acetylation of glucosamine was indicated. The degree of cross-linkage was found to be about 60% . No differences in peptidoglycan composition and degree of cross-linkage were found between swarmer-and chain-cells as examined with strain Rm 5.

Upon slicing cotyledons of chickpea, Cicer arietinum L.. accumulate the pterocarpan phyto­alexins medicarpin and maackiain. Treatment of this tissue with an elicitor from the phytopathogcnic deuteromyccte Ascochyta rabiei (Pass.) Lab. greatly enhances accumulation of the pterocarpans and of other isoflavones and flavonoids. Isolation, chromatographic purification and structural elucidation by spectroscopic techniques of 16 phenolic compounds is described. Cotyledons induced for phytoalexin biosynthesis readily accumulate the isoflavones daidzein, formononetin, calycosin and pseudobaptigenin which are thought to be intermediates in pterocarpan formation.

Extracts from ripe fruit and seeds of Sorbus aucuparia inhibit germination of other seeds, tested with Amaranthus caudatus and Lepidium sativum. The main compound of the “neutral fraction” of fruit extracts is the lactone compound parasorbic acid (4 -7 mg/g fresh weight) which inhibits germination at concentrations ≧ 5 × 10 -4 ᴍ. The “acid fraction” contains abscisic acid (1.3-2.5 µg/g fresh weight) and isopropylmalic acid (1.0-1.5 µg/g fresh weight) as germination inhibitors. Whereas abscisic acid inhibits germination of L. sativum at concentration ≧ 5 × 10 -7 ᴍ, germination of A. caudatus is inhibited only at concentrations ≧ 10 -5 ᴍ. This is probably due to differences in uptake of the acid because abscisic acid methylester inhibits germination of both species at concentrations ≧ 5 × 10 -7 ᴍ. Isopropylmalic acid belongs to a structural type of germination inhibitors which had already been detected in oat extracts.

Data of the velocity (v) of an enzyme-catalyzed reaction at a fixed concentration of substrat (S) and various concentrations of an inhibitor (I) may be presented in a v versus v[I] plot. This plot is the counterpart of the Eadie-Hofstee plot (v versus v/[S]) which may be used to present data of the velocity at various substrate concentrations.

The application of the thin-agar-layer coated filter culture technique (Z. Naturforsch. 42c, 1082 (1987)) has been extended to the detection of ester hydrolysis and 2-hydroxyacid oxidation by microbial colonies. The former was performed by spraying with bromocresol purple and the latter with a salicylhydrazide reagent. Under the optimized conditions, the hydrolysis activity of more than 20 µmol/h·g-wet cells and the oxidation activity of more than 40 µmol/h·g-wet cells were usually detected directly on the filter-plate cultures of bacteria, yeasts and molds.

Flowers of Sinningia (syn. Rechsteineria) cardinalis contain glycosides of the flavones apigenin (4′-OH) and luteolin (3′,4′-OH) respectively, and of the related 3-deoxyanthocyanidins apigeninidin and luteolinidin. Studies on substrate specificity of the key enzyme of flavonoid biosynthesis, chalcone synthase, revealed that the 3′,4′-hydroxylated flavonoids are formed by hydroxylation of flavonoid compounds rather than by incorporation of caffeoyl-CoA into the flavonoid skeleton during the condensation reaction. In fact, flavonoid 3′-hydroxylase activity could be demonstrat­ed in the microsomal fraction of the flower extracts. The enzyme catalyses hydroxylation of naringenin and apigenin in the 3′-position to eriodictyol and luteolin, respectively, with NADPH as cofactor. Besides flavanone 3′-hydroxylase a further NADPH-dependent enzyme activity (flavone synthase II) was observed in the microsomal fraction catalysing the oxidation of naringenin to apigenin and of eriodictyol to luteolin. The Cytochrome P-450 inhibitor ancymidol was found to abolish completely flavone synthase II activity, whereas flavonoid 3′-hydroxylase activity was not impaired.

Incubation of soybean cell suspension cultures in B-5 medium containing 0.4 ᴍ sucrose caused induction of chalcone synthase (CHS) up to a specific activity of 8 µkat/kg. CHS from these cultures was purified to apparent homogeneity by a 5-step procedure. Isoelectric focussing of pure CHS gave a major band at pH 5.45 and two weaker bands at pH 5.35 and 5.5. At least the bands at pH 5.35 and 5.45 had CHS activity. Analysis of pure CHS by two-dimensional electrophoresis gave a set ot six proteins with a M, of 40 kDa and pIs between 6.0 and 6.6. One-dimensional PAGE of CHS under non-denaturing conditions gave three closely spaced protein bands. A specific antibody was raised against soybean CHS which cross-reacted with parsley CHS. Attempts to find synthesis of deoxychalconc or of the corresponding 7.4′-dihydroxyflavanonc with CHS of different purification stages and with various cofactors failed.

Enzyme preparations from Mycobacterium phlei, Escherichia coli and Galium mollugo cell suspension cultures were incubated in the presence of 4-(2′-carboxyphenyl)-4-oxobutyrate (i.e. o- succinylbenzoic acid. OSB. 1). ATP. coenzyme A and Mg 2+ . The main product isolated from the incubation mixture was 4-(2′-carboxyphenyl)-4-oxobutyryl coenzyme A ester (2) as determined by comparison with synthetic coenzyme A esters. Synthetic and enzymically formed 4-(2′-car-boxyphenyl)-4-oxobutyryl coenzyme A ester (2) was shown to be enzymically converted to an intermediate in vitamin K 2 biosynthesis viz. 1.4-dihydroxy-2′-naphthoic acid (5). The enzymic formation of 2-(3′-Carboxypropionyl)benzoyl coenzyme A ester (3) and 4-(2′-carboxyphenyl)-4-oxobutyryl-di-coenzyme A ester (4) was also observed. They appeared in minor amounts, how­ever. These esters were not convertible to 1.4-dihydroxy-2-naphthoic acid (5).

The maximum catalytic activity of pyrophosphate: fructosc-6-phosphate 1-phosphotransferase (PPi-PFK) was approximately three fold greater than that of ATP: fructosc-6-phosphate 1-phosphotransferase (ATP-PFK) in Catharanthus roseus cells at any stage of culture. The levels of both enzymes increased after subculture of the cells, reached their maximum levels on day 3-4, and then decreased. PPi-PFK partially purified from Catharanthus roseus required fructose-2,6-bis- phosphate (F2,6BP) for its activity. The Ka value of the enzyme for F2,6BP was 26 nᴍ. The Km values for fructose-6-phosphate (F6P) and sodium pyrophosphate (PPi), at physiological pH (7.2) in the presence of 1 µᴍ F2,6BP, were 0.59 mᴍ and 48 µᴍ, respectively. Intracellular levels of PPi and F6P varied from 17-71 nmol and from 37-65 nm per g fresh weight of the cells during culture. These results suggest that PPi-PFK is functional in Catharanthus roseus cells in vivo. The role of PPi-PFK in carbohydrate metabolism in heterotrophic, cultured plant cells is discussed.

Protein extracts from anthers of Tulipa cv. Apcldoorn catalyze the formation of glucosidcs and glucose esters of hydroxycinnamic acid with UDP-glucose as the glucosyl donor. By chromatofocusing and by HPLC (anion exchange chromatography) it could be demonstrated for the first time that two different enzymes are involved in these reactions. By using the molecular sieving (HPLC) a molecular weight of about 45000 D was determined for the GT (E) (= catalyz­ing the formation of esters) and of about 25000 D for the GT (G) (= catalyzing the formation of glucosidcs). Both enzymes exhibit a high spezificity for free hydroxycinnamic acids. It is assumed that these transferases arc involved in the formation of feruloylglucose and ferulic acid glucoside, the latter of which can be isolated from anthers at early developmental stages. Furthermore, it is hypothesized that feruloylglucose functions as a starter molecule for the transacylation reaction by which di- and triferulovlsucrose are formed.

Chloroplast ATP-synthase (CF 1 ) subunit delta (δ) has been isolated from spinach thylakoids in the presence of SDS. By automated Edman degradation and online analysis of PTH derivatives the 35 N-terminal amino acid residues were sequenced. The mature protein starts with: NH 2 -Val-Asp-Ser-Thr-Ala-Ser-Arg-Tyr-Ala-. This protein sequence allows alignment of spinach δ with the sequences of Z. mays 25 kDa polypeptide, the δ subunit of Rps. blastica, Rsp. rubrum and E. coli F 1 , and of bovine OSCP, but not with mitochondrial δ. Secondary structure calculations and helical wheel plots reveal a conserved secondary structure. The analyzed N-terminal sequences probably build a short amphipathic alpha helix with two adjacent turns. The such aligned polar residues around Tyr 8 of subunit δ are suitable to channel protons.

In SDS gels of purified, highly active ATP-synthase from chloroplasts, CF 0 F 1 a protein band was detected at an apparent molecular weight of 100 kDa. This protein was isolated on a prepara­tive SDS gel. The 100 kDa protein can be dissociated at increased temperature or increased incubation time into an 8 kDa protein, which is identical with the subunit III of CF 0 (DCCD- binding protein or proteolipid). This implies that the 100 kDa band is a stable supramolccular complex containing at least 12 copies of subunit III. Electron micrographs reveal a diameter of 6.3 nm and a membrane spanning length of 6.1 nm. We assume that this supramolecular complex represents a stable native substructure of CF 0 F 1 .

Applying a rapid modulation system for measurement of chlorophyll fluorescence yield (U. Schreiber. Photosynth. Res. 9. 261-272 (1986)) the induction kinetics upon onset of strong actinic illumination previously studied by Delosme (Biochim, Biophys, Acta 143, 108-128 (1967)) are reinvestigated. With increasing actinic intensity the fluorescence rise is changed from the typical O-I-P characteristic to a more complex rise curve with two intermediary levels I 1 and I 2 both of which show saturation at high intensity. The typical kinetics at saturating light intensity (O-I 1 -D-I 2 -P) are observed in a variety of plant species. The properties of the kinetics with respect to light intensity, temperature, electron acceptors and PS II inhibitors suggest that the O-I 1 phase is controlled by photochemical charge separation (photochemical phase), while the I 1 -D-I 2 -P transients are limited by dark reactions (thermal phases). Dichlorophenyl-dimethylurea (DCMU) eliminates the thermal phases by raising I, to the original I level. While in principal the previous findings by Delosme are confirmed, there, is the new aspect of two distinct components in the thermal part of the rise curve, which display different properties. Electron acceptors suppress only the I 2 -P phase, which appears to parallel the reduction of the plastoquinonc pool, which is a fluorescence quencher when oxidized. While the DCMU effect suggests quenching control during I 1 -I 2 by reoxidation of PS II acceptors, this suggestion is contradicted by the observed saturation of I 1 with light intensity and at low temperatures. The relevance of these results with respect to quenching analysis of chlorophyll fluorescence by the saturation pulse method is discussed.

The fluorescence rise kinetics in saturating light display two well separated components with largely different properties. The rapid rise from F 0 to a first intermediate level, I 1 is photochemically controlled, while the following phases leading to a secondary intermediate level, I 2 and to a peak level, P, are limited by thermal reactions. Treatments which primarily affect components at the photosystem II donor side are shown to increase quenching at I 1 and/or to suppress the secondary fluorescence rise to I 2 . Preillumination by single turnover saturating flashes causes I 1 - quenching oscillating with period-4 in dependence of flash number. It is suggested that this quenching correlates with (S 2 + S 3 ) states of the watersplitting enzyme system. Suppression of the secondary, I 1 - I 2 rise component is invariably found with treatments which lower electron donation rate by the watersplitting system and are known to favor the low potential form of cyt b 559. Three different mechanisms are discussed on the basis of which donor-side dependent quench­ing could be interpreted: 1) Non-photochemical quenching by accumulation of the P 680 + radical cation. 2) Dissipative photochemical quenching at a special population of PS II centers (β- or non- B centers) displaying low donor capacity and high rates of charge recombination. 3) Dissipative photochemical quenching via cyclic electron flow around PS II, involving alternate donors to P 680 + (like cyt b 559 or carotenoid in their low potential forms), which can compete when donation rate from the water splitting system is slowed down. The possibility of donor-side limitation also being involved in “energy dependent” quenching is discussed.

The midpoint potential of BFO, the sensitivity of its photoreduction to DCM, DBMIB and KCN, and the photosystem I activity, suggest that the photoreduction of BFO in the chloroplast is at the primary electron acceptor x of photosystem I. and is irreversible. Rates of electron transport are similar in basal phosphorylating or uncoupled conditions al­though electron transport is coupled to photophosphorylation.

Titration of trimers of C-phycocyanin with p-chloromercuribenzenesulfonate (PCMS) changes spectroscopic and kinetic properties of chromophore B84. The resonance-enhanced CARS spec­tra of room temperature solutions indicate that these changes are due to a modification in B84 chromophore geometry (movement of ring D) as judged by the disappearance of the 1245 cm -1 vibration.

The cyclohcxanedionc derivatives sethoxydim and alloxydim block leaf growth and inhibit the accumulation of photosynthetic pigments (chlorophylls, carotenoids) in expanding leaves of oat seedlings, but do not affect the rate of photosynthesis in the primary or secondary leaves. In isolated intact oat chloroplasts the incorporation of [2- 14 C)acetate into the total fatty acid fraction is strongly inhibited by the two herbicides sethoxydim and alloxydim. The I 50 -values for the inhibition of [ 14 C]acetate incorporation into fatty acids are 5 × 10 -7 ᴍ for sethoxydim and 2 × 10 -6 ᴍ for alloxydim. The desethoxyimino derivative of sethoxydim. M1-S, a degradation product of sethoxydim, does not interfere with the fatty acid biosynthesis of isolated oat chloro­plasts. In isolated chloroplasts of the dicotyledonous plants pea and spinach, which as whole plants are tolerant towards sethoxydim, no significant inhibition of the fatty acid biosynthesis by sethoxydim could be found. It is assumed that the primary mode of action of sethoxydim and alloxydim is in blocking the fatty acid biosynthesis in the sensitive gramineous plants.

A cell-free system exhibiting both photophosphorylation (P/2e= 1) and oxidative phosphoryltion (P/O up to 0.8) is described for the cyanobacterium Anabaena variabilis. NADH ant NADPH were found to be equally effective as electron donors for oxidative phosphorylation. Low concentrations of UHDBT, an inhibitor of the cytochrome b/c complex of mitochondria ant loroplasts, were found to inhibit photosystem-II electron transport reactions, but did not affet the cytochrome b 6 /f-complex of Anabaena. The inhibition by myxothiazol, antimycin and heptyihydroxyquinoline corroborates the hypothesis that both respiration and photosynthesis share the cytochrome b 6 /f-complex.

Reactions involving lipase-catalyzed interesterification of lipids, which are of commendable interest in biotechnology, have been monitored and assayed by radiochemical methods using 14 C-labeled substrates. Medium chain (C 12 plus C u ) triacylglycerols were reacted in the presence of an immobilized lipase from Mucor miehei and hexane at 45 °C with methyl [1- 14 C]oleate. [1- 14 C]oleic acid, [carboxyl- 14 C]trioleoylglycerol. [1- 14 C)octadecenyl alcohol, and [U- 14 C)glycerol, each of known specific activity. The reactions were monitored and the rate of interesterification determined by radio thin layer chromatography from the incorporation of radioactivity into acyl moieties of triacylglycerols (from methyl oleate, oleic acid, and trioleoylglycerol), alkyl moieties of wax esters (from octadecenyl alcohol), and into glycerol backbone of monoacylglycerols and diacylglycerols (from glycerol).

Two different cAMP-binding proteins have been identified in yeast mitochondria by photo­ affinity labelling and based on the occurrence of cAMP-binding activity in two different sub-mito­ chondrial fractions. One protein (M r 45-46000) is tightly bound to the inner mitochondrial membrane whereas the other (M r 42000) is found in the soluble intermembrane space. With endogenous substrate cAMP-dependent protein kinase activity could not be demonstrated with sufficient clarity. However, using acidic heterologous substrates, like casein and phosvitin, one cAMP-dependent protein kinase was identified in the intermembrane space. Only low phosphate incorporation was found using histone fractions as substrate. cAMP-dependent modification of proteins appears to be very shortlived in mitochondria. Its physiological significance remains unknown, since neither mitochondrial transcription, translation, respiration nor import of cyto-plasmically synthesized precursors into mitochondria appear to be influenced by exogenous cAMP either in vivo or in vitro. It is shown that cAMP is not actively transported into the inner mitochondrial compartment but rather binds to a receptor(s) localized outside the permeability barrier provided by the inner membrane.

X-ray diffraction analysis of connective tissue samples, which contain type I and type III collagen shows that twisted collagen fibrils are a general principle of assembly. The occurrence of twisted fibrils in native wet Chordae tendineae, skin and Aorta is combined with a shorter axial periodicity of about 65 nm. This shorter D period is shown to be directly related to the tilt of the molecules, which have to be curved to build-up twisted fibrils.

The purification and molecular properties of lysine decarboxylase from Hafnia alvei and the preparation of polyvalent antibodies specific for this enzyme are described. The enzyme was purified within two HPLC steps on a TSK G 4000 SW and a MonoQ column to homogeneity. The subunit of the enzyme has a molecular weight of approximately 80.000 d. Under “native” conditions it seems to form aggregates up to ten subunits. Lysine decarboxylase from H. alvei contains one mol pyridoxal phosphate per mol subunit. Antibodies against the lysine decarboxylase were purified by affinity chromatography.

Repeated immunizations of rabbits with chemically synthesized peptides from selected regions of HLA-DP histocompatibility antigens resulted in the production of specific antibodies that were then isolated from the immune sera by chromatography on Sepharose-peptide immunoadsorbents. The purified antibodies, when tested with an enzyme-linked immunosorbant assay, specifically bound to the inciting fragments; moreover, two of them recognized glycoproteins extracted by nonionic detergents from human chronic lymphocytic leukemia cells, as revealed by binding assays. The results suggest that amino acid stretches 51 - 61 of the alpha chain and 80-90 of the beta chain of HLA-DP histocompatibility antigens are likely exposed on the surface of the protein molecule. The specific recognition of DP regions is strongly suggested by the difference in the binding of those antibodies to soluble membrane proteins, as compared to the binding of monomorphic anti-Class II monoclonal antibodies to the same antigens.

The liberation of hydrocyanic acid by intact not damaged living insects is described as “active cyanogenesis”. This phenomenon - as in contrast to “passive cyanogenesis” observed in plants, where enzyme and substrate get in contact only after tissue damage - is reported from the Zygaenidae. Quantitative data demonstrate that the Zygaenidae can increase the amount of emitted HCN upon irritation. The significance of this phenomenon as a mean of defense is discussed.

In previous publications from this laboratory we suggested the use of radioprotective drugs in a sustained-release form as a practical way to cope with their high toxicity and quick metabolism and excretion. Cysteine and cysteamine, well-established radioprotectants, were used as model drugs and compressed at various concentrations (0-65%) into an insoluble tablet matrix, composed of ethylcellulose and stearic acid at various ratios and compression pressures. We demonstrated in vitro that when the release rate of the radioprotectants was measured under nitrogen, the kinetic data conformed with the Higuchi square root of time equation, indicating that the release of both drugs correlates with Higuchi’s diffusional mechanism. In the present in vivo study, tablets containing cysteine or cysteamine in a slow-release matrix were implanted, into the stomachs of female rats. The rats were irradiated at various time intervals up to 12 h after implantation and their survival recorded daily. Utilizing a 1:3 ratio of ethylcellulose: stearic acid as a matrix, the protective effect of the drugs was remarkable eight hours after tablet implantation. The results reported indicate that slow-release tablet formulation is a possible method for delivering of radioprotective drugs over an extended period of time.

Immunoelectron microscopy was applied to study the antigenic make-up of human and simian immunodeficiency viruses (HIV, SIV) grown in cells expressing either MHC class I (Molt-3) or MHC class I and II (H9) antigens. A variety of antibodies directed against the surface glycopro­ tein gpl20 of HIV and against MHC class I and II antigens were employed. Consistent with earlier observations on the loss of HIV envelope components, gp120 was only weakly demonstra­ ble on the mature virion. MHC class I determinants were present regularly in small amounts on HIV and SIV. Class II antigens, e.g. HLA-DR were found in high density on HIV and SIV grown in H9 cells, but were absent, as expected, on virus grown in Molt-3 cells. These cellular surface antigens are con­ stituents of the virion. The presence of MHC class II antigens in virus preparations used for diagnostic purposes might explain some of the false positive results in HIV serology. Possible biological implications of these virus associated cellular antigens for the pathogenicity of HIV are discussed.

per° Mutants of Drosophila melanogaster which are exposed to light-dark cycles (LD) with different Zeitgeber period (T) have a limited range of entrainment. Entrained flies show a characteristic phase relationship of activity to the LD which depends on the period of the driving cycle as expected by oscillator theory. Both facts are taken as evidence that per° possesses endogenous oscillators and that the per gene product is not concerned with central clock structures but rather might be responsible for the mutual coupling between the individual oscillators in a multioscillatory system controlling locomotor activity.

Infrared spectra of hemoglobin (met-hemoglobin) and myoglobin were recorded in the temperature range -110 °C to 30 °C. On cooling hydroalcoholic solutions of hemoglobin, the spectra indicate a conformational change (revealed by the appearance of a band at 1665 cm -1 ) compatible with the appearance of distortions in its α-helical structure. In the case of myoglobin smaller effects are ob­ served. These conformational changes are entirely reversible and do not occur in frozen aqueous solutions.

Thermal lability of bovine erythrocyte membrane proteins was studied by electron spin resonance using maleimide spin label. The temperature of the sample during measurements could be varied for the first time be­ tween 0 and 60 °C with an accuracy of ± 0.1 °C. Our results show that “old” erythrocyte membrane proteins are less stable against thermal denaturation then “young” cells.

Lipids from the gular glands of the American alligator (Alligator mississippiensis) were examined by gas chromatography-mass spectroscopy. C 14 , C 16 , and C 18 fatty acids, squalene, and α-tocopherol (vitamin E) were detected in nearly all samples. Cholesterol was detected clearly in several samples.

(E)11-Hexadecenyl acetate was identified from sex pheromone gland extract of female eggplant borer. The acetate synthesized in the laboratory showed high attractant activity in the field.

Sex Pheromone, A ttraction-Inhibitor, (Z)-Alkenols, C oleoph ora laricella, Coleophoridae

The title compound, unreported as an insect pheromone component, effectively attracted certain male Gelechiidae (genera Chionodes, Monochroa, Argolamprotes) as a sin­gle chemical. Trap captures with this chemical decreased on addition of either (E)-3-dodecenyl acetate. (E)-3-tetra- decenyl acetate or (Z)-3-tetradecen-1-ol. the sexual attractants of other, closely related species. Results on an Aproaerema test species showing a synergistic attraction response to combinations of (Z)-3-tetradecenyl acetate with its homologue (Z)-3-dodecenyl acetate are included.

Forty five volatile compounds, mostly straight- and branched-chain alcohols and ketones, as well as derivatives of two of these alcohols, two y-lactones, an aromatic thiol ester and other simple aromatic compounds, have been identified in the preorbital secretion of the blue duiker, Cephalophus monticola.

A new idea that elucidates the electron carrier ability of plastocyanin (and of azurin) is proposed. It emphasizes the fact that two lobes of the d-orbital, where one unpaired electron of copper (II) ion lies, are not screened by the ligand atoms, which would facilitate the electron transfer between the d-orbital and the redox partners (cytochrom f and P-700 in the case of plastocyanin). Several evidences which support the above proposal are provided.

The effect of the three cyclohexane-1,3-dione derivatives cycloxydim, sethoxydim and clethodim on the incorpora­tion of 14 C-labelled acetate, malonate. acctyl-CoA or malonyl-CoA into fatty acids was studied in an enzyme preparation isolated from barley chloroplasts (Hordeum vulgare L. var. “Alexis”). The herbicides cycloxydim, clethodim and sethoxydim block the de novo fatty acid biosynthesis from [2- 14 C]acetatc and [1- 14 C]acetyl-CoA, whereas that of [2- 14 C]malonatc and [2- 14 C)malonyl-CoA is not affected. The data indicate that the mode of action of the cyclohexane-1,3-dione derivatives in the sensitive bar­ley plant consists in the inhibition of de novo fatty acid biosynthesis by blocking the acetyl-CoA carboxylase (EC 6.4.1.2.).

Chloroplast-free mutant cells C-2A′ of the green algae Scenedesmus obliquus lack thioredoxin f, which functions in the light activation of chloroplast enzymes, but do con­tain the regular thioredoxins I and II. When dark-grown algae are transferred to light, thioredoxin f activity appears rapidly and increases in parallel with photosynthetic ac­tivities: however it precedes chlorophyll biosynthesis. The formation of thioredoxin f is inhibited by cydoheximide indicating that it occurs on the cytoplasmic ribosomes, in accord with the lack of thioredoxin genes on the chloroplast genomes.

Rotation of living and dead yeast cells with and without buds was examined in rotating electric fields through a frequency range of 90 Hz to 140 MHz. For living yeast maximum rotation was observed in co-field direction at 30 MHz as predicted from model calculations, but with an unexpected sharp second resonance at 80 MHz for nonbud­ding cells. Also in the high frequency range the rotation rate was found to be proportional to the square of the applied field strength. The resonance of dead cells lies at 4 MHz; at lower frequencies these cells spin against the field analog to living cells, but without any resonance.

The melting pressure and the specific volume of human blood was measured up to pressures of 1000 bar or more. The melting pressure curve has a slope of -138 bar K -1 . The compressibility of blood is nearly twice the value of blood scrum. After application of high pressure the blood exhibits some haemolysis most probably due to the effect of the steel surface of the autoclave.