Volume 36, Issue 1-2

The effect of 1 g of ascorbic acid, administered intravenously to healthy male and female volunteers, on blood and its constituents was investigated by means of electron spin resonance (ESR) spectroscopy and by differential hematologic examinations. The native blood ESR spectrum exhibits 2 min after injection of vitamin C a considerable increase in spin concentration and a new signal at about g = 2.005 which we previously had found to correlate to the semidehydroascorbate radical. This spectrum is identical to that obtained in acute lymphatic leukemia. While it prevails in untreated leukemic patients, spin concentration and shape of the spectrum obtained return to normal within several hours to one day in healthy individuals. Since neither in erythrocytes nor in plasma modifications could be observed, the ESR changes detected must have their origin in the leukocytes. Hematologic studies of the peripheral blood show that the number of granulocytes, lymphocytes, and thrombocytes was not drastically affected by the vitamin C injection.

Electron spin resonance studies on healthy and tumerous human lung samples have been con­ducted in order to determine possible differences in free radical concentration and shape of the spectra between the different sections of the lung. It could be shown that in healthy lung tissue the signal caused by the sem idehydroascorbate (SDA) radical is not prominent because of the prevailing high partial oxygen pressure. On formation of a tumor, the spin concentration increases, possibly due to the higher metabolic rate; here, the SDA peak is also more pronounced which indicates alterations in the interaction between cell constituents and ascorbic acid. Within the tumor, the spin concentration is considerably reduced which is probably caused by a still higher concentration of ascorbic acid. Addition of ascorbic acid to the different lung specimens enhanced the just described effect while oxidizing substances, such as H 2 O 2 , reversed it.

The reaction of hydrogenocobalamin or hydrogenocobyric acid (both isolated from Chromatium vinosum) with iron(III) acetate and iron powder in acetic acid under N 2 at 80 °C leads to the incorporation of iron into these cobalt-free corrinoids. The products, Fe(III)cobalamin and Fe(III)cobyric acid, were separated by means of a column of Amberlite XAD-2. They have the electrophoretic mobility of the corresponding cobalt-corrinoids. The brown aqua-forms react with cyanide, rhodanide and azide, and can be reduced by means of NaBH 4 to the green Fe(I) forms. The new compounds were analyzed and characterized by means of elemental analysis, paper chromatography, electrophoresis and spectra (UV/VIS, NMR, ESR).

10 different desulfo-glucosinolates belonging to 9 different homologous series have been isolated from the parent glucosinolates by means of a glucosinolate sulfohydrolase from the edible snail Helix pomatia. They were characterized by the following physical-chemical data: molecular weight, melting point, wavelength of the absorption maximum in the UV-region, molar absorption coefficient at this maximum, angle of optical rotation and R f -values (thin layer and paper chromatography).

By use of 13 CNMR, GLC and GC-MS analysis, 75 compounds, mainly mono-and sesquiterpenes, were identified structurally out of the essential oil of Majorana hortensis Moench. A distinct seasonal dependence in the biosynthesis of terpenoids was observed. The specific application of 13 CNMR spectroscopy enabled the structure elucidation of components of an essential oil even of that complexity.

Chalcone synthase was isolated from both anthers of Tulipa cv. “Apeldoorn” and petals of Cosmos sulphureus Cav. After certain prepurification steps, the enzymes were further purified using gel chromatography on Sephadex G-200 followed by repeated hydroxylapatite absorption chromatography. Both the enzymes showed the same chromatographic properties. After gel chromatography as well as after the first hydroxylapatite fractionation, the reaction products appeared as flavanones. However, after the second hydroxylapatite step, production of chalcones was observed. Like the enzyme from tulip anthers, the synthase from Cosmos petals produced the correspondingly substituted chalcones when p-coumaroyl-CoA, caffeoyl-CoA and feruloyl-CoA, respectively, were used as substractes. In both the cases, the ratios of the different chalcones produced were found to be about the same. The appearance of chalcone synthesis in this in vitro assay is caused by the complete elimination of chalcone isomerase in the purification procedure. The importance of the isomerase for flavonoid biosynthesis, particularly in plant systems which are accumulating chalcones, is discussed.

new enzyme, usnic acid dehydrogenase, which catalyzes the reduction of ʟ-usnic acid, has been isolated from cell-free extract of Evernia prunastri thallus. Purification of the enzyme (approx. 150-fold with a recovery of 42%) can be achieved by using gel adsorption and gel filtration techniques. The apparent molecular weight of the enzyme is 450000. Cofactor requirement is restricted to NADH. Kinetics of the enzyme show an allosteric behaviour for both ʟ-usnic acid and NADH. Structure of the reaction product is described.

Recently medium conditions have been developed which stimulate the formation of the indole alkaloid ajmalicine in cell suspension cultures of Catharanthus roseus [6]. When cells were subjected to these conditions the alkaloid accumulation was preceded by a 12-fold increase of the specific activity of tryptophan decarboxylase. The enzyme activity showed a maximum two days after the cell transfer into the induction medium and subsequently declined. In contrast the activity of strictosidine synthase, the enzyme condensing tryptamine and secologanin, was present over the entire measuring period at a constant level. The intracellular content of tryp­tamine and ajmalicine increased during a period of 6 days after cell transfer and reached a plateau after that time. A possible regulatory function of tryptophan decarboxylase in indole alkaloid biosynthesis is discussed.

We describe and discuss an evolutionary tree derived from data which were obtained using monoclonal antibodies. Monoclonal antibodies (see e.g. Köhler and Milstein, Nature 256, 495 (1975)) were prepared against 5-aminolevulinate dehydratase (ALAD) from spinach (Spinacia oleracea) and enabled us to study 13 different ALAD antigenic determinant characters from origins as diverse as algae, mosses, ferns, gymnosperms and angiosperms. The results show that a dendrogram based on these characters is largely in accord with evolutionary trees based on classical characters. Species, such as Chara or Gnetum, whose system­atic positions are doubtful, are separated from their alleged relatives. ALAD from the photosynthetic bacterium Rhodopseudomonas spheroides showed antigenic similarities with the plastid ALAD enzyme from spinach, while none of the antibodies against the spinach enzyme reacted with ALAD from the blue-green alga Nostoc muscorum. This finding is relevant to the problem of the origin of plastids and shows that monoclonal antibodies may also provide a new approach to the solution of this problem. The results imply that monoclonal antibodies will prove themselves efficient tools for taxonomic or evolutionary studies.

The esterification of various chlorophyllides with geranylgeranyl diphosphate was investigated as catalyzed by the enzyme chlorophyll synthetase. The enzyme source was an etioplast membrane fraction from etiolated oat seedlings (Avena sativa L.). The following chlorophyllides were prepared from the corresponding chlorophylls by the chlorophyllase reaction: chlorophyllide a (2) and b (4), bacteriochlorophyllide a (5), 3-acetyl-3-devinylchlorophyllide a (6), and pyrochlorophyllide a (7). The substrates were solubilized with cholate which reproducibly reduced the activity of chlorophyll synthetase by 40-50% . It was found that the following compounds were good substrates for chlorophyll synthetase: chlorophyllide a and b, 3-acetyl-3-devinylchloro-phyllide a, and pyrochlorophyllide a. Only a poor or no reaction was found with protochloro­phyllide, pheophorbide a, and bacteriochlorophyllide. This difference of reactivity was not due to distribution differences of the substrates between solution and pelletable membrane fraction. Furthermore, no interference between good and poor substrate was detected. Structural features necessary for chlorophyll synthetase substrates were discussed.

Etioplast membranes were fractionated into enriched prothylakoid (PT) and prolamellar body fraction (PLB) by known procedures [2]. The photoconversion of Protochlide to Chlide was 77% in the PT fraction but only 65% in the PLB fraction with optimum NADPH concentrations. The subsequent esterification reaction proceeds in both fractions indicating that the enzyme chlorophyll synthetase is present in both fractions. In the PLB fraction, 10-15% more Chl P is formed than in the PT fraction. It is concluded that the concentration of the endogenous phytol precursor is higher in the membranes still present in the PLB fraction than in the PT fraction.

De novo-synthesis of glycerolipids in chloroplasts is initiated by a stroma enzyme which catalyzes the formation of lyso-phosphatidic acid from glycerophosphate and acyl-CoA. When these substrates are added to isolated, intact chloroplasts, only glycerophosphate can readily pass through the chloroplast envelope which represents a permeation barrier for acyl-CoA, although higher thioester concentrations destroy this membrane system. At low concentrations of acyl-CoA, which do not impair the envelope, intact chloroplasts metabolize exogenous acyl-CoA in two ways to give free fatty acids and labelled phosphatidyl choline. This indicates that the envelope thioesterase can use exogenous substrates. Isolated, intact chloroplasts fixing radioactive CO 2 label free fatty acids and acylglycerols but not galactolipids, since they cannot convert 3-phosphoglycerate into UDP-galactose which in vivo is supplied by the cytoplasm. This cooperation was simulated in vitro by adding all enzymes and cofactors necessary for conversion of 3-phosphoglycerate into UDP-galactose to intact chloro­plasts which then formed labelled monogalactosyl diacylglycerol from labelled CO 2 . The time required to transfer envelope-made galactolipids from the envelope into thylakoids was studied by incubating intact chloroplasts with radioactive UDP-galactose, subsequent osmotic disruption of organelles with concomitant enzymatic degradation of UDP-galactose followed by separation of envelopes and thylakoids. Only after short times (< 1min) appreciable proportions 920-30%) of radioactive galactolipid export from envelopes into thylakoids.

The cell wall of the mutant R 595 of Salmonella minnesola contains a lipopolysaccharide in which only a trisaccharide consisting of three KDO * residues is linked to a lipid termed lipid A. Considering the sterical requirements of fourteen rotation angles, we have calculated allowed conformation of this trisyccharide unit and its linkage to lipid A. The calculations have been based on averaged crystallographic data of pyranose rings, ester-, N-acetyl-, phosphate-and carboxylgroups. Because of considerable sterical hindrance, there are unique positions for the rotation around the axes O 3 -C 3 of the glucosamine residue and O 1 -C 1 of KDO residue 1 as well as for the rota­tion of the N-acetylgroup at the C 2 -atom of glucosamine. Similarly, the rotation angle of the carboxylgroup on KDO residue 1 and the rotation angles of the phosphategroup linked to glucos­ amine are highly restricted, while a large range of angles is allowed for the bond of the ester group to glucosamine. Chemical sequence analysis yields two possibilities for the linkage between the KDO residues 1 and 2. Linkage of O 4 of KDO 1 in equatorial position is restricted to a narrow range of angles, whereas the linkage to O 4 in axial -and to O 3 in axial and equatorial position is unfavourable. Furtheron chemical sequence analysis suggests two ways how to link KDO residue 1 and 3. The linkage to the oxygen atom on C 7 of KDO residue 1 can be described by four, the linkage to the oxygen on C 6 with three rotation angles. In either case two of the rotations are highly restricted. In the first case the two remaining angles have large rotational freedom, while the second case is sterically unfavorable. The feasibility of the computer calculations has been demonstrated by the construction of a three-dimensional atomic model.

The distribution of acyl moieties at sn-1 and sn-2 positions of cholinephosphoglycerides (CPG) and ethanolaminephosphoglycerides (EPG) has been determined for neurosarcoma, sarcoma 180 and leukemia L 1210. In all the three samples, the positional distribution of acyl moieties in the two major classes of phospholipids is found to be similar to that in cellular phospholipids of most mammalian tissues. The saturated acyl moieties are located predominantly at sn-1 and polyunsaturated acyl moieties at sn-2, whereas the monounsaturated acyl moieties are randomly distributed between these two positions. Apparently, a disruption of specific positioning of acyl moieties in phospholipids, which hitherto has been considered to be a general metabolic deletion in neoplasia, does not exist in all neoplastic cells.

Enzymological studies at high hydrostatic pressure generally involve temperature, pH and pressure as variables, owing to the effect of adiabatic compression and the ionization volume of the buffer system. In the case of NAD dependent oxidoreductases this implies that the extinction coefficient of the coenzyme may be affected by p, T and pH, apart from the spectral change accompanying the redox reaction. Measurements of the pressure dependence of the absorbance of NADH show a slight red shift and a 1% decrease (3% increase) of the absorbance at 339 nm (360 nm) at 2 kbar. The pH depen­dence at the given wavelengths amounts to -(2.4 ± 0.1)% per pH unit (25 °C), while the intrinsic temperature effect (after correction for thermal expansion) is of the order of -0.2% per degree (20-30 °C). Applying buffers with negligible ionization volume, 366 nm is the optimum wavelength for high pressure studies up to 2 kbar because here the pressure dependent spectral changes of the NADH absorption vanish.

Cultures of Anabaena cylindrica, grown on media containing 5 mᴍ NH 4 Cl (which represses heterocyst formation), evolved hydrogen after a period of dark incubation under an argon atmosphere. This hydrogen production was not due to nitrogenase activity, which was nearly undetectable, but was due to a hydrogenase. Cultures grown on media with tungsten substituted for molybdenum had a high frequency of heterocysts (15%) and inactive nitrogenase after nitrogen starvation. The hydrogenase activity of these cultures was three-fold greater than the activity of non-heterocystous cultures. The effects of oxygen inhibition on hydrogen evolution by hetero-cystous cultures suggest that two pools of hydrogenase activity exist - an oxygen sensitive hydrogen evolution in vegetative cells and a relatively oxygen-resistent hydrogen evolution in heterocysts. In either case, inhibition by oxygen was reversible. Light had an inhibitory effect on net hydrogen evolution. Hydrogen production in vitro was much higher than in vivo, indicating that in vivo hydrogenase activity is limited by endogenous reductant supply.

The cyanobacterium Synechococcus (Anacystis nidulans strain L 1402-1) was grown at +35 °C in air and in air enriched with 2.2 vol.% CO 2 . The effect of different oxygen concentrations (0, 2, 20, 50, 75 and 99.97 or 97.8 vol.%) was studied in low (0.03 vol.%) and high (2.2 vol.%) CO 2 concentrations at + 35 °C. After exposure to a nitrogen atmosphere and low CO 2 content I4 C-bicarbonate was mainly incorporated into aspartate and glycine/serine. During oxygenic photosynthetic CO 2 fixation label in aspartate decreased and a high degree of radioactivity could be found in 3-phosphoglyceric acid and sugar monophosphates. The Calvin cycle was the main fixing pathway in 2.2 vol.% CO 2 during anoxygenic and oxygenic conditions independent on the O 2 concentrations during the experiments. No oxygen enhancement of photosynthetic CO 2 fixation could be found. Possible mechanism involved in CO 2 fixation pathways and glycolate metabolism underlying the effect of oxygen was discussed.

Trypsin treatment of isolated chloroplast thylakoids resulted in a step-wise modification of surface exposed membrane polypeptides. Early effects of the protease action resulted in a decrease in inhibitory activity of atrazine, diuron, pyrazon, and bromacil, but an initial increase in the activity of bromnitrothymol and dinoseb. Direct measurements of atrazine binding demonstrated that decreased inhibitory activity corresponded to a decreased binding affinity in the treated membranes. Longer term effects of trypsin caused removal of atrazine binding sites and a concomitant block of electron transport chains. The data are consistent with a concept that the traizine receptor protein is a component of the electron transport chain which is successively degraded in two or more steps by protease attack. Polyacrylamide gel electrophoresis of trypsin-treated membranes and sub-membrane fragments derived from these membranes revealed that several polypeptides are membrane surface exposed. The involvement of a 32000 dalton polypeptide in creating the atrazine binding site is discussed.

The effects of disalicylidenepropanediamine (DSPD) and 2-heptyl-4-hydroxyquinoline-Noxide (HQNO) on photosynthetic electron transport have been reexamined. The results confirm earlier observations that lower concentrations of DSPD (< 100μᴍ) block electron transport at the levels of ferredoxin and plastocyanin. High concentrations of DSPD even inhibit electron transport from H 2 O → pBQ, suggesting that DSPD has an inhibitory site in PS II as well. Thermoluminescence curves of DSPD and DCMU treated chloroplasts were very similar, showing that the third inhibitory site of DSPD is similar to that of DCMU. Both oxidized and reduced HQNO, (0.6-6 μᴍ) blocked electron transport from H 2 O → pBQ, H 2 O → MV/FeCy to a similar extent. The effect of HQNO on thermoluminescence showed that its inhibitory site is probably located before that of DCMU. At higher concentration (> 6 μᴍ), the H 2 O → MV/FeCy reactions were more strongly inhibited by oxidized HQNO than those occuring from H 2 O → pBQ, suggesting that a new site of inhibition must also be considered. The dark decay of the P 700 signal was not influenced by the addition of oxidized HQNO which shows that the new inhibitory site of HQNO is located between plastoquinone and P 700. The reduced form of HQNO did not inhibit non-cyclic electron transport around PS I. Indeed, at higher concentrations, reduced HQNO even accelerates electron flow from DCIP → MV and the dark reduction of P 700, thus suggesting that this compound has a “donor-mediator” function in PS I.

Thiabendazole (TBZ), an antifungal and antihelmintic benzimidazole derivative, after 6 min treatment with a 0.1 mᴍ aqueous solution enhances CO 2 release in intact potato tubers for up to two hours. There are also indications for a reduced water permeability of isolated periderm layers from TBZ - treated potato tubers. Potato slices (ca. 3 mm thick) or discs (with ca. 5 mm diameter) from potato slices show enhanced ethane formation after TBZ - treatment exhibiting maximal rates ca. two hours after treatment, indicating enhanced unsaturated fatty acid peroxidation. This lipid peroxidation is not enhanced by TBZ in potato homogenates or in isolated potato mitochondria. The results of this communication might partly explain macroscopically observable, preservative effects of treatment of freshly harvested potatoes by a stimulation of certain metabolic responses after mechanical wounding.

Acetone extracts of 9 out of 12 plants of Lamiaceae family exhibited high oviposition deterrance (OD) activity against the potato tuber moth, P. operculella (PTM) 4 of these completely prevented egg laying by the latter and A. aegypti. In case of PTM this activity persisted for a varying number of days. 3 of them were also active against D. koenigii and M. domestica. None of the active extracts showed significant antifeedant or repellent activity against any pest species except D. koenigii. It was concluded that except in the case of the latter, the OD activity exhibited was not a corollary of antifeedant or repellent action, as is usually presumed. Magnitude and persistence of OD activity of at least one plant extract against the PTM was considered sufficient for employment in insectistatic management of this pest.

The 4,6-dibromo-and 5,7-dibromo-derivatives of 1-β-ᴅ-ribofuranosylbenzimidazole, and the 4,6-dibromo-derivative of 1-α-ᴅ-arabinofuranosylbenzimidazole, have been synthesized by condensation of the trimethylsilylated derivative of 4,6-dibromobenzimidazole with the appro­priate protected sugar in the presence of SnCl 4 . Application of the fusion method led to the β-ribofuranoside of 2-methyl-5,6-dichlorobenzimidazole. Two additional analogues of the biologi­cally active ribofuranoside of 5,6-dichlorobenzimidazole, viz. the 2′,3′-O-isopropylidene and the 5′-chloro-5′-deoxy derivatives have been synthesized. Analyses of the 1 H NMR spectra of the foregoing, and of previously synthesized 5(6)-mono-halogeno and 5,6-dihalogeno derivatives, were employed to determine solution conformations of these nucleosides. Conformations of the sugar rings and exocyclic groups were evaluated from vicinal proton-proton coupling constants, as for purine nucleosides. The conformation of the benzimidazole ring about the glycosidic bond was determined from the chemical shifts of the sugar protons, principally H(2′), with the aid of model analogues in fixed syn and anti conforma­tions; and, independently, from the chemical shifts of the benzimidazole ring protons, principally H(4) and H(7). The halogenated benzimidazole ribofuranosides exhibit conformations of the sugar ring similar to those for purine β-nucleosides, but differ from the latter in their preference for the conformation syn about the glycosidic bond.

We report on the chemical preparation of 5′,5″-phosphate bridged dinucleosides (1-16) by applying the 1,1′-carbonyl-diimidazole activation method. Nucleotides of this unusual type function as 5′-terminal cap structures of most eukaryotic mRNAs and on the monomer level as regulators in macromolecular biosynthesis.

Conditions for the binding of Met-tRNA i to 40 s ribosomal subunits and to proteins isolated out of the yeast ribosomal KCl wash were investigated. Sucrose density gradient experiments revealed that binding of Met-tRNA i to 40 s ribosomal subunits was catalyzed in a AUG and GTP dependent reaction. Binding of Met-tRNA i to proteins of the ribosomal KCl wash as assayed by the Millipore filter technique was found to be independent of AUG, GTP and 40 s ribosomal subunits. Additions of GTP yielded only slight stimulation, whereas Mg 2+ caused dissociation of complexes. It was concluded that these reactions were most likely catalyzed by initiation factor eIF-2 although stimulation by GTP did not occur.

Ethidium bromide and polylysine interact with nucleosomal DNA and lead to changes of biochemical properties and to morphological changes as to the distance between the two core particles of a nucleosome dimer. With increasing polylysine concentration, the buoyant density of nucleosomes decreases and the accessibility of the nucleosomal DNA to micrococcal nuclease is lowered. Electron microscopy of polylysine treated nucleosome dimers reveals a shortening of the intemucleosomal distance as compared with controls. Treatment of nucleosomes with ethidium bromide leads to an enhanced accessibility of the nucleosomal DNA to micrococcal nuclease. Electron microscopy reveals an increase in length of the DNA connecting the two nucleosome cores in the presence of the dye. Both the binding of polylysine and the treatment with ethidium bromide apparently do not affect the histone arrangement within the nucleosome core as suggested by chemical cross-linking of histones and DNA with formaldehyde, and no obvious morphological changes of the nucleosome cores can be observed.

The four components of the genome of cowpea chlorotic mottle virus have been prepared in a highly active and highly purified state by a method based on their resolution by polyacrylamide gel electrophoresis. Activity and purity have been confirmed by gel electrophoresis under denaturing and non-denaturing conditions, infectivity tests on whole plants, translation in an mRNA dependent rabbit reticulocyte lysate and fingerprinting of T 1 ribonuclease digests after labelling with 32 P at the 5′ ends of the oligonucleotide products. The quality of the RNAs obtained was superior to those previously obtained by zonal centrifugation but only comparatively small batches of whole RNA can be handled with ease.

The cysteine content of poliovirus particles and naturally occuring empty capsids was determined by two methods: (1) reaction with vinylpyridine and subsequent amino acid analyses and (2) treatment with 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) and measurement in the change of absorption. Both methods were performed under dissociating conditions in order to expose all sulfhydryl groups. Poliovirus, type 1, strain Mahoney, contains 10-11 cysteine/cystine residues per protomer, irrespective of the use of virus particles or empty capsids. Poliovirus, type 3, strain Saukett, contains 12-13 cysteine/cystine residues per protomer. Poliovirus particles are completely free of disulfide bridges, whereas empty capsids contain 2-4 cystine residues/protomer. No sulfhydryl groups are present on the surface of the virus particle, because of lack of reaction with DTNB. The tryptophan content was determined to be 13 ± 1 residues/protomer. By amino acid analysis under controlled hydrolyzing conditions 12 residues/protomer were found, whereas formylation in hydrochloric acid/formic acid revealed 14 residues/protomer; 13 tryptophan residues were calculated from the tyrosine-tryptophan relation and the optical density at 293.5 nm and 280 nm. The following parameters of poliovirus particles were calculated from the improved and complete amino acid analysis and the cysteine and tryptophan content: 1. The molecular weight of a protomer to be 92 700 ± 900 Dalton and of the poliovirus particle, type 1, strain Mahoney, to be 7.97 × 10 6 Dalton. 2. The relative hydrophobicity of the poliovirus polypeptide to be 1.18. 3. The extinction coefficients of poliovirus E 1% 260 = 7 4 and of empty capsids E 1% 280 = 16.2 ± 0.2.

Cells suspended in a low-conducting medium were exposed to an alternating electric field whose frequency was altered between 1 kHz and 2 MHz. A resonance frequency was observed at which all suspended cells rotated about an axis normal to the field lines (when the electric field strength was larger than a threshold value of about 400 V/cm). This resonance frequency varied from species to species of cells (mesophyll protoplasts of Avena sativa = 20-40 kHz, human erythrocytes and ghost cells = 80-100 kHz, yeast cells = 140-180 kHz, Friend cells = 30-40 kHz, at room temperature). The resonance frequency of cell rotation was observed only under specific experimental conditions which excluded interference by reversible electrical breakdown of cell membranes and by gravitational forces. Glutardialdehyde fixed and heated cells exhibited no rotation in the frequency and field range investigated. The phenomenon of rotation is discussed in terms of dipole orientation within the membrane.

Traps baited with approx. 2:1 mixtures of (E)-, and (Z)-11-tetradecenyl acetates caught male Sperchia intrac­tana Walker in the field. Analyses of extracts obtained from virgin female moths revealed the presence of these two compounds, which are presumably the major components of the sex pheromone.

An effective and versatile synthesis of 5-hydroxytrypto-phane derivatives offers good access to the conjugation in­ducing hormone blepharismone of the ciliate Blepharisma japonicum and to derivatives and analogues of this biolog­ically active compound. 5′-Fluoroblepharismone and 2′-des-formamidoblepharismone induce conjugation at 500 and 1200 times, respectively, the concentration of the true effector. At high concentration, however, the 2′-des-formamido derivative desensitizes the receptor system for the natural gamone.

The biosynthesis of a 12000 dalton protein species released into the medium by mouse spleen was resistant to the inhibitory effect of hypertonic medium on protein syn­ thesis. This protein fraction comprised 10% or more of the total radioactive protein in the medium but could hardly be detected in the spleens. It was labeled very often to a higher extent in diseased animals. It is not related antigenically to either β-microglobin, mouse-interferon, or to mouse immuno-globulins. A preferential uptake into cells of certain organs, which, when themselves incubated in organ cultures did not synthesize and release the protein, was observed.

The stridulation signals of three species of the Genus Corixa were investigated especially with respect to their spectral composition. Thee dominant frequencies are: 2.7 kHz for C. panzeri, 2.2 kHz for C. dentipes and 2.0 kHz for C. punctata. For C. punctata the threshold frequency responses, especially for one (A1) of both receptor units of the mesothoracic tympanic organ, correspond well to the frequency spectrum of the emitted sounds.