Nachweis der Selbst-Erregung der circadianen Periodizität bei Carabiden (Coleoptera Ins.)

Summary Most of the active individuals ofCarabus cancellatus (Coleoptera) investigated were synchronized by zeitgeber-lengths of 8/8 10/10 or 16/16 h. On the other hand, a smaller number of beetles lost the periodicities of these Zeitgebers and showed a circadian activity rhythm. According to these experiments, the existence of a self-sustained circadian oscillation in carabid beetles is demonstrated. As we believe, a special numerical method of computing the length of activity periodicities was used for the first time.     

Unusual antimicrobial compounds fromAeollanthus buchnerianus

Using bioassay guided isolation, three novel 12 carbon polyoxygenated fatty acids and a novel abietane diterpene have been isolated from the the chloroform extract of aerial parts ofAeollanthus buchnerianus (Lamiaceae). Rigorous spectroscopic methods were used for compound identification. (Z,Z)-8-acetoxy-5-hydroxydodeca-2,6-dienoic acid and (Z,Z)-5,8-dihydroxydodeca-2,6-dienoic acid inhibited the spore germination ofCladosporium cucumerinum (both with Minimum Inhibitory Dose (MID) values of 1 g) andAspergillus niger (MID 5 and 25 g respectively). Further, they also reduced the hyphal growth ofPythium ultimum. (Z)-5-hydroxy-6,7,8-triacetoxydodeca-2-dienoic acid exhibited short term inhibition of the growth ofCladosporium cucumerinum. The novel abietane diterpenoid, (rel)-14-acetoxyabiet-7-en-18-oic acid inhibited the growth of the gram positive bacteriaBacillus subtilis, staphylococcus aureus andStreptomyces scabies (MIC values 80, 20 and 20 g ml^–1 respectively).     

Total synthesis of orellinine,a minor toxic component of the fungusCortinarius orellanus fries

Summary The 3,3,4,4-tetrahydroxy-2,2-bipyridyl-N-oxide has been synthesized by dealkylation of the corresponding tetramethyl derivative. The chemical properties of this compound are identical to those reported for the minor fungal toxin ofCortinarius orellanus, orellinine.This work is part of the Tesi di Laurea of Miss Cinzia Pierucci.     

γ-Glutamyl-transpeptidase in lymphatic tissues ofMastomys natalensis during an infection withAcanthocheilonema viteae

Summary DuringAcanthocheilonema viteae infection, the specific activity of -glutamyltranspeptidase (-GT) increased in peritoneal exudate cells and bone marrow and decreased in lymphnodes ofMastomys natalensis throughout the course of infection. However, though there was an increase in specific activity of -GT in thymus and spleen during the prepatent phase ofA. viteae infection, the level either returned to normal or decreased during the latent phase of infection. A close correlation was observed between the host's immune status duringA. viteae infection and the level of -GT in lymphoid tissues.Communication No. 4535 from Central Drug Research Institute, Lucknow.     

Allozyme polymorphism and linkage disequilibrium ofAdh and α-Gpdh loci in wine cellar and field populations ofDrosophila melanogaster

Summary Over three years, theAdh and -Gpdh loci have been studied in two cellar populations ofDrosophila melanogaster and in two field populations which were each near to one of the cellars. Analyses of gene frequencies indicate that the divergence among subpopulations is greater in theAdh locus than in the -Gpdh locus. Selection for or againstAdh ^S allele acting on theIn(2L)t inversion influences of the -Gpdh alleles. This phenomenon may contribute to explain the maintenance of theAdh and -Gpdh polymorphism and of theIn(2L)t inversion.     

Identification of a plant growth inhibiting iridoid lactone fromDuroia hirsuta,the allelopathic tree of the ‘Devil's Garden’

Bioactivity-directed fractionation of a root extract ofDuroia hirsuta (Rubiaceae), a toxic and potentially allelopathic understory tree from the western Amazon, has led to the isolation of the tetracyclic iridoid lactone, plumericin (1). Bioassays showing plumericin strongly inhibited lettuce radicle elongation at a concentration (IC₅₀) of 35.8 m/ml (123 M). The isolation of a highly potent inhibitor of plant growth fromDuroia hirsuta supports the hypothesis that the lack of vegetation surrounding this tree is the result of allelopathy.     

Selective protection of cells against X-irradiation. Isoproterenol protects only those cells that possesβ-adrenoreceptors

Summary In mixed culture of Chinese hamster fibroblatst, clone 431, and transformed murine L fibroblasts, clone B-82, isoproterenol was found to protect only 431 cells against ionizing radiation. It was shown that 431 cells, in contrast to B-82 cells, possess-adrenoreceptors, and the radioprotective effect of isoproterenol can be realized only if this agent interacts with-adrenoreceptors coupled with the cAMP system. Since malignization often causes the disappearance of-adrenergic and other hormone receptors, the combined culturing and irradiation of the cells studied can be regarded as a model of the growth of malignant cells (B-82) among normal tissue cells (431 cells) under conditions of radiation therapy. A possibility of selective protection against radiation damage of normal tissue cells, with retention of the former radiosensitivity of tumor cells, is discussed.     

Anti-muscarinic activity of a family of C11N5 compounds isolated fromAgelas sponges

In a search for potential target sites for C₁₁N₅ compounds obtained from marine sponges of the genusAgelas we evaluated their interaction with muscarinic acetylcholine receptors from rat brain membranes. In competition experiments with³H-QNB these compounds displayed the following rank order of potency: sceptrin>oroidindibromosceptrinclathrodin. Sceptrin (50 M) was shown to be a competitive inhibitor of³H-QNB binding as revealed by Scatchard analysis. The results demonstrate the ability of these compounds to interact with multiple target molecules in the micromolar range.     

Antigénicité et pouvoir immunogène des toxines extraites des venins d'Elapidae et d'Hydrophiidae

Summary In this article the results are reported of recent experiments concerning the antigenicity and the immunogenic properties of some basic toxic proteins recently extracted from snake venoms. A serological classification of these substances is proposed. 3 groups have now been determined. As most of the low molecular weight proteins (<10.000) the immunogenicity of the toxin ofNaja nigricollis, taken as an example, is poor. The influence of polymerization of this toxin, and the adjuvant effect of the Freund mixture on the production of specific antibodies, are described. By affinity chromatography, using Sepharose 4B as a carrier, antibodies against this toxin were separated from the other proteins of the antiNaja nigricollis horse immune-serum. They belong to the IgT immunoglobulins. By the same technique, when erabutoxin a fromLaticauda semifasciata is covalently linked to the Sepharose, antibodies reacting with both this toxin and the toxin were separated from the same immuneserum. This confirms that an immunological relationship exists between the toxin of an Elapidae:Naja nigricollis, and the erabutoxin a of an HydrophiidaeLaticauda semifasciata.     

Protective effect of vitamins against trichothecene toxicity towards Saccharomyces cerevisiae

Several trichothecene mycotoxins were shown to inhibit the growth of Saccharomyces cerevisiae. This effect was most pronounced with the macrocyclic trichothecenes, especially verrucarin A. Much less growth inhibition was observed with T-2 toxin. Verrucarol, diacetoxyscirpenol, acetyl T-2 toxin, HT-2 toxin, T-2 tetraol and neosolaniol were inactive at a concentration of 75 micrograms of toxin per disc. Incubation of S. cerevisiae with verrucarin A together with vitamins resulted in a decrease in toxicity. Pyridoxine-HCl, Ca-pantothenate, thiamine-HCl and alpha-tocopheryl acetate were amongst the most potent of the vitamins tested which reversed growth inhibition, overcoming the inhibitory potential of the toxins.     

Occurrence of 3-epi-22-deoxy-20-hydroxyecdysone and its phosphoric ester in diapause eggs of the silkworm,Bombyx mori

Ecdysteroids in diapause eggs of the silkworm,Bombyx mori, were analyzed using high-performance liquid chromatography (HPLC) combined with radioimmunoassay (RIA). A relatively large amount of an unidentified free ecdysteroid and its phosphoric ester (conjugated form) were detected. These two compounds were isolated by a combination of column chromatography on silicic acid, thin-layer chromatography (TLC), and HPLC using a reverse-phase (RP) column. The purified compounds were identified as 3-epi-22-deoxy-20-hydroxyecdysone (22d20E) and 3-epi-22-deoxy-20-hydroxyecdysone 2-phosphate (22d20E2P) by means of mass spectrometry and nuclear magnetic resonance spectroscopy. to our knowledge, this is the first report of 22d20E and 22d20E2P.     

Cardenolide glycosides from the adults and eggs ofChrysolina fuliginosa (Coleoptera: Chrysomelidae)

Besides the known sarmentogenin 3-O--D-allopyranoside (1) and digitoxigenin-3-O-[-D-xylopyranosyl-(14)-2, 3-di-O-acetyl--D-allopyranoside] (4), four new cardiac glycosides (2, 3, 5 and6) have been isolated from the defensive glands of adults ofChrysolina fuliginosa. The structures of the new compounds were determined by¹H NMR at 600 MHz and FABMS. Compounds1–6, present in the adults ofC. fuliginosa, have also been identified in the eggs.     

Can we predict the mating pattern ofDrosophila females from the sperm length distribution in males?

Summary In order to test the validity of the prediction of the mating pattern of females from the sperm length distribution in males, three species ofDrosophila were analysed. Males in the three species are equally polygynous but females differ in the level of polyandry. A low recurrence polyandry is observed in the sperm dimorphic speciesD. affinis while a high recurrence polyandry is observed in the sperm monomorphic speciesD. latifasciaeformis andD. littoralis. These results are consistent with the hypothesis proposed previously that sperm dimorphism in males can only be maintained by a selective alternative in females (i.e. facultative female polygamy), whereas a stricter mating system (e.g., obligatory polyandry) should only result in sperm monomorphism irrespective of the absolute value of sperm length.     

Determination of diel periodicity of sex pheromone release in three species of Lepidoptera by ‘closed-loop-stripping’

Summary By means of closed-loop-stripping and subsequent GC analyses the diel periodicity of release of (Z)-11-hexadecenyl acetate, (E)-8-dodecenyl acetate, and (Z)-9-tetradecenyl acetate, the main constituents of the respective sex pheromone blends ofMamestra brassicae, Cryptophlebia leucotreta andSpodoptera sunia females, was determined.Pheromones, 64. For the 63rd contribution we have taken from: Szöcs, G., Toth, M., Bestmann, H. J., Vostrowsky, O., Heath, R. R., and Tumlinson, J. H., Z. Naturforsch.42c (1987) 165; Pheromones, 62: Bestmann et al.¹³.     

Hotspots of homologous recombination

Homologous recombination occurs at higher than average frequency at and near hotspots. Hotspots are special nucleotide sequences recognized by proteins that promote, directly or indirectly, a rate limiting step of recombination. This review focuses on two well-studied examples, the Chi sites of the bacteriumEscherichia coli and the M26 site of the fission yeastSchizosaccharomyces pombe. Chi, 5 G-C-T-G-G-T-G-G 3, is recognized by the RecBCD enzyme, which nicks the DNA near Chi and produces a 3-ended single-stranded DNA tail; this tail is a potent substrate for homologous pairing by RecA and single-stranded DNA binding proteins. M26, 5 A-T-G-A-C-G-T 3, is recognized by a heterodimeric protein and stimulates, by an as-yet-unknown mechanism, meiotic recombination at and near theade6 gene. Additional hotspots in bacteria, fungi, and mammals enhance recombination directly or indirectly via a variety of mechanisms. Although hotspots are widespread among organisms, the biological role of their localized enhancement of recombination remains a matter of speculation.     

Single amino acid substitutions insn-glycerol-3-phosphate dehydrogenase allozymes fromDrosophila virilis

Summary The amino acid sequence was compared among the three allelic variants (allozymes) ofsn-glycerol-3-phosphate dehydrogenase inD. virilis, which are detected by one-dimensional electrophoresis. The GPDH^f variant was different from the GPDH^m by only one substitution of 68-lysine for asparagine; GPDH^s differed from GPDH^m by substitution of 127-glycine for arginine. No electrophoretically silent substitutions were found in a total of 352 amino acid residues.     

Occurrence of thiaminase II inSaccharomyces cerevisiae

Summary It was found that cell-free extracts ofSaccharomyces cerevisiae contain thiaminase II which hydrolyzes thiamine and thiamine analogs. The possible involvement of this enzyme and thiamine-synthesizing enzymes in thiamine production from thiamine antagonists is discussed.30 September 1986Acknowledgments. We thank the late Dr S. Yurugi, Takeda Pharmaceutical Industries, Osaka, for his generous gifts of dimethialium, 2-northiamine, -hydroxyethylthiamine, hydroxymethylpyrimidine, 2-norhydroxymethylpyrimidine and hydroxyethylthiazole. We also thank Prof. H. Nakayama, Yamaguchi Women's College, for his kind supply ofEscherichia coli 70–17 and 26–43.     

A new indolic antiauxin, α-(5,7-dichloroindole-3-)isobutyric acid: its chemical synthesis and biological activity

Summary A new potent antiauxin, -(5,7-dichloroindole-3-)isobutyric acid has been synthesized and shown to inhibit auxin-mediated elongation ofAvena coleoptiles and to stimulate root growth of rice seedlings. Its activity is stronger than -(p-chlorophenoxy)isobutyric acid and is comparable to that of 2,3,5-triiodobenzoic acid, which are typical antiauxins.     

Versuche zum enzymatischen Abbau der «gebundenen» gibberelline vonPharbitis purpurea

Summary Seeds and fruit walls ofPharbitis purpurea contain in addition to the free gibberellins A₈, A₃, A₅, more polar gibberellin-like substances, so-called bound gibberellins tentatively namedPharbitis and. After purification by thin layer chromatography, these 2 substances were treated with both Ficin and Emulsin in buffered solutions of pH 6.2. After treatment with Emulsin, the free gibberellins A₈ and A₅, after treatment with Ficin the gibberellins A₃ and A₅, were detectable in thin layer chromatograms.     

Phenology of fruit and leaf production by ‘strangler’ figs on Barro Colorado Island,Panamá

Summary Fruit and leaf initiation by 26 trees representing five stranglerFicus species in the subgenusUrostigma were monitored for 5–8 years in a seasonal lowland forest of central Panamá. Individual trees of each species initiated fruit in synchronized crops. High variation in the number of crops, intervals between crops and dates of crop initiation indicate that these species, like species in the subgenusPharmacosycea, initiate fruit crops the year around. Nevertheless, mean crop initiation dates for four of five species fell within the four-month dry season. Similarly, all species produced new leaf flushes throughout the year, however, mean leaf flush dates of all species fell within the first three months of the dry season.