Effects of ibotenic acid,quisqualic acid and their relatives on the excitability of an identifiable giant neurone of an African giant snail (Achatina fulica Férussac)

Summary An identifiable giant neurone, PON (periodically oscillating neurone), of Achatina fulica Férussac, inhibited by erythro--hydroxy-L-glutamic acid, was also inhibited by 2 relatives of -hydroxy glutamic acid, ibotenic acid and quisqualic acid. These substances similarly showed the effect on the neurone even in the chloride-free medium.The authors wish to thank Professor Emeritus T. Takemoto of Tohoku University, Dr H. Iwasaki of Takeda Chemical Co. and Professor C. H. Eugster of Zurich University for the donation of precious substances, and Miss H. Tamura for technical assistance.     

Current(I)-voltage(V) relationships of the neuromembrane of an identifiable giant neurone of an Afican giant snail (Achatina fulica Férussac) in the presence of an inhibitory tripeptide,L-Lys-L-Phe-L-Tyr

Summary An inhibitory tripeptide, L-Lys-L-Phe-L-Tyr, caused membrane hyperpolarization of the TAN (tonically autoactive neurone) resulting in an elevated firing level. The tripeptide, however, did not markedly affect either the TAN I–V curve or the firing pattern obtained by transmembrane triangular current injection.The authors wish to express their thanks to Prof. M. Kohsaka and Prof. A. Mori of Okayama University for the helpful advice, and to Dr A. Inoue of Daiichi Pharmaceutical Co. for the donation of L-Lys-L-Phe-L-Tyr.     

Slow current changes underlying square shaped potential waves in warmedAplysia neurones

Summary On warming, the regularly firing L₁₁ neurone ofAplysia turns into a bursting-type neurone. The bursts of spikes are produced by slow square waves which can also be obtained at room temperature by adding TTX or Co⁺⁺. Experiments with slow ramp voltage clamp show that warming induces a negative slope (or negative resistance) on the current-voltage characteristic and very slow current variations (=10 to 50 sec) in response to potential changes. The square waves are explained by these two phenomena.     

Alternariol,a dibenzopyrone mycotoxin ofAlternaria spp., is a new photosensitizing and DNA cross-linking agent

Summary The mycotoxin alternariol (3,4,5-trihydroxy-6-methyldibenzo [a] pyrone) but not alternariol monomethyl ether (3,4-dihydroxy-5-methoxy-6-methyldibenzo [a] pyrone) is phototoxic toEscherichia coli in the presence of near UV light (320–400 nm). The phototoxicity bioassays with a DNA repair-deficient mutant ofE. coli suggested that DNA may be the molecular target for photo-induced toxicity of alternariol. Interactions between alternariol and double-stranded, supercoiled DNA suggest that alternariol interacts with DNA by intercalation. No DNA breakage was detected in this system; however, alternariol forms a complex and cross-links double-stranded DNA in near UV light. These results suggest that alternariol is a new phototoxic, DNA-intercalating agent and is a DNA cross-linking mycotoxin in near UV light.Acknowledgment. Dr Albert Stoessl (Agriculture Canada, London, Ontario, Canada) generously provided a mixture of alternariol and alternariol monomethyl ether, and made many helpful suggestions. Dr Ashwood-Smith (University of Victoria, Victoria, British Columbia, Canada) kindly supplied the microorganisms through Dr G.H.N. Towers (University of British Columbia, Vancouver). We gratefully acknowledge the gifts. It is a pleasure to acknowledge the able assistance of Mr S. Tallevi.     

Hydroxydihydroergosine,a new ergot alkaloid analogue from directed biosynthesis bySphacelia sorghi

Summary A new ergot alkaloid, 9-hydroxydihydroergosine, has been produced by axenic cultures ofSphacelia sorghi to which 4-hydroxy-proline was added when biomass accumulation was complete. Evidence for a lack of biosynthetic specificity for the first, second and third amino acid in cyclic tripeptide alkaloids has now been found amongst ergot fungi.Supported by the Science Research Council and Roche Products Ltd.     

Cleavage of des-Arg9-bradykinin by angiotensin I-converting enzyme from pig kidney cortex

Summary Fast and very slow hydrolyses of des-Arg⁹-bradykinin and angiotensin II by angiotensin I-converting enzyme were detected by high performance liquid chromatography. The Michaelis constants of the enzyme, K_m values, for des-Arg⁹-bradykinin and bradykinin were found to be 0.24 mM and 4.4 M, and the maximum velocities, V_max values (mol·min^–1·mg protein^–1) for these compounds to be 3.24 and 0.34, respectively. The enzyme also hydrolyzed Z-Gly-Pro-Gly-Gly-Pro-Ala to a tripeptide that was identified as dansyl-Gly-Pro-Ala by TLC on polyamide. These observations show that the enzyme hydrolyzes the peptides at the bond before the prolyl residue in the penultimate position.Acknowledgments. We thank Dr Kinzo Nagasawa of Kitasato University for encouragement in this work and Dr Ervin G. Erdös, University of Texas, Health Science Center, Dallas, for valuable discussion and suggestions.Abbreviations used: Z, carbobenzoxy; Bz, benzoyl; ACE, angiotensin I-converting enzyme; BK, bradykinin; HPLC, high performance liquid chromatography.     

Tartessol,a new diterpene fromSideritis grandiflora Salzm

Résumé Un nouveau diterpène tartessol (1) a été isolé de laSideritis grandiflora Salzm. (Labiées) est sa structure est proposée comme étantent-14-acétoxy-15-beyèren-18-ol.

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Part XVIII in the series Studies on diterpenes from genusSideritis. For Part XVII seeT. G. de Quesada, B. Rodríguez andS. Valverde,Phytochemistry, in press.

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The authors thank Dr.J. Borja, Botany Department, Faculty of Pharmacy, Madrid, for the collection and botanical classification of the plant material and Dr.Juana Bellanato, Institute of Optics, C.S.I.C., Madrid, for the high resolution IR spectra.     

Hormonal rupture of larval diapause in the tickRhipicephalus sanguineus (Lat.)

Zusammenfassung Die Diapause von Larven der ZeckeRhipicephalus sanguineus (Lat.) wird durch- and-Ecdyson beendet.

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We would like to thank Dr.J. B. Siddal for generously providing-ecdysone, Dr.T. Takemoto for-ecdysone and Dr.N. Krishnan for the juvenile hormone analogue,trans, trans-10, 11-epoxy faresenic acid methyl ester.     

Narciclasine,an inhibitor of protein synthesis. Action onAllium cepa L. root meristems

Summary Shortening of nucleologenesis time in a synchronous cell population, labelled as binucleate, by a caffeine pulse and fall in frequency of prophases are related to narciclasine inhibition of protein synthesis inAllium cepa L. meristems.Acknowledgments. We gratefully acknowledge Dr D. Vázquez and Dr A. Jiménez, from the Instituto de Bioquímica de Macromoléculas, for calling our attention to this protein synthesis inhibitor and providing us samples both of narciclasine andNarcissus bulbs. We also greatly appreciate Dr B. Rodriguez and Dr F. M. Panizo of the Instituto de Química Orgánica (Departamento de Productos Naturales) for their valuable help in isolation and characterization of narciclasine, and for laboratory facilities. The work has been partially supported by the Comisión Asesora para la Investigación Científica (Spain). A.S. has a fellowship awarded by the Instituto de Cultura Hispánica, Spain.     

Methyllycaconitine,a naturally occurring insecticide with a high affinity for the insect cholinergic receptor

Summary Studies of extracts ofDelphinium seeds, long known to be insecticidal, revealed that a principal insecticidal toxin was methyllycaconitine, which is shown to be a potent inhibitor of -bungarotoxin binding to housefly heads (K_inh=2.5×10^–10±0.5×10^–10M).Calgary for gifts of MLA, citrate and lycoctonine, and Dr W. Bowers of the University of Arizona for the original extract ofDelphinium seeds. We would also like to acknowledge the able technical support of Ms C. Dushin, Mr E.L. Bowman, Dr C. C. Gagne, Mr R. F. Borysewicz and Dr P. Mowery for his assistance in obtaining and interpreting the carbon-13 NMR spectra.     

Experimental immunity against trypanosomiasis

Summary 9 groups of 6 female rats were used in an experiment using fraction 3 ofTrypanosoma rhodesiense. 500 g gave 100% immunoprotection and 1000 and 1500 g gave 66% immunoprotection when challenged with 5×10² T. brucei. 2 groups of 10 female rats were tested for a short period inoculation immune response. In this, 750 g of fraction 3 ofT. rhodesiense gave 70% immunoprotection when challenged withT. brucei.I thank the University of Zambia for support; Dr M. A. Q. Awan, Mazabuka, Zambia, forT. rhodesiense andT. brucei; Prof. J. W. Kibukamusoke, Dr O. Okong'o and Dr W. W. Anokbonggo for advice; Mr L. Nyaliti for technical help.     

Identification of (3R,4R)-gD 1(6) as an isolation artefact of cannabinoid acids formed by callus cultures ofCannabis sativa L

Summary For the first time we have isolated a major psychoactive cannabinoid, (3R, 4R)- ¹⁽⁶⁾-tetrahydrocannabinol3 from callus cultures ofCannabis sativa L.3 was obtained as an artefact of the actually formed (3R, 4R)- ¹-tetrahydrocannabinol-3- and/or 5-carboxylic acids1 and2 by subjecting the culture material to a decarboxylation step prior to extraction. No attempt was made to isolated acids1 and2. The identity of3 was confirmed by comparison with an authentic sample of (3R, 4R)- ¹-tetrahydrocannabinol. Culture conditions, isolation procedure and identification of the cannabinoid are described.Acknowledgment. The authors are greatly indebted to Dr W. Heller and Dr G. Schroeder-Frey for deriving the callus cultures from seedlings ofC. sativa and to Prof. N. Amrhein for valuable gifts of culture media and growth regulators.     

Methoxymercuration-demercuration and mass spectrometry in the identification of the sex pheromones ofPanolis flammea,the pine beauty moth

Summary The major components of the sex pheromone system ofPanolis flammea, pine beauty moth have been identified as (Z)-9-tetradecenyl acetate, (Z)-11-hexadecenyl acetate and (Z)-11-tetradecenyl acetate in the ratio 10051; the double bond position of these derivatives was established by microscale application of a methoxymercuration-demercuration technique and GC-MS followed by multiple ion monitoring.We thank the Science Research Council and Forestry Commission for financial support. We are grateful for the collaboration of Messrs Stoakley and Bevan, Dr C. Longhurst and Mrs J. Edwards.     

Volatiles associated with scolytus scolytus beetles on English elm

Summary -Multistriatin, 4-methyl-3-heptanol and-cubebene, the components of the aggregation pheromone of Scolytus multistriatus are also associated with virgin female Scolytus scolytus on English elm, Ulmus procera.We thank Dr J. F. Grove for advice and encouragement, Mrs J. Allsop for technical assistance, Dr J. W. Peacock for authentic samples of multistriatin, 4-methyl-3-heptanol and-cubebene, and the Parks and Gardens Dept., Brighton Corporation, for supplies of English elm.     

The identification of ecdysterone (20-hydroxyecdysone) in 3 species of molluscs (Gastropoda: Pulmonata)

Summary Ecdysterone has been identified in the schistosomiasis vectorBiomphalaria glabrata Say and inHelix aspersa Müller as well as inLymmaea stagnalis L. by chromatography, bioassay, radioimmunoassay, derivatization and by mass spectroscopy. Analysis of the food, faeces and hepatopancreas suggest that the sterol is derived from the diet. The probable function of ecdysterone in relation to calcification of the shell is discussed in this paper.We wish to thank Professor P. Karlson and Dr J. Koolman (Phillips University, Marburg-Lahn, FRG) for providing facilities for RIA. The initial study was begun at the University of Sussex and continued at the Courtauld Institute of Biochemistry, Middlesex Hospital Medical School, London, while D.L.W. was supported by the Ministry of Overseas Development. London and the Medical Research Council of Great Britain (grant G974/525/T). We thank Mr P. Mellon for the mass spectrum and Dr G.B. Russell for his interest in the earlier part of this study. We also thank Professor E. Scherer and Dr Q. Uwe (University of Essen, FRG) for their help in the irradiation ofL. stagnalis.Gauss Str. 82, D-4630 Bochum 5 (Federal Republic of Germany). Research results usingL. stagnalis were submitted for the Philips Europa Wettbewerb für junge Forscher und Erfinder (1979) in a thesis entitled Zur Frage der Existenz von Steroiden und Gonadoliberin bei der Grossen Schlammschnecke (Lymmaea stagnalis L.): ein Beitrag zur Evolution der Insekten- und Wirbeltierhormone.     

3,5-Dibromo-2′-chloro-4′-isothiocyanatosalicylanilide,a potent anthelminitic

Summary The compound, 3,5-dibromo-2-chloro-4-isothiocyanatosalicylanilide, has been tested against various nematode and cestode parasites in experimental and domestric animals. It shoved 100% activity againstAncylostoma ceylanicum, A. tubaeformis, Syphacia obvelata, Ascaridia galli, Toxocara spp.,Toxascaris sp.,Gnathostoma spinigerum, Hymenolepis nana, Raillietina spp. andTaenia spp. in doses 25–70 mg/kg given in single or multiple administrations.Acknowledgments. We express sincere thanks to Dr Nitya Nand, F.N.A., CDRI, Lucknow, for his keen interest in the work, to Dr B. N. Dhawan, F.N.A. for providing informations about general pharmacology of the compound, and to Dr R. K. Chatterjee and Dr P. K. Murthy for carrying out antifilarial sreening. Technical assistance of Mr S. C. Bhar and Mr S. Ram is acknowledged.     

Wound healing properties of naphthaquinone pigments fromAlkanna tinctoria

Summary From the roots ofAlkanna tinctoria Tausch, the alkannin esters of the following acids were isolated and identified: ,-dimethylacrylic acid, -acetoxy-isovaleric acid, isovaleric acid, and angelic acid. These esteric pigments showed excellent wound healing properties in a clinical study on 72 patients with ulcus cruris.I thank Dr A. Winkler, Heidberg Hospital and Prof. K. Kanitakis, Aristotle University, for the clinical studies. Prof. A. Sagredos, Aristotle University, for his help and Dr C. Gairola, Tobacco and Health Research Institute, for the mutagenicity tests. I also thank Dr G. A. Digenis and Dr L. Hurley, University of Kentucky, College of Pharmacy, for their critical reviews and comments.     

Microbiological oxidation of the pentyl side chain of cannabinoids

Summary Syncephalastrum racemosum ATCC 18192 andMycobacterium rhodochrous ATCC 19067 partially degrade the n-pentyl side chain of cannabidiol, cannabinol, ⁸-tetrahydrocannabinol and ⁹-tetrahydrocannabinol. Carboxylic acid and alcohol side chain derivatives are major metabolites.Acknowledgment. The authors wish to express their gratitude to Dr E. H. Fairchild for pmr and mass spectra, Dr R. L. Foltz for gc-ms analysis and to the National Institute on Drug Abuse for financial assistance in the form of a research grant.     

The presence of β-phenylethylamine,p-tyramine,m-tyramine and tryptamine in ganglia and foot muscle of the garden snail (Helix aspersa)

Summary The concentrations of -phenylethylamine,p-tyramine,m-tyramine,m-octopamine and tryptamine in the ganglia or foot muscle ofHelix aspersa range from <0.6 to 11 ng/g.p-Octopamine levels are higher in ganglia (327 ng/g) than in foot muscle (4.1 ng/g). Dopamine and 5-hydroxytryptamine range from 840 to 2710 ng/g while their acid metabolites, 3,4-dihydroxyphenylacetic acid, 3-methoxy-4-hydroxyphenylacetic acid and 5-hydroxyindoleacetic acid range from <20 to 130 ng/g.Acknowledgments. We thank Dr A.A. Boulton for helpful discus sion, Dr D.A. Durden for supervising the mass spectrometric analyses, Dr B.A. Davis for the synthesis of the deuterated standards, G.H. Wheatley, E.P. Zarycki and M. Mizuno for expert technical assistance, and Saskatchewan Health and the MRC of Canada for providing financial support.     

Karyotypes of bats of the subfamily carolliinae (mammalia; phyllostomatidae) and their evolutionary implications

Zusammenfassung Es werden die Kennzeichen der Chromosomen vonRhinophylla fischeri, R. pumilio undCarollia castanea beschrieben. Für die GattungCarollia ist bei niedriger Diploidzahl (21 , 20 ) eine niedrige « nombre fondamental » (34–36) charakteristisch. Für die GattungRhinophylla wird eine grössere Diploidzahl (34–36) und eine grössere « nombre fondamental » (56–62) gefunden.

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We thank Dr.C. J. Marinkelle andA. Cadena of the Universidad de Los Andes for assistance and facilities.Pvt. Genaro Lopez assisted with the field work. Dr.R. Strandtmann translated the summary. Supported by National Science Foundation Grant No. GB-8120.