Instar-specific defensive secretions of stink bugs (Heteroptera: Pentatomidae)

Defensive secretions (allomones) from first-instar nymphs of stink bugs in the subfamily Pentatominae contain (E)-4-oxo-2-decenal as a major constituent, whereas this compound is absent from later instars. In contrast, first instars ofEdessa meditabunda (Edessinae) produce allomones like those of later instars. The C₆ and C₈ (E)-4-oxo-2-alkenals are common, characteristic exocrine compounds of nymphal and adult Heteroptera, but (E)-4-oxo-2-decenal is previously unknown as a major natural product for which a biological role has yet to be established.     

A reinvestigation of the chemistry of the Dufours gland of the formicine ant,Anoplolepis custodiens

The components of individual Dufours glands excised fromAnoplolepis custodiens workers were analysed by GC-MS. In addition to then-alkanes andn-alkenes previously reported² in these glands, primary alcohols (C₁₉-C₂₂), secondary alcohols (C₂₀-C₂₃), 2-ketones (C₂₀-C₂₃) and possibly carboxylate ethyl esters (C₁₉ and C₂₁) were identified as components of these glands. It seems possible that these high-boiling compounds are used by the workers in laying trails on the hot sandy surfaces of their characteristic habitat and in lining of the inner walls of nests, but no standard compounds have been available to us for any behavioral studies.     

Chemical analysis of the pheromone blends produced by males and females of the neotropical moth,Mocis megas (Guénée) (Lepidoptera,Noctuidae, Catocalinae)

Summary Pheromonal secretions produced by females and males of the noctuid moth,Mocis megas (Guénée) have been analyzed by gas chromatography and mass spectrometry (EI (electron impact) and CI (chemical ionization)). The female sex pheromone was a blend of (Z,Z,Z) 3,6,9 heneicosatriene (55%) and (Z,Z) 3,6-cis-9S, 10R-epoxyheneicosadiene (45%). Male secretion produced at the level of a prothoracic organ was a blend of two unsaturated major hydrocarbons: (Z,Z) 6,9 heneicosadiene, (64%) and (Z,Z,Z) 3,6,9 heneicosatriene (24%) and C₁₉, C₂₀ and C₂₂ homologues (total ratio 12%), as minor components. The trienic hydrocarbon was present in both sexes. The behavioral role of this male secretion has not yet been elucidated.     

Chemical defense in the three European species ofCrematogaster ants

The composition of the Dufour gland of the antC. scutellaris has been reinvestigated by gas chromatography/mass spectrometry. The major components of the gland are (2E,5E,12Z)-4-oxoheneicosa-2,5,12-trien-1-ol acetate (1a) its ¹⁴ and ¹⁶ double bond isomers (1b and1c), and the corresponding (Z,Z)-dienes5a and5b, all containing an acetylated C₂₁ chain. The previously proposed structures1d, 1e, and5c, which are based on an homologous acetylated C₂₃ chain, correspond to minor derivatives present in the gland. Traces of acetylated C₁₉ homologs, tentatively identified as1g-1i, have also been found. The Dufour gland contents of the two other EuropeanCrematogaster species have also been studied.C. auberti is very similar toC. scutellaris in producing mainly1a, 1b and1c, together with the same higher and lower homologs, but it lacks the dienic derivatives5, whereasC. sordidula contains essentially the acetylated C₁₉ compounds1g, 1h, and1i, accompanied by acetylated C₁₇ homologs.     

The C4-dicarboxylate transport system ofRhizobium meliloti and its role in nitrogen fixation during symbiosis with alfalfa (Medicago sativa)

TheRhizobium meliloti C₄-dicarboxylate transport (Dct) system is essential for an effective symbiosis with alfalfa plants. C₄-dicarboxylates are the major carbon source taken up by bacteroids. Genetic analysis of Dct^– mutant strains led to the isolation of thedct carrier genedctA and the regulatory genesdctB anddctD. The carrier genedctA is regulated in free-living cells by the alternative sigma factor RpoN and the two-component regulatory system DctB/D. In addition, DctA is involved in its own regulation, possibly by interacting with DctB. In bacteroids, besides the DctB/DctD system an additional symbiotic activator is thought to be involved indctA expression. Further regulation ofdctA in the free-living state is reflected by diauxic growth of rhizobia, with succinate being the preferred carbon source. The tight coupling of C₄-dicarboxylate transport and nitrogen fixation is revealed by a reduced level of C₄-dicarboxylate transport in nitrogenase negative bacteroids.     

Nest cell lining of the solitary beeHylaeus bisinuatus (Hymenoptera: Colletidae)

The nest cell lining ofHylaeus bisinuatus (Hymenoptera: Colletidae) was shown by high-resolution solidstate [¹³C]NMR to be composed of lipid polymer and protein. The lipid polymer was shown by reduction and subsequent GC/MS analysis to be comprised of -hydroxy fatty acids (C₂₀, C₂₂, C₂₄ and C₂₆) and fatty alcohols (C₁₆ to C₃₀). The protein portion of the lining had a silk-like amino acid composition.     

Secretion of the Dufour gland of the antNothomyrmecia macrops (Hymenoptera:Formicidae)

Summary The Dufour gland of the primitive Australian antNothomyrmecia macrops contains microgram quantities in total of linear alkanes and alkenes from C₁₃ to C₃₀ with heptadecene the major component (66%). In all, 50 substances, including methyl-branched hydrocarbons, aldehydes and acetates, -farnesene and -springene in low nanogram amounts, were identified by gas chromatography-mass spectrometry.     

Drosophila melanogaster does not dealkylate [14C]sitosterol

Summary Drosophila melanogaster was unable to dealkylate and convert [¹⁴C]sitosterol to cholesterol and no evidence was found for conversion of [¹⁴C]desmosterol to cholesterol. Therefore,D. melanogaster is incapable of dealkylating and converting C₂₈ and C₂₉ phytosterols to cholesterol.The authors thank O. J. Duncan III, and H. S. Symonds for technical assistance. Mention of a company name or proprietary product does not imply endorsement by the U.S. Department of Agriculture.     

Structure of victorin C,the major host-selective toxin fromCochliobolus victoriae

Summary The predominant host-selective toxin fromCochliobolus victoriae, victorin C, is a peptide with an apparent mol. wt of 796, representing a cyclic array of the subunits1–6. The structure of the toxin has now been established as in16 through analysis of the degradation products generated by enzymic and non-enzymic partial hydrolysis. The presence of a hydrated aldehydo group requires for victorin C the composition C₃₁H₄₅O₁₃N₆Cl₃ with an amended mol. wt of 814, for which independent experimental support has been secured.     

Giffordene, 2Z, 4Z, 6E, 8Z-undecatetraene,is the odoriferous principle of the marine brown algaGiffordia mitchellae

Summary Giffordene, 2Z, 4Z, 6E, 8Z-undecatetraene, and five stereoisomers are new odoriferous C₁₁H₁₆-hydrocarbons from the marine brown algaGiffordia mitchellae. Their isolation and identification is described.Acknowledgments. We thank Prof. G. Ohloff for kindly providing us with synthetic 1,3,5,7-undecatetraenes and Prof. P. Schreier for GC/FTIR-analyses.     

The sterols of the khapra beetle,Trogoderma granarium everts

Summary The khapra beetle,Trogoderma granarium Everts, does not dealkylate and convert dietary C₂₈- or C₂₉-phytostorols to C _2T sterols such as cholesterol. There is, however, an increase in the concentration of cholesterol and campesterol in its tissues relative to the dietary concentrations of these sterols, presumably as a result of selective uptake.We thank Dr S. R. Dutky of the Insect Physiology Laboratory, Agricultural Research, SEA, USDA, Beltsville, Maryland for providing GC-MS analyses.     

Composition of epicuticular wax of rice,Oryza sativa

Summary The epicuticular wax of rice, varietyRibe, comprised n-alkanes, esters, aldehydes and free alcohols. The nalkanes contained 4 major chain lengths, C₂₇, C₂₉, C₃₁ and C₃₃. Triacontanal and dotriacontanal were the major aldehydes. Octacosanol comprised 89% of the free alcohols. The esters were mainly esters of C₁₆ to C₂₄ acids with C₂₂ to C₃₀ alcohols.This research was supported by the Consiglio Nazionale delle Ricerche, Rome.     

Sexual pheromones and gamete chemotaxis inAnalipus japonicus (Phaeophyceae)

Summary Female gametes of the marine brown algaAnalipus japonicus secrete a complex bouquet of olefinic C₁₁-hydrocarbons. The major compound is ectocarpene, while hormosirene and dictyotene are present at levels of 2%. Although a minor constituent of the pheromone bouquet, hormosirene is 100 times more active as a male-attractant than ectocarpene. Thus, sex attraction inAnalipus is mediated by two compounds, which diverge largely in concentration and biological activity.     

Hydrolysis of isoprenyl diphosphates with the acid phosphatase fromCinnamomum camphora

Direct observations of the enzymatic hydrolysis of C₁₀ acyclic allylic isoprenyl diphosphates by an acid phosphatase from the leaves ofCinnamomum camphora (camphor tree) were made using¹H and³¹P NMR spectrometers. The measurements indicated that the allylic primary diphosphates, geranyl diphosphate and neryl diphosphate, were hydrolyzed to their corresponding alcohols in a sequential manner via their corresponding monophosphates, whereas the allylic tertiary diphosphate, linalyl diphosphate, was hydrolyzed only to its corresponding monophosphate.     

Is ATP synthesized by a vacuolar-ATPase in the extremely halophilic bacteria?

The proton-dependent synthesis of ATP was demonstrated in representative members of the generaHalobacterium, Haloarcula, andHaloferax. In all cases, synthesis was not inhibited by nitrate or N-ethylmaleimide, inhibitors of the vacuolar-like ATPase found in Archaea, but was affected by azide, an inhibitor of F₀F₁-ATP syntheses. These observations extend the earlier observations withHalobacterium saccharovorum and suggest that ATP synthesis in these organisms is brought about by an F₀F₁-APT synthase.     

Alkaloid biosynthesis

Zusammenfassung Es wird eine neue Theorie der Alkaloidbiosynthese vorgeschlagen, die alle Alkaloidtypen vereinigt. Die Grundidee dieser Theorie beruht auf der Überlegung, dass die Alkaloide eher mit Kohlehydraten als mit Aminosäuren genetisch verwandt sind. Alle Strukturtypen der Alkaloide sind hypothetisch teilbar in C₄, C₆-C₁, C₆-C₂ und C₆-C₃-Fragmente, und können daher in Beziehung zum Davis-Sprinson-Schema, welches die Biosynthese aromatischer Naturstoffe behandelt, gebracht werden.

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From a lecture, entitledAlkaloid Biosynthesis, presented on October 8, 1958, as one of a series of ten lectures onRecent Advances in the Chemistry of Natural Products sponsored by the New York Section of the American Chemical Society during fall of 1958.     

The isolation,culture and organ differentiation from mesophyll protoplasts ofMollugo nudicaulis Lam., a C4 species

Summary Isolation and culture of mesophyll protoplasts fromMollugo nudicaulis, a C₄ species, is reported. Protoplasts developed into callus with root formation. However, no shoot was differentiated. This work was carried out as a part of our overall objective of inducing somatic fusion between the protoplasts of C₃ and C₄ species ofMollugo.     

Furodendin,a C22 degraded terpene from the spongePhyllospongia dendyi

Summary The structure of furodendin (5), a minor secondary metabolite of the spongePhyllospongia dendyi, has been solved by spectral methods. Furodendin is probably derived, biosynthetically, by elimination of a C₃ unit from a C₂₅ geranyl-farnesol precursor.Acknowledgment. We thank Dr C. Evans for sponge identification, RRIMP Museum number FN 1516/000.     

Vincanorin und Vincarein,zwei neue Alkaloide ausVinca minor L.

Summary The isolation of two new alkaloids fromVinca minor L. (Apocynaceae) is described. Vincarein, C₂₁H₂₄N₂O₄, and Vincanorin, C₁₉H₂₂N₂O, both probably belong to the group of indol alkaloids.     

Über physiologische,durch einen Gehalt an verschiedenen Alkaloiden charakterisierte Rassen vonSedum acre L

Summary It is shown thatSedum acre L. collected near Darmstadt contains an alkaloid Sedridin C₈H₁₇ON, while in the literature a sample of the plant collected in Canada showed a content of Sedamin (C₁₄H₂₁ON) and Nicotine. The constitution of Sedridin has been proved and its biogenesis is discussed.