bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthèse de l'évernine
Authors: Nicollier Gilles , Rebetez Michel , Tabacchi Raffaele , Gerlach Hans , Thalmann Adolf 
Published: December 2004

Synthesis of EverninTwo syntheses of the depside evernin 6 are described. Condensation of methyl acetoacetate and methyl crotonate followed by aromatization and reduction with Raney‐Ni led to methyl orsellinate (3). The condensation of everninic acid (4), obtained by partial methylation of 3 and saponification of the methyl ester, with methyl 2, 4‐dihydroxy‐3, 6‐dimethylbenzoate (methyl β‐orcin carboxylate) (5) in presence of cyclohexylcarbodiimide gave evernin (6). In a second syntheis methyl dihydroorsellinate (1) was regiospecifically converted into its 4‐methyl enol ether and aromatized via the benzene selenenyl derivative to yield methyl evernate (7). Benzylation followed by saponification gave the free acid 8. Methyl β‐orcin carboxylate (5) was synthesized in an analogous way from methyl 3,6‐dimethyl‐2,4‐dioxocyclohexanecarboxylate. Condensation of 8 with the methyl ester 5 by treatment with trifluoroacetic anhydride in toluene yielded 9, which could be converted into evernin (6) by hydrogenolysis of the benzyl ether.
Synthèse photochimique de biaryles et hétérobiaryles à partir d'aryl‐et hétéroarylamines, d'un nitrite d'alkyle et d'un substrat aromatique ou hétéroaromatique
Authors: Julliard Michel , Siv Chhan , Vernin Gaston , Metzger Jacques 
Published: December 2004

Photochemical synthesis of biaryls and heterobiaryls from aryl and heteroarylamines, alkylnitrite and aromatic or heteromatic substratesThe photochemical reaction of aromatic and heteroaromatic amines with excess t‐butyl nitrite in aromatic solvents (benzene, p‐xylene, mesitylene) and in hetero‐aromatic solvents (furan, thiophene) leads to biaryls or heterobiaryls. t‐Butyl nitrite is more convenient than isopentyl nitrite which gives by‐products. This new method has been used to synthesize 28 compounds in 17 to 60% yield.
Etudes sur les composés organométalliques. XVII. Synthèse du tétracyclohexyltitane
Authors: Weber Jean‐Bernard , Porret Jacques , Jacot‐Guillarmod André 
Published: December 2004

Studies of Organometallic Compounds. XVII Synthesis of TetracyclohexyltitaniumTetracyclohexyltitanium is prepared by reaction of TiCl4 or Ti(OC4H9)4 with dicyclohexylmagnesium in pentane or ether at ‐ 30°. Some aspects of its reactivity and its decomposition are described.
Etude sur les composés organométalliques. XVIII. Synthèse et caractérisation du μ‐oxo‐bis (dicyclopentadiènylméthyltitane IV)
Authors: Surer Hansruedi , Claude Saturnin , Jacot‐Guillarmod André 
Published: December 2004

Studies of Organometallic Compounds. XVII: Synthesis and Caracterisation of μ‐oxo‐bis(dicyclopentadienylmethyltitane IV)(Cp2TiCH3)2O is obtained by reacting (Cp2TiCl)2O with methyllithium. IR., NMR. and MS. spectrum are reported. Autocatalytic decomposition of the product is inferred from differential thermal analytic measurements.
Radical Ions in the Pentalene Series [1]. Part II. Dibenzo [b,f]pentalene and its 5, 10‐dimethyl derivative
Authors: Fürderer Peter , Gerson Fabian , Rabinovitz Mordecai , Willner Itamar 
Published: December 2004

AbstractProton hyperfine data have been determined for the radical anions and cations of dibenzo [b,f]pentalene (III) and its 5, 10‐dimethyl derivative (IV). The assignment of the coupling constants to pairs of equivalent protons follows from a simple MO model, the use of which enables one to reproduce satisfactorily the experimental values. The proton hyperfine data, aHμThe meaning of aHμis aHC(x),HC(y),whereas only x and y are given in the particular cases.
, for the radical anion III⊖. correlate fairly well with the π‐charge populations ϵμ derived from 1H‐NMR. spectra for the carbon centres μ in the dianion III2⊖. The analogous correlation is less good in the case of the radical cation III⊕. and the dication III2⊕., presumably due to the rough approximations involved in the evaluation of the numbers ϵμ for the latter species. The coupling constants aH5,10 for III⊖. and III⊕. are very close to the corresponding values aH4,6 for the radical ions of 1,3,5‐tri‐t‐butylpentalene (II), in accord with the prediction of the MO model. A similarity is also found between the proton hyperfine data for III⊖. and those for the radical anions of structurally related 1,4‐diphenyl‐1,3‐butadiene (V). On the other hand, there are striking changes in the coupling constants of the analogous protons on passing from III⊖. to the radical anions of dibenzo [a,e] cyclooctene (VI) and [16] annulene (VII), as a consequence of raising the symmetry from C2h to D2h and D4h, respectively.
Beitrag zum Mechanismus der stossinduzierten Fragmentierungen von quaternären Stickstoffverbindungen. 2. Mitteilung über stossinduzierte Fragmentierungen von felddesorbierten Kationen
Authors: Fischer Matthias , Veith Hans‐Jürgen 
Published: December 2004

Mechanistic studies on the collision‐induced fragmentations of quaternary ammonium ionsThe collision‐induced fragmentation behaviour of field desorbed quarternary ammonium ions has been investigated. A main reaction of these ions is the cleavage of the NC bond accompanied by hydrogen rearrangement, i.e. alkane loss from the tetraalkyl substituted ammonium ions of the iodides 1, 2 and 3, respectively, Deuterium labelling indicates that the hydrogen transfer to the leaving group occurs to the extent of about 80% from the α‐position and about 20% from the other positions of an alkyl group. Pronounced heterolytic cleavage of the NC bond is observed in the benzyl substituted ammonium ion of 4. The β‐phenylethyl substituted ammonium ion of 5 shows a homobenzylic heterolysis, possibly yielding the phenonium ion j.
1,1‐Disilyl‐2‐Alkenes: Preparation and Some Synthetic Applications. Preliminary communication
Authors: Wetter Hansjürg 
Published: December 2004

AbstractAllyl sulfides and a selenide are metallated and silylated with chloro (penta‐methyl)disilane. Treatment of the resulting disilanylmethyl sulfides 4 with trimethyloxonium tetrafluoroborate furnishes 1,1‐disilyl‐2‐alkenes 5 in good yields. Some synthetic possibilities of 5 are outlined.
Structural Studies of Crystalline Enamines
Authors: Brown Kevin L. , Damm Lorenz , Dunitz Jack D. , Eschenmoser Albert , Hobi Reinhard , Kratky Christoph 
Published: December 2004

AbstractCrystal structure analyses of five crystalline enamines together with recently published structural data for two other enamines reveal varying degree of pyramidality at the enamine nitrogen atom. The pyramidality appears to be most pronounced in enamines from piperidine and morpholine, less so in enamines derived from prolinoid amines. A pyrolidine enamine obtained from a derivative of cyclohexane‐1,4‐dione seems to have a virtually planar enamine group. The implications of these findings for current stereochemical problems in enamine chemistry are discussed.
Natural Abundance 13C‐NMR. of Reduced Isoalloxazine
Authors: Van Schagen Cees G. , Müller Franz 
Published: December 2004

AbstractWhen an isoalloxazine derivative (1) was reduced (2) its 13C‐NMR. resonances were all shifted upfield and the largest shifts were observed for C (4a), C(6) and C(8) but downfield shifts for C(2), C(4) and C(10a). The results and their biochemical implications are shortly discussed.
S‐Alkylation en série hétérocyclique par catalyse par transfert de phase: thioalkyl‐2‐thiazoles, thioalkyl‐2‐Δ‐4‐thiazolines et thioalkyl‐2‐benzothiazoles
Authors: Dou Henri J. M. , Hassanaly Parina , Kister Jacky , Vernin Gaston , Metzger Jacques 
Published: December 2004

S‐Alkylation in heterocyclic serie by phase transfer catalysis: 2‐alkylthiothiazoles, 2‐alkylthio‐Δ‐4‐thiazolines and 2‐alkylthiobenzothiazolesSome Δ‐4‐thiazoline‐, thiazolidine‐, and benzothiazoline‐2‐thiones have been S‐alkylated by phase transfer catalysis; yields averaged 80 to 90%. With halogenated heterocyclic compounds of poor reactivity, the main reaction consisted in a dequaternization of the catalyst by the thiones acting as nucleophiles.
Thermogravimetrische Untersuchung der reduzierenden Chlorierung von Tonerde
Authors: Müller Hans‐Peter , Baiker Alfons , Richarz Werner 
Published: December 2004

Thermogravimetric analysis of the reducing chlorination of aluminaThe kinetics of the chlorination of dehydrated alumina with (CO/Cl2) mixtures were studied in the temperature range of 400–900°. The temperature of dehydration of the alumina was shown to be critical for the reaction rates of the subsequent chlorination. Optimal reaction rates could be observed with equimolar (CO/Cl2) mixtures in the range of 600–700°. At higher temperatures, only a very small increase in reaction rates with increasing temperature could be observed which is thought to be due to the influence of gaseous diffusion gradients in the porous alumina and a progressive decrease in surface area. Granulometric as well as scanning electron microscope studies have shown that with progressing reaction the alumina particles become hollow while retaining their outer shape and size up to a high degree of conversion.
5α‐24‐Norcholestan‐3β‐ol and (24Z)‐Stigmasta‐5,7,24(28)‐trien‐3β‐ol, Two New Marine Sterols from the Pacific Sponges Terpios zeteki and Dysidea herbacea
Authors: Delseth Claude , Tolela Luhata , Djerassi Carl , Scheuer Paul J. , Wells Robert J. 
Published: December 2004

AbstractThe steroidal components of 2 marine sponges, Terpios zeteki (from Hawaii) and Dysidea herbacea (from Australia) were fractionated through a combination of chromatographic methods, including reversed phase HPLC., and were analyzed by a combination of physical methods, including high resolution GC.‐MS. and 360 MHz 1H‐NMR. T. zeteki contains 6 conventional 5α‐stanols which comprise 91% of the sterol mixture, and traces (0.5%) of a new C26 sterol, 5α‐24‐norcholestan‐3β‐ol. Minor amounts of conventional Δ5‐sterols (6.5%) and of a single Δ4‐3‐ketosteroid (1.5%) were also present. In contrast, the Australian sponge (D. herbacea) contains 3 Δ5,7‐sterols which comprise 1.5% of the sterol mixture, and one new C29 sterol, (24 Z)‐stigmasta‐5,7,24(28)‐trien‐3β‐ol, as the major component (75%). In addition, minor amounts of conventional 5α‐stanols (0.5%), Δ5‐sterols (5%) and 5α‐Δ7‐sterols (18%) were present in this complex sterol mixture. The possible dietary or endosymbiotic origins of these sterols are discussed.
Halochrome Molekeln. Synthese und acidobasisches Verhalten substituierter 3′,6′‐Bis (dimethylamino)‐spiro [5H‐imidazo [2, 1‐α]‐isoindolin‐5,9′‐xanthene]
Authors: Gunzenhauser Sigmund , Hellrung Bruno , Balli Heinz 
Published: December 2004

Halochromic Molecules. Synthesis and Acidobasic Behaviour of Substituted 3′,6′‐Bis(dimethylamino)‐spiro [5H‐imidazo [2,1‐α]isoindolin‐5,9′‐xanthenes]Substituted 3′,6′‐Bis (dimethylamino)‐spiro [5H‐imidazo [2, 1‐α]isoindolin‐5,9′‐xanthenes] are prepared and their 1H‐NMR. spectra are discussed. An investigation of the complex protonation equilibria is made by stopped flow kinetic and spectrophotometric methods. pK values are determined and the results are discussed.
Nucleophilic Addition to C, C Double Bonds. Proximity and homoconjugative effects. Preliminary communication
Authors: Pfund Rolland A. , Ganter Camille 
Published: December 2004

AbstractProximity effects alone as well as in combination with electronic effects are responsible for the observed phenomenon of base‐catalyzed ether formation initiated by nucleophilic attack on a C, C double bond of the tricyclic olefin alcohols 1–10 (Scheme 1, Table 1).With compounds 1–4, bearing a keto group, formation of the ethers 11–14 proceeds through a corresponding homoenolate b (Scheme 2) as an intermediate. In one case such a species could be trapped as the methyl ether 21 (Scheme 3).Special attention is given to the stereochemical course of the homoketonization. Ring opening in 21 under acidic conditions occurs regioselectively, however non‐stereoselectively (Scheme 3). Full regio‐ and stereoselectivity (retention) is observed under basic conditions starting from the unsaturated keto alcohols 1 and 2 (Scheme 4) as well as from the keto ethers 11 and 12 (Scheme 5, Table 2).
Zur Photochemie von 1, 2‐Benzisoxazolen in stark saurer Lösung
Authors: Doppler Thomas , Schmid Hans , Hansen Hans‐Jürgen 
Published: December 2004

On the Photochemistry of 1, 2‐Benzisoxazoles in Strongly Acidic SolutionThe 1, 2‐benzisoxazoles 1a, 1b and 1d when dissolved in 96% sulfuric acid and irradiated through a quartz filter with a mercury high‐presure lamp yield, after work‐up, mixtures of 2, 5‐ and 2, 3‐dihydroxy‐acylbenzenes (2 and 3, respectively; cf. Schemes 1 and 3 and Table 1). Irradiation of 3, 5‐dimethyl‐1, 2‐benzisoxazole (1c) in 96% sulfuric acid leads to the formation of 2, 3‐dihydroxy‐5‐methyl‐acetophenone (3c) in only 6% yield (cf. Table 1). It is assumed that the 1, 2‐benzisoxazolium ions react in the excited singlet state by heterolytic cleavage of the N, O‐bond to yield the corresponding aryl oxenium ions 7 in the singlet ground state (see Scheme 5). Reaction of 7 with HSO4⊖ ions, present in 96% sulfuric acid, yields, after hydrolysis, the dihydroxy compounds 2 and 3. Photolysis of 3‐methyl‐1, 2‐benzisoxazole (1b) in diluted sulfuric acid (0,5 to 9 M) in methanol or water leads only to the formation of 2‐amino‐phenol (6; see Scheme 3), presumable via photo‐isomerization of 1b to 2‐methylbenzoxazole (5b) which then is hydrolyzed to give 6.
Über die Herstellung des Methyl‐α‐D‐fructopyranosides und die Struktur der dabei gebildeten Orthoester
Authors: Steinlin Heinrich , Camarda Lorenzo , Vasella Andrea 
Published: December 2004

Concerning the preparation of methyl α‐D‐fructopyranoside and the structure of the orthoester by‐productsKoenigs‐Knorr glycosidation (AgClO4/Ag2CO3) of the easily accessible p‐nitrobenzoylated fructosylchloride 7 yields mainly the protected glycoside 3 which was deacylated to the known title compound 1. The orthoesters 15 and 16 were formed as by‐products in this glycosidation whilst the analogous orthoesters 21 and 22 are formed as main products in the glycosidation (Ag2CO3) of the benzoylated fructosylchloride 12. The structure of these orthoesters was deduced mainly from their spectroscopic data, from those of their derivatives 17, 18, 19, 20, 25 and 26 and by comparison of the latter with the model compounds 31 and 34.
The Effect of Choleates on the Solubilization of Water in Water/AOT/Cyclohexane (W/O)‐Microemulsions
Authors: Eicke Hans‐Friedrich 
Published: December 2004

AbstractExperimental investigations on the cosurfactant effect of alkali and tetraalkylammonium choleates in water/AOT/cyclohexane (W/O)‐microemulsions were carried out. The results prompted considerations on a thermodynamic and molecular level. The molecular view emphasizes the significance of hydration interactions between cosurfactant and solubilized water.
Papain‐induced Oligomerization of α‐Amino Acid Esters
Authors: Anderson Gregory , Luisi Pier Luigi 
Published: December 2004

AbstractOligomers of leucine, methionine, phenylalanine, and tyrosine were prepared enzymatically (using papain) from the respective methyl esters, with yields ranging from 51–96%. The effect of pH, buffer and salt concentration, and addition of alcohol on the oligomerization of leucine methyl ester was examined. The limits and potentialities of the enzymatic reaction as a method for obtaining monodisperse oligomers are discussed.
Synthese von 4(5)‐acyl‐5(4)‐alkylimidazolen aus symmetrischen 1,3‐dicarbonylverbindungen
Authors: Krebs Ernst‐Peter , Bondi Enrico 
Published: December 2004

Synthesis of 4(5)‐Acyl‐5(4)‐alkylimidazoles from Symmetrical 1,3‐DionesA new synthesis of 4(5)‐acyl‐5(4)‐alkylimidazoles 1 is described. The symmetrical 1,3‐diones 5a and 5b were reacted with N2O4 to give the nitro compounds 7a and 7b, respectively; 5c was treated with NaNO2 to give the nitroso compound 7c (Scheme 2). Hydrogenation of 7a, 7b and 7c over Pd/C in acetic acid/acetic formic anhydride yielded the formamides 9a, 9b and 9c, whose cyclization in formamide/formic acid afforded the 4(5)‐acyl‐5(4)‐alkylimidazoles 1a, 1b and 1c, respectively. Oxazoles 11a and 11b were obtained from the corresponding formamides 9a and 9b with methanesulfonic acid/P2O5.
Synthese von rac‐2‐Cyano‐1‐methyl‐3‐[2‐[(4,5,6,7‐tetrahydro‐4‐benzimidazolyl)thio]äthyl]guanidin; ein konformationell gehindertes Cimetidin‐Analogon
Authors: Krebs Ernst‐Peter 
Published: December 2004

Synthesis of rac‐2‐Cyano‐1‐methyl‐3‐[2‐[(4,5,6,7‐tetrahydro‐4‐benzimidazolyl)thio]ethyl]guanidin, a Conformationally Restricted CimetidineInternationaler Freiname (‘generic name’) für 2‐Cyano‐1‐methyl‐3‐[2‐[(5‐methyl‐imidazol‐4‐yl)‐methylthio]äthyl]guanidin (2) [1].

Analogue
The physiological actions of histamine (1) are mediated by at least two classes of receptors. A short definition of histamine H1‐ and H2‐receptors is given. Cimetidine (2) is a known specific H2‐blocking agent. Compound 3 is a cimetidine analogue with a conformationally restricted side chain. The synthesis of 3 as well as some physicochemical and pharmacological data of 3 are described.
[D‐Ala2, Phe (p‐NO2)4, Leu5]Enkephalin Amide and Nα‐[D‐Ala2, Leu5]‐Enkephalyl‐Nε‐Acetyl‐Lysine Amide: Synthesis and Biological Properties of Prospective Enkephalin Cooperative‐Affinity and Photoaffinity Labels. Preliminary communication
Authors: Castell José V. , Eberle Alex N. , Kriwaczek V. Marly , Tun‐Kyi Aung , Schiller Peter W. , Do Kim Quang , Thanei Peter , Schwyzer Robert 
Published: December 2004

AbstractAs a study preliminary to attempts at photoaffinity and cooperative affinity labelling of cells and cell membrane vesicles bearing opiate receptors, the title compounds were prepared and tested by rat brain membrane binding assays and by a modified guinea‐pig ileum bio‐assay. The potency of the two compounds in both systems was considerably greater than that of the standard peptide, [Leu5]enkephalin, justifying further work with these and similar compounds.
Struktur der Sesquiterpene von Petasites hybridus (L.) G. M.et SCH.: Petasol‐ und Isopetasol‐Abkömmlinge
Authors: Neuenschwander Markus , Neuenschwander Andreas , Steinegger Ernst , Engel Peter 
Published: December 2004

Structure of the Sesquiterpenes of Petasites hybridus (L.) G. M. et SCH.: Petasol and Isopetasol DerivativesThe structure of 11 compounds of the sesquiterpene fraction of petasites hybridus has been determined by combination of spectroscopic methods, especially by analysis of the 360‐MHz‐1H‐NMR. spectra. Most natural products are esters of two isomeric sesquiterpene alcohols, characterized by an eremophilan skeleton, namely of petasol as well as of isopetasol. The structure of one key product has been confirmed by X‐ray analysis.
Struktur der Sesquiterpene von Petasites hybridus (L.) G. M. et SCH.: Neopetasol‐Abkömmlinge
Authors: Neuenschwander Markus , Neuenschwander Andreas , Steinegger Ernst 
Published: December 2004

Structure of Sesquiterpenes of Petasites hybridus (L.) G. M. et SCH.: Derivatives of NeopetasolThe structure of 5 compounds of the sesquiterpene fraction of petasites hybridus has been determined by combination of spectroscopic methods, especially by analysis of the 360‐MHz‐1H‐NMR. spectra. Most natural products are esters of a sesquiterpene alcohol, which is the 7 β‐epimer of petasol. The alcohol is named neopetasol.
Nouveaux exemples d'acétonides d'aldéhydosucres furanniques
Authors: Tronchet Jean M. J. , Gentile Bernard , Bonenfant Alain P. , Martin Olivier R. 
Published: December 2004

Further examples of O‐isopropylidenaldehydosugars in the furanose seriesFormyl‐bearing furanose derivatives 1–3 (α‐D‐xylo or α‐D‐erythro configurations) and 5–8 (configurations α‐D‐ribo, α‐D‐lyxo, β‐L‐threo and D‐arabino) have been prepared by classical synthetic steps and their properties mainly spectroscopic, reported. The coupling constant between the formyl and the vicinal proton is always small. Like other members of the series, these new aldehydosugars constitute very useful and flexible synthetic intermediates.
Micellar Solubilization of Proteins in Aprotic Solvents and their Spectroscopic Characterisation
Authors: Luisi Pier Luigi , Bonner Francis J. , Pellegrini Antonio , Wiget Peter , Wolf Romain 
Published: December 2004

AbstractThe quaternary ammonium salt methyl‐trioctylammonium chloride enables the transfer of α‐chymotrypsin, trypsin, pepsin and glucagone from water to cyclohexane. Reversed micelles, whose polar core solubilizes both protein and water, are probably formed in the apolar phase. The influence of various parameters on the phase transfer (concentration, pH, solvent, temperature, etc.) has been investigated.Absorption, fluorescence and circular dichroism studies of the biopolymers in the cyclohexane system have been carried out. For trypsin and chymotrypsin, the CD. signal in the 200 nm region is very similar in water and in cyclohexane, which suggests that the polypeptide folding is not substantially different in the two phases. The fluorescence quantum yield is always much larger in the cyclohexane phase than in water. The longer wavelength region of the UV. absorption spectrum is slightly red‐shifted relative to water, and a band at 225 nm, probably arising from the aromatic chromophore, is apparent in the organic phase. Reasons for these spectral perturbations are discussed. The enzymes transferred from water into cyclohexane phases can be continuously retransferred into a second water phase. The possible relevance of this ‘double transfer’ as a model for the vectorial transport of biopolymers or a separation technique is discussed.
31P‐NMR. Measurements on Palladium‐Phosphine Complexes. Nuclear overhauser effects and spin‐lattice relaxation times
Authors: Bosch Werner , Pregosin Paul S. 
Published: December 2004

AbstractThe 31P{1H} nuclear Overhauser effects (NOE's) and 31P‐spin‐lattice relaxation times (T1) for a series of trans‐[PdCl2P2], P  PEt3, PPr3n, PBu3n, PMe2Ph, PMePh2, P(p‐Tol)3, P(cyclohexyl)3 complexes are reported. Both the NOE and T1 values depend upon the choice of solvent. The dipole‐dipole mechanism dominates the spin‐lattice relaxation of the coordinated phosphorus atom with the T1 values for the PEt3, PPr3n, and P (cyclohexyl)3 complexes decreasing with increasing molecular weight of the phosphine.
Stereoselektive Synthese von Cyclopropylkohlenhydraten
Authors: Sele Alex , Baehler Bruno , Tronchet Jean M. J. 
Published: December 2004

Stereoselective synthesis of cyclopropylsugarsUse of the phase‐transfer catalysis significantly increased the yield of the reactions leading to the known compounds 2 and 3. Stereoselective cyclopropylation of 3 and 4 and 8, was brought about using in the first instance the Simmons‐Smith's reagent, whereas the reaction of dichlorocarbene led to 6 easily dechlorinated to 8. Both diastereoisomeric cyclopropylsugars 4 and 8 were transformed into the corresponding ethyl glycosides.
Lucibufagines. Partie III. Oxo‐11‐et oxo‐12‐bufalines, stéroïdes défensifs des lampyres Photinus ignitus et P. marginellus (Coleoptera: Lampyridae)
Authors: Goetz Michel , Wiemer David F. , Haynes Le Roy W. , Meinwald Jerrold , Eisner Thomas 
Published: December 2004

Lucibufagins. Part IIICommunication no. 63 de la série ‘Defense Mechanisms of Arthropods’. Pour no. 62, voir [1].

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11‐Oxo‐and 12‐oxo‐bufalins, defensive steroids from the fireflies Photinus ignitus and P. marginellus (Coleoptera: Lampyridae)
Four lucibufagins (4, 8, 9 and 10), defensive bufadienolides from the fireflies Photinus ignitus and P. marginellus (Coleoptera: Lampyrida), have been isolated and are characterized by spectroscopic means.