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Showing papers by "University of Basel published in 1968"




Journal ArticleDOI
01 Jan 1968
TL;DR: Bienengift enthalt neben dem universell zellschadigenden Melittin und der uber Lysolecithinbildung wirksamen Phospholipase A ein drittes mastzelldegranulierendes (MCD-)Peptid.
Abstract: Bienengift enthalt neben dem universell zellschadigenden Melittin und der uber Lysolecithinbildung wirksamen Phospholipase A ein drittes mastzelldegranulierendes (MCD-)Peptid. Seine Isolierung gelingt durch Kombination von Gelfiltration an Sephadex G 50 mit Ionenaustauschchromatographie an Carboxymethylcellulose und an Amberlite IRC-50. MCD-Peptid ist stark basisch (Isoelektrischer Punkt um pH 12). Sein minimales Molekulargewicht errechnet sich aus der Aminosaurenanalyse zu 2593. Das Peptid besteht aus 22 Aminosauren, darunter 4 Halbcystinen. Es liegt in zwei verschiedenen Ladungszustanden vor, die sich bei Papierchromatographie, Papierelektrophorese und Aminosaurenanalyse einheitlich verhalten. MCD-Peptid ist an isolierten Rattenmastzellen (Histaminfreisetzung) und am Mesenterialhautchen der Ratte (Mastzelldegranulation) etwa wirkungsgleich mit dem synthetischen Histaminliberator Compound 48/80. Melittin wirkt ca. 100- bzw. 10 mal schwacher und zeichnet sich uberdies durch eine sehr flache Dosis-Wirkungsbeziehung bei der Histaminfreisetzung aus. Der Rattenblutdruck wird durch MCD-Peptid und Compound 48/80 in quantitativ und qualitativ vergleichbarer Weise gesenkt. Zwischen beiden Substanzen besteht kreuzweise Tachyphylaxie. Die Permeabilitat der Hautgefase der Ratte fur zirkulierendes Evans-Blau steigt bei intracutaner Applikation von MCD-Peptid und Compound 48/80. Beide Substanzen sind hier starker wirksam als Melittin. Die Hautgefase des Kaninchens sprechen jedoch auf MCD-Peptid schwacher an als auf Melittin und Compound 48/80. Die Ratte reagiert auf i.v. Injektion von 0,5–10 mg/kg MCD-Peptid mit massiver Hyperamie der Acren. Eine kurzdauernde Spastik der Extremitaten weist auf einen zusatzlichen Angriff am motorischen System hin.

80 citations


Journal ArticleDOI
TL;DR: In this article, the equilibrium curves of 15 reactions occuring during metamorphism of siliceous dolomites are presented, and these curves intersect at four isobaric invariant points.
Abstract: Basing on calculations and experiments the equilibrium curves of 15 reactions occuring during metamorphism of siliceous dolomites are presented. In a T—XCO2 diagram these curves intersect at four isobaric invariant points. This is consistent with the fact, that different reaction sequences are known from the nature.

66 citations


Journal ArticleDOI
TL;DR: In this paper, the optical properties of some kinked and deformed areas differ significantly from those of the original bronzite, and the new clinoenstatite lattice is untwinned.
Abstract: Bronzite in a highly deformed and partially metamorphosed gabbro from Central Australia shows intensive bending and kinking. The optical properties of some kinked and deformed areas differ significantly from those of the original bronzite. Single crystal X-ray and optical investigations show that some highly strained areas of bronzite have inverted to clinoenstatite (2V=50±6°; sign +;ZΛc=32±2°). Mixed phases of both also occur. The new clinoenstatite lattice is untwinned.

62 citations



Journal ArticleDOI
TL;DR: The isolation of aristolochic acid-I from Pachlioptera aristolchiae (Fabr.) is described and the larvae feed exlusively on plants of the family Aristolochiaceae and presumably ingest the acid which is stored and carried through the pupal stage to the adult insect.
Abstract: The isolation of aristolochic acid-I from Pachlioptera aristolochiae (Fabr.) is described. About 0.1 mg is present in each butterfly. The larvae feed exlusively on plants of the family Aristolochiaceae and presumably ingest the acid which is stored and carried through the pupal stage to the adult insect.

60 citations


Journal ArticleDOI
H. Allgeier1
TL;DR: Pachybiose (1) is shown to be 4-O-(3-O-methyl-6-deoxy-β-D-allopyranosyl)-D-cymarose.
Abstract: Pachybiose (1) is shown to be 4-O-(3-O-methyl-6-deoxy-β-D-allopyranosyl)-D-oleandrose and asclepobiose (14) 4-O-(3-O-methyl-6-deoxy-β-D-allopyranosyl)-D-cymarose.

53 citations


Journal ArticleDOI
TL;DR: The reaction rates of heterolytic fragmentation of 5-(p, -toluenesulfonyloxyimino)-1-oxo-9-methyl-trans-decalin (1), induced by sodium hydroxide in 80% ethanol and by sodium ethoxide in 100% ethanol, has been determined in this article.
Abstract: The reaction rates of heterolytic fragmentation of 5-(p, -toluenesulfonyloxyimino)-1-oxo-9-methyl-trans-decalin (1), induced by sodium hydroxide in 80% ethanol and by sodium ethoxide in 100% ethanol, has been determined. The reaction of the oxime tosylate 1 with sodium ethoxide is first order with respect to both reactants. A similar base-dependence is observed in the reaction of the oxime tosylate 1 with sodium hydroxide. These results are explained in terms of an addition-fragmentation mechanism. This involves reversible addition of NaOH or NaOC2H5 to the carbonyl group of the oxime tosylate 1 and concerted fragmentation of the addition compounds 5a and 5b, yielding 9-cyano-6-methyl-trans-non-5-enoic acid (4a) and the corresponding ethyl ester 4b, respectively. These reaction appear to be the first cases of concerted and stereospecific 7-centre fragmentation.

36 citations


Journal ArticleDOI
TL;DR: In the NMR-spectra of sarcostin and of many (not all) of its derivatives a strong signal (mostly a singlet corresponding to ca. 3 protons at ca. δ = 2 ppm) is present, which cannot be explained with the suggested structures as mentioned in this paper.
Abstract: The dried twigs and stems of Sarcostemma viminale (the climbing shrub form from South Rhodesia) contain about 1% phenolic and a similar amount of glycosidic compounds derived from 2-deoxysugars; only traces of cardenolides are present. After mild acidic hydrolysis 5 sugars could be detected and subsequently isolated in pure form. Three of them (d-cymarose, d-digitoxose and lilacinobiose) were obtained crystalline, the two others (d-oleandrose and viminose) in amorphous form. Viminose is a new sugar, a disaccharide which contains d-thevetose, and d-Digitoxose at the reducing end [30 b]. The mixture of aglycones, obtained after mild acidic hydrolysis, contained mainly five components (F, G, H. J and K), all of which could be isolated in pure form. F, G and J were crystalline. F was identified as metaplexigenin (1), J as mono-O-acetyl-mono-O-benzoyl-sarcostin (5) and K as 12,20-di-O-benzoyl-sarcostin (6). G and H are new compounds whose structures (G = 12-O-benzoyl-deacetyl-metaplexigenin (2), H = di-O-benzoyl-viminolone (3)) are deduced in the following paper. After alkaline hydrolysis of the aglycone mixture, sarcostin, deacetylmetaplexigenin and small amounts of lineolon could be dedected by paper- and thinlayerchromatography. The two pregnane derivatives EA-42 and EA-43 described by Abisch et al. [21] could be identified with 3, 20-di-O-benzoyl-utendin and 3, 20-di-O-benzoyl-sarcostin, respectively. In the NMR.-spectra of sarcostin and of many (not all) of its derivatives a strong signal (mostly a singlet corresponding to ca. 3 protons at ca. δ = 2 ppm) is present, which cannot be explained with the suggested structures. The cause of this extra signal could not be elucidated.

28 citations



Journal ArticleDOI
TL;DR: In this paper, the proton spectrum of furan oriented in the nematic phase of anisoleazophenyl-n-capronate has been analyzed and the ratios of the various interproton distances as well as the orientation parameters and the signs of the indirect coupling constants for furan are determined.
Abstract: The proton spectrum of furan oriented in the nematic phase of anisoleazophenyl-n-capronate has been analysed. The ratios of the various interproton distances as well as the orientation parameters and the signs of the indirect coupling constants for furan are determined.

Journal ArticleDOI
01 Oct 1968
TL;DR: In this article, the Pharmakokinetik von Sulfisomidin and of sulfisoxazol wurde bei 52 Kindern im Alter zwischen 5 and 357 Tagen untersucht.
Abstract: Die Pharmakokinetik von Sulfisomidin und von Sulfisoxazol wurde bei 52 Kindern im Alter zwischen 5 and 357 Tagen untersucht. Dosen zwisehen 50 and 100 mg/kg Korpergewicht wurden peroral oder intravenos appliziert. Aus den Konzentrationswerten im Serum wurden mit Hilfe eines programmgesteuerten Digitalrechners die folgenden pharmakokinetischen Konstanten ermittelt: Die gastrointestinale Invasionskonstante, das relative Verteilungsvolumen und die Eliminationshalbwertszeit. Eine Eliminationskinetik erster Ordnung konnte in allen Fallen nachgewiesen werden. Fur die Geschwindigkeitskonstanten der gastrointestinalen Absorption wurden hohe Werte gefunden, namlich 0.95 h−1 fur Sulfisomidin and 0.99 h−1 fur Sulfisoxazol. Zwischen dem 5. und 9. Lebenstag war die Eliminationshalbwertszeit etwa doppelt so lang wie beim Erwachsenen. Mit zunehmendem Alter der Kinder fand sick eine kontinuierliche Zunahme der Eliminationsgeschwindigkeit. Diese war bei beiden Sulfonamiden am Ende des ersten Lebensjahres etwa doppelt so gros wie beim Erwachsenen. Demgegenuber war mit zunehmendem Alter nur eine masige Abnahme des relativen Verteilungsvolumens festzustellen. Aus diesen Befunden mus auf eine betrachtliche Zunahme der totalen Clearance dieser Sulfonamide wahrend des ersten Lebensjahres geschlossen werden. Diese Zunahme ist von einem derartigen Ausmas, das sie durch einen Reifungsprozes arzneimittelmetabolisierender Enzyme nicht erklart werden kann. Aufgrund der Ergebnisse fruherer Experimente besteht die Moglichkeit, das die altersabhangigen kinetischen Unterschiede durch altersabhangige Unterschiede im Wachzustand der Kinder bedingt sind.

Journal ArticleDOI
H. Allgeier1
TL;DR: The structures of disaccharides from Asclepiadaceae have been elucidated in this paper, including Drebyssobiose, lilacinobiose, and viminose.
Abstract: The structures of the following three disaccharides, isolated from Asclepiadaceae, have been elucidated: Drebyssobiose (1) = 4–0-(3–0-methyl-6-deoxy-β-d-allopyranosyl)-d-digitoxose, lilacinobiose (7) = 4-O-(3-O-methyl-6-deoxy-β-d-glucopyranosyl)-d-cymarose, and viminose (13) = 4-O-(3-O-methyl-6-deoxy-β-d-glucopyranosyl)-d-digitoxose.


Journal ArticleDOI
TL;DR: In this article, the initial rate v0 of H2O2 decomposition was found to be proportional to [H+]−1, [H2O 2], and [Cu2+-en]2.
Abstract: Kinetic studies of the Cu2+-ethylenediamine catalysed decomposition of H2O2 show the initial rate v0 of H2O2 decomposition to be proportional to [H+]−1, [H2O2], and [Cu2+-en]2. Maximal velocity is found at a ratio of [Cu2+]tot:[en]tot = 1:1,5. It is suggested that the active complex has a binuclear structure. This structure and probable mechanisms of the reaction are discussed. The kinetic measurements of the Cu2+-diethylenetriamine-H2O2 system are difficult to interprete because of degradation of the ligand by H2O2.

Journal ArticleDOI
TL;DR: In this article, the decomposition of H2O2 (8 · 10−3M) catalyzed by complexes of Cu2+ with various oligomers and polymers of glycine, L-lysine or L-glutamic acid was investigated in aqueous solution in the pH range 5 − 11, at 24°C and at low ionic strength.
Abstract: The decomposition of H2O2 (8 · 10−3M) catalyzed by complexes of Cu2+ (4 · 10−4M) with various oligomers and polymers of glycine, L-lysine or L-glutamic acid was investigated in aqueous solution in the pH range 5–11, at 24°C and at low ionic strength. Previous investigations have shown that the decomposition of H2O2 is catalyzed by Cu2+-complexes capable of forming Cu2+-peroxocomplexes. With increasing pH the catalytic activity of Cu2+-complexes with glycine or glycylglycine (1:1) increases while the activity of Cu2+-complexes with tri- or tetraglycine (1:1) is comparatively small at higher pH values apparently because in the latter cases the coordination positions of the copper become progressively occupied by the peptides. This interpretation is in accordance with the pH-dependence of the light-absorption spectra of the latter complexes. Cu2+-complexes with poly-α, L-lysines of various molecular weights (molar ratios Cu2+: lysine residues = 1:15) have a catalytic activity comparable to or higher than that of the complex Cu2+-ethylenediamine (1:1), indicating two available coordination positions for formation of peroxo-complexes. On the other hand, the system Cu2+-L-lysine (1:15) showed no significant activity probably because all coordination positions at the Cu2+ are occupied by lysine. Despite the excess of ligand groups over Cu2+ in the polylysine systems the structure of this polyamino acid apparently does not allow its full coordination with these groups under the conditions investigated. Two adjacent chelating e-amino groups are considered as the main ligand groups of the polymer to each copper ion. The Cu2+-poly-α, L-glutamic acid complex examined (Cu2+: glutamic acid residues = 1:5) shows comparatively little activity. In this case, absorption spectra indicate formation of hydroxo-complexes at higher pH. Besides the effects of structure, the electrostatic fields of the charged polyelectrolytes polylysine or polyglutamic acid are also considered to affect the rates of catalysis.

Journal ArticleDOI
TL;DR: In this paper, a mixture of the 1, 2-isopropylidene derivatives of 3-O-methyl-6-deoxy-D-allose and 3-MgBr gave the corresponding crystalline lactone, which could be indentified with a sample obtained from natural L-acovenose.
Abstract: 3-O-methly-6-deoxy-L-talose has been synthesized starting from 1, 2–5, 6-di-O-isopropylidene-α-D-allose (1). Methylation, selective acidic hydrolysis, sodium periodate oxidation and GRIGNARD reaction with CH3MgBr gave a mixture of the 1, 2-isopropylidene derivatives of 3-O-methyl-6-deoxy-D-allose and 3-O-methyl-6-deoxy-D-allose (7) and 3-O-methyl-6-deoxy-L-talose (8) (L-acovenose) could be obtained. Oxidation of the latter gave the corresponding crystalline lactone, which could be indentified with a sample obtained from natural L-acovenose.

Journal ArticleDOI
01 Mar 1968-Planta
TL;DR: In this paper, the Kinetik der Ionenaufnahme in das Cytoplasma (einschlieslich der Plastiden and anderer Organelle) wurde mit Hilfe der Mikroautoradiographie and der Rontgen-Mikrosonde untersucht.
Abstract: Methoden der quantitativen Auswertung von Mikroautoradiogrammen werden beschrieben. Die Kinetik der Ionenaufnahme in das Cytoplasma (einschlieslich der Plastiden und anderer Organelle) wurde mit Hilfe der Mikroautoradiographie und der Rontgen-Mikrosonde untersucht. Die autoradiographischen Ergebnisse zeigen, das unter den Versuchsbedingungen am Ende der Experimente das Cytoplasma sehr viel mehr Radioaktivitat pro Volumeneiheit enthielt als die Vacuolen. Die Kinetik dieses “Auffullens” des Cytoplasmas entspricht der System-1-Isotherme der Ionenaufnahme. Da die System-1-Isotherme den auffullenden Vorgang (=Plasmalemmatransport) widerspiegelt, die in der vorliegenden Arbeit mitgeteilten Ergebnisse aber die damit nicht notwendigerweise identische Kinetik des Sich-Fullens der cytoplasmatischen Phase zeigen, ist diese Ubereinstimmung von Bedeutung fur die Theorie der Ionenaufnahme in die Zellen hoherer Pflanzen. Der zeitliche Verlauf der Auffullung des Cytoplasmas hangt von der Ausenkonzentration ab. Messungen mit der Rontgen-Mikrosonde fuhren zu ubereinstimmenden kinetischen Ergebnissen. Die experimentellen Moglichkeiten des parallelen Einsatzes der Mikroautoradiographie und der Rontgen-Mikrosonde bei kinetischen Transportuntersuchungen werden diskutiert.

Journal ArticleDOI
TL;DR: In this paper, the Cerebro-Pleural-Ganglien von funf Nudibranchierarten (Coryphella pedata, Flabellina affinis, Cratena peregrina, Trinchesia coerulea, Goniodoris castanea) wurden licht-and elektronenmikroskopisch untersucht.
Abstract: Die Cerebro-Pleural-Ganglien von funf Nudibranchierarten (Coryphella pedata, Flabellina affinis, Cratena peregrina, Trinchesia coerulea, Goniodoris castanea) wurden licht- und elektronenmikroskopisch untersucht. Auf Grund der Befunde an den Perikarya lassen sich die Nervenzellen in vier Gruppen einteilen: Riesenzellen, grose, mittelgrose und kleine Nervenzellen. Die Riesenzellen sind durch ein ungeordnetes, granulares und agranulares endoplasmatisches Retikulum und einen grosen Golgi-Apparat charakterisiert. Sie enthalten keine Neurosekretgrana, aber sehr viele Zytosomen. Die grosen Nervenzellen dagegen besitzen nur wenige Zytosomen. Die Zellen treten in zwei, von uns als Funktionstypen gedeuteten Varianten (A und B) auf, die beide ein hochorganisiertes endoplasmatisches Retikulum aufweisen. In den A-Zellen ist es glatt und tubular, in den B-Zellen besteht es aus granularen Parallelformationen. Beide Zellvarianten enthalten viele Vesikel mit osmiophilem Inhalt. Sie sind in den A-Zellen mit dem grosen Golgi-Apparat assoziiert und messen zwischen 300 und 1500 A. In den B-Zellen fehlt eine Beziehung der Vesikel zum Golgi-Apparat. Auserdem sind sie durchschnittlich groser (Durchmesser 1000–2000 A, manchmal bis zu 5000 A). Wir bezeichnen diese Grana als neurosekretorisch und nehmen an, das sie zumindest teilweise neurohormonale Funktionen ausuben. Die mittelgrosen Nervenzellen besitzen auffallend viele Mitochondrien, Lipoidtropfen und ein gut entwickeltes granuliertes endoplasmatisches Retikulum. Auserdem kommen zahlreiche Vesikel mit osmiophilem Inhalt vor, deren Durchmesser 1000 A nie uberschreitet. Wir vermuten, das diese Grana im Unterschied zu den osmiophilen Grana der grosen Nervenzellen Neurotransmitter vom Typ der Monoamine enthalten. Die kleinen Nervenzellen haben einen sehr schmalen Zytoplasmamantel von einfacher Feinstruktur: Das endoplasmatische Retikulum ist sparlich, freie Ribosomen dominieren. Mitochondrien und Golgi-Zonen bleiben klein. Vereinzelt treten Vesikel mit osmiophilem Inhalt auf (Durchmesser 300–400 A).

Journal ArticleDOI
TL;DR: The stability constants of some 1:1 Me2+-complexes of the following five-membered heterocyclic carboxylic acids have been measured in 50 perc. NMR. spectra as discussed by the authors.
Abstract: The stability constants of some 1:1 Me2+-complexes of the following five-membered heterocyclic carboxylic acids have been measured in 50 perc. aqueous dioxane (I = 0,1; t = 25°): thiophene-2- (I), 3-phenylisothiazole-5- (II), tetrahydrothiophene-2- (III), furan-2- (IV), pyrrole-2- (V), and tetrahydrofuran-2-carboxylic acid (VI) (table 1 and 2). A comparison of the stability constants of the Cu2+-complexes of acetic acid (VII), benzoic acid (VIII), m-chlorobenzoic acid (IX), p-nitrobenzoic acid (X), and chloroacetic acid (VI) shows that the heterocyclic S and O atoms coordinate with Cu2+, i.e. Cu2+ chelates (structure XII) are formed (Figure 1). NMR. spectra (Fig. 2) give evidence for the coordination of the «aromatic» S atom in the Cu2+ complexes of thiophene-2-carboxylic acid (I), i.e. at least a part of the complexes are chelates. The NMR. spectra of furan-2-carboxylic acid (IV) gave no unequivocal results; in the case of pyrrole-2-carboxylic acid (V) the interaction between Cu2+ and the NH-group is very small (Fig. 4), i.e. a simple carboxylic acid complex is formed.

Journal ArticleDOI
TL;DR: In this article, spectra of pyrazine and p-benzoquinone have been studied in the nematic phase of p,p′-di-n-hexyloxyazoxybenzene.
Abstract: N.M.R. spectra of pyrazine and p-benzoquinone have been studied in the nematic phase of p,p′-di-n-hexyloxyazoxybenzene. Information about the geometry of these molecules has been obtained. The angle between the CH and the CC bonds has been determined. The chemical shift anisotropy in both the molecules is reported.

Journal ArticleDOI
TL;DR: Nach oraler Verabfolgung von14C-Prenylamin (Segontin®) an Ratten werden nur Spuren des unveränderten Pharmakons im Harn ausgeschieden.
Abstract: Nach oraler Verabfolgung von14C-Prenylamin (Segontin®) an Ratten werden nur Spuren des unveranderten Pharmakons im Harn ausgeschieden. Folgende Metabolite (ca. 40% der ausgeschiedenen Radioaktivitat) wurden identifiziert:p-Hydroxyprenylamin, Amphetamin,p-Hydroxy-amphetamin, Norephedrin undp-Hydroxy-norephedrin. Auch beim Menschen konnte nach zweitagiger Behandlung mit Segontin® in therapeutischer Dosierung das Auftreten geringer Mengen von Amphetamin im Harn nachgewiesen werden.

Journal ArticleDOI
TL;DR: The spin-orbit coupling constant of the 3p molecular Rydberg state C2π(μ = 0) of the nitric oxide molecule was determined to be Ao = 3.0 cm−1.

Journal ArticleDOI
TL;DR: By feeding growing cultures of Penicillium brefeldianum Dodge with [-14C]-acetate radioactive brefeldin A (C16H24O4), the individual radioactivity of 12 of the 16 carbon atoms was determined quantitatively.
Abstract: By feeding growing cultures of Penicillium brefeldianum Dodge with [-14C]-acetate radioactive brefeldin A (C16H24O4) was obtained. By extensive degradation of [14C]-brefeldin A, the individual radioactivity of 12 of the 16 carbon atoms was determined quantitatively. The pattern of the distribution of the radioactivity shows that 8 acetate units have been incorporated into the metabolite in a regular manner. These findings suggest an octaketide as an intermediate. Possible mechanisms for the formation of the trans-fused cyclopentane ring are discussed.

Journal ArticleDOI
TL;DR: In this paper, the structure determinations of Dregea abyssinica are reported, and the four drebyssogenins (F, G, J, and H) are esters of the drevogenins P (7) and D(9) and have the following structures: Drebyssogenin F (5) = 11-O-acetyl-12-O-(α-hydroxyisovaleryl)-drevogenin P, dreensteinogenin G (14) = δ-12)-O-Isovaleryl-
Abstract: The total or partial structure determinations of some new components from Dregea abyssinica are reported. The four drebyssogenins (F, G, J and H) are esters of the drevogenins P (7) and D(9) and have the following structures: Drebyssogenin F (5) = 11-O-acetyl-12-O-(α-hydroxyisovaleryl)-drevogenin P, drebyssogenin G (14) = 11-O-acetyl-12-O-isovaleryl-drevogenin D, drebyssogenin J (15) = 11, 12-di-O-acetyl-drevogenin D. Drebyssogenin K is a mixture of K1 (16) and K2 (17), the mono-O-tiglyl and mono-O-isovaleryl derivatives of drevogenin D respectively, with as yet undetermined position of the acyl residues. The drebyssosides 1, 2 and 3 are glycosides of trisaccharides. Drebyssoside 1 (2) is pachybiosyl-cymarosyl-drevogenin A, drebyssoside 2 (3) asclepobiosyl-cymarosyl-drevogenin A and drebyssoside 3 (6) pachybiosyl-cymarosyl-drebyssogenin F. Drebyssoside 4 is a mixture of at least two components and contains the same aglycones and the same sugar units as the drebyssosides 1 and 3, but is different from them. The full structure of the two sugars (drebyssobiose (25) and sugar T (24)) has not been determined; it is only shown that both are disaccharides which contain 3-O-methyl-6-deoxy-allose linked to a 2-deoxyhexose.

Journal ArticleDOI
W. Stöcklin1
TL;DR: The structure of gymnestrogenin, a triterpene from the leaves of Gymnema sylvestre R. Br. (Asclepiadaceae), is proposed to be that of 3β, 16β, 21β, 23, 28-pentahydroxy-olean-12-ene as mentioned in this paper.
Abstract: The structure of gymnestrogenin, a new triterpene from the leaves of Gymnema sylvestre R. Br. (Asclepiadaceae), is proposed to be that of 3β, 16β, 21β, 23, 28-pentahydroxy-olean-12-ene.

Journal ArticleDOI
TL;DR: In this article, the partialsynthese der isomeren 4,5-Epoxide des Canarigenins, 3-O-[β-D-Digitoxopyranosido]-4,5α-epoxy-canarigenin, and 14,15β-Epoxids des 14-Anhydrodigoxins werden beschrieben.
Abstract: Die Partialsynthese der isomeren 4,5-Epoxide des Canarigenins, des 3-O-[β-D-Digitoxopyranosido]-4,5α-epoxy-canarigenins sowie der isomeren 14,15-Epoxide des 14-Anhydrodigitoxins und des 14,15β-Epoxids des 14-Anhydrodigoxins werden beschrieben.

Journal ArticleDOI
TL;DR: In this paper, the structure of roridin A with ozone and NaBH4 was proved beyond any doubt, and the degradation products proved the sites of the ester linkages.
Abstract: Epoxidation of di-O-acetyl-roridin A (2) gave the two mono-epoxides 3 (not pure) and 4 (main product) and the di-epoxide 5. Subsequent treatment of 4 with ozone and NaBH4 led to the esters 6 and 8. They yielded the acetylderivatives 7 and 9 respectively. Since the degradation products prove the sites of the ester linkages also in roridin A (1), the structure of this antibiotic is proved beyond any doubt.

Journal ArticleDOI
TL;DR: In this article, the morphologischen Untersuchungen der Wehrdrtisensysteme are kombiniert, wie neuere Ver6ffentlichungen [t 5, t6] zeigen, ist das natfirliche System der Adephaga keineswegs geklirt.
Abstract: lung des nattirlichen Systems der Carabiden und wohl auch anderer adephager K~tfer seEr gut eignen, besonders dann, wenn man sie mit morphologischen Untersuchungen der Wehrdrtisensysteme kombiniert. Wie neuere Ver6ffentlichungen [t 5, t6] zeigen, ist das natfirliche System der Adephaga keineswegs gekl~irt. Seine Erforschung mittels chitin-morphologischer Strukturen erscheint wegen der Vielzahl der vermuteten Konvergenzen aul3erordentlich schwierig. Weitere chemische Untersuchungen dfirften daEer yon Wert sein. Gleichzeitig bietet sich Gelegenheit, die Evolution chemischer Merkmale in einem gut abgrenzbaren Gebiet zu untersuchen.