On the synthesis of serine and homoserine samples asymmetrically labelled with tritium and deuterium in the hydroxymethylene group

Summary (1 R) [1-³H,²H₁] 3-Phenylpropanol, the key intermediate in the synthesis of (4 R) [4-³H,²H₁] D, L-homoserine and of the (4 S)-isomer, is obtained from (1 S) [1-²H₁] 3-phenylpropanol and (1 RS) [1-³H] ethanol upon incubation with yeast alcohol dehydrogenase and NAD⁺; under similar conditions 2-phenylethanol undergoes very small exchange with [1-²H₂] ethanol.     

ZNS-aktive Phenylpropylamine vonCatha edulis FORSK. (Celastraceae) kenyanischer Herkunft

Summary The phenylpropylamine fraction ofCatha edulis FORSK. grown in Kenya has been investigated. The major components have been found to be (S)-(–)--aminopropiophenone (1), (+)-norpseudoephedrine (2) and(–)-norephedrine (3). Quantitative ratios of1, 2, 3 in tissues of different age are discussed.

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ZNS-aktive Phenylpropylamine vonCatha edulis FORSK. (Celastraceae) kenyanischer Herkunft

     

The molecular composition of a photographic fixing bath

Zusammenfassung In Thiosulfatlösungen von mäßiger Stärke bildet Silber die zwei Ionen Ag(S₂O₃) ₂ ^3– und Ag(S₂O₃) ₃ ^5– , deren Komplexkonstanten bestimmt wurden.     

Ion-solvent interaction from viscosity,apparent molar volume and conductivity data of bromates,iodates and sulphates of potassium and sodium in dioxane-water mixtures at different temperatures

Summary The viscosity, apparent molar volume and conductivity of KBrO₃, NaBrO₃, KIO₃, NaIO₃, K₂SO₄ and Na₂SO₄ at mass fraction of dioxane (10, 20 and 30%) — water mixtures at 30–45°C±0.01°C have been measured. The ions appear to interact and the ion-solvent interaction is of the order BrO ₃ ^– >IO ₃ ^– >SO ₄ ^2– .     

New C26 δ-lactones from the Dufour's gland of the urticating antTetramorium aculeatum

(6R^*)-{(2S^*)-2-hydroxyheneicos-12-enyl}-5,6-dihydro-2H-pyran-2-one (1)^o is the major constituent of the secretion of freshly dissected Dufour's gland of the urticating antTetramorium aculeatum. In solution, compound 1 is slowly transformed into (1S^*, 5R^*, 7S^*)-7-(nonadec-10-enyl)-2,6-dioxabicyclo[3.3.1]nonan-3-one (2)^o on standing. The structures of compounds 1 and 2 have been established on the basis of their spectral and chemical properties. Compound 1 could be responsible for the urticating properties of the ant.^o IUPAC numbering.     

Differential vascular effects of neuropeptide Y(NPY) selective receptor agonists

Neuropeptide Y (NPY) increases blood pressure either directly or indirectly by potentiating the effect of various vasoconstrictors. Only one (the Y₁-receptor) of two subtypes of receptors (Y₁ and Y₂) is thought to mediate the vascular smooth muscle contraction. To test this hypothesis we challenged isolated rat mesenteric arteries that had a functional endothelium with (1–36) NPY and with specific Y₁-receptor ([Leu³¹, Pro³⁴] NPY) and Y₂-receptor ([Ahx^5–24, -Glu²--Lys³⁰] NPY) agonists. The Y₁-receptor agonist elicited a contractile response similar to that of NPY, whereas the Y₂-receptor agonist had no effect on wall tension. We also found that the presence of a functional endothelium has no influence on the contractile response to NPY. From these data we conclude that the direct contractile effect of NPY in the mesenteric artery is mediated by stimulation of Y₁-receptors and is not endothelium-dependent.     

Detection and substitution-pattern determination of guanidines

Summary The guanidine function can be detected and its substitution pattern determined taking into account the¹H-NMR signals of the N–H and N–C–H groups. Satisfactory results were obtained with mono-to penta-substituted guanidines (as picrate salts).Part XX ofStudies on Plants; preceding part,R. A. Corral, O. O. Orazi andI. A. Benages, Tetrahedron29, 205 (1973).     

Zur Biosynthese der C9–10-Einheit der Indolalkaloide

Summary After administration of various C₂-compounds as well as leucine-2-¹⁴C toCatharanthus roseus shoots and glycine-2-¹⁴C toStrychnos nux vomica plants no specific incorporation into the non-tryptophan C_9–10 moiety of indole alkaloids was observed. The results indicate that glycine-2-¹⁴C is transformed into serine and is incorporated via tryptophan into strychnine.     

Abbau von Quarz mit Brenzkatechin

Summary Fine divided HF-etched quartz was dissolved in a 0.2M solution of pyrocatechol at pH 9.6. Between 17 and 40 °C the dissolution rate (v _s ) follows the equation: logv _s =0.0295 T-20.87 At 25 °Cv _s amounts to 0.8 · 10^–12 g cm^–2 sec^–1. With several phenols the dissolution rate of quartz decreases in the order: pyrocatechol > pyrogallol > 2, 3-dihydroxynaphthalene.     

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.     

A potent attractant of zoospores ofAphanomyces cochlioides isolated from its host,Spinacia oleracea

A highly potent attractant of zoospores ofAphanomyces cochlioides, a causal fungus of the root rot disease of spinach (Spinacia oleracea), was isolated from spinach roots, and its structure was determined by spectroscopic evidence and chemical synthesis as cochliophilin A (5-hydroxy-6,7-methylenedioxyflavone,1). A chromosorb particle prepared by soaking in solution of1 showed a potent attracting activity toward the zoospores using concentrations of1 above 10^–9 or 10^–10 M.     

Respiratory burst in peritoneal exudate cells in response to a modified tuftsin

Intraperitoneal administration of tuftsin-M [Thr–Lys–Pro–Arg–NH–(CH₂)₂–NH–CO–C₁₅H₃₁] to Balb/C mice has been shown to induce a respiratory burst in the peritoneal exudate cells. The macrophages exhibited enhanced levels of O₂ ^–, H₂O₂, NADPH oxidase and myeloperoxidase, but the activities of superoxide dismutase, catalase and glutathione peroxidase remained virtually unchanged. The magnitude of the oxidative burst depended directly on the dose of tuftsin-M; higher activity was observed at higher doses of the peptide. Tuftsin-M enhanced the generation of both O ₂ ^– and H₂O₂ under in vitro conditions, as did phorbol myristate acetate. These results suggest that tuftsin-M could enhance non-specific defence against infections by activating the macrophages.     

Kinetics and subcellular distribution of S35-taurine uptake in rat cerebral cortex slices

Zusammenfassung Die Kinetik der Aufnahme von S³⁵-Taurin in Rattencortex-Schnittchen wird im Konzentrationsbereich von 9×10^–8 M bis 5×10^–3 M untersucht. Nach Abzug des Transportes durch Diffusion (K _D ×S) findet man einen Mechanismus, der Michaelis-Menten Kinetik folgt (v _sat ), mitK _m =1,73×10^–4 M. Ein solcher Transport liegt nicht im Bereich des spezifischen «uptake» der Neurotransmitter. Auch die sehr niedrige Aufnahme-Rate und die subzelluläre Verteilung nach «uptake» sprechen gegen eine Neurotransmitter-Funktion von Taurin.     

Monoclonal antibodies to L-asparaginase

Summary Five hybridomas secreting monoclonal antibody toE. coli L-asparaginase were isolated. These monoclonal antibodies were classified into 3 different subclasses; Ig G₁ (1 clone), Ig G₂ (2 clones) and Ig G₃ (2 clones). One of them possessed anti-L-asparaginase neutralizing activity. Four antibodies examined demonstrated a linear Langmuir binding plot and binding affinities, with equilibrium dissociation constant (K_d) ranging between 2.5×10^–9M and 6.3×10^–10 M. The monoclonal antibodies should be useful probes for investigation of the enzyme activity.     

Interaction du 2,4-dichlorophénol et de l'eau oxygénée dans la destruction enzymatique de l'acideβ-indolylacétique

Summary DCP increases IAA destruction by bothLens andPhaseolus root breis. H₂O₂ inhibits catabolism byLens extracts but activates it whenPhaseolus is used, mainly when roots are cultivated in the dark and contain inhibitors of IAA destruction. DCP 1·10^–3 M and H₂O₂ 1·10^–4 or 1·10^–3 volume forLens and DCP 1·10^–4 M and H₂O₂ 1·10^–3 volume forPhaseolus nullify auxin catabolism.     

Ein bicyclischer Abkömmling von (−)-longifolen ausHelminthosporium sativum undH. victoriae

Summary (–)-Longifolene,4, and a new secolongifolane derivative, shown to possess structure5, have been isolated fromHelminthosporium sativum andH. victoriae.     

Ion-solvent interaction: Viscosity,apparent molar volume and conductivity of univalent electrolytes in dioxanewater mixtures at different temperatures

Summary The viscosity, apparent molar volume and conductivity of NaCl, KCl, NaBr, KBr, NaNO₃ and KNO₃ solutions at mass fraction of dioxane (10, 20 and 30%)-water mixtures at 30–45°C±0.01°C have been measured. The ions appear to interact appreciably, and the ion-solvent interaction is of the order NO₃ ^–>Br^–>Cl^–.     

Dissociation-constants of metal-ion-complexes with alkaline phosphatase from pig kidney

Summary Using metal-ion buffers it was possible to remove Zn²⁺, Mg²⁺ and Mn²⁺ ions of pig kidney alkaline phosphatase reversibly. The dissociation constants obtained are K_EMg:4·10^–7 M, K_EMn:4·10^–8 M and K_EZn:8·10^–13 M (22°C, pH:9.6, :0.07).Acknowledgement: The authors thank Dr.H. U. Wolf for helpful suggestions and valuable discussion and MissH. Köth for technical assistance.     

Vorgänge bei pH-Änderung und bei Belichtung eines Anthocyanidins

Summary The anthocyanidin investigated here exists below pH 4 as a cationAH ₂ ⁺ (wave length of absorption maximum _max=459 mµ), between pH 5 and 7 in the neutral formAH ( _max=492 mµ) and above pH 8 as an anionA ^– ( _max=537 mµ). At pH 5 the freshly dissolved substance is partially converted into a colourless formBH ( _max=372 mµ) and a chemical equilibrium betweenAH andBH is reached within 1 h. A kinetic study of the process of formation ofBH shows that an intermediate productZ is formed. This process can be reversed by light exposure. It can be concluded from a kinetic investigation by using flash light thatBH is transformed by the absorbing light into a new substanceL ( _max 275 mµ and 225 mµ), andL changes partially intoBH, partially intoZ, which itself is transformed partially intoAH ₂ ⁺ ,AH,A ^–, partially intoBH. The reactionZ AH,AH ₂ ⁺ ,A ^– is proportional to the concentration of protons [H ⁺], the reactionZ BH independent of [H ⁺]. Thus a photochemical production ofAH ₂ ⁺ ,AH,A ^– fromBH is readily obtained in the presence ofH ⁺ and not obtained in the absence ofH ⁺.     

Ouabain-induced release of extraneuronal catecholamine in the isolated guinea-pig vas deferens

Summary It was found that ouabain (10^–5 M) was effective in releasing the extraneuronal catecholamine which was taken up by uptake₂ process in the guinea-pig vas deferens. This result shows that a Na–K ATPase is essential for the storage of catecholamine in the extraneuronal site.