Volume 33, Issue 7-8

We describe the preparation of the amino-1,3-benzodioxoles 1b-10b. They were prepared by reduction of 5-nitro-(1a), 6-nitro-5-methoxy-(3a), 6-nitro-5-methoxy-(4a) , and 5-nitro-4,7-dimethoxy-1,3-benzodioxole (7a) with hydrogen and palladium as catalyst.Further the amides of 1,3-benzodioxole- 4-(2a) , 4-methoxy-1,3-benzodioxole-5- (5a), 4-methoxy-1,3-benzodioxole-7- (6a), 4,5-dimethoxy- 1,3-benzodioxole-6-(8a), 4,5-dimethoxy-1,3-benzodioxole-7-(9a), and 5,6-dimethoxy-1,3-benzodioxole-4-carboxylic acid (10a) were subjected to Hofmann’s reaction. The pK BH +-values of the amino-1,3-benzodioxoles 1b-10b and of 2,3-dimethoxyaniline were measured. 5-Amino-1,3-benzodioxole (1b) was found to be the strongest, and 4-amino-5,6-dimethoxy-1,3- benzodioxole (10b) the slightest base.

We describe the possibilities of formation and preparation of the “natural” 1,3-benzodioxolecarboxylic acids 1, 2, 4, 6 b, and 7, already mentioned in literature. Myristic acid (3e) was prepared in good yield from 3-methoxy-4,5-dihydroxy-benzoic acid ester (3c) , which could be easily made from 3-methoxy-2,3-carbonyldioxy-benzoic acid methylester (3b). Myristicic acid methylester (3d) could be subjected to methylation and hydrolysis leading to 3e without any difficulties. 4.6-dimethoxy-1,3-benzodioxole-5-carboxylic acid (5b) was prepared in good yields by oxidation of 4,6-dimethoxy-1,3-benzodioxole-5-aldehyde (5a). 5.7-dimethoxy-1,3-benzodioxole-carboxylic acid (13f), one of the “unnatural” 1,3-benzodioxolecarboxylic acids, derivatives of o-ipiperonylic acid (8), was prepared from 5-amino-7-methoxy-1,3- benzodioxole-4carboxylic acid methyl ester (13b) by diazotisation, elimination of nitrogen, methylation, and hydrolysis. A comparison of our measured pk A -values showed the strongest acidity belonging to 5,6-dimethoxy-1,3-benzodioxole-4-carbocylic acid (11).

N-methyl-N-formylhydrazones, the toxic compounds identified in the fruitbodies of the false morel Gyromitra esculenta, were also found in the mycelia grown from isolated ascospores. The amounts of acetaldehyde N-m ethyl-N-formylhydrazone, the main hydrazone compound of the false morel, varied significantly among the strains studied. Especially low levels occurred in some of the strains isolated from one fruitbody.

Anthocyanin pigments present in petals of various genotypes of Silene dioica were identified by R F -values, UV-spectra, partial and total hydrolysis, alkalysis, NMR-and IR-spectra. Both the 3-glucosides, 3,5-diglucosides, 3-rutinosides and 3-rutinosides-5-glucosides of cyanidin and pelargonidin were found. The location of the acyl group at the 3-O-bound sugar in acylated anthocyanins - p-coumaric acid in pelargonidin-glycosides and caffeic acid in cyanidin-glycosides - has been determined by partial hydrolysis, peroxide oxidation, and oxidative cleavage with sodium periodate followed by reduction with sodium borohydride and identification of the polyalcohols formed after hydrolysis. The phenolic acids have been shown to be attached to the 4-hydroxyl group of rhamnose in anthocyanidin 3-rhamnosylglucosides and to the 6-hydroxyl group of the 3-O -bound glucose in anthocyanidin 3-O-glucosides.

The utility of field desorption mass spectrometry for quantitative metal cation analysis in forensic sciences is demonstrated by the determination of a lethal thallium level in the brain tissue of an experimental animal. Stable isotope dilution and accumulation of the electrically recorded field desorption ion currents with a multi-channel analyzer allowed a direct estimation of thallium in homogenized tissue samples without further pretreatment. Experiments with standard solutions revealed the limit of detection for thallium to be about 10pg of the metal cation.

57 Fe Mössbauer spectra of oxygenated sperm whale myoglobin (MbO 2 ) show a well resolved quadrupole doublet with a temperature dependent splitting. The temperature dependence of the corresponding electric field gradient tensor (EFG) can be calculated from a Fe 3+ term scheme for the iron at the active center. The Mössbauer spectra as well as the diamagnetic character of the MbO 2 -complex are then understood by an exchange coupling of the Fe 3+ -ion with the O 2 - oxygen molecule ion. The resulting groundstate is a diamagnetic singlet. In order to keep the whole com­plex diamagnetic at room temperature, an exchange coupling with |J| ≧300cm is necessary. As the whole model is in fair agreement with many other spectroscopic data, it believed to be a good starting point for further detailed calculations.

A rapid procedure for the purification of ferredoxin from spinach is described, which is based on the finding that ferredoxins can be precipitated with polyethyleneimines from acetone containing solutions. The ferredoxin was obtained in high yields (25-35 mg/kg spinach) and high purity (A 420 /A 275 = O.47) within less than 8 hours.

Papiliochrome II, one of the yellow wing pigments of the Papilionid butterfly, Papilio xuthus, can be split into ʟ-kynurenine and a catecholamine derivative, SN-1, by 10 -3 n HCI. The latter is hydrolyzed by ɴ HCI into β-alanine and noradrenaline. The structure of SN-1 has been elucidated as N-(β-alanyl)-ʟ-noradrenaline by NMR and MS data as well as by synthesis. Preparation of the N-hydroxysuccinimide ester of benzyloxycarbonyl-β-alanine, its condensation with ʟ-noradrenaline to the corresponding benzyloxycarbonyl protected SN-1 and of N- (β-alanyl)-ʟ-noradrenaline by hydrogenolysis of the protecting group are described.

Binding of the substrates to the anisometric enzyme causes slight changes of some molecular parameters (Zipper and Durchschlag, Eur. J. Biochem., 1978). Estimations based on several plausible assumptions allow a separation of the experimentally observed effects into effects caused by the substrates or by the enzyme in the enzyme-substrate complexes or by binding of buffer molecules. The results show that the observed changes of molecular parameters are primarily due to structural changes in the enzyme molecule. From the changes in the radius of gyration upon substrate binding, the binding sites of the substrates may be localized to be at a radial distance of 5.3 nm from the centre of the enzyme particle. Binding of one or both of the substrates induces different structural changes of the enzyme particle. On formation of the [enzyme·acetyl-CoA], [enzyme·glyoxylate], or [enzyme·pyruvate] complexes, an increase of the short axis by 4.5 + 1% occurs, while the formation of the [enzyme·acetyl-CoA·pyruvate] complex does not change this axis significantly. A t the same time, binding of the substrates leads to a decrease of the long axes of the enzyme particle by 2.0 ± 0.2%, independent on the kind of the complex formed. These changes of the axes correspond to an increase of the axial ratio by 6.7 ± 1% on formation of the [enzyme·acetyl-CoA], [enzyme·glyoxylate], or [enzyme-pyruvate] complexes and by 2.7.% on formation of the [enzyme-acetyl·CoA·pyruvate] complex, i. e. in all cases to a decrease of anisometry of the enzyme particle.

Oxygen tension in the suspension medium and oxygen uptake of the isolated diaphragm of the mouse have been determined simultaneously with systematic variation of shaking frequency and oxygen concentration of the gas phase. Oxygen tension in the suspension medium readies its final value during the usual equilibration period of 10 minutes and remains constant for the whole measuring period. Each combination of shaking frequency and oxygen concentration of the gas phase results in a reproducible value of oxygen tension in the medium. Equal oxygen tension in the fluid phase can be attained by different combinations of shaking frequency and oxygen concentration of the gas phase. Oxygen uptake at the same oxygen tension of the suspension medium can be very different; it is the higher the higher the shaking rate in the combination. On the other hand the same oxygen consumption of the tissue samples can be observed with highly different oxygen tensions in the medium. It must be concluded from the data in this paper, that the influence of shaking rate per se on the oxygen uptake of isolated tissue can be of the same order as the influence of oxygen tension.

Reduced thioredoxins from microbial and plant cells, both of cytoplasmic or chloroplast origin, are interchangeable in stimulating such diverse enzyme activities as ribonucleoside diphosphate reductase (E. coli) , PAPS sulfotransferase (Synechococcus), and fructose-1,6-bis-phosphatase (from spinach) in vitro. It is suggested that reduced thioredoxins are unspecific, multifunctional cellular proteins while in contrast the oxidized froms require specific enzymes for their reduction.

1. A substrate-specific sedoheptulose-1,7-bisphosphatase has been found in chloroplasts and separated from its fructose-1,6-bisphosphatase counterpart. Experiments with antibodies indicate that the two enzymes are structurally different. 2. Activity of the sedoheptulose-1,7-bisphosphatase enzyme was dependent on Mg 2+ and a reductant. The most effective reductant tested was thioredoxin that was reduced either photochemically via ferredoxin with chloroplasts or chemically with dithiothreitol. Dithiothreitol added alone also activated the enzyme, but reduced glutathione or 2-mercaptoethanol did not. The thioredoxin-activated enzyme was deactivated by oxidized glutathione. 3. The results suggest that the new substrate-specific sedoheptulose-1,7-bisphosphatase depends on light for activity and resembles certain other regulatory enzymes of the reductive pentose phos­phate cycle in its mode of regulation.

Stroma-freed chloroplasts were extracted with sucrose palmitate-stearate containing buffer. After the addition of dodecyl sulfate and mercaptoethanol to the extract a series of polypeptides was isolated from the mixture by gel filtration. These polypeptides were later used for immunization. Antisera to four polypeptides reacted in the Ouchterlony double diffusion test with authentic coupling factor yielding a precipitation band. According to the observed apparent molecular weights the polypeptides are the α, β , δ and ε subunits of the coupling factor. An antiserum to the γ subunit has been obtained already previously. All antisera inhibit photophosphorylation reactions and electron transport considerably. Addition of gramicidin inhibits photophosphorylation completely whereas gramicidin restores electron transport in the assays with the antisera to the α, β , γ and δ subunit. In the case of the antiserum to the ε subunit gramicidin does not regenerate electron transport. As in the presence of the serum to the ε subunit pH changes in the suspension medium are not observed, this serum seems to open a proton channel. Also, upon addition of dicyclohexyl carbodiimide (DCCD) pH changes in the suspension medium in the assay with antiserum do not reoccur. According to these unexpected results the identity of the antigen with the ε subunit of the coupling factor is not certain. ATP-ase reactions are only inhibited by the antisera to the α and γ subunit and what is thought to be the ε subunit. The antiserum to the α subunit uncouples electron transport as the only one when used in sufficient concentrations. The dosis-effect curves of the inhibition of the electron transport exhibits a maximum. The dosis-effect curves for the other components rise after a lag phase in an approximately hyperbolic manner. The inhibitory action on electron transport is exerted by all antisera in the region of the reaction center I or in its immediate vicinity. This is thought to be due to the fact that a protein of the reation center I is inhibited in its function by the increasing proton concentration inside the thylakoid. The inhibition of electron transport by the antiserum to the ε subunit is considered to be a direct serum effect. Besides the increase in fluorescence yield, due to the inhibition of electron transport in the region of photosystem I, decreases of the fluorescence yield are observed in the presence of DCMU, which do not depend on the redox state of Q but rather on the condition of the thylakoid mem­brane. Moreover, the antisera affect in a differing manner the energy spill-over of excitation from photosystem II to photosystem I.

An attempt is reported to link changes in thylakoid lipid composition with the electron-transport and ATP-formation capability of the chloroplast. The observation that the monogalactolipid : phosphatid-ratio (MGDG/PL) of leaf sections shows a linear correlation with the P/2e value of simultaneously isolated Jensen-Bassham plastids was followed up experimentally for an in vitro plastid system. Lipid composition in these experiments was changed by illuminating the suspension with white light. The result shows, that similar dependencies can be obtained with both Jensen-Bassham chloroplasts and, up to a certain degree, chloroplast membrane fragments.

Nittrogen-fixing cells of Nostoc muscorum grown under nitrogen or in the presence of nitrate exhibit substantial light-induced hydrogen production for over 15 hours in the presence of electron transport inhibitors. Rates attain levels of 12 μmol H 2 evolved/ml packed cell volume and hour. The ATP-dependent nitrogenase, not a hydrogenase, is responsible for hydrogen production. This is indicated by poor sensitivity to CO and inhibition of the reaction by uncouplers, acetylene, and N 2 . An active uptake hydrogenase minimizes light-induced H 2 production. Although nitrogenase activity is somewhat decreased by several photosynthetic electron transport inhibitors, hydrogen production is markedly increased. This is due to lowering the partial pressure of oxygen in the cell, preventing oxidative hydrogen consumption.

Infection of tobacco protoplasts with RNA of tobacco mosaic virus and the bromoviruses has been studied. The quality of the RNA was very important. Ribonuclease activity was controlled by incorporating 5 mᴍ ZnCl 2 in the inoculum. Up to 60% infection has been observed with bromovirus RNA but infection with TMV RNA was much less efficient. A procedure for inoculating in 40% polyethylene glycol was developed. High levels of infection were obtained with all the viruses and viral RNA examined.

The conformationally restricted adenine nucleotide analogs 8,3′anhydro-8-oxy-9-(β-ᴅ-xylofurano-syl) adenine-5′-O-tri (di) -phosphate (I) , and 8,2′-anhydro-8-oxy-9-(β-ᴅ-arabinofuranosyl) adenine-5′-O-tri (di)-phosphate (II), were prepared chemically as their α- 32 P-labelled compounds and compared with syn-structured 8-bromo AT(D) P in mitochondrial adenine nucleotide translocation. The experimental findings demonstrate that the heterocycle-ribose orientation affects the carrier mediated adenine nucleotide transport very strongly, i. e. a non fixed adenine heterocycle in the anti region is prerequisite for the bound nucleotide to induce the transfer action of the adenine nucleotide carrier.

The ecdysone titer of larvae and pupae of Chironomus thummi was determined by radioimmune assay (RIA) and revealed a concentration of about 150 ng/g fresh weigth in late third instar larvae and a peak of more than 450 ng/g fresh weight just preceding pupation. The ecdysone titer curve shows a high degree of correlation with previously observed puffing activity at the ecdysone sensitive chromosomal site IIIdl. Further, β-ecdysone is the only endogenous ecdysone detected by high pressure liquid chromatography during larval-pupal development. It was also observed that developmentally arrested Chironomus contain less ecdysone than “normal” larvae.

When various cations, including Ca 2+ , are in the fixative, both sarcoplasmic reticulum (SR) of whole skeletal muscle and isolated SR vesicles collapse to form pentalaminate “compound membranes” that result from the apparent fusion of the lumenal lamellae of the membranous envelope of the SR. The process may be reversed by subsequently soaking the tissue in 1 ᴍ NaCl. An identical morphological phenomenon is observed in unfixed quickly frozen isolated frog skeletal muscle fibers, the cation in that case coming from endogenous sources. The hypothesis is advanced that the collapse is an in vivo process mediated by the sequestration of Ca 2+ after contraction. The resulting obliteration of the SR lumen would have the effect of displacing the SR contents into the junctional SR, as well as electrically isolating the free SR from the junctional SR during relaxation. As a consequence, resistive coupling between the plasmalemma and the junctional SR becomes a plausible mechanism for the translation of the action potential into Ca 2+ release, since the bulk of the SR membrane capacitance would now remain separated from the plasmalemma during relaxation.

The membrane potential in the dark and the saturated response height of the ventral nerve photoreceptor of Limulus was measured by an intracellular electrode while the external concentration of calcium, magnesium and sodium ions was varied. Decreasing the extracellular calcium concentration from 10 -2 mol/l causes a calcium-dependent lowering of the dark membrane potential and at very low concentrations (<10 -8 mol/l a reversal to ca. +5 to +11 mV, if the external magnesium concentration is also low. Also, the light response diminishes with decreasing extracellular calcium concentration and disappears at a concentration of 10 -9 mol/l. External magnesium can substitute for certain properties of extracellular calcium. Lowering the extracellular sodium concentration from 543 mmol/l to 30 - 50 mmol/1 reduces the dark membrane potential and the light responses at normal calcium concentration, whereas at low calcium concentration it causes a substantial rise of both. Interpretation: The results are in accordance with our working hypothesis that a strong reduction of the external calcium (and magnesium) concentration causes a calcium concentration dependent opening of “ light channels” in the dark. Additional lowering the extracellular sodium concentration counteracts this effect; opening and closing of light channels is controlled by negative binding sites on the cell membrane for which calcium and sodium ions compete with an antagonistic action.

An important new model universal oscillator proposed by Seelig which depends on substrate inhibition is considered. In a finite spatial domain with zero flux boundary conditions and in which the substrates can diffuse it is shown that diffusion-driven instability is possible and can result in finite amplitude spatial structures. Illustrative numerical results are presented which exhibit this behaviour.

Kaempferol-3-O-rhamnoglucoside, a flavonoid glycoside, was isolated from fresh withe petals of Zephyranthes candida.

The essential oil of chamomil roots has been investigated. Three sesquiterpenoids could be isolated and characterized by their retention time in reference to authentic substances and by their mass spectre. These are α-farnesene, β-farnesene and bisabololoxid A. Other sesquiterpenoids and polyentype substances are present and will be identified later.

1,2,5-Trihydroxy-3-methylanthraquinone (4), 2-hydroxy-3-(hydroxymethyl)-anthraquinone (2) and three dihydroxymonomethyl-anthraquinones (5, 6, 7) have been synthesized. 2 and 4 are new synthetic compounds.

Hepatitis A-Yirus-Single-Sranded D N A , Electron Microscopy, Length Measurements, Parvovirus Hepatitis A-virus was purified from human stools by three purification steps. Virus was identified by radioimmuno-assay and purity monitored with immune electron microscopy. Virus particles, serologically and morphologically identical, banded in CsCl in two density ranges at 1.31 — 1.34 g/cm3 and at 1.41 — 1.43 g/cm3. Virions of density 1.31 — 1.34 g/cm3 were shown to contain single-stranded D N A of different size classes. Class I 1.33 kb, class I I 4.61 kb in addition a small amount of molecules was de­ tected with lengths up to 15 kb.

Cells bearing two cilia are found in the mid-gut of the Phyllopod Leptestheria dahalacensis. These cells seem to be sensory cells. They may be in contact with the muscle cells of the mid-gut.

In chromatic adapted barnacle median and lateral photo­receptors the two stable states of the photopigment (rhodopsin R and metarhodopsin M) were interconverted with intense, colored light flashes of 1 ms duration. Only after conversion of the red adapted photoreceptor in K + -Ringer solution with an intense flash the negative early receptor potential, ERP (of R) gradually appeared detected with an indicator flash. For the opposite conversion (blue adapted, R→M) the gradual appearence of the positive ERP (M) was not measurable in the same time span. In artificial seawater all flash stimuli yielded - irrespective of color - the transient component of the late receptor potential (LRP). ERP results for the lateral photoreceptor are dis­cussed in view of an existing kinetic model and an attempt is made to give an explanation which covers the new LRP transient and ERP results for both types of photoreceptor (appendix).