Volume 27, Issue 10

The nuclear quadrupole coupling constants of the 4 radicals 14 NO ( 2 Π 3/2 ), 14 NCO ( 2 Π 3/2 , 14 NS ( 2 Π 3/2 ), 33 SO ( 3 Σ - ) and the 17 diamagnetic molecules 14 N 2 O, 14 N 2 H, 14 NSF 3 , 14 NSF, 33 SCNH, 33 SCO, 33 SC, 33 SSi, 73 GeSe, 14 NP, 14 N≡C-H, 14 N≡C-CH 3 , 14 N≡C-CF 3 , 14 N≡C-SiH3, 14 N≡C-GeH 3 , 14 N≡C-C-C≡C-H, 14 N≡C-C≡C-CH 3 have been analyzed in terms of the π-bond order. Satisfactory results are obtained when the π-bond order is expanded in powers of the ratio The validity range of this function is defined.

IR and Raman spectra of LiBF 4 · n H 2 O and LiBF 4 · n D 2 O (n = 1, 3) and the normal vibrations of crystal water in the temperature range from 20° to - 125°C are reported. The hydrogen bond strength is correlated with relative force constants and thermogravimetric data.

1,2-Dimethylhydrazine co-ordinates to numerous metal cations. The structures of the complexes of Cr, Mn, Co, Ni, Cu, Zn, Cd, Hg and Pt are discussed and the complexing abilities of the 1,2-dimethylhydrazine molecule are determined on the basis of the ligand field spectra of the nickel and the chromium derivative. The results of polarography, cyclic voltammetry and photoelectron spectroscopy yield evidence on the redox properties of the neutral molecule. By means of EPR spectroscopy the nature of the radical products obtained by irradiation of 1,2-dimethylhydrazine, especially of the radical cation, is determined.

By reacting S = PX 2 NHCH 3 or O = PX 2 NHCH 3 (X = F and/or Cl) with S = PF 2 Br in the presence of triethylamine the following compounds are prepared: S = PCl 2 NCH 3 F 2 P = S, S = PFClNCH 3 F 2 P = S, O = PCl 2 NCH 3 F 2 P = S and O = PFClNCH 3 F 2 P = S. Also, the infrared, proton NMR, fluorine NMR, phosphorus NMR, and mass spectral data of these compounds are presented and discussed.

Complexes of the type trans-X 2 Pt (NH 2 CHRCOOH) 2 (X = Cl, Br, J; R = H, CH 3 , CH(CH 3 ) 2 , CH 2 OH) react with amino acid esters (GlyOCH 3 , GlyOC 2 H 5 ) and N,N′-dicyclohexylcarbodiimide as coupling agent to form the corresponding dipeptide ester derivatives trans-X 2 Pt (NH 2 CHRC (O) NHCH 2 CO 2 R′) 2 . In these reactions the metal ion acts as N-terminal protecting group. The infrared spectra of the new compounds are reported.

The reactions of ethoxides and isopropoxides of aluminium and titanium with bis (acetoacetates) in various molar ratios have been carried out. In all the cases, the treatment in the molar ratio 1 : 0.5 and 1 : 1.0 liberated one and two moles of alcohol respectively. The isopropoxy groups could be fully replaced only in the case of aluminium, when the reactions was carried out in higher molar ratio (1 : 1.5). However, even with excess of the ligand, the replacement of the fourth molecule of alcohol in case of titanium could not be accomplished.

This paper reports the isolation of a series of new coordination compounds formed with substituted 2-pyridinalphenylimines and iron (II). Susceptibility data, electronic spectra and infrared spectra leading to the characterisation of the compounds [FeL 3 ] (ClO 4 ) 2 , [FeL 2 (NCS) 2 ] and [FeL 2 ′ (NCS) 2 ] (L = 2-pyridinalphenylimine or phenylsubstituted 2-pyridinalphenylimine, L′ = 6-methyl-2-pyridinalphenylimine) are presented. Fully low-spin, fully high-spin and a temperature dependent spin-equilibrium between intermediate spin state and high-spin can be produced by appropiate substitution.

The ternary intermetallic compounds CaBe 2 Ge 2 , BaMg 2 Pb 2 and BaZn 2 Sn 2 have been prepared. Their crystal-structures have been determined. They are isotypic and crystallize in a new variant of the BaAl 4 -type (Space group: P4/nmm — D 4h 7 , lattice parameters: CaBe 2 Ge 2 : a = 4,02 ± 0,02 Å c = 9,92 ± 0,02 Å BaMg 2 Pb 2 : a = 5,00 ± 0,02 Å c = 12,11 ± 0,02 Å BaZn 2 Sn 2 : a = 4,69 ± 0,02 Å c = 11,33 ± 0,02 Å).

In the binary system Li—Ge we have found the new compound Li 7 Ge2. It crystallizes orthorhombic, space group Cmmm—D 2h 19 , a = 9,24 ±0,02 Å b = 13,21 ± 0,02 A and c = 4,63 ± 0,01 A. Li 7 Ge 2 is not isotypic to Li 7 Si 2 , but there are many structural relations between their structures.

The Osmium (VIII) catalyzed oxidation of acetone and ethylmethyl ketone by chloramine-T, in highly alkaline solutions showed first order dependence to chloramine-T and osmium (VIII). The order of the reactions with respect to alkali and ketone were found to be fractional, being ~-0.82 and 0.3 respectively. No effects of ionic strength were evident. The mechanism has been proposed on the basis of the formation of a complex between N-chlorotoluene-p-sulfonamide and osmium (VIII) in the slow step, which in turn oxidizes the enol anion of the reducing substrate in the fast step. During the study of the mechanism of oxidations by chloramine-T, the kinetics of the oxidation of α-hydroxy acids 1 in presence of osmium (VIII) as catalyst, glycerol 2 in neutral and alkaline media, p-cresol 3 in an acidic medium, hexacyanoferrate (II) 4 in a feebly acidic medium (pH 6-7) and aliphatic aldehydes 5 in alkaline media have been investigated. Despite the high redox potential 6 of the chloramine-T/toluene sulfonamide system (1.138 V at pH 12), the oxidation of acetone does not take place in absence of catalyst and that of ethylmethyl ketone proceeds only in highly alkaline solutions 7 (NaOH>0.01 M). In the present note the kinetics of the osmium (VIII) catalyzed oxidation of acetone and ethylmethyl ketone have been recorded.

It is shown, that the calculation of chemical proton shifts and coupling constants of linear di-aza-acenes within the framework of HMO-theory gives values close to experimental ones.

In contrast to aqueous and methanolic solutions the polarographic reduction of diazoaminobenzenes (DAAB) in the aprotic solvent dimethylformamid occurs in two waves with the combined hight corresponding to a four electron reduction. The first wave results from the four electron reduction of the fraction (1/5) of the DAAB molecules which obtain the necessary protons from the remaining (4/5) DAAB molecules. The resulting DAAB anions are only reduced at the considerably more negative potentials of the second wave. Then the reduction occurs also in a four electron step and leads to the cleavage of the molecule. Potentiostatic electrolysis at the limiting current region of the first polarographic wave results in coloured solutions. The colour depends on the nature of the substituent. Salt formation was monitored spectrophotometrically and inferences pertaining to structure are drawn. The experimental results show that mercury compounds which might possibly be formed as intermediary species react immediately with the cations of the supporting electrolyte to form the corresponding DAAB salts.

Amidoxime Ethers react with malonic acid in acetic anhydride at 20° to pyrano-pyrimidones (1 a- d), however, with monosubstituted malonic acids acetoxy-pyrimidones (2 a- f) are formed at the boiling point.

The spectrophotometric and spectrofluorometric investigations of the enzyme-substrate complex formation of p-hydroxybenzoate hydroxylase was made by the stopped-flow technique. The apparent velocity of the formation of the enzyme-substrate complex (the velocity of the absorbance change in visible and UV regions, and the velocity of the quenching of the fluorescence intensity in the FAD moiety of the holoenzyme by the substrate) was rapid enough to explain the maximal overall velocity (72 sec -1 ) or the activated anaerobic reduction rate (k red max = 200 sec -1 ). The results were consistent with a two-step mechanism involving a rapid bimolecular association of enzyme and substrate, and a slower follow-up unimolecular process.

The reduction by CO of diaquo-cobinamide, diaquo-cobyric acid and several complete aquocorrinoids in aqueous solutions was studied. Aquo-cobalamin-lactam and all the other corrinoids under study were reduced to (Co II ). At 37°C the reaction is about two to three times faster than at 22°C, and it is inhibited by benzimidazole and (more strongly) by histidine. CO is a better reductans for diaquo-cobinamide and diaquo-cobyric acid than for the complete corrinoids. Corrinoids with a purine base are more quickly reduced than those with a benzimidazole base. The experiments show that the reaction of CO with corrinoids is inhibited or delayed by those trans ligands, which are strong electron donors.

Alkaryl triazenes were synthesized in two steps from the isolated intermediary diazonium tetrafluoroborates and hexafluorophosphates by coupling the arenediazonium cations with dimethylamine in an aqueous solution but without the use of mineral base. The method enables the preparation of triazenes which are not readily accessible by conventional procedures; it also leads to higher yields and purer products in the preparation of known compounds.

In addition to 5- (γ-methoxy) -cinnamylidene-4-methoxy-but-3-enolide (= piperolide), whose occurrence in roots and stems of Piper sanctum was described previously, there has been found the corresponding 7,8-oxidoderivative as its main concomitant. The isolation procedure - chromatography on charcoal columns using lipophilic solvents - is described. The structure 3 is mainly based on spectroscopic studies of its tetrahydro-derivative.

Binding of ecdysone to a protein fraction of the hemolymph of mature Calliphora larvae has been demonstrated by use of the gelfiltration technique. Binding occurs in vivo after injection of labelled ecdysone as well as in vitro on incubation of either hemolymph or a 100 000 g-supernatant of a homogenate with ecdysone. The protein-ecdysone complex can be fractionated by DEAE- or CM-cellulose chromatography; however, the protein seems to be denatured on prolonged dialysis, so that a measurement of the equilibrium constant was not possible.

Changes caused in the PMR spectra of aqueous solutions of four pyrimidine nucleosides (uridine, deoxyuridine, cytidine and thymidine) containing benzene (0.12 molal) by the variation of concentration and temperature have been investigated. From the data obtained, the participation of the benzene molecules in the stacking of the nucleosides is deduced.

The greening process of etiolated bean and maize leafs was followed by measuring the prompt and delayed light emission of chlorophyll. Above all it was concluded that the development of photosynthetic Systems I and II could be observed by studying the formation of the Kautsky -effect. First light-induced changes in the chlorophyll fluorescence intensity do not occur until 2,5 h of irradiation. It could be shown that they reflect the function of PS II reaction centers and under anaerobic conditions the electron flow between PS II and PS I. Full active electron flow from water to NADP is first to presume with the appearence of all characteristics of the Kautsky -effect (O—I—D—P curve at 3 h of irradiation).

The RNA metabolism in tissue cultures of Nicotiana tabacum has been studied by incorporation of radioactive phosphate. The RNA was extracted by phenol-kresol-hydroxychinon and fractionated by MAK columns. A rapidly labelled RNA fraction was eluted from the MAK column after the rRNA components. Its base ratio differed from the latter in that the AMP content (28,6%) was higher than the GMP content (26,0%). Sedimentation analysis on sucrose gradients showed a sedimentation coefficient of 37 -38s. The life time of the 37-38s RNA fraction in chase experiments was 3,5-4 hours. Differential centrifugation of tissue homogenates revealed that the labelled 37-38s RNA was associated with particles sedimented by low speed centrifugation. No 37-38s RNA could be detected in the ribosomal fraction and the supernatant. During chase experiments label appeared in the rRNA components. It could be excluded by thin layer chromatographic separation of 32 P labelled compounds that this label originated from 32 P-o-phosphate or labelled organic phosphates except of the rapidly labelled 37-38s RNA. From this it was concluded that the 37-38s RNA is a precursor of the rRNA.

Etioplasts aqueously isolated from leaves of etiolated plants of two varieties of Avena sativa contain all the flavonoid compounds of the whole leaf: apigenin-7-methoxy (?)-8-C-rhamnosylglucosylgly (u) coside (or -8-C-glucosylrhamnosylgly (u) coside), apigenin-6-C-arabinosylglucoside, apigenin-8-C-glucosylglucoside and in variety 1 a derivative of kaempferol, in variety 2 the flavone-C-glycoside saponaretin. The distribution of these compounds however is different in etioplasts and leaves: in etioplasts of variety 1 the kaempferol-derivative, in those of variety 2 saponaretin is relatively enriched. Presence of flavonoids could also be demonstrated in isolated prolamellar bodies from etioplasts of Avena variety 2.

After solubilization of stroma-freed chloroplasts with deoxycholate, the lipids and the detergent used are separated from the proteins by gel filtration. In this way not denatured pigment-con-taining protein preparations were obtained. The particles in fraction 1 exhibited a molecular weight of 600 000 and contained an average of 25 chlorophyll molecules. The circular dichroism spectrum showed exciton splitting of the red band. The particles in fraction 2 contained 1 chlorophyll molecule and exhibited a molecular weight of 110 000. The particles in fraction 3 also contained only 1 chlorophyll molecule and had a molecular weight of between 80 000 and 100 000. Pure preparations of fraction 1 only carried out the methylviologen Mehler reaction with the dichlorophenol indophenol/ascorbate couple as electron donor. Fraction 3 only reduced ferricyanide with diphenylcarbazide as an electron donor in the light. Fraction 2 exhibited both the photosystem I reaction and the photosystem II reaction. An antiserum to extracted fraction 1 does not inhibit electron transport in the intact lamellar system. The photoreduction of methylviologen is only inhibited after disruption of the thylakoids. The antiserum to fraction 2 inhibits the photoreduction of methylviologen in the intact lamellar system. Consequently, one inhibition site for this photosystem I reaction must be located on the inner and another on the outer surface of the thylakoid membrane. In addition, antibodies to fraction 1 are specifically adsorbed onto the lamellar system without any effect on electron transport and without a concomitant agglutination. Antibodies to fraction 3 partially inhibit the photoreduction of ferricyanide with diphenylcarbazide as an electron donor in the intact lamellar system. Hence, the inhibition site of this system II reaction is located on the outer surface of the thylakoids. We have reason to believe that the inhibition sites not reacting are located in the partitions, which are not accessible to antibodies.

The effect of 5·10 -7 and 5·10 -6 Μ IAA on K + , Cl - and SO 4 -- uptake by young and old Mnium gametophytes from 0.2 mM or 10 mM salt solutions has been investigated. These IAA concentrations selectively enhance K + uptake from 0.2 mM KCl or K 2 SO 4 in old gametophytes. IAA up to 10 -5 M does not affect the membrane potential (P.D.). At 0.2 mM KCl the observed P.D. of -200 to - 220 mV is more negative than the calculated Nernst potential of +84 to +107 mV for Cl - and -136 to -157 mV for K + . These results are discussed in relation to a recent model of IAA regulation of cell elongation involving a proton extrusion pump.

The action of ultraviolet light on certain membrane properties of protozoa was investigated in Paramecium, Euplotes, and Opalina using the following methods: observation of morphological changes of the animals, recording of the osmoregulatory organelle (Paramecium), and measurement of membrane potential and resistance by means of intracellularly inserted microelectrodes. This paper presents only slow effects which occur within some minutes after uv irradiation and does not directly concern excitability of protozoa. Due to large uv doses swelling was observed both in Paramecium and Opalina; in Euplotes a liquid-filled vacuole was formed. Small uv doses cause an increase in the frequency of the contractile vacuole of Paramecium; larger doses diminish the frequency reversibly (Fig. 4), and even larger doses lead to an irreversible inactivation of this organelle. Membrane potential and membrane resistance in Opalina are shown to change in different ways under continuous irradiation (Fig. 13): After a transient decrease the membrane potential increases to about the initial value and after this it decreases to zero, whereas the membrane resistance decreases from the beginning of irradiation. The spectral sensitivity curve (Fig. 9) obtained from a standard decrease of the membrane potential shows a maximum at about 280 nm and a rise from 250 nm towards shorter wavelengths. The results indicate an influx of water following the osmotic gradient and an increase of the membrane permeability to cations. With respect to the different behavior of membrane potential and conductivity the mechanism of uv action is discussed. The most probable assumption is that the permeability increases unspecifically but gradually in succession for water, chloride, potassium, and sodium. The possibility of disruption of disulfide links is discussed with respect to the spectral sensitivity curve. It is suggested that the altered permeability is based on photochemically induced changes of the structure of proteins which are either part of the membrane or have an important function in the regulation of the membrane permeability.

The different radioautographic patterns were observed on the upper surface of fore wings of Inachis io L. when 35 S-sodium sulfate, 3 H-tryptophane and 14 C-hydrolysed protein were orally applied or injected to the larvae or pupae of the butterfly. 35 S-sodium sulfate and 3 H-tryptophane were found in ommochrome containing scale areas, whereas 14 C-hydrolysed protein could be detected only in melanine containing scale areas by radioautographic methods. These results prove that the 35 S-sodium sulfate can be utilized in the synthesis of ommatin D as ester of sulfuric acid. By means of particular UV-radiation the colour and form of wings were changed. This change is either due to the interruption of the flow of determination responsible for the formation of pattern or the blockage of lymphatic fluid. The radioautographic pattern of the treated wing shows also the change of form, colour and position of the scale areas.

Short (15 min) and long (1 hour or more) pulses with P 32 have been compared at different developmental stages of Limnaea. In short pulses, as opposed to long-pulses, the relative percentage of 4S RNA is at a more or less constant level at all stages of development. Heavy RNA, i. e. heavier than 28S, is traceable with both short and long pulses in the uncleaved and early morula stages. Transcription of heavy RNA seems to decrease significantly immediately before mitosis. No other RNA fraction shows such a marked rhythm associated with mitosis.

The capacity of mouse uterine chromatin, prepared according to TENG and HAMILTON, to degrade 8- 14 C-ATP to ADP, AMP and adenosine and to cleave γ- 32 P-ATP to inorganic phosphate and other still unknown phosphorylated byproducts has been demonstrated over a wide range of conditions of the template assay. The dependence of the reactions on the time course of incubation, on the chromatin quantity and on the temperature was studied. In vivo administration of oestradiol depresses the apparent ATPase activity of mouse uterine chromatin consistently by 10-35 per cent, depending on chromatin preparation, amount and incubation period. The data are compatible with the suggestion that mouse uterine chromatin may contain low quantities of ATPases which are firmly bound to the chromatin structure and which might interfere with the template assay under average conditions, depending on the chromatin preparation. The findings are discussed in view of the possible role of ATPases in uterine chromatin under oestradiol influence.