Volume 26, Issue 11

The compounds Ba 3 CaU 2 O 9 and Ba 3 SrU 2 O 9 crystallize in an ordered cubic perovskite lattice. According to the results of the magnetic and optic investigations both compounds contain U (V) in a distorted octahedral coordination.

0.01 ᴍ solutions of Mn (ClO 4 ) 2 , MnCl 2 and MnSO 4 in water-methanol mixtures were studied at 25 °C to determine the effect of these anions and of solvent composition on the ESR intensity and linewidth of Mn(II). A significant feature of the data was the large difference between the intensity of Mn(ClO 4 ) 2 and that for MnCl 2 and MnSO 4 in solutions containing greater than about 0.5 mole fraction methanol. A plot of linewidth versus mole fraction methanol shows little difference between Mn(ClO 4 ) 2 and MnCl 2 but an increasingly greater difference between these salts and MnSO 4 with increasing methanol content. These results are interpreted as being due to first coordination sphere complex formation in solutions containing Cl ⊖ , while the SO 4 2⊖ data are affected by both first and second coordination sphere complexes depending upon the solvent dielectric constant. The Mn(ClO 4 ) 2 data were interpreted as showing that the primary solvation sphere of the Mn(II) ions was changing as the composition of the bulk solvent changed. These results are compared with similar data in aqueous solution and confirm that complex formation involving Cl ⊖ or SO 4 2⊖ ions and Mn(II) is extensive in water-methanol mixtures.

The following sulphides were precipitated with hydrogen sulphide from solutions of naphthenates in organic solvents: In 2 S 3 , CoS, NiS, CuS, ZnS, CdS, HgS, PbS, Ag 2 S and the thiospinels NiIn 2 S 4 , CdIn 2 S 4 and HgIn 2 S 4 . Not precipitated are chromium (II) and chromium (III). The ir-spectra of the naphthenates are discussed.

The effect of various non-SH-containing amino acids on an electron spin resonance spectrum as well as on an optical absorption spectrum of an aqueous copper (II) solution was investigated. The data obtained indicate that a charge-transfer complex is formed with amino acids acting as electron donors. A plot of the wavelength of the CT-band vs. the pK values of the carboxyl group exhibits a straight line with the larger pK values appearing at shorter wavelengths. Similar results were obtained when the intensity was plotted vs. the pK values of the amino group; again, higher pK values correspond to lower intensities. Thus, the method allows the determination of the pK values of prosthetic groups of amino acids. The data obtained are in good agreement with the CT-theory.

The vitrational spectrum (IR and Raman) of trichloroisocyanuric acid, (CINCO) 3 is recorded and assigned on the basis of a planar molecule with symmetry D 3h .

The reduction of carbon tetrachloride by hydrated electrons, H atoms and reducing radicals has been investigated by pulse radiolysis conductivity methods. It has been found that one Cl® ion is formed per reducing species. A chain reaction is observed in the γ-radiolysis of solutions of CCl 4 and iso-propanol, diethylether, and tetrahydrofurane. Mechanisms and kinetic data are discussed.

The reactions of chlorinated ethylenes with hydrated electrons and OH radicals have been investigated by using the method of pulse radiolysis. In addition γ-ray experiments were carried out. The reduction of the solutes occurs via a dissoziation electron capture process. The rate constant for the reaction of e aq ⊖ with the more chlorinated compounds is essentially diffusion controlled (k= (1 - 2×10 10 l-mole -1 sec -1 ). Vinylchloride and 1,2-trans-dichloroethylene react more slowly. This can be related to the higher stability of the C-Cl bond in these compounds. Hydroxyl radicals add to the C=C double bond of the chlorinated ethylenes. The rate constant for the reaction with vinylchloride was determined to 7.1 × 10 9 1 · mole -1 sec -1 , and decreases with increasing degree of chlorination of the ethylenes. This effect is explained by the decreasing electron density on the C-atoms and steric hinderance. The hydroxyl radical always adds to the C-atom carrying the smallest number of Cl-atoms. In its reaction with 1,2-dichloro-, trichloro- and tetrachloroethylene a radical is produced with an OH group and a Cl-atom on the same C-atom. It eliminates HCl to form a C=O bond with k>7 × 10 5 sec -1 . The type radical produced in this reaction has an optical absorption in the near UV (ε 265 nm = (1-3)×10 3 1 · mole -1 cm -1 ). The OH radical addition products of vinylchloride and 1,1-dichloroethylene do not eliminate HCl and have no absorption in the visible and near UV.

EHT-modell calculations give an exact information concerning the tautomeric structures of pyrrole or fuane-2,3-diones. In connection with this, a method is presented, by which a phenylgroup is replaced by a three atom modell for the calculations.

The tropylium-ion, C 7 H 7⊕ , is reduced by the H atom to yield the tropyl radical C 7 H 7 . C 7 H 7 absorbs at 3150 Å with ε=2800 mole -1 l cm -1 . The rate constant of the reaction C 7 H 7 + +H → C 7 H 7 + H 3 O ⨁ is (7 ± 2) 10 9 mole -1 l s -1 . C 7 H 7 ⨁ is also reduced by α-alcohol radicals but not by β-alcohol radicals. Tropylcarbinol C 7 H 7 OH reacts with e aq ⊖ with k= (6 ± 2) 10 9 mole -1 l s -1 . The product is non conducting and absorbs at 3150 Å with ε=4200 mole -1 l cm -1 . This absorption is attributed to the hydroxycycloheptadienyl radical.

The condensation of 2-hydroxy-1-naphthaldehyde with ethyl cyanoacetate is investigated. Rearrangement for the obtained naphthopyranyl-ethyl-cyanoacetate (5) is reported, yielding 5,6-benzocoumarin-carbonitrile and naphthopyranyl-aminoacrylate (6). Enamine-lactone-rearrangement of 6 leads to chromene-carboxylic acid (7). By hydrolysis of the benzopyranyl-ethyl-cyanoacetate (8) and addition of cyanoaceticacid derivatives to 3-cyanocoumarin or 3-carboxyamido-coumarin resp., the benzopyrano-pyridines 12 are obtained.

The Authors have studied the capacity to photoreact with native DNA and r-RNA using six coumarins and four 4′,5′-dihydro-furo-coumarins. Six of these substances have shown a definite photoreactivity both with DNA and r-RNA, even if in a very much lower extent in respect to that of skin-photosensitizing furocoumarins. The low capacity to photoreact with nucleic acids of these substances is discussed, also in connection with the absence of skin-photosensitizing activity.

Nodososide and emodin from the flowers of Cassia nodosa and physcion-1-glucoside and physcion from the seeds of Cassia occidentalis can be determined in micro amounts by oxidation with eerie sulphate in presence of sulphuric acid. The reactions required 48, 26, 54 and 30 moles of oxidant respectively, resulting in the formation of formic and acetic acids in each case while carbon dioxide was also produced in the cases of nodososide and physcion-1-glucoside. The conditions of stoichiometric oxidation of the anthraquinones have been studied. Methylation of the hydroxyl groups has been found to retard the rate of oxidation of the anthraquinones whereas free hydroxyl groups are easily attacked by ceric ions. The ranges of errors observed are 0.2 -1.7%, 0.3 - 2.9%, 0.2 -3.5% and 0.2 - 3.5% respectively.

Cyclodehydrohalogenation-beta-Lactams-Morpholin-3-ones-H'-NMR Spectroscopy N-Aryl-N-chloroacetyl-2-chlorophenacylamines (2) give morpholinones 3, or beta-lactams 4, depending upon the N-aryl-substituent. N-Phenyl-N- (2,3-dibromo-3-phenylpropionyl) -4-nitrophenacylamine did not undergo base-catalysed cyclization but gave, instead, the α,β-unsaturated, open-chain amide 5. N-Aryl-N-chloroacetyl-aminomethyl-2-naphthylketones afford only beta-lactams. The first attempt at the synthesis of a 2-chloro-3-oxo-morpholine resulted in the isolation of the 2-hydroxyderivative. The H 1 -NMR spectra of some more 3-oxo-morpholines have been recorded.

The synthesis of cyclo (c)-cys-ser, c-cys-asp and c-cys-try via cyclisation of the corresponding cystin-dipeptidesters and subsequent reduction of the disulfides of the diketopiperazines with mercapto-ethanole is described. The ir-spectra of the cyclo-dipeptides and their disulfides were studied with regard to interactions of the functional groups. The spectra indicate a strong hydrogen bridge between the OH-groups of c-cys-ser-disulfide and interactions between the SH and other functional groups of the above mentioned diketopiperazines. The kinetics of the reaction of cysdiketopiperazines with N-ethylmaleimide and p-nitro-phenylacetate were studied. The SH-groug of cys-diketopiperazines has a greater nucleophilic reactivity towards p-nitro-phenylacetate than was expected on the basis of the pK SH -values.

The incorporation of 14 C- (fatty acid-) / 32 P-phosphatidylcholine containing high amounts of linoleic acid into rat liver and bile was studied. After injection into the intestine, 3.5% of the lipid was incorporated into the liver and 0.2% into the bile. Upon the injection into the portal vein, the corresponding values were 20% and 1 percent. The results show that about 20% of the phospholipid injected into the intestine was absorbed without splitting. From the 14 C/ 32 P-ratio of the bile phospholipid it could be concluded that temporarily the injected phospholipid was excreted from the liver into the bile in intact form.

In the brain-metabolism of experimental chronic epileptic cats (modificated Kopeloffmethod of intracerebrale alumina-gel injection) some alterations were observed in the lesioned cortical hemisphere. An increase of tissue-respiration in vitro (gray-matter of the cerebral cortex), increase of the activities of alkaline (E.C. 3.1.3.1) and acid phosphomonoesterases (E.C. 3.1.3.2) and a decrease of K-Na-stimulated, Ouabain-inhibited adenosintriphosphatase (E.C. 3.6.1.3) were determined. Postconvulsive (one to six hours after seizures) these changes were found to be more extensive than one or more days after discharge. They couldn’t be found in brain tissues of cats only with mechanical lesions without injection of aluminagel 2 which didn’t have convulsions. Because the good reproducibility the communicated method for experimental chronic epilepsy is proposed for pharmacological investigations.

The longitudinal proton relaxation time T 1 of aqueous solutions of bovine ferrihemoglobin and carboxilated hemoglobin was measured in the Larmor frequency range 3·10 3 Hz to 1,2·10 8 Hz. The dispersion curves are explained by diamagnetic and electron paramagnetic relaxation mechanisms. An efficient direct dipolar coupling between the paramagnetic heme-groups and the water protons in ferrihemoglobin solutions can be excluded. The flat dispersion behaviour of the diamagnetic contribution suggests a broad distribution of molecular motions i. e. a certain flexibility of the hemoglobin molecule.

Electrons produced by Chl-a II in a short flash are finally transfered to Chl-ai after having passed several intermediates. The reaction between Chl- aI and its primary electron donators PD (probably Cyt-f and PC) has been studied by means of high time resolution flash photometry in isolated spinach chloroplasts with the following results: 1. When PD are in the oxidized state, the reduction of Chl-a I ⊕ takes place with the rate limiting reaction time of the electron transport chain (≈ 20 ms). 2. When PD are in the reduced state, the reduction of Chl-a I ⊕ takes place with the reaction times between the PD and Chl-ai. We found two half life times: one of about 200 μs and one of about 10 μs. The reduced state of PD is realized when weak monitoring light or hv II -preillumination is used. The two reaction times of ≈ 200 μs and of ≈ 10 µs are interpreted to represent the electron transfers between Cyt-f and Chl-a I and between PC and Chl-a I resp. Equilibrium constants of the electron transfer from PD to Chl-a I and the arrangement of the intermediates in the electron transport chain are discussed.

The time courses of formation of the enzyme phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) mediated by far-red light (i. e. by phytochrome, P fr ) in cotyledons and hypocotyl of the mustard seedling (Sinapis alba L.) are described. While PAL activity in the cotyledons can scarcely be detected in the dark-grown seedling, the enzyme can be synthesized in the hypocotyl even in the dark. However, the degree of induction by far-red light is much greater in the cotyledons than in the hypocotyl. In the cotyledons the enzyme is not stable. The enzyme level eventually returns to nearly zero even under continuous far-red light. The time course of the level of PAL in the cotyledons (Fig. 1) can be explained by the following 3 factors (Fig. 2): 1. Induction of PAL synthesis by P fr , whereby P fr is continuously required; 2. Inactivation (degradation) of PAL by an inactivating principle; 3. Repression of PAL synthesis. The time course of the level of PAL in the hypocotyl is completely different (Fig. 1). An explanation of the hypocotyl data is presented which is based on the assumption that PAL synthesis in the dark and PAL synthesis mediated by phytochrome are independent phenomena which occur in different tissues of the hypocotyl. It appears that the occurrence of dark synthesis of a stable enzyme in the hypocotyl explains the seemingly dramatic difference between the cotyledons and the hypocotyl with respect to PAL.

Stroma-containing chloroplasts from Zea mays and Antirrhinum majus were isolated in aqueous medium. The average dry weight of chloroplasts from Zea mays is 27·10 -12 g, that of Antirrhinum majus 30·10 -12 g. Water freed chloroplasts consist up to 49 or 45 percent respectively of lamellar system. The lipid content of the lamellar system of Zea mays is 49 percent, that of Antirrhinum majus 45 percent. A chloroplast of Zea mays contains on the average 920·10 6 chlorophyll molecules, 220·10 6 carotenoid molecules, 2000·10 6 molecules of galactolipids, 190·10 6 molecules of sulpholipid, 260·10 6 phosphatide molecules and 64·10 6 molecules of lipophilic quinones. In addition to phosphatidylglycerol also phosphatidylinositol and phosphatidylcholine were found. It is very probable that besides vitamin K 1 the homologeous compound lacking one methylgroup is present in the chloroplasts. In contrast to the literature only 62 percent of the total leaf galactolipids are found in the chloroplasts.

The terpenoid excretion on buds of Alnus glutinosa is shown to contain free flavonoid aglycones. These are pectolinarigenine, centaureidin, the 3,6-dimethylether, 6,4′-dimethylether and 3,6,4′-trimethylether of 6-hydroxykaempferol and isorhamnetin.