Volume 31, Issue 3-4

The precise determination of the natural isotopic abundance ratios of carbon and hydrogen in several production batches of the commercial product 7-chlor-1,3-dihydro-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-on (diazepam) gave results which allowed certain batches to be differentiated. The differences in the ratios appear to be mainly due to differences in the isotopic composition of the (fossile) starting materials of the synthesis. The measurement of the natural isotopic ratios may therefore offer another possibility to deter­ mine the origin of a drug.

The studied macrotetrolide negative mutant of Streptomyces griseus showed a different specificity of potassium accumulation than the macrotetrolide producing wild-type, indicating, that the macrotetrolides may be part of the physiological potassium carrier.

Extracts of the skin of some amphibians from Australia and Papua New Guinea contained, in addition to the usual 5-hydroxyindolealkylamines and histamine: a. two new, hitherto unknown indolealkylamines, i.e . O-sulphate of bufotenidine and 2-(3-indolyl)ethyltrimethylammonium, a quaternary ammonium base of tryptamine. The rare O-sulphate of bufotenine was also present, the occurrence of which had previously been demonstrated only in the skin of some South American toads; b. a series of uncommon imidazolealkylamines, such as N′-acetylhistamine, N′-methyl-histamine, N′,N′-dimethylhistamine, spinaceamine and 6-methylspinaceamine. It appears evident that amphibian skin continues to be an exceptionally rich source of aromatic amines.

The monohydroxy carotenoid from the moth Cerura vinula has been shown to be β,β-caroten-2-ol on the basis of electronic, infrared, proton magnetic-resonance, and mass spectra. On acid treatment in the presence of molecular oxygen this carotenoid is dehydrogenated to 4′,5-retro-β, β-caroten-2-one. The identification of β, β-caroten-2-ol by its retro product, its time course of acetylation, and its chromatographic properties relative to β, β-caroten-3-ol and β, β-caroten-4-ol is discussed. This is the first demonstration of a 2-hydroxylated carotenoid in an insect. Implications on the biogenesis of this pigment are considered.

Juvenile Hormone, Manduca sexta The juvenile hormones (JH) in extracts of M anduca sexta blood were converted to 10-(2,4-di-chlorobenzoyloxy)-11-methoxy derivatives and quantitatively determined by gas chromatography with electron capture detection. Early IVth instar larvae contained 0.62 ng JH-I, 1.1 ng JH-II and 0.07 ng JH -III per ml blood. Early Vth instar larvae, and adult of both sexes contained the hormones in concentrations from 0 to 0.24 ng/ml blood. No hormone was detected in late Vth instar (wandering) larvae. The detection limit in our experiments was ≦ 0.003 ng/ml blood.

The diapause hormone (D H) responsible for arrested development of the silkworm Bombix mori consists of two active principles of peptide (A and B) . Since both hormones form aggregates in aqueous phases, the molecular weights were determined by gel permeation chromatography of Merckogel OR 6000 using methanol-dichloromethane mixture as the developing agent. Gramicidins and modified peptides soluble in the organic solvents were used as the standard markers for the molecular weight measurements of the hormones. The molecular weights of DH -A and -B are estimated to be 3300 ± 400 and 2000 ± 200, respectively.

The ribose conformations of 8-azaadenosine, 8-azaguanosine, and 8-azainosine have been studied using proton magnetic resonance in ND 3 solutions, in D 2 O solutions, and in pyridine solutions. The temperature was varied between - 60 and + 40 ° C in ND 3 and between + 10 and + 60 °C in D 2 O solutions. The analysis is based on the two state S ⇌ N model of the ribose moiety proposed by Altona and Sundaralingam. In D 2 O, the 8-aza substitution destabilizes the gg rotamer and simultaneously diminishes the population of the S state of the ribose. It is deduced that the anti population of the base is greater in the 8-azapurine (β) ribosides than in the common purine (β) -ribosides.

After efficient extraction by para-aminosalicylate, (hopping, grinding and eventual sonication, the macropolyanions are transformed into their cetyltrimethylammonium salts. These have differing solubilities, strongly depending on ionic strength. The cationic detergent-macropolyanionic salts are solubilized by high salt concentration. Salt is then dialysed out, rendering the polyanions highly insoluble in a sequential fashion. The insolubilized components are determined quantitatively by monitoring turbidity, which in case of DNA is strictly proportionate to its concentration. This relation is not affected by other components. This makes DNA determination possible even in crude aqueous extracts. The method has been applied to different objects, such as bacteria, plants, animals, soil and activated sludge. The method may prove to be especially useful in research of environmental poisons e. g. in rivers, lakes or clarifiers.

Further to anatomical and physiological studies performed on the pika (Ochotona rufescens rufescens), a new laboratory animal, the main characteristics of the mitochondrial DNA from its liver are defined. The buoyant density of this DNA is 1.695 g/cm 3 , its length 5.30 µm, i.e., 3.17 times that of the replicative form of ΦX 174. It could have approximatively 16 500 base pairs. The DNA from the pika is very similar to that of the rat or the rabbit, although these animals show great physiological differences.

Human erythrocytes were suspended in Hank’s solution containing mammalian or viral DNA or RNA. After dialysis at 0 °C first against water and subsequently against Hank’s solution, and a further incubation at 37 °C , the erythrocytes were found to be loaded with the nucleic acids. The nucleic acid trapped in the erythrocytes exhibited up to 35 per cent of the external concentration.

In photosynthesis of chloroplasts and bacterial chromatophores an induced artificial electron flow bypass may restore the inhibition of electron flow and of coupled ATP formation by two possible mechanisms. An artificial transmembrane electron flow bypass will lead to artificial energy conservation, when the redox reaction cycle of the added mediator across the membrane acts as proton pump. In an artificial internal electron flow bypass an inhibited native energy conservation may be reactivated; here an electron flow bypass induced by the mediator in the inside space restores the native proton translocation. The inhibition and the restoration of electron flow by antimycin, dibromothymoquinone and valinomycin is compared.

Proplastids in dark grown Euglena gracilis cells undergo a developmental process during illumination yielding full functional chloroplasts. The appearance of chlorophyll, cytochrome 552, cytochrome 563, and ribulose-1,5-bisphosphate carboxylase in these cells was investigated and different kinetics of synthesis were observed for each component. Light adaptation experiments on dark grown cells in the presence of the 70S ribosome in­ hibitor, chloramphenicol, revealed that the synthesis of cytochrome 552 was blocked but not cytochrome 563. In presence of the 80S ribosome inhibitor cycloheximide, the synthesis of both cytochromes as well as of chlorophyll (a + b) and of ribulose-1,5-bisphosphate carboxylase were inhibited. However, at low concentrations of cycloheximide (3.5 to 9 x 10 -8 ᴍ), a stimulation of the synthesis per cell of the cytochromes, of chlorophyll (a + b) and of ribulose-1,5-bisphosphate carboxylase was observed.

Liposomes (lipid, ᴅʟ-α-dipalmitoyl-phosphatidylcholine) containing chlorophyll a (ratio lipid to chlorophyll 30:1) exhibit an absorption maximum at 670 nm. Upon oxidation with iodine these liposomes yield a chlorophyll radical that shows a ESR signal with a line width (peak to peak) ⊿Y = ~0.1 G and a g-value of 2.0022, consistent with the presence of monomeric chlorophyll. Under anaerobic conditions, in the absence of acceptors, no light induced ESR signal is observed, whereas under aerobic conditions the chlorophyll free radical is generated in the light. Acceptors having access to the lipid membrane, like Fe 3+ -pyrophosphate and methylviologen, give rise to chlorophyll radical formation, or, like quinones, form a semiquinone radical in the light. Non-permeable acceptors, such as ferricyanide, NADP, FMN and cytochrome c do not act as acceptors and no chlorophyll radicals can be produced by light. Furthermore, light dependent and completely reversible electron transfer from N,N,N′,N′-tetramethyl-p-phenylenediamine to ubiquinone can be demonstrated. Liposomes containing chlorophyll, therefore, can serve as a model system for photosynthetic electron transport.

A method to prepare polyribosomes from yeasts by using the french-press is described. The highest yield of polyribosomes was derived from late log-phase cells. These polyribosomes, incubated in a cell-free system, were able to reinitiate protein synthesis, which was shown by inhibiting aminoacid incorporation by aurintricarboxylic acid, edeine and sodiumfluoride. We developed the translational system in order to look for the optimal ion-conditions of a DNA-dependent protein-synthesizing system. We found out that at the optimal MgCL 2 -concentration (6 mᴍ) protein synthesis was strongly inhibited by Mangan ions which are required for transcription in yeast. If protein-synthesis was carried out with 2 mᴍ and 3 mᴍ MgCl 2 maximal aminoacid incorporation was observed at 2 mᴍ and 1.5 mᴍ MnCl 2 .

The sedimentation at low speed centrifugation of a lipoprotein recombined from the lipids, and the strongly bound proteins of the human erythrocyte membrane depends on pH : between 4.5 and 6.0, most of the liproprotein sediments, whereas at pH 7.0 - 8.5, up to 90% remains in the supernatant. Precipitation of the lipoprotein can be reversed by increasing the pH, followed by a brief sonication. The mobility of spin-labelled protein groups in the lipoprotein increases with increasing pH. This mobility increase is also reversible and is of equal magnitude in precipitated and nonprecipitated recombinates. It is concluded that, because of these reversibilities, determination of the yield of liproprotein formation in recombination experiments must include analysis of both precipitated and nonprecipitated lipoproteins.

The lipid class compositions of subcellular fractions of SV40-transformed mouse fibroblasts derived from the logarithmic and stationary growth phase were compared. Cell populations of the stationary growth phase showed a relative decrease of the protein content and an increase of triglycerides and alkoxydiglycerides which could be located in the non-sedimenting fraction and in the nuclei and mitochondria containing fraction, respectively. Furtheron, distinct shifts in the subcellular distribution of those lipid classes could be observed which exhibited no relative overall increase or decrease when the cells of both growth phases were compared. In the crude plasma membrane fraction the ratio “lipid class/protein” remained about constant with the exception of the phospholipids and alkoxydiglycerides.

In spread preparations of whole spermatocytes of Trichosia pubescens the ribosomal transcription units could be identified by virtue of their “Christmas-tree-like” morphology. The ultrastructural features of these matrices are similar to those described in other eucaryotes. However, in contrast to the previously described systems the “spacer” unit between these matrix units is very small or non-existent at all. In addition, axial fibers displaying much longer lateral fibrils, irregularly spaced, and not as closely packed as in the ribosomal cistrons, were found. These are likely to represent active nonribosomal transcription. In a few instances these lateral fibrils show a gradual increase in their length.

Freeze-fracture studies reveal that extrusive organelles displaying saltatory particle movements in centrohelidian axopod are attached to highly ordered domains within the plasma membrane. It is postulated that the motive force for lateral displacement of these membrane domains with the adhering organelle is located immediately underneath the plasma membrane being either part of the peripheral membrane proteins or attached filaments alined parallel to the axopodial micro­ tubules. The attachment domain is interpreted organelle discharge by membrane fusion.

The mobility of Zn 2⊕ was assessed by supplying 65 Zn 2⊕ to the different leaves of maize plants, and radioassaying the plant parts after 2 days. It was found that the 3rd leaf (from the base) absorbed more Zn 2⊕ than other leaves. A larger percentage of Zn 2⊕ transported, was identified in the stem in general. The study further revealed that there was a close link between the 1st and the 4th leaf for the transport of Zn 2⊕

Besides the known pigments solorinic acid (1) and norsolorinic acid (2) the lichen Solorina crocea contains 4.4′-disolorinic acid (3), averantin 6-methyl ether (4), and averantin (5).

Gas chromatographic determinations, bioassays, and radio­ labelling experiments show that the juvenile hormone in adult male Hyalophora cecropia is accumulated exclusively in the accessory sex glands. Moths do not store measurable quantities of juvenile hormone if their accessory sex glands are removed shortly after adult eclosion.

The ATPase is not lacking in the ATPase mutants DL 54 and AN120 but has very different kinetic properties including a higher Cl - optimum and higher K m values for MgATP. In AN 120, the ATPase activity also has a higher Mg 2+ optimum.

EPR spectroscopy is used to analyse the influence of D 2 O and NaN 3 on the free radicals induced in frozen aqueous solutions of 5′-thymidine monophosphate photo­ sensitized (λ>320 nm) by proflavine at 205 K. The results can be explained if the production of singlet oxygen during the process is assumed.

Antibody-like substances with anti-carbohydrate specificities directed against different structures of galactans have been detected in several invertebrates.

In addition to the bifunctional adducts (cross-linkages), that furocoumarins on radiation at 365 nm form in DNA, monofunctional adducts also proved able to inhibit the nucleic acid synthesis in Ehrlich ascites tumor cells.

The possibility of using 2-methyladenine, previously reported as a specific component of prokaryotic tRNA, as a marker for the presence of bacterial informations in plant tumour cells was investigated. Normal and transformed, bacteria-free, tobacco cells exhibited slightly different me­ thylation patterns in their tRNA . However, 2-methyladenine was present in both normal and transformed cells. This makes it impossible to detect the occurrence of tRNA from tumour-inciting bacteria in crown-gall cells on the basis of methylation patterns.

The number of polyomavirus genome equivalents in three transformed hamster cell lines were shown by DNA reassociation assay to be 1.3, 1.9 and 2.5 per cell.

Distamycin A caused no significant inhibition of polyoma-virus growth or capsid and m RNA formation in embryonic mouse cells.

After being cultivated in the dark for some months and after being fed with food free of carotenoids during the time Aiptasia mutabilis (Coelenterata) loses its symbiontic algae (rich in brown fucoxanthin) and becomes transparent white. This disarranged symbiosis may be regenerated under light cultivation by adding different species of Chlorophyceae (Chlorella, Dunaliella) and Chrysophyceae (Ochromonas, Cyclotella), but not of Cyanophyceae (Anabaena, Nostoc, Oscillatoria, Anacystis). - This changeable life system between coelenterata and algae may be a good example for further studies of the endosymbiosis problem.

The length of the epidermal cells at the 10 th intemode was studied by means of the analysis of variance in the normal type and 6 of each long-stemmed and short-stemmed mutants of Pisum sativum. The effect of samples of four different sizes on the result of the analysis of variance was investigated. It was found that, based on 78 comparisons of 13 means each, an increase of the sample size from ti= 25 to n = 100 increases the significant differences from 53 to 64.