Volume 49, Issue 7-8

Gibberellin A 19 (GA 19 ) and GA 24 were identified by gas chromatography-mass spectrometry from growing shoots of four strains of three species of D ioscorea, D. bulbifera var. vera, D. pentaphylla and D. oppositifolia (yams), which are distributed in the subtropical and tropical regions of Asia. An earlier report indicated the presence of several GAs including GA 19 and GA 24 in a cultivated temperate species of East Asia, D. opposita; these findings suggest possible coexistence of two GA biosynthetic pathways, early 13-hydroxylation and non-13-hydroxylation pathways comm only in Asian species of Dioscorea

The anthraquinone glycoside contents of various parts of Rumex crispus L. (Polygonaceae) in different vegetation stages were investigated by thin layer chromatographic and spectro-photometric methods. The data showed that the percentage of anthraquinone glycoside in all parts of plant increased at each stage. Anthraquinone glycoside content was increased in leaf, stem, fruit and root from 0.05 to 0.40%, from 0.03 to 0.46%, from 0.08 to 0.34%, and from 0.35 to 0.91% respectively. From the roots of R. crispus, emodin-8-glucoside, RGA (isolated in our laboratory, its structure was not elucidated), traceable amount of glucofrangulin B and an unknown glycoside (R f = 0.28 in ethyl acetate:m ethanol:water/100:20:10) was detected in which the concentration was increased from May to August. The other parts of plant contained only emodin-8-glucoside

Two antibiotic metabolites were isolated from cultures of Leucoagaricus carneifolia. Their structures were elucidated by spectroscopic methods. The first compound, 7-chloro-4,6-di-methoxy-1(3 H)-isobenzofurane (1) had to our knowledge not been described from natural sources whereas the second, basidalin (2), is a known metabolite of L. naucina (H. Iinuma et al., 1983). 1 exhibits antibiotic activities with minimal inhibitory concentrations of 20 μg/ml against Botrytis cinerea, the most sensitive microorganism

Syringaldehyde readily reacted in the horse-radish peroxidase (HRPOD) system. The ethyl acetate extract of the reaction mixture showed a marked antimicrobial activity against bacteria and fungi. After repeated column chromatography three potential antimicrobial compounds were obtained from the extract. The structural elucidation of active compounds was achieved by a combination of spectroscopic techniques and chemical modification

Quinate:oxidoreductase (QORase, EC 1.1.1.24) was isolated and purified from etiolated mung bean (Phaseolus mungo L.) sprouts and a monospecific antiserum was raised in rabbit to the homogeneous protein. Highly intact etioplasts were isolated from the same plant material. The stroma of the purified etioplasts was enzymatically characterized. Contamination by cytosol, mitochondria and vacuole was estimated from activities of marker en­zymes. QORase activity was localized in the stroma (about 91% for both NAD + and NADP + as a cofactor). Western blotting and immunoprinting of the stroma proteins revealed a single band that migrated identically with the purified QORase. The results suggest that the QOR-ase is localized predominantly, if not exclusively, in the etioplast stroma. The physiological role of the enzyme is discussed

The activity of the plastidic pyruvate dehydrogenase complex (pPDHC) is one source of acetyl-CoA in plastids of higher plants needed for de novo fatty acid biosynthesis. This plastidic enzyme reaction is specifically inhibited by acetylmethylphosphinate (AMPI), a com ­ pound which had hitherto been known only as an inhibitor of the mitochondrial pyruvate dehydrogenase complex (mPDHC). In the test system of isolated intact oat plastids (Avena sativa) [2- 14 C]pyruvate was used for de novo fatty acid biosynthesis. The incorporation of label from [2- 14 C]pyruvate in fatty acids was inhibited by AMPI in a dose-dependent manner. The inhibition rose with increasing preincubation time of plastids with the inhibitor. I 50 values for the inhibition of de novo fatty acid biosynthesis from [2- 14 C]pyruvate by AMPI for iso­lated etioplasts and chloroplasts were 4.5 and 80 μm , respectively. The activity of the pPDHC decreased during greening of oat seedlings, as is seen from the decreasing incorporation of [2- 14 C]pyruvate into fatty acids during the light-induced transformation of etioplasts into chloroplasts. In contrast to the decreasing pPDHC activity, the activity of the plastidic acetyl-C oA synthetase (ACS), which transfers acetate to acetyl-CoA, rose parallel to the transfor­mation of etioplasts into chloroplasts. During the assay time of 20 min we could not detect an incorporation of radiolabel from pyruvate or acetate into β-carotene or any other carotenoid

Photosystem I preparations were obtained from wild type tobacco Nicotiana tabacum var. John William’s Broadleaf (JWB) and from the two chlorophyll-deficient mutants N. tabacum Su/su and N. tabacum Su/su var. Aurea. The preparations were characterized with respect to the chlorophyll a/b ratio, their photosynthetic activity and their absorption spectroscopic properties. Peptides from these preparations were analyzed by SDS polyacrylamide gel electrophoresis and transferred for the detection of bound carotenoids according to the Western blot procedure to nitrocellulose or Immobilon membranes. The PS I preparation from the wild type JWB consisted of the core and the LHCP complex. The core complex contains the two core peptides with the same apparent MW of 66 kDa and several peptides with the lesser molecular masses of 22, 20, 19, 17, 16, 10 and 9 kDa. The light-harvesting protein complex consists of 4 subunits with the molecular masses 28, 26, 25 and 24 kDa. The PS I preparations of the yellow-green mutant Su/su and of the Aurea mutant Su/su var. Aurea contain as impurity traces of the D 1 and D 2 core peptides of photosystem II and also traces of the chlorophyll-binding photosystem II peptides with the molecular masses 42 and 47 kDa. The peptides of the photosystem I preparation were characterized by specific photosystem I antisera: An antiserum to the photosystem I complex reacts in the Western blot only with the homologous peptides of photosystem I. In comparative analyses with photosystem II preparations this antiserum (directed to photosystem I) reacts, as expected, only with the peptides of the light-harvesting complex. An antiserum to the CP 1 core peptides reacts only with the 66 kDa peptides of photosystem I and gives no cross reaction with heterodimer forms of the D 1 /D 2 core peptides of photosystem II. In the Western blot procedure by means of polyclonal monospecific antisera to carotenoids it was demonstrated that β-carotene is bound in high concentration onto the core peptides CP 1 and to a lesser extent onto the two larger subunits of the LHCP complex, exhibiting the molecular masses of 28 and 26 kDa. Neoxanthin is bound onto the same peptides. In contrast to this, lutein was only identified on the core peptides CP 1 and violaxanthin only on the larger subunits of the LHCP complex. As the carotenoids are labelled with antibodies, even after SDS treatment in the electrophoresis, it is assumed, that the carotenoids are covalently bound via the ionon ring to the respective peptide

A hypothesis is presented on the events in the degradation of the D 1 protein of photosys­tem II in the light. It proposes the existence of a nuclear encoded cleavage system that is turning over and which is modulated by its phosphorylation state. A new experimental approach is presented in which the D 1 protein degradation under photoinhibitory light is tested in Chlamydomonas reinhardtii grown under phosphate deficiency and pretreated with cyclo-heximide. Under these conditions the degradation of the D 1 protein is delayed whereas in Chlamydomonas reinhardtii grown in full medium the D 1 protein is rapidly disappearing in high light upon addition of chloramphenicol (CAP) or lincomycin for inhibiting the resynthesis of the D 1 protein . Cycloheximide (CHI) has little effect on photoinhibition in such control cells. In cells grown, however, for 20 h in phosphate deficiency - such that there is not yet loss of photosynthesis capacity -pretreatment with cycloheximide or canavanine in low light the degradation of the D 1 protein even in 6 h high light is prevented to an appreciable extent. Further addition of CAP or lincomycin has only a small effect. [ 14 C]leucine incorporation was used to show that there is no resynthesis and that the presence of the D 1 protein is due to a delay of degradation. The results are interpreted to show that excess high light which converts the D 1 protein into a potentially, degradable mode is not sufficient for degradation of the D 1 protein. A cleavage system is needed as well. It is postulated that under phosphate deficiency and pre-treatment with CHI or canavanine a nuclear coded cleavage system for the D 1 protein is depleted, i.e. the cleavage system for the rapidly turning over D 1 is also turning over. It is shown that under phosphate deficiency an alkaline phosphatase activity in the chloroplast and the thylakoid membrane of Chlamydomonas reinhardtii is increased. It is proposed that the ratio of kinase/phosphatase converts an active, stable phosphorylated cleavage system into a labile unphosphorylated and turning over state

Modulation of plasma membrane-bound NADH:hexacyanoferrate III oxidoreductase activities by dicumarol and warfarin was investigated with plasma membrane vesicles of Zea mays L. (cv. Sil Anjou 18) roots, prepared by aqueous two phase partitioning. Vesicles were about 65% right-side out orientated as demonstrated by enzyme latency of vanadate sensitive ATPase activity. Dicumarol or warfarin, respectively, inhibited NADH:hexacyanoferrate III oxidoreductase activity in a concentration-dependent manner and inhibition could be reversed partially by addition of quinones

The interaction of calmodulin with purified guinea pig liver transglutaminase was studied. The nucleotide (ATP and GTP) hydrolysis activity of this tissue transglutaminase was tran­siently increased and then gradually decreased depending on calmodulin concentration. The peak activation was obtained in the presence of a stoichiometric amount of calmodulin. The effect of calmodulin on the classical transglutaminase activity was minimal. Fluorescence spectroscopy demonstrated that the enzyme produced a significant blue shift in the emission peak of dansylated calmodulin. Interestingly, Ca 2+ was not required for the interaction between the two proteins. The results described here give an additional regulatory role to calmodulin

Animal species that store bilins from external sources are very rare. A new example is described here. - Since the primitive marine metazoon Trichoplax adhaerens stains crimsonred when feeding on a phycoerythrin-containing alga. i.e. Pyrenomonas sp. (Cryptophyceae), the question arose whether an algal pigment can be identified as the staining matter. Thin layer chromatography and visible light absorption spectrography of aqueous Trichoplax extract disclosed several bilin components representing chromophores of phycoerythrin, a photosynthetic antenna protein that occurs only in certain algae and cyanobacteria. - Additional experiments showed that a cell-free Trichoplax extract kills and incompletely digests Pyrenomonas algae releasing phycoerythrin into the medium. These digestive faculties of Trichoplax tissue components, probably enzymes, contribute to the animal’s natural feeding mechanisms that proceed extra-as well as intracorporally. While the large apoprotein component of phycoerythrin is metabolized as a nutrient, the remaining chromophore bilins, strikingly coloured tetrapyrroles, are stored within Trichoplax’ distinct cellular inclusions, staining the animal crimson

A novel antimitotic compound named Nostodione A (Nd A) was isolated from a terrestrial blue-green alga Nostoc commune. Nostodione A disturbed the mitotic spindle formation of sea-urchin eggs and gave small spindles with low birefringence density. Nostodione A. how­ever, had no phytotoxicity on the germination of a dicotyledonous plant Medicago sativa. Based on the spectral analysis and chemical degradation, the structure of Nostodione A was elucidated

The determinants for recognition at H 3 histamine receptors are considered. Findings based on quantum-chemical calculations suggest that H 3 histamine receptor is less hydrophilic than the H 2 . The form most likely to be recognized by the H 3 receptor is an intramolecularly hydrogen-bonded form of α-methylhistamine. Receptor environment and hydration effects of active form of histamine analogs are of crucial importance

In Inachis io, a pupal melanization reducing factor (PMRF) which controls morphological color adaptation is located in the brain, suboesophageal ganglion, thoracic ganglia, and all abdominal ganglia. Higher PMRF amounts were extracted from abdominal ganglia than from the anterior ganglia. No PMRF activity could be found in the Corpora cardiaca-Corpora allata complex, in segmentally branching nerves of abdominal ganglia and their connectives. Extracts from brain-thoracic ganglia and abdominal ganglia complex of I. io contained also a factor with melanization and reddish coloration hormone (MRCH) activity in Pseudaletia separata and with pheromone biosynthesis activating neuropeptide (PBAN) activity in Bom-byx mori. However, injection of synthetic Pseudaletia pheromonotropin (Pss-PT) (= Pss-MRCH) into prepupae of I. io did not yield a melanization reducing effect. Therefore, PMRF and the PBAN/MRCH related neuropeptides seem to be different molecules. The PBAN-like factor from I. io is possibly related to the myotropins and pyrokinins of insects

In this study, the in vitro interaction of epirubicin (EPR), a cytostatic antibiotic, with plasma proteins (PP), namely α-HSA, γ-HSG, α+β-HSG and with isolated human red blood cells (RBCs) was investigated and further correlated with the in vivo pharmacokinetics and binding of EPR and two of its metabolites, 13-dihydroepirubicin and 7-deoxydoxorubicinone to RBCs. The in vitro encapsulation rate in isolated erythrocytes amounts to 52.9 ± 2.8% and remains constant within the range of studied concentrations (2.5-20 μg/ml). EPR was found to bind differently to the various PP in vitro. Binding to α-HSA amounted up to 51.0 ± 7.10%, to α + β-HSG 79.45 ± 2.7%, to γ-HSG 57.1 ± 2.8%. The in vivo-binding rate of EPR, dihydroepirubicin and deoxydoxorubicinone to RBCs after 5 min of injection was 32 ± 6.96%, 11.6 ± 3.1% and 10.05 ± 3.5% respectively, their availability in serum was 42.6 ± 11.8%, 2.4 ± 0.4% and 1.2 ± 0.67% respectively

Bone samples of a ptolemeic mummy have been employed to study the mode of conservation on the intactness of Zn 2 Mg alkaline phosphatase in both structure and catalytic activity. A protein of M r = 190 ± 10 kDa being identical to the 200 kDa enzyme of fresh human bones was successfully isolated. Regardless of age 200 kDa protein bands and a distinct sub­ unit at 60 kDa were seen in SDS-PAGE electrophoresis. The 200 kDa band was also monitored by activity staining. The specific activity was 120 mU/mg and 65% of the respective activity obtained in the identical preparation using fresh human tibia or rib. The enzymic activity was inhibited in the presence of 1,10-phenanthroline and ʟ-homoarginine. Radiocarbon dating supported the assignment of the mummy to the early ptolemeic period. Among the many bactericidal and fungicidal components employed for mummification were aromatic alcohols, mono-and sesquiterpenes. Pistachio resin was the major balm resin used. The microbiological sterility of the bone surface was ascertained by independent bacterial and fungal examinations

Biochemical modification of the acetylcholinesterase (AChE) and non-specific esterases of a planarian species [Dugesia tigrina (Girard)] were studied as a function of regeneration. The enzymatic activities were measured in regenerating planarians at regular time intervals from the beginning of the regeneration process to the complete restoration of the animal. Both enzymatic activities were substantially altered during the regeneration process of caudal and cephalic segments. Polyacrylamide gel zymograms for soluble α-naphthyl acetate hydrolytic activity revealed four bands of activities. These activities were fractioned into two major on cation exchange high performance h between 6 and 7 and were inhibited by PMSF, TPCK, TLCK and n-ethyl maleimide.

According to the EAG study and the field trapping tests, fluoranalogs of the main phero­mone component of Mamestra brassicae females have been found to possess disguising properties for males when used together with the main pheromone component itself. In males, at low concentrations of the above substances the diminishing of attractivity of these blends correlates with the absence of EAG responses to them. An unequal action of these substances has been revealed in different concentration ranges of odours. The mechanisms of the action of these substances are under discussion

In pheromone extracts of calling female Chiasma clathrata L. (Lepidoptera: Geometridae), a defoliator pest of alfalfa, (Z,Z,Z)-3,6,9-heptadecatriene and (Z,Z)-6,9-cis-3,4-epoxyheptadecadiene was identified. Chiral gas chromatography using a modified cyclodextrin and synthetic reference samples proved the natural epoxide to show (3R, 4S)-configuration. In field trapping tests, only the pure (3R, 4S)-enantiom er of the epoxide attracted males. The addition of the triene component was synergistic. Males of the sympatric species Tephrina arenacearia Hbn. (Lepidoptera: Geometridae) were caught only in traps with baits containing the (3S, 4R)-enantiomer [together with a previously described minor component, (Z,Z)-3,9-cis- 6,7-epoxyheptadecadiene]. In trapping tests conducted in a different biotope, Abraxas grossulariata L. (Lepidoptera: Geometridae) males were attracted by the (3S, 4R)-enantiomer, whereas the (3R, 4S)-enantiomer attracted a close relative, Abraxas sylvata Scop. (Lepidoptera: Geometridae). The present results suggest that one of the key mechanisms responsible for pheromone specificity among both the two alfalfa geometrids and the two A braxas species in their respective biotops, may be the use of different enantiomers of the same polyenederived epoxide as a sex pheromone component. It is probable that this discrimination mechanism is widespread among moth species utilizing epoxide pheromone components

We analysed testicular samples of NMRI mice every 2 h of a day in order to determine whether there is a circadian rhythm in spermatogenetic activity. We used flow cytometry after staining the DNA with DAPI. The highest proportion of DNA synthesizing cells (mainly spermatogonia and preleptotene spermatocytes) was seen at 8 p.m. and especially at 10 p.m.; the lowest proportion was observed at 2 p.m. At 6 a.m., the percentage of round spermatids increased significantly, whereas the fraction of 4c-cells decreased at that time. Our results of a diurnal rhythm of spermatogenic DNA synthesis rate are in contrast to another publication of other authors (Oakberg and Crosswait, 1983)

Antifilarial activity of 5/6/7/8-mono-or disubstituted 1 H /1-phenyl-9H -pyrido[3,4-b]indoles (I) has been described. The 1,6-and 8 -substituted 9H-pyrido[3,4-b]indoles (I) elicited inter­esting filaricidal activity against Litomosoides carinii and Acanthocheilonema viteae in rodent hosts