Volume 45, Issue 11-12

Four kaempferol glycosides and five quercetin glycosides have been isolated from a methanolic extract of Paederia scandens var. mairei leaves and stems, in which in addition four un­known glycosides of kaempferol and quercetin are present in a trace. Nine flavonol glycosides including a new glycoside quercetin 3-O-rutinoside-7-O-xylosylglucoside (paederinin) were identified by PC, HPLC, UV spectral and NMR studies.

The alkaloid pattern of Spartium junceum has been investigated. Cytisine, N-methylcytisine, anagyrine, rhombifoline and epi-baptifoline occur as major compounds in most of the samples studied. Considerable quantitative differences were found between various parts of the plant. The alkaloid content changed strongly dependent on the seasons. Only a limited variation can be ascribed to geographical origin.

The surface waxes of several gymnosperm and angiosperm pollen were separated into different lipid classes. n-Alkanes were found to be common constituents of these waxes. They appeared as a homologous series ranging from C 20 to C 33 . The distribution patterns of n-alkanes from gymnosperm pollen displayed little variation whereas those of angiosperm pollen exhib­ited pronounced differences from one another. It is noteworthy that especially for the gymno­sperm species, homologues with even and odd numbers of carbons occurred in similar amounts.

A new test system for the detection of plant growth regulating activities was successfully employed. In a screening for inhibitors of the gibberellic acid controlled synthesis of hydrolytic enzymes in embryoless wheat seeds (Triticum aestivum) 160 cultures of ascomycetes and basi­diomycetes were tested. In the extracts of two cultures inhibitory activities were detected. From fermentations of a Hypholoma-species (basidiomycetes) 3,5-dichloro-4-methoxybenzyl alcohol was isolated as the active principle. Galiellalactone and two other new phytotoxins were isolated from cultures of the ascomycete Galiella rufa. At concentrations of 50 μg/ml all four compounds inhibited the de-novo synthesis of α-amylases, proteases, and phosphatases. Further investigations on the mode of action revealed, that all four metabolites interfere with early steps of the biosynthetic path­ ways induced by gibberellic acids. In vivo, the germination of the seeds of several plants was inhibited by these compounds.

After incubation with 5-aminolevulinic acid and cysteine or 5-amino-levulinic acid and glutathione, Cyanidium caldarium excreted two new bile pigments 1 and 2. Their structures are identified by spectroscopical methods. By chemical addition of cysteine, glutathione and hydrogen sulfide to the ethyliden double bond of E-phycocyanobilin, the bile pigments 3-6 were obtained.

The pigment composition of needles of Picea abies L. taken from sites in the Bavarian forest has been determined. Needles were removed from (a) healthy, control trees, (b) trees which showed visible signs of damage for either 6 months or 3.5 years, and (c) trees which had received supplemental fertilizer application. In general, needles taken from these trees could be placed into three categories; (i) green, (ii) partially chlorotic, and (iii) partially necrotic (brown). Whilst the pigment composition of needles taken from healthy trees was typical of any higher plant, substantial changes in the chlorophyll and carotenoid content of the damaged needles were recorded. Particularly noticeable was an increase in the ratio of total carotenoid/chlorophyll and losses of neoxanthin and violaxanthin. Levels of total carotene (α- and β-carotene) and, especially, of lutein remained high in damaged needles. Levels of zeaxanthin were highest in the brown, partially necrotic, needles.

Measurement of photosynthetic oxygen evolution in tobacco chloroplasts and thylakoids of the filamentous cyanobacterium Oscillatoria chalybea by means of the “Three-Electrode-System”, described by Schmid and Thibault in 1979, yields half-rise times for the directly measured amperometric O 2 -signal of approximately 2 msec for tobacco chloroplasts and slightly more than 2 msec for thylakoids of Oscillatoria chalybea. An estimate of the possible contribution of the diffusion time required for oxygen to leave the thylakoid membrane (7.5 nm thickness) or the chloroplast (diameter 4 -5 μm) might bring the measured O 2 -release time below 1 msec in full agreement with measurements by Joliot et al. in 1966.

3-Acyl-5-(1-aminoalkylidene)-4-hydroxy-2 H- pyran-2,6(3 H)-dione derivatives carrying lipophilic amino groups were found to be highly potent inhibitors of photosynthetic electron transport, and both the acyl and the aminoalkylidene groups on the pyran ring appeared to be indispensable for high activity. The structural features needed for activity in the 3-acyl-5- (l-am inoalkylidene)-4-hydroxy -2 H-pyran -2 ,6 (3 H)-dione derivatives were very similar to those for 3 -(l-aminoalkylidene)-2H-pyran-2,4(3H)-diones, except for the acyl group in the former compounds. Thermoluminescence measurements indicated that the 3-acyl-5- (1-aminoalkylidene)-4 -hydroxy -2H-pyran -2 ,6 (3 H )-dione derivatives bind to the D 1 protein in a manner similar to that of DCMU .

Modulated 685-nm chlorophyll fluorescence was measured under steady-state conditions in pea leaves adapted to moderate actinic light. When the measurements were performed after a short exposure to heat (42 °C) in darkness, the maximal (F m ) and steady-state (F s ) fluorescence levels were dramatically and irreversibly quenched whereas the basic fluorescence F o remained unchanged. Concomitantly , photo synthetic O 2 evolution was irreversibly inhibited. Analysis of the fluorescence data suggested that the heat treatment affected primarily the PS II reaction center, with the main effect being presumably an increased thermal dissipation of the excita­tion energy transferred to the reaction centers. In contrast, when heat stress was imposed in the presence of light, the loss of variable fluorescence (F m -F o ) was much less marked and was fully reversible. In addition , no inhibition of in vivo O 2 : evolution was observed when the samples heated in the light were recooled at 25 °C. The results indicate that light acted as an efficient protector of PS II against heat injury.

The resistance against herbicides (inhibitors of the electron accepting side) of photosystem II originates from mutations of the psb A gene, coding for the D 1 or Q B binding protein. Each of the five mutants used in the present study had single base changes in the psbA gene that resulted in a unique amino acid substitution at a different residue of the D1 protein (Val-219, Ala-251, Phe-255, Ser-264, Leu-275). The differences of the I 50 -values in the electron transfer reaction of H 2 O to dichlorophenolindophenol were used to analyze the correlation of these amino acid residue changes to their impact on the binding of diverse chemical classes of inhibitors. The binding domains on the D1 protein of the inhibitors overlap, but are nevertheless distinct. Even minor changes in the chemical structure of the inhibitors resulted in changes of the resistance toward a specific amino acid residue. A pattern of response of the inhibitors to the amino acid substitutions evolves that allows easy differentiation between the groups of PS II inhibitors. Two principally different response curves emerge for two different families of PS II inhibitors, that had been proposed earlier already on functional studies with wild types. But the response pattern of newly described inhibitors, like ketonitrile and quinolone derivatives, in the mutants allows to group them with confidence and in turn generalize the phenol type family. In none of the five mutants, studied here, is there a marked cross-resistance to the new phenol type inhibitors. Just the opposite, in several cases, there is negative cross-resistance (or supersensitivity). Because of this response pattern this group of inhibitors cannot be oriented with certainty in the three dimensional folding model of the D1 protein.

The contents of 1,4-benzoxazinone derivatives in wheat plants infected with Puccinia graminis Pers. f. sp. tritici Ericss. & Henn, race 32, and in uninfected controls were examined in four near-isogenic lines of different infection types: Triticum aestivum L., cultivar Prelude Sr5 (highly resistant), Sr24, Sr26 (moderately resistant), and srx (susceptible). In all infection types the contents of DIMBOA -glc and HMBOA -glc decrease with time in the uninfected controls as well as in the infected plants. However, following inoculation, the synthesis of HDIBOA -glc is drastically increased in the moderately resistant cultivars. The results suggest that this fully methylated 1,4-benzoxazinone may function as a phytoalexin in this type of interaction. The benzoxazolinone MBOA which has been described as an in vitro conversion product of the benzoxazinones mentioned above is not detected in inoculated or uninoculated leaves.

Incubation of chick embryo myoblasts with 1,25-dihydroxyvitam in D 3 [1,25(OH) 2 D 3 ] (10 -10 M , 24 h). markedly stimulated the incorporation of [ 3 H]leucine into total cytoskeletal proteins and this effect was abolished when the sterol treatment was performed in the presence of cycloheximide or actinomycin D. 1,2 5 (OH) 2 D 3 selectively stimulated the de novo synthesis of several proteins with apparent molecular masses (isoelectric points) of 220 kDa (6.1 and 9.7), 150 kDa (7.5), 110 kDa (7.2), 68 kDa (9.5, 7.5 and 4.5), 50 kDa (8.5), 44 kDa (6.3), 27 kDa (7.8) and 15 kDa (5.5). Labelling of proteins with [ 125 I]calmodulin after their separation on SDS-polyacrylamide gels showed that 1,25(O H) 2 D 3 -dependent protein of 110 kDa is the major calmodulin-binding component of myoblasts cytoskeleton. In addition , the sterol increased the phosphorylation of several cytoskeletal proteins including that of 110 and 15 kDa whose synthesis potentiates.

Substrate recognition mechanism of soybean lipoxygenase-1 (L -1) was studied by using an entire series of (ω3Z,ω6Z,ω9Z)-C 12~ C 22 -trienoic acids and -trienols. The maximum activity of L-1 was obtained with C 20 -trienoic acid of all the substrates used. Among trienols, the maximum activity was obtained with C 15 -trienol. Analysis of the products obtained by the reaction of these substrates with L-1 revealed that trienoic acids were oxygenated mostly at ω6 position independently on the chain length. The hydroperoxy group at ω6 was introduced at (S)-configuration with over 98% enantioselectivity. Although the products formed from most trienols were also selectively oxygenated at ω6 position, only C 15 -trienol was oxygenated at both ω6 and ω10 positions in the ratio of ω6/ω10 = 48/52.

Monomeric G actin, total actin and the F :G actin ratio were determined in the rat liver cytosol and nucleoplasm by measuring the inhibition of standard crystalline DNase I. Actin was purified from rat liver nucleoplasm by Sephadex filtration. Accompanying the considera­ble amount of actin an endogenous DNase I like activity was found in rat liver cytosol and nucleoplasm. It was shown, that similarly to DNase I from bovine pancreas the liver DNase was inhibited by mammalian and avian skeletal muscle actin as well as by endogenous liver actin, as verified by electrophoresis of DNase containing extracts on polyacrylamide gels with incorporated DNA .

A direct structural identification, and quantitative assessment below the 50 nmol/ml level, of the full pattern of renally excreted metabolites is made possible by 13 C NMR measurements of untreated urine samples when stable isotope-labelled ( 13 C) drug analogues are administered to humans. The full potential of the new ex vivo NMR approach is exemplified by a study, for a group of volunteers, of S-carboxymethyl-ʟ-cysteine metabolism. The metabolic sulphoxidation pathway of S-Carboxymethyl-ʟ-cysteine in man, accepted so far, needs to be profoundly revised on the basis of the 13 C NMR results.

The principle neuropeptide separated by reversed-phase liquid chromatography RP -HPLC from extracts of the corpora cardica of Acheta domesticus showed strong adipokinetic activity when injected into Acheta. The N -terminal pyroglutamate of the peptide was removed by enzymatic digestion, and the remaining peptide sequenced. The structure is identical to the peptide Grb -AKH previously described from the corpus cardiacum (CC) of Gryllus bimaculatus ( pGlu - Val - Asn - Phe - Ser - Thr - Gly - Trp - NH 2 ). The ED 50 was (0.8 pmol) and saturation was achieved with injection of 2 pmol of synthetic Grb-AKH . The time to maximum hyperlipaemic response was 90 -120 min. The response of the fat body to injected synthetic Grb- AKH doubled in 4 days during the last stadium , but was never greater than half the maximum response of the adult stage. The adult adipokinetic response doubled from the first to the fourth day then gradually declined through day 16. The increased AKH response was timecorrelated to fat storage in the larvae and to lipid diposits in the oocytes in the adult. Synthetic Grb -AKH activated glycogen phosphorylase in the fat body of Acheta. The amount of Grb- AKH present in the CC changed very little throughout the last larval stadium and through the first 9 days of the adult stage, averaging about 15 pmol/gland pair. A second peptide (a hexadecapeptide) was isolated from the CC of Acheta and sequenced. Its structure is identical to a putative diuretic hormone previously described in Acheta.

Larvae of the arctiid moth Tyria jacobaeae reared on Senecio jacobaea or S. vulgaris take up and store pyrrolizidine alkaloids (PAs) from their host plants. Individual PAs are taken up without preference. The PA patterns found in the insect bodies correspond to the PA composi­tion of their host plants. Like plants the insects store PAs as N-oxides, and larvae as well as pupae are specifically able to N -oxidize any tertiary PA. Callimorphine (O 9 -(2-methyl-2-acetoxybutanoyl)-retronecine), an insect PA well known from several arctiids, was found in pupae and imagines of Tyria which as larvae had been fed on S. jacobaea. It is accompanied by small amounts of its isomer O 7 -(2-methyl-2-acetoxybutanoyl)-retronecine named isocallimor-phine. The callimorphines may well account for 45% of total PAs found in the insect. Only small amounts of callimorphine were detected in pupae of Tyria which as larvae had been fed on S. vulgaris. [ 14 C]Callimorphine N -oxide was isolated and identified from Tyria pupae which as larvae received [ 14 C]retronecine. It is suggested that Tyria is able to esterify retronecine, derived from hydrolysis of ingested plant PAs with a necic acid produced by the insect. During metamorphosis the formation of callimorphine is restricted to the early stage of pupa­tion.

A peptide corresponding to the α-domain of rat liver metallothionein-2 was chemically syn­thesized employing the solid phase peptide synthesis technique. Its luminescence properties that depend on the coordinated Cu(I) have been studied using luminescence spectrometric titration in the presence of Cu(I). Unlike the intact metallothionein which has been converted into the Cu species, the emission and excitation spectra of the Cu-α-fragment showed a red shift by 20 nm and 65 nm, respectively, suggesting a more compact and stable luminophore in the a-domain. Saturation of Cu(I) coordination was reached in the presence of 6.5 mol eq Cu(I) when the α-fragment was used and 12 mol eq Cu(I) were specifically bound by the intact metallothionein. The emission bands were homogeneous and no decline of the cluster struc­ture was observed when excessive Cu(I) was added after saturation. A rearrangement of the Cu-cluster in metallothionein during its formation seems to be plausible.

The rate of interaction between H 2 O 2 and the DNA -Cu (I) complex increases with pH and with salt (NaCl) concentration, suggesting that HO 2 - is involved. The pH dependence can be fitted, assuming k(DNA - Cu(I) + H 2 O 2 ) = 1 м -1 s-1 and k (DNA -Cu(I) + HO 2 - ) = 10 5 м -1 s -1 (at low salt concentrations). These interactions cause DNA damage, probably due to the for­mation of · OH radicals near the site of Cu(I) fixation at DNA bases. About 70% of the inter­mediates DNA · OH , formed by free · OH radicals, were found capable of reducing Cu(II) to regenerate DNA -Cu (I); thus a (limited) reaction chain involving “reductive propagation” by DNA · OH species appears feasible upon reaction of H 2 O 2 with DNA -Cu (I). · OH-induced in­termediates of poly(C) are more efficient (about 80%), those of poly(A) and poly(G) are less efficient (about 38%), in reducing Cu(II). Certain organic buffers, particulary HEPES and PIPES, promote autoxidation in DNA /Cu (II)/H 2 O 2 systems, and it is shown that · OH-induced buffer intermediates as well as secondary stable buffer products can engage in “reductive propagation” of redox cycles.

Differential pulse polarography study was used to investigate the influence of glutathion on cis-and trans-DDP induced alterations of DNA structure. Though the applied concentration of glutathion has no effect on the reaction of DNA with cis -DDP , it greatly modifies the reac­tion with trans isomer. This may be an important reason for the ineffectivness of the trans-DDP as an antitumor drug.

The design and synthesis of a series of alkyl 5(6)-substituted benzimidazole-2-carbamates (1-13), 7-chloro-4-(4-substituted phenyl)aminoquinolines (14-16), l,2-dim ethyl-3-m ethoxycarbonyl- 4,5-disubstituted pyrroles (17-19) and some compounds belonging to the class pimelonitrile (20), dihydroquinoline (21), pyridine (22), pyridoquinoline (23) and tetrahydropyrimidine (24) have been carried out as possible antifilarial agents. All these compounds have been evaluated for their activity against male and female adult worms of Litomosoides carinii in cotton rats. The effect of these compounds was also observed on the reproductive system (condition of developing microfilariae and their release from uterus) of adult female worms. In this study, three types of compounds were discovered: (a) those which showed activity on both the male and female adult worms and also had sterilizing effects on surviving adult females (1 -3 , 6 - 9 , 13, 19), (b) those which only sterilized the adult females (14-16 , 21, 24), and (c) those which had no effect on female reproduction but killed only adult worms (4, 5, 11, 12, 17,18, 20, 22, 23). This tends to open up a new avenue in the chemotherapy of filariasis and the future scope of work on chemosterilization of adult females has been discussed.

Two naturally occurring lignanolides, isolated from the tropical climbing shrub Ipomoea cairica, (-)-arctigen in and (-)-trachelogen in , were found to inhibit strongly replication of human immunodeficiency virus type 1 (HIV-1; strain HTLV-III B) in vitro. At a concentration of 0.5 (μм , (-)-arctigenin and (-)-trachelogenin inhibited the expression of HIV-1 proteins p 17 and p24 by 80 -90 % and 60 -70 % , respectively. The reverse transcriptase activity in the cul­ture fluids was reduced by 80 -90 % when the cells (HTLV-III B/H 9) were cultivated in the presence of 0.5 μм (-)-arctigen in or 1 μм (-)-trachelogenin . At the same concentrations, the formation of syncytia in the HTLV-III B/H 9-Jurkat cell system was inhibited by the compounds by more than 80%. A series of other lignan type compounds displayed no anti-HIV activity. Studying the molecular mechanism of action of (-)-arctigenin and (-)-trachelogenin we found that both compounds are efficient inhibitors of the nuclear matrix-associated DNA topoisomerase II activity, particularly of the enzyme from HIV -1-infected cells. Our results suggest that both compounds prevent the increase of topoisomerase II activity, involved in virus replication, after infection of cells with HIV -1.

Intracellular recordings and impedance measurements from directionally-selective visual interneurons of the lobula plate of flies show that during motion, transmembrane conductance increases during both depolarizing responses to preferred directions and hyperpolarizing re­sponses to anti-preferred directions. This provides direct evidence that these interneurons are postsynaptic to two separate populations of excitatory and inhibitory input elements.

The present study was undertaken to verify ancient data in the literature on ovipositional preference of the cuttlefish Sepia officinalis for the terrestrial plant Pistacia lentiscus (mastic tree). -Adult specimens of Sepia were placed in basins together with aerial parts not only of P. lentiscus, but also of Artemisia arborescens, Centaurea alba var. deusta, Quercus ilex and Laurus nobilis. The egg masses deposited on the plants were quantified on a daily basis during the 16 day observation period. By far the largest amounts of eggs were found attached to the stems and petioles of P. lentiscus (51.8%), but Q. ilex and A. arborescens also scored high as ovipositional host plants (23.1 and 20.2% respectively). L. nobilis and C. alba var. deusta ranked very low (3.6 and 1.3% respectively). Considering the extremely divergent shape of the three preferred oviposition substrates, which excludes affinity for a uniform type of plant, the possibility of chemical attraction cannot be ruled out.

The two-dimensional reaction diffusion equations for the spread of rabies in a logistically growing fox population are solved numerically. The method, based upon Galerkin’s approach, uses space-time finite elements. The numerical model is shown, quantitatively, to possess the essential features of earlier one and two-dimensional models and to reproduce the values of field data accurately. A more realistic illustration of the use of the model, a study of the spread of rabies over the Isle of Anglesey, is then discussed.

It is shown that chemotaxis, galvanotaxis, galvanotropism , etc. are functions of cells having a goal-seeking system. Even when the involved physicochemical signals are unknown, the cel­lular system can be treated phenomenologically like an automatic controller having a closed-loop feedback system. The model is verified by means of galvanotaxis and chemotaxis data of human granulocytes. The galvanotaxis and chemotaxis coefficient quantifying the cellular sensi­bility can be predicted from the coefficient which characterizes the deterministic part of the signal transduction/response system of the cell divided by the coefficient which characterizes the noise strength in the cellular signal transduction/response system. The model is not restricted to directed movement of granulocytes. It is very general and can be applied to any cell type for directed phenomena like chemotaxis, galvanotaxis, phototaxis, magnetotaxis, directed growth, etc. The virus-disturbed directed migration of granulocytes is discussed and it is shown that the virus alters the deterministic part of the cellular controller.

The Ge contents of plants and animals were investigated by a wet ashing procedure by hydride generation and inductively coupled plasma atomic emission spectrometry with flow injection. The analytical results obtained indicated that Ge contents widely vary in plant and animal kingdoms in the range of 8 -203 ppb.