Volume 51, Issue 9-10

The last decade has seen a surge in the knowledge on primary structures of insect neuropeptides. Particularly successful were isolations and sequence determinations of more than 30 members of the adipokinetic hormone/red pigment-concentrating hormone (AKH/RPCH) family of peptides. This brief overview describes the techniques used to obtain data on purification and structure such as high performance liquid chromatography, Edman sequencing and mass spectrometry. Moreover, a short account on the precursors and on the multiple functions of the peptides of the AKH/RPCH family in various crustacean and insect species is given

The present paper reports the results of the methanol extract of Haplophyllum hispanicum Spach on single or repeated local 12-O-tetradecanoylphorbol acetate (TPA) administration and in the oxazolone-induced contact-delayed hypersensitivity mouse ear edemas. Two topical anti-inflammatory aryl naphthalide lignans were isolated from the active fractions of the methanol extract. They were identified by spectroscopic methods, including 13 C NMR and heteronuclear multiple bond correlation (HMBC), as diphyllin acetyl apioside and tuberculatin. The former was the most active on acute TPA edema with a ID 50 of 0.27 μmol/ear

The Asteracea Galactites tomentosa. known as a plant causing allergic contact reactions, was investigated for new constituents in leaves and stems. Chlorogenic acid and 3,5-dicaffeoylquinic acid could be detected by HPLC in tissues and trichome preparations as well

In addition to the known hydroxamate siderophores ornibactin C6 and C8 a catecholate siderophore named cepaciachelin, 1-N-[2-N′,6-N′-di(2,3-dihydroxybenzoyl)-ʟ-lysyl]-1,4-diaminobutane, was isolated from a Burkholderia (Pseudomonas) cepacia PHP7 culture and its structure elucidated by chemical degradation and spectroscopic methods. This is the first case of a member of the Pseudomonas group which produces both hydroxamate and catecholate siderophores

The coumarin and iridoid composition of Crucianella graeca, Cruciata glabra, Cruciata laevipes and Cruciata pedemontana has been studied. Daphnin and daphnetin glucoside dominated in C. glabra along with low concentrations of daphnetin, deacetylasperulosidic acid and scandoside. In C. laevipes and C. pedemontana were found the same coumarin glucosides along with six iridoid glucosides. In Crucianella graeca were found ten iridoid glucosides

From aerial parts of the fern Pteris multifida Poir. (Polypodiaceae) two diterpenes, entkaurane- 2β,16α-diol and ent-kaur-16-ene-2β,15α-diol, were isolated by repeated column chromatography using silica gel and silica gel impregnated with silver nitrate. The structures were confirmed by spectroscopic methods. Both compounds showed a moderate cytotoxicity to Ehrlich ascites tumour cells

Fast protein liquid chromatography on Superose 6 of partially purified FBPase II from Chlorella reveals a 1350 kDa-form at pH 6.0 and a 67 kDa-form at pH 8.5. Treatment of the large enzyme form with 5mᴍ concentrations of Mg 2+ , F1,6P 2 , DTT or ATP leads to dissociation into smaller ones of 215 -470 kDa. Aggregation/dissoziation is a reversible process, as has been shown for the effect of F1,6P 2 and of pH, by rechromatography. The change in mole mass results in alterations of the activitiy and of the kinetic properties of the enzyme forms, obtained. Dissociation results in a 4 - 6 fold increase in activity, as can be shown for F1,6P 2 -treated samples. Halfsaturation constants, as well as the degree of cooperativity of the 67- and the 1350- kDa form, are different for substrate affinity, activation by Mg 2+ and DTT, and for inhibition by ATP. Both enzyme forms hydrolyse fructose 1,6 bisphosphate and seduheptulose 1,7 bisphosphate better than other phosphorylated compounds. The ratio of F1,6P 2 - to SDP-cleavage is 100:58 for the small enzyme form and 100: 84 for the large one. Activation of FBPase II in the light and inactivation in the dark is discussed on the basis of different oligomeric forms of the enzyme, generated by changes in the concentration of intermediates and effectors in the chloroplast stroma, leading to dissociation or aggregation. The conclusion is drawn that oligomerization of key enzymes, resulting in enzyme forms with different activities and different kinetic properties, might provide an effective mechanism for enzyme regulation in vivo

Algae are known to produce extracellular organic substances under optimum conditions and increase their production under stress. The changes in amount and composition of extracellular carbohydrates and proteins of three green algae Scenedesmus quadricauda, Chlorella kessleri and Raphidocelis subcapitata (known as Selenastrum capricornutum) were studied after a 5-days’ cultivation under the influence of different types of stress factors (osmotic, organic, and heavy metal stressors). NaCl enhanced the quantity of carbohydrates more than proteins. A higher increase of proteins than carbohydrates was observed after addition of 3,5-dichlorophenol, glyphosate and cadmium chloride to algal cultures. The production of dissolved organic matter differs from species to species, with the age of a culture and the type of stressor

Oxidative processes, especially lipid peroxidation (LPO), are assumed to increase during ageing. In an attempt to provide experimental evidence for this assumption lemon balm plants (Melissa officinalis L.) of different age and location were analyzed for oxidatively caused changes in the etheric oil composition. The investigation revealed that the caryophyllene oxide (CarO) content of lemon balm plants - a main constituent - depends on two factors: age and habitat. The content of CarO increased with age continuously up to a factor of 3. Poor nutritive conditions, as growth on unfertilized soil, also caused an increase in CarO content. Addition of Fe 2+ /ascorbate - enhancing oxidative processes - promoted the formation of CarO. Hydroperoxides of unsaturated fatty acids (LOOHs) in the lipid extract of lemon balm leaves were converted to corresponding hydroxy acids (LOHs) by sodium borohydride reduction. These were hydrogenated and subjected to GC/MS analysis after derivatisation. A surplus of 9-hydroxy-octadecanoic acid over the 13 isomer indicated at least in part enzymatic lipid peroxidation. Polarographie determination of the oxygen consumption revealed a generally low but in ageing plants increased lipoxygenase activity. This indicates a contribution of lipid peroxidation in the epoxidation process of caryophyllene

Heterotrophically or photomixotrophically initiated callus cultures of Citrus paradisi, C. limon and C.aurantifolia were grown on different nutrient media and under different light regimes. Calli of C.paradisi that contained > 140 mg chlorophyll per kg wet weight accumulated about 40 volatile mono- and sesquiterpene hydrocarbons, oxigenated terpenes and aliphatic aldehydes. Upon five subcultivations the best yielding callus contained about 5% (186 mg × kg -1 wet wt) of the volatiles found in peel tissue (exo/mesocarp section), and about the twentyfold amount of that found in the fleshy endocarp. The composition of the essential oils from most of the cell cultures equalled grapefruit peel oil, but was shifted to a more fruit flesh-like composition, after the concentration of gellan gum in the medium was increased from 3 to 9 g per L. C.limon produced 11 monoterpenes and n-nonanal (40 mg × kg -1 wet wt max.), and C.aurantifolia yielded limonene only (4.4 mg × kg -1 wet wt max.). For all of the indicated species chlorophyll content and accumulation of volatiles were positively correlated. Addition of exogenous valencene to suspended cells of C.paradisi led to a stable concentration of the conversion product nootkatone. This stably maintained level suggested that a decreased catabolism of available carbon sources might have accounted for the significant accumulation of essential oil constituents

UV-C (254 nm)- and UV-B (280-320 nm)-light were irradiated onto bright-yellow capitula of dyer’s saffron and their effects on carthamine accumulation compared. UV-C light promotes reddening of florets more prominently than UV-B light, yielding higher amounts of carthamine after the radiation process. The enhancement of carthamine synthesis by UV-C light was investigated on cellulose columns loaded with floret extracts under O 2 -sufficient or O 2 -deficient conditions. Externally charged O 2 inhibits the UV-C- stimulated carthamine formation. The results are discussed in relation to light stimulation of carthamine synthesis in dyer’s saffron florets

Treatment of Gnaphalium vira-vira plants with UV-B radiation caused changes in plant growth and in plant chemistry. The leaf surface contained two O-methylated flavones, araneol and 7-O-methylaraneol. HPLC analysis showed that 20 days of UV-B radiation increased the synthesis of 7-O-methylaraneol at the expense of araneol. Spectrophotometric analysis of the photosynthetic pigments showed that UV-B radiation also increases the pigment content in treated plants. Another U V alteration is epidermal hair damage, as observed in SEM pictures of treated leaves. This combination of physiological and phytochemical effects may be interpreted as a plant response to UV-B stress

Experiments with porous ceramic membranes and leaves of Nymphaea alba L. are described which demonstrate that the counter diffusion of gaseous components of different molar mass governed by Graham’s law of diffusion (not to be confused with Graham’s law of effusion) has to be taken into account to understand the exchange processes of gases between leaves of aquatic and amphibic plants and the outer atmosphere. The experiments are carried out under conditions under which the ratio of the maximum pore size r of the ceramic material to the mean free path length λ. of the molecules in air has a value of the order of λ/r ≈ 1

An antiserum to α-tocoquinone was prepared by immunization of rabbits. Immunization was obtained by injection of a conjugate consisting of the hapten α-tocoquinone attached to methylated ovalbumin into the rabbit. The antiserum recognizes the 3,4-dimethyl-p-benzoquinone group of the molecule as well as part of the immediate vicinity to the side chain. This is concluded from the fact that the antibody has some affinity also to plastoquinone. No reaction of the antibody is observed with α-tocopherol hydroquinone or α-tocopherol. Reaction of the antiserum to α-tocoquinone with photosystem Il-particle preparations from tobacco affects the functionality of the preparation. Chlorophylla-fluorescence emission is quenched without an alteration of the emission spectrum. Concomitant with this fluorescence quenching, the lifetime of two fluorescence components namely that of a fast and a slower component are shortened. By analogy with the literature the fast component is associated with chlorophylla of the reaction center core and that of the slow component with the antenna system in which the lifetime parameter is shortened by the antibody from 3.42 ns to 1.795 ns. The action on the fast component is less and leads to a shortening of the lifetime parameter from 0.373 ns to only 0.249 ns. The effect is interpreted in terms of an enhancement of linear photosynthetic electron transport possibly due to an inhibition of the cyclic electron transport around PS II, discovered by Gruszecki et al. (1995), Z. Naturforsch. 50c, 61 -68

Microsomes isolated from excised shoots of 3-day-old. dark grown, grain sorghum [Sorghum bicolor (L.) Moench, Funk G522DR and DK 41Y] and corn seedlings [Zea mays (L.), Pioneer 3245] metabolized the sulfonylurea herbicide prosulfuron (CGA-152005). Corn microsomes predominantly formed a single major metabolite that resulted from hydroxylation of the phenyl ring at the C5 position. However, sorghum microsomes formed two major metabolites in an approximate 1:1 ratio. One was the 5-hydroxyphenyl metabolite, whereas the second metabolite resulted from ö-demethylation at C4 of the triazine ring. Metabolite identity was established by mass spectrometry and co-chromatography with authentic standards. Metabolism in both corn and sorghum was greatly enhanced by pretreatment of the seed with naphthalic anhydride and by subirrigation with 2.5% ethanol 24 h prior to harvest. Metabolism required a reduced pyridine nucleotide and was affected by several cytochrome P450 monooxygenase inhibitors (carbon monoxide, tetcyclacis, piperonyl butoxide, 1 aminobenzotriazole, and SKF-525A). The inhibitors differentially affected metabolism of prosulfuron. Microsomal oxidations from both untreated and inducer-treated tissue responded similarly to the inhibitors. In exploratory studies, microsomes isolated from shoots of wheat [Triticum aestivum L., Pioneer 2548], barley [Hordeum vulgare L., Boone], oats [Avena sativa L., Southern States 76-30-P242] and rice [Oryza sativa L„ Gulfmont], and room ripened avocado [Persea americana, Mill., Hass] mesocarp tissue also primarily formed the 5-hydroxyphenyl metabolite. Titration of seven different avocado microsomal preparations with prosulfuron provided typical type I difference spectra from which an average binding constant (K s ) of 187 ± 35 μm was obtained

Mutations conferring herbicide resistance have been detected in two new strains (ZR250 and ZR480) of Euglena gracilis Z by partial gene cloning and sequencing. These mutants were originally derived from Z cells grown in medium containing progressively increasing concentrations of DCMU. Each of these strains have been characterized by measuring their growth kinetics, O 2 evolution, and resistance to DCMU and atrazine. Partial sequences of the psbA gene of these strains were compared to those published for strains Z and ZR25. The ZR250 and ZR480 strains were found to be double mutants. Besides the expected mutation S265A , they showed an additional point mutation at codon 219 (equivalent to codon 218 of other organisms). This mutation results in leucine being substituted by phenylalanine. For each of the ZR strains, two growth conditions (with or without DCMU in the medium ) have been compared. The presence of the second mutation (at codon 219) leads to notable increase (20-fold) in resistance to DCMU, whereas the resistance to atrazine is only 2-fold. The presence of DCMU, as the selective agent, was responsible for an enhanced herbicide resistance, irrespective of the concentrations used. Substantial modifications in the rate of cell growth and O 2 yields were observed when the maximal concentration (480 μm) of DCMU was used. These modifications were reversible on withdrawal of the DCMU. Thus the reversible adaptative modifications also adds to the mutational effect observed

Synthetic pyrethroid insecticides with different molecular structures have been investigated with respect to their effect on photosynthetic electron transport reactions in chloroplast suspensions and cell cultures from higher plants. The fluorescence induction curves of tobacco (Nicotiana tabacum) leaves and tomato cells were substantially affected by permethrin and cypermethrin resulting in a strong increase of the maximum fluorescence. Application of different concentrations (0.3-1.2 mᴍ ) of the respective chemical abolishes virtually any kinetics of the normal Kautsky effect. Oxygen evolution from cell cultures from tomato (Lycopersicon peruvianum) was completely inhibited by cypermethrin. Analysis of partial reactions of the photosynthetic electron transport showed that both a methylviologen-mediated Mehler reaction and a ferricyanide-driven Hill reaction were quantitatively inhibited by e.g. fenvalerate. On the other hand, neither a silicomolybdate-driven Hill reaction nor a methylviologen- driven Mehler reaction using dichlorophenol indophenol/ascorbate as electron donors could be inhibited by the pyrethroid. The analyses suggest that pyrethroid insecticides interfere with the photosynthetic electron transport at the same site as urea-type herbicides do. Depending on the molecular structure and on the halogen compound in the molecule, however, different pyrethroids are more or less phytotoxic to the investigated photosynthetic membranes - cypermethrin with two Cl-substituents requires much higher concentrations to be applied for significant inhibition of the electron transport reactions than the Br-derivative deltamethrin does. Moreover, qualitative differences have to be taken into account. In the case of fenvalerate the effect seems to exist in a type of all-or-nothing reaction when the reaction centres are inhibited by the pyrethroid. None of the S-states nor the transition probabilities are specifically influenced by increasing concentrations of fenvalerate. In the case of deltamethrin, however, it was found that the overreduced state S -1 is significantly increased at the expense of both S 1 and S 0 . Moreover, the miss parameter a is increased in the case of deltamethrin addition. The results and the significance of different substituents for the investigated pyrethroids are discussed

The apterous generation of the viviparous aphid Chaitophorus salijaponicus was propagated aseptically on in vitro cultures of host shoots for more than 34 passages and 17 months. On the best suited host (Salix alba) a single nymph yielded a colony of 126.3 ± 24.4 individuals within 4 weeks. Other tissues than normal host shoots (callus, root cultures, fasciated shoots) did not support aphid propagation. Aphid colony development accelerated the senescence of host shoots and severely inhibited the development of adventitious root systems. The aspects of insect surface sterility, aphid colony development and its influence on the host are discussed

The known flavonoid kaempferid 4 and a new benzofurane lignan 1 were isolated from Brazilian propolis. The new lignan is a suitable taxonomic marker and gives new possibilities for identification of propolis plant sources in the tropical regions

A convenient method for preparing a stable chitinase solution from a pest insect. Spodopteralitura, and a bioassay method for insect chitinase inhibitors using this enzyme solution were developed. Allosamidin, the first insect chitinase inhibitor, exhibited an IC 50 of 0.2 μᴍ in the present Spodoptera litura chitinase assay, whereas allosamidin was reported to exhibit an IC 50 of 0.7 μᴍ in the Bombyx mori chitinase assay. Thus, the present assay using Spodopteralitura chitinase was 3.5-fold more sensitive than the B. mori chitinase assay. Screening of 300 supernatants of microbial cultures for chitinase inhibitors using the Spodoptera litura chitinase assay found 13 active supernatants

Uropygial gland secretions from five out of a total of seven species forming the genus Ciconia (family Ciconiidae; order Ciconiiformes) were found to consist of mixtures of monoester waxes, diester waxes, triester waxes, and triglycerides. Monoester waxes were composed of unbranched fatty acids and alcohols, whereas diester waxes derived from both 2- and 3-hydroxy fatty acids esterified with unbranched alcohols and fatty acids. Interestingly, triester waxes were also found deriving from either 2-hydroxy alkylmalonic acids or from erythro-2,3-dihydroxy fatty acids the latter of which have not yet been found in vertebrates so far. To compare the typical mass spectrometric fragmentation of this class of compounds erythro-2,3-dihydroxyhexadecanoic acid has been synthesized

From the farinose frond exudate of the fern Notholaena rigida two new triterpenes have been identified. They were found to be the C-24 epimers of 3β-acetoxy- 24, 25-diO-isopropylidene-12β, 20(S),24,25-tetrahydroxy- dammarane. A third triterpene is identical with the known compound pyxinol, (20S,24R)-20.24-epoxydammarane- 3β,12β,25-triol

Phenolic antioxidants such as butylated hydroxytoluene, a-tocopherol, eugenol, isoeugenol, sesamol and quercetin effectively prevented thermal decomposition of methyl 13-hydroperoxyoctadecadienoate in methanolic solutions. Ascorbic acid, however, was found to promote the decomposition and the acidic nature of the vitamin was suggested to be involved in the mechanism

Two recent reports from another laboratory on hinokiflavone and robustaflavone in S. selaginoides, and hinokiflavone, isocryptom erin, cryptomerin B and amentoflavone 7-methylether in S. denticulata are shown to be based on 1 H -NMR data that are inconsistent with the biflavone structures proposed. In the current paper a comparison of the 1 H -nmr spectra is made both with published data and with new data derived from authentic samples. It is concluded that in both reports, only for am entoflavone the NMR data provide convincing supportive evidence. These reports are considered therefore to merely confirm an earlier identification of am entoflavone in these species

A pupal melanization reducing factor (PMRF) controls incorporation of pigments into the cuticle of pupae of the nymphalid butterfly, Inachis io, to adapt their coloration to the background colors of their pupation sites. In the present paper, we report on the presence of PMRF in the central nervous system (CNS) of further butterfly species which exhibit a pupal morphological color adaptation. Interestingly, two butterfly species which do not show such an adaptation, and even two moth species which pupate in cocoons also contained PMRF in their CNS. The ganglionic extracts of non-lepidopteran species did not show a PMRF activity. The occurrence of PMRF (or PMRF-like molecules), therefore, may be restricted to the lepidopteran order