Volume 54, Issue 1-2

From Pseudomonas aureofaciens a new pyoverdin was isolated and its structure was determined by various spectroscopic methods and by partial degradation

A biflavone was isolated from a liverwort (Chandonanthus hirtellus ssp. giganteus) for the first time. Its structure was determined as dicranolomin. Moreover luteolin and the new compound vanillic acid-4-O-neohesperidoside were identified from this Chandonanthus species. From Plagiochila asplenioides we isolated the new sesquiterpenoid (-)-gymnomitr-8(12)-en-9β-ol with chair conformation of the cyclohexane ring together with plagiochiline P and the diterpenoid anadensin, both new to this liverwort

Hairy roots of Hyssopus officinalis L. were induced by infection of petioles with Agrobacte­rium rhizogenes LBA 9402 and studied for production of phenolic acids, especially rosmarinic acid (RA). The highest content of rosmarinic acid (about 6 % of dry weight) was obtained in hairy roots grown in Gamborg’s B5 liquid medium containing 10% (w/v) sucrose. The level was at least 60% higher than those found in callus, cell suspension culture and roots of one-year-old field grow n plants. Apart from RA , nine other phenolic acids were detected in transformed roots and quantified by gas chromatography

The compositions of epicuticular waxes from conifers constituting the predom inant species of western North America were determined by GC and GC-MS. The primary components identified include alkanes, fatty acids, fatty alcohols, aldehydes, ketones, phytosterols, triterpenoids and wax esters. Average chain lengths (ACL) for alkanes in Oregon conifers decreased with increasing distance away from the Coastal range which suggests an adaptation by conifers to humid climate conditions. Differences in the chemical compositions make this information useful for chemotaxonomic purposes, for identifying natural organic aerosol input sources to the atmosphere, for comparison with the tracers in smoke emissions from burning of these biomass fuels, and for monitoring in assessment of global climate change

The ACT STATIS method, a multi-table comparison, was applied to 62 Rosa species to be clustered into four sections (Carolinae, Cinnamomeae, Pimpinellifoliae and Synstylae); the data sets were dealing with morphology (15 criteria), anthocyanin pattern (10 compounds), flavonol heteroside pattern (26 compounds) and superoxide dismutase isozyme (SOD) polymorphism (11 bands). This method appeared very powerful to recognize the rose sections and to set up a marker hierarchy which places at the first level the flavonol hetero­ side pattern, then the morphological data, the SOD isozyme data and finally the anthocyanin pattern. The correlation studies between the markers underlined the relatively common view by means of flavonol patterns and the morphological features

Variable fluorescence (F v ), i.e., F v = F m - F 0 where F 0 is the minimal fluorescence and F m the maximum fluorescence, and difference Fourier transform infrared (FT-IR) spectroscopy were used to study the effect of heat stress in the 25-55 °C range on photosystem II (PSII) structure and function. First, the F v intensity reflects accurately the changes in the number of open photochemical centers in PSII. Secondly, the use of F v in combination with FT-IR spectroscopy can disclose structure-function correlations in the heat inactivation of the PSII complex. Analysis of the midpoint temperatures of thermal denaturation, i.e., 50% inactivation, reported so far in investigations of the thylakoid membrane components has revealed that most of the thermal transitions attributed to PSII are in the 39 -46 °C range. In this work, it is shown specifically that the midpoint temperature of PSII inactivation is at about 40 °C. Moreover, it was clearly demonstrated that the heat-induced changes above 40 °C are the result of a marked decrease in the number of open photochemical centers in PSII. It was also seen that above this same temperature the loss of photochemical centers has its structural counterpart in overall modifications of the secondary structures of the PSII proteins resulting from the decrease in the α-helix content concomitant with the increase in extended chain (β-strand) conformations. In brief, a novel finding reported here is that the number of open photochemical centers in PSII is dependent on a dynamic equilibrium between the contents of the PSII proteins in α-helix and extended chains (β-strands), but not in β-sheets and β-turn structures except for the antiparallel-β-sheet conformations. This therefore associates the thermal inactivation of the photochemical centers in photosystem II with distinct conformational changes in the proteins of the PSII supramolecular complex. In the particular context of the present study, these findings constitute a significant contribution to the investigation of structure-function correlations in the photosynthetic membrane. In a broader context, this information might be essential for the comprehension of the molecular arrangements or local structure order that are involved directly or indirectly in biological catalysis

Acetone extracts from the seeds of Pisum sativum L. sensu lato (Leguminoseae) separated by thin layer chromatography revealed the occurrence of hands with chromatographic mobility and color reaction with Fast Blue B characteristic for 1,3-dihydroxy-5-alkyIbenzenes. These polyketide metabolites have been isolated and identified by Spectroscopic means. The occurrence of homologous series of saturated (approximately 70%) and enoic (mono and diunsaturated) homologs with chain length of C15 to C25 has been revealed with C17 as the main homolog

The addition of 2.5 mᴍ glufosinate ammonium (BASTA), a well known plant killer, to Haematococcus pluvialis culture efficiently inhibits cell growth, blocks the activity of glutamine synthetase (GS) and induces astaxanthin accumulation. Conversely, methionine-S-sulfoximine (MSX), a well known GS inhibitor, had no effect on neither these parameters. When GS activity was tested in vitro, MSX inhibited the activity at high concentrations (mᴍ), while glufosinate was effective in the μm range. We have found that in the presence of glufosinate, ammonia is excreted from the cells. Therefore, we suggest that this process enables Haematococcus cells to escape the potentially harmful effect of glufosinate. As a consequence of the inability to assimilate nitrogen, astaxanthin is accumulated. This situation resembles the response of Haematococcus cells to nitrogen starvation

Eleven rocaglamide derivatives (cyclopentatetrahydrobenzofurans) and one structurally related aglain congener all isolated from different Aglaia species (Meliaceae) were tested for growth inhibiting properties using the human cancer cell lines MONO-MAC-6 and MEL-JUSO. Proliferation of both cell lines was efficiently inhibited in a dose and compound dependent manner. Applying a MTT-Assay, the IC 50 of the most active compound didesmethyl-rocaglamide (1) was observed at 0.002 and 0.006 μg/ml (0.004 and 0.013 μM) depending on the cell line investigated. Bulky aminoacyl substituents at C-2, acetylation of the OH substituent at C-1 or insertion of a OH or OMe substituent at C-3 ’of the rocaglamide skeleton all diminished the activity of the compounds investigated. The aglain derivative 12 was inactive up to a concentration of 3 μg/ml (4.6 μᴍ) . This loss of activity is assumed to be mainly due to the presence of a pyran ring in the aglains vs. a furan ring as found in rocaglamide derivatives. Rocaglamide derivatives may act primarily by inhibition of cell proliferation as evidenced by the absence of a significant cytotoxic effect in long-term cultures of MONO-MAC-6 cells treated with high doses of didesmethylrocaglamide. Our data suggest that rocaglamide derivatives could exert a potential role in the treatment of malignant diseases and are worth to be investigated in further studies of experimental medicine and pharmacology

This paper reports the effect of phenylbut-3-en-2-one, of its analogues, bearing 3-nitro, 4-nitro, 4-chloro- and 4-dimethylamino substituents at the phenyl moiety, and of the hydrazide, phenylhydrazide and oxime of 4-nitrophenylbut-3-en-2-one on the growth and germ-tube formation of Candida spp., as well as their ability to interact with ergosterol in water/dimethylformamide (DMF) solution and their acute toxicity for mice. 3-Nitro-, 4-nitro- and 4-chlorophenylbut-3-en-2-ones inhibit candidial growth in vitro in concentrations ranging from 0.01 to >0.4 mᴍ and their activity is comparable to that of ketoconazole (in mg/l) and lower than that of amphotericin B. The rest of the compounds are inactive at >0.4 mᴍ. Germ-tube formation of C.albicans is inhibited at 0.04 mᴍ 4-nitrophenylbut-3-en-2-one and at 0.005 mᴍ of the 3-nitro isomer. A decrease in the absorption maxima in ergosterol mixtures with 4-dimethylamino, 3-nitrophenylbut-3-en-2-one and the oxime of the 4-nitrophenylbut-3-en-2-one was observed, indicative of interaction in water/DMF solutions, while no changes in the UV spectra of the remaining compounds were detectable. That suggests that the growth inhibiting effect is not in correlation with their ability to interact with ergosterol, despite the resemblance to polyenes. LD 50 for mice is 367 mg/kg for 4-nitrophenylbut-3-en-2-one and 398 mg/ kg for the 3-nitro isomer

Amides of cinnamic acid derivatives with 3α-and 3β-cholestanylamines, as well as with 3α-and 3β-amino-(2’-aminoethyl)-cholest-5-en were synthesized using dicyclohexylcarbodiimide (DCC) and 1-hydroxy-benzotriazole as efficient additives. Their structure was determined by UV and 1 HNMR . 3β-Amino-(2’-aminoethyl)-cholest-5-en, amides of p-hydroxy-cinnamic acid 4 and 9, and N-cholest-5-en-3α-aminoethyl-di-(3’’,-phenyl-trans-2’’-propene)-amide 10 showed moderate antibacterial activity against Staphylococcus aureus

Octanoic acid 2-hydroxymethyl-4-oxo-4H-pyran-5-yl ester (kojic acid 5-O-capryloate, 2), octanoic acid 4-oxo-2-(1-oxooctyloxymethyl)-4H-pyran-5-yl ester (kojic acid 5,7-di-O-di-capryloate, 3), and octanoic acid (5-hydroxy-4-oxo-4H-pyran-2-yl)-methyl ester (kojic acid 7-O-capryloate, 5) were prepared from 5-hydroxy-2-hydroxymethyl-4H-4-pyrone (kojic acid, 1) and caprylic acid. We also describe the synthesis of 11-aminoundecanoic acid (5-hydroxy-4-oxo-4H-pyran-2-yl)-methyl ester (6). In solution, the monoesters are non-competitive in­hibitors of mushroom tyrosinase (EC 1.14.18.1) (2: IC 50 = 107 μM, 5: IC 50 = 15 μᴍ, 6 : IC 50 = 20 μᴍ; cf. 1: IC 50 = 45 μᴍ, mixed type inhibition). When tyrosinase is immobilized in a polyvi-nylalcohol membrane, 5 is a weaker inhibitor than 1 or 2

New 3’-, 5’-, 5-bromo-2’-deoxyuridine (3 a-g) and 3’-, 5’-thymidine (4 a-i) analogues with amino acid and peptide residues were synthesized and evaluated for antiviral activity. The influence of long peptide chains, essential amino acids and the effect of this structural modification on the antiviral activity has been also reported. Three 5-bromo-2’-deoxyuridine derivatives containing glycyl-, glycyl-glycyl-and glycyl-gly-cyl-glycyl-residues (3a, 3b, 3c) showed a strong activity against the herpes virus PsRV and a moderate one vs. HSV-1. The corresponding thymidine analogues were considerably less effective, and only compounds 4d and 4h showed a borderline effect against PsRV

Continuing our studies on cGMP in growing yeast we detected a particulate cGMPdependent protein kinase (Pk-G), which was solubilized by detergents and NaCl. It achieves maximum activity at 25 °C and pH = 6.8, high concentrations of substrate proteins or cGMP produce saturation. Casein and histones are appropriate substrates, phosphatase-pretreated histone H-2a provokes outstandingly high activity. Pk-G differs from cAMP-dependent protein kinase (Pk-A) with respect to pH optimum, temperature tolerance above 50 °C, and stability. Partial purification is achieved by chromatography with DEAE-cellulose, Sepharose, and cGMP-substituted Sepharose. The latter step also markedly removes Pk-A. At least three proteins with Pk-G-activity and high cGMP-affinity are separated by polyacrylamide-gel-electrophoresis. Their apparent molecular masses, as deduced from comigrating marker proteins, differ considerably from those of other Pk-G’s, but also of Pk-A’s

The reactivity of copper(II) compounds with several tetradentate ligands towards some spin-trapping reagents was studied in the presence of hydrogen peroxide. The compounds used in this study are roughly divided into two groups based on the reactivity towards 2 ,2 ,6 ,6 -tetramethyl-4-piperidinol(and also 2,2,6,6-tetramethyl-4-piperidone), which are trapping agents for singlet oxygen, 1 O 2 ( 1 Δg); The A-group compounds exhibited a high activity to form the corresponding nitrone radical, which was detected by ESR spectroscopy, but corresponding activity of the B-group compounds was very low. The A-group compounds defined as above exhibited high activity for cleavage of DNA(supercoiled Form I) in the presence of hydrogen peroxide, yielding DNA Form II (relaxed circular) or Form III (linear duplex) under our experimental conditions ([Cu(II)]=0.1~0.5 mᴍ). On the other hand, the B-group compounds effected complete degradation of the DNA (double-strand scission) under the same experimental conditions, formation of Form II or Form III DNA was negligible. Two different DNA cleavage patterns observed for A-and B-group compounds were elucidated by the different structural property of the copper(II)-peroxide adducts, which is controlled by the interaction through both DNA and the peripheral group of the ligand system

In the present paper, the presence of a ouabain-insensitive Na + -stimulated, Mg 2+ -dependent ATPase activity in T. cruzi epimastigotes CL14 clone and Y strain was investigated. The increase in Na + concentration (from 5 to 170 mᴍ), in the presence of 2 mᴍ ouabain, increases the ATPase activity in a saturable manner along a rectangular hyperbola. The was 18.0 ± 1.0 and 21.1 ± 1.1 nmoles Pi x mg -1 x min -1 and the half-activation value (K 50 ) for Na + was 34.3 ± 5.8 mᴍ and 37.7 ± 5.3 in CL14 clone and in Y strain, respectively. The Na + -stimulated ATPase activity was inhibited by 5-[aminosulfonyl]-4-chloro-2-[(2-furanylmethyl)-amino] benzoic acid (furosemide) in a dose-dependent manner. The half-inhibition value (I 50 ) was 0.22 ± 0.03 and 0.24 ± 0.07 mᴍ, and the Hill number (n) was 0.99 ± 0.2 and 2.16 ± 0.29 for CL14 clone and Y strain, respectively. These data indicate that both cell types express the ouabain-insensitive Na + -ATPase activity, which might be considered the bio­chemical expression of the second Na + pump

A chromosomal locus encoding biosynthetic genes for a putative peptide synthetase of Pseudomonas fluorescens was identified and cloned. To achieve this, two sets of degenerated oligonucleotide primers KAGGA:SGTTG and TGD :LGG were used in PCR. These primers were selected based on highly conserved units of known peptide synthetases involved in adenylation and thiolation regions of Bacillus subtilis. The discrete amplified bands from PCR ca. 300 bp for KAGGA:SGTTG and ca. 500 bp for TGD:LGG proved to be integral part of the genomic DNA of P. fluorescens were cloned and sequenced. Sequence alignments of both fragments confirmed the putative peptide synthetase genes in P. fluorescens. The present study describes the identification and cloning of peptide synthetase genes of P. fluorescens, which can be used to identify a genetic locus encoding peptide synthetase in other microbial species

An existing test to monitor the rate of adipokinetic hormone release from the corpora cardiaca (C C) of Locusta migratoria in vitro was improved, so that a constant basal rate of release was achieved and the amount of released Lom-AKH-I, II and III could be quantified by HPLC . This test system was subsequently used to demonstrate that a small peptide, which has been found in a few insect species including L. migratoria, crustacean cardioactive peptide (CCAP), induces release of all three AKHs. Moreover, 80 mᴍ trehalose reduces CCAP-induced release of AKHs in vitro, and 160 mᴍ glucose reduces this release even further. Glucose also had a greater inhibitory effect than trehalose on the spontaneous release and inhibited the high potassium-stimulated release of AKH from the CC in vitro. Eighty mᴍ sucrose, on the other hand, had no effect on the release of AKH . The effect of trehalose and glucose could be due to their use as an energy source, with trehalose first having to be converted to glucose. Whatever the stimulus, the three AKHs are released in the same proportions as they are found in the CC, which in vivo would make Lom-AKH-I, the most abundant AKH, the major effector of the biological effects of AKHs in adult locusts

Rhesus monkey kidney MA104 cells are a polarized epithelium with some unusual characteristics, including a resistance to ouabain, although their Na + -K + -ATPase has normal affinity with this drug. This work suggests that MA104 cells have high expression of functionally P-glycoprotein in their membranes. This was established using four complementary methods to investigate the expression and function of P-glycoprotein in these cells. MA104 cells were strongly resistant to vincristine, which could be reversed by three know n P-glycoprotein modulators; verapamil, cyclosporin A and trifluoperazine. In addition, MA104 cells accumulate little rhodamine 123, and the incubation with verapamil increased this accumulation. The mdr1-mRNA was detected by reverse transcription-polymerase chain reaction and a subcloned 283-bp product was identified. Its nucleotide sequence was compared with the related region of hum an mdr1, showing a high identity (96% ) between the two sequences. The expression of P-glycoprotein in the cell membrane was observed by Western blot and immunofluorescence. The results taken together suggest that MA104 cells intrinsically have a high expression of functionally P-glycoprotein in their membranes

We present a simplified binocular neural network model of the primary visual cortex with separate ON/OFF-pathways and modifiable afferent as well as intracortical synaptic couplings. Random as well as natural image stimuli drive the weight adaptation which follows Hebbian learning rules stabilized with constant norm and constant sum constraints. The simulations consider the development of orientation and ocular dominance maps under different conditions concerning stimulus patterns and lateral couplings. With random input patterns realistic orientation maps with ± 1/2-vortices mostly develop and plastic lateral couplings self-organize into mexican hat type structures on average. Using natural greyscale images as input patterns, realistic orientation maps develop as well and the lateral coupling profiles of the cortical neurons represent the two point correlations of the input image used

A new procedure is given to isolate the components that constitute the translucent lines present in some layered plant cuticles. These electron-translucent lines are mainly composed of fatty acids and n-alkanes. This waxy material is capable to form molecular bilayers with a constant thickness of approximately 5 nm. This special arrangement have a strong contribution in water transport across the cuticle

Three triterpenoid quinonemethides. one triterpene (β-amyrin) and three phenolic compounds were isolated from the roots of Maytenus chubutensis (Speg.) Lourt., O’Don. et Sleum. and Maytenus disticha (Hook. f.) (Celastraceae). The triterpenoid quinonemethides were identified as tingenone, celastrol and pristimerin. The triterpenoid was identified as β-amyrin and phenolic compounds were identified as catechin, galocatechin and (-)epicatechin