Band 64, Heft 5-6

Twenty-one alkaloids and related compounds were found in Sternbergia colchiciflora (Amaryllidaceae), a hitherto not studied plant species. Twenty of them were detected by GC-MS in the crude extracts of this plant species. Ten alkaloids were isolated and their structures confirmed by NMR, MS and CD measurements. Many of the compounds found in this species, such as lycorine, tazettine, haemanthidine, are known to possess strong bioactivity. Variations in the alkaloid pattern were found during the phenological cycle of the plant. Lycorine-type compounds were dominant in the plant organs during both the fl owering period and dormancy. The alkaloid pattern during both periods of leaf development and fructification was dominated by haemanthamine-type in the leaves and lycorine-type compounds in the bulbs, respectively

Bladder cancer is one of the most common cancers worldwide, with the highest incidence in industrialized countries. There are three major histological subtypes of bladder cancer: transitional cell carcinoma (TCC) (>90%), squamous cell carcinoma (<10%) and adenocarcinoma (1 - 2%). The present study was carried out to assess the effects of conferone, a sesquiterpene coumarin isolated from Ferula badrakema, on a TCC subline, 5637 cells. In order to test the effects of conferone, 5637 cells were treated with different concentrations (16, 32, 64, 128 μg/ml) of conferone. The results indicated that conferone did not have any significant cytotoxic effect on these neoplastic cells. To determine the combining effects, the cells were cultured in the presence of different concentrations of conferone (16, 32, 64, 128 μg/ ml) and vincristine (30, 40, 50 μg/ml) in combination. The morphological changes were then observed and cytotoxicity effects were studied using the MTT assay 24, 48 and 72 h following drug administration. The cells were more rounded and granulated after treatments with both drugs in comparison to vincristine only. The results of the MTT assay confi rmed the morphological observations. After 48 h of combined treatment with 40 μg/ml vincristine and 16 μg/ml conferone, the cytotoxicity of vincristine was increased by 23.6%

1 The reaction of 6-hydrazinyl-1,3-dimethylpyrimidine-2,4-(1H,3H)-dione () with ethoxymethylenemalononitrile afforded 5-amino-1-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydropyrimidin- 6-yl)-1H-pyrazole-4-carbonitrile ( 2 ). The latter was reacted with formamide and urea affording the corresponding 4-aminopyrazolo[3,4-d]pyrimidines 3 and 4 . The reaction of monosaccharide aldoses with 3 and 4 gave stereoselectively the β-N-glycosides 5a - d and 6a - d which were treated with acetic anhydride in pyridine to afford the corresponding acetylated derivatives 7a - d and 8a - d . The prepared compounds were tested for their antiviral activity against hepatitis B virus (HBV) and showed moderate to high activities

Mussaenda ‘dona aurora’ (sepals) has been investigated for its hepatoprotective and antioxidant activities. The highest activity was observed in the ethyl acetate fraction. The separation of the ethyl acetate fraction gave two iridoids, sanshiside-D and lamalbide. Sanshiside-D exhibited a hepatoprotective activity greater than silimarin as was evidenced by significant reduction of ALT and AST in the serum enzyme levels

Cassiaindoline is a new dimeric indole alkaloid isolated from Cassia alata L. leaves whose structure was elucidated through spectroscopic analyses. It exhibited analgesic activity at a dosage of 125.0 mg/kg mouse and decreased the number of writhings induced by acetic acid by 49.4%. It also showed a 57.1% anti-inflammatory activity at a dosage of 75 mg/kg mouse

Methanolic extracts of flowers and leaves of Gentiana lutea L., together with the isolated compounds mangiferin, isogentisin and gentiopicrin, were used to investigate the antimicrobial activity of the plant. A variety of Gram-positive and Gram-negative bacteria as well as the yeast Candida albicans has been included in this study. Both extracts and isolated compounds showed antimicrobial activity with MIC values ranging from 0.12 - 0.31 mg/ml. Our study indicated that the synergistic activity of the pure compounds may be responsible for the good antimicrobial effect of the extracts. Quantification of the secondary metabolites was performed using HPLC

1 Bioassay-guided fractionation of a CHCl3 extract of the leaves of Xanthium italicum Moretti led to the isolation of four xanthanolides: xanthatin (), 4-epixanthanol ( 2 ), 4-epiisoxanthanol ( 3 ), and 2-hydroxyxanthinosin ( 4 ). Their structures were determined by means of 1D and 2D NMR spectroscopy, including 1 H- 1 H COSY, NOESY, HSQC and HMBC experiments, which resulted in complete and unambiguous 1 H and 13 C NMR chemical shift assignments. The isolated compounds 1 - 4 were evaluated for their antiproliferative activities, and were demonstrated to exert significant cell growth inhibitory activity against human cervix adenocarcinoma (HeLa), skin carcinoma (A431), and breast adenocarcinoma (MCF7) cells

1 A hitherto unidentified endophytic strain of the genus Chaetomium, isolated from the medicinal plant Otanthus maritimus, yielded a new tetrahydrofuran derivative, aureonitolic acid (), along with 5 known natural products, 2 - 6 . The structure of 1 was determined by extensive spectroscopic analysis and comparison with reported data. Extracts of the fungus, grown either in liquid culture or on solid rice media, exhibited considerable cytotoxic activity when tested in vitro against L5178Y mouse lymphoma cells. Compounds 2 and 6 showed significant growth inhibition against L5178Y cells with EC 50 values of 7.0 and 2.7 μg/mL, respectively, whereas 1 was inactive

A fungus, isolated from the root bark of Melia azedarach (Meliaceae), from which a series of meroterpenes have been reported, was identified as Penicillium brasilianum based on analysis of the ITS region of ribosomal DNA. From a rice culture of this fungus, the known phenylpropanoid amides brasiliamide A and B were obtained together with and a new, slightly modified congener, along with the meroterpenoids preaustinoid A1, preaustinoid B2 and austinolide. The compounds were isolated by the use of combined chromatographic procedures and identified by physical methods, mainly 1D and 2D NMR experiments, with distinction for 1 H{ 15 N} HMBC applied to brasiliamide A. The amides were tested for their antimicrobial activity and showed only weak inhibitory effects, against a set of pathogenic bacteria

I From osthole [7-methoxy-8-(3-methyl-but-2-enyl)-chromen-2-one] (), obtained by selective extraction of Peucedanum ostruthium (L.) W. Koch roots, ostholic acid ( II ) was synthetized as a result of its oxidation with chromium trioxide. From ostholic acid, through its chloride, four amides were obtained: the morpholide 1 , the p-chloro-benzylamide 2 , the piperidine 3 and the N-methyl-piperazide 4 . Except for 1 , other compounds have not been described before. The amides 1 - 4 and their precursor osthole ( I ) were tested for their potential activities in selected immunological assays. The compounds showed moderate inhibitory activity in the humoral immune response to sheep erythrocytes in mice in vitro, and 4 was the most suppressive. The effects of 1 and 3 on concanavalin A- and pokeweed mitogen-induced mouse splenocyte proliferation were inhibitory and those of 4 stimulatory. The compounds were also tested for their activity on tumour necrosis factor α and interleukin 6 production, induced by lipopolysaccharide, in cultures of rat peritoneal cells and human peripheral blood mononuclear cells. Compounds 1 , 3 and 4 inhibited tumour necrosis factor α (rat cells), whereas compound 2 stimulated the production of both cytokines. Compounds 1 , 2 and 3 were also strongly inhibitory on tumour necrosis factor α production in human blood cells (73, 78 and 80% inhibition at 10 μg/ml, respectively). On the other hand, 2 and 4 stimulated the interleukin 6 production (2- to 3-fold stimulation). In addition, 2 and 4 suppressed the carrageenan-induced inflammation in mice (56.5% and 68.3% inhibition, respectively). In summary, the compounds predominantly displayed suppressive and anti inflammatory activities in the investigated models

1 Echinocystic acid (), an echinocystic acid saponin, 2 , and four of its ester saponins, 3 - 6 , obtained from the active fraction of Impatiens pritzellii var. hupehensis, an traditional Chinese medicine for rheumatoid arthritis, were investigated for their effects on lipopolysaccharide (LPS)-induced interleukin (IL)-18 in human peripheral blood mononuclear cells. Three of them, 1 , 2 and 6 , showed obvious activity to inhibit the production of IL-18, especially the ester saponins with a sugar chain at C-28, 6 . Structure-activity relationships are discussed in brief

Crude extracts of a callus culture (two culture media) and adult plants (two collections) from Alternanthera tenella Colla (Amaranthaceae) were evaluated for their antibacterial and antifungal activity, in order to investigate the maintenance of antimicrobial activity of the extracts obtained from plants in vivo and in vitro. The antibacterial and antifungal activity was determined against thirty strains of microorganisms including Gram-positive and Gram-negative bacteria, yeasts and dermatophytes. Ethanolic and hexanic extracts of adult plants collected during the same period of the years 1997 and 2002 [Ribeirão Preto (SP), collections 1 and 2] and obtained from plant cell callus culture in two different hormonal media (AtT43 and AtT11) inhibited the growth of bacteria, yeasts and dermatophytes with inhibition halos between 6 and 20 mm. For the crude extracts of adult plants bioassay-guided fractionation, purification, and isolation were performed by chromatographic methods, and the structures of the isolated compounds were established by analysis of chemical and spectral evidences (UV, IR, NMR and ES-MS). Steroids, saponins and flavonoids (aglycones and C-glycosides) were isolated. The minimum inhibitory concentration (MIC) of the isolated compounds varied from 50 to 500 μg/mL

A method to estimate the content of selenium in organics was introduced based on reversed phase-high performance liquid chromatography (RP-HPLC). The maximum absorption peak of piazselenol was at 330 nm and the optimized temperature and pH value were 40 °C and 2.8, respectively. The minimum detection concentration of selenium(IV) was 0.06 μg/mL and the measurable range was 0.12 - 12.0 μg/mL. The organic selenium accumulation in golden needle mushroom (Flammulina velutipes) mycelia was obtained by subtracting the amount of inorganic selenium from that of total selenium. The organic selenium accumulation of various inoculation amounts showed that organic selenium accumulation in a unit volume of the fermentation broth was positively related the inoculation amount. Compared with the methods reported previously, the method used here is simple, reliable and less toxic

We examined the distribution of ethylamine, glutamic acid and alanine, which are utilized in theanine biosynthesis, and other major amino acids in leaves, stems, cotyledons and roots of 6-week-old tea seedlings. Ethylamine and glutamic acid, which are substrates of theanine synthetase, were distributed almost uniformly in all parts of the seedlings; the contents in μmol/g fresh wt varied from 0.44 - 0.88 (ethylamine) and 1.6 - 2.4 (glutamic acid). The content of alanine, a possible precursor of ethylamine synthesis, was significantly higher in roots (3.1 μmol/g fresh wt) than in other parts. Incorporation of radioactivity from [U- 14 C]- alanine into theanine was also higher in roots than in other organs. In 10-week-old seedlings, [1- 14 C]ethylamine was converted to theanine in young and developed leaves, stems, main and lateral roots; the highest rates of conversion were detected in the main and lateral roots. These results suggest that the theanine synthesis preferentially takes place in roots but is not restricted to them; substrates and the enzymatic machinery for theanine synthesis are available in all parts of tea seedlings

The effect of heavy metal stress on the cell viability and leakage of electrolytes of Avicennia germinans leaf discs was investigated by the tissue tolerance test. Foliar discs were incubated with different Cd 2+ or Cu 2+ concentrations for 24 h; thereafter, the cell membrane stability of the tissue was assayed by the cell viability Evans blue and leakage electrolytes methods. The results indicated that electrolyte leakage of the leaf discs increased 24 h after exposure to heavy metal stress, as shown by a reduction of the cell viability by 30% in discs exposed to higher doses of Cd 2+ (0.546 M) and Cu 2+ (0.7 M), respectively. Additionally, the histological analysis of the leaf discs exposed to heavy metal stress revealed that at higher Cd 2+ and/or Cu2+ concentrations an increase in the intercellular spaces and destruction of mesophyll cells was observed 24 h after exposure. In summary, the biochemical and structural changes observed in foliar tissues of A. germinans suggest that higher cadmium and copper concentrations may result in structural changes and altered physiological characters in leaves

The neurotoxicity induced by beta-amyloid (Aβ), which is one of the major causes of Alzheimer’s disease (AD), leads to synaptic loss and subsequent neuronal death. Therefore, modulation of Aβ-induced neurotoxicity, as well as regeneration of damaged synapses could be important therapeutic approaches to control AD. In this study, we found that isorosmanol, an abietane-type diterpene, protected PC12 cells against Aβ-induced toxicity. Furthermore, isorosmanol promoted the generation of neurites. The neurotrophic effect of isorosmanol was enhanced by co-treatment with nerve growth factor (NGF). In addition, the neurite outgrowth induced by isorosmanol was accompanied by F-actin redistribution and increased expression of neurofilaments. Taken together, these results suggest that isorosmanol possesses both neuroprotective and neurotrophic effects, that might be beneficial for controlling A`D

The redox potentials of poplar plastocyanins a and b (PCa, PCb) were determined by spectro photometric titrations of their reduced forms with [Fe(CN) 6 ] 3- . It was found that the two isoforms have the following millimolar extinction coefficients ε 597 , equilibrium constants K eq of one-electron exchange with [Fe(CN) 6 ] 4- /[Fe(CN) 6 ] 3- , and standard electron potentials E 0′ : PCa: ε 597 = (4.72 ± 0.08) mM -1 cm -1 , K eq = 0.133 ± 0.009, E 0′ = (354 ± 11) mV; PCb: ε 597 = (5.23 ± 0.16) mM -1 cm -1 , K eq = 0.175 ± 0.010, E 0′ = (363 ± 12) mV. The pH dependence of the redox potential of PCb was studied too. It was found, that the value of E 0′ for PCb is constant in the pH range 6.5 - 9.5, but decreases in the range 4.8 - 6.5. On the whole, the dependence resembles that of PC from some well-known plant species, including poplar PCa. The changes of E 0′ in the pH-dependent region for poplar PCb, however, are smaller and are 13 mV per pH unit, whereas in the other well-known plant species the changes are about 50 - 60 mV per pH unit. It has been assumed that the weaker pH dependence of E 0′ of PCb accounts for some structural differences between PCa and PCb

Metschnikowia pulcherrima is a highly effective biocontrol yeast due to its pigment pulcherrimin that accumulates in the cells and in the growth medium. Three different strains of M. pulcherrima were isolated from local grapes. The yeast isolates were characterized on the basis of their biochemical, physiological and ITS1-5.8 s rDNA-ITS2 region. Based on the obtained results, the M. pulcherrima isolates were identifi ed as new strains of M. pulcherrima. Strong antagonistic activities of the M. pulcherrima strains on the human pathogens Proteus vulgaris, Escherichia coli, Candida albicans, Candida parapsilosis, Candida krusei, and Trichosporon mucoides were determined. In addition, antagonistic effects of these M. pulcherrima strains were also tested against Aspergillus fl avus, Aspergillus fumigatus, Aspergillus niger, Trichoderma spp., Paecilomyces spp., and Bipolaris spp. and it was shown that the three different strains of M. pulcherrima also have an antagonistic effect on the growth of these fungal species at different extents. This study showed that all three strains of M. pulcherrima produce the same amount of the pigment pulcherrimin, but their antimicrobial activities on different microorganisms show important variations

Impact of copper on the oxidative and calcium signal transductions leading to cell death in plant cells and the effects of the copper-binding peptide derived from the human prion protein (PrP) as a novel plant-protecting agent were assessed using a cell suspension culture of transgenic tobacco (Nicotiana tabacum L., cell line BY-2) expressing the aequorin gene. Copper induces a series of biological and chemical reactions in plant cells including the oxidative burst reflecting the production of reactive oxygen species (ROS), such as hydroxyl radicals, and stimulation of calcium channel opening, allowing a transient increase in cytosolic calcium concentrations. The former was proven by the action of specifiC ROS scavengers blocking the calcium responses and the latter was proven by an increase in aequorin luminescence and its inhibition by specifi c channel blockers. Following these early events completed within 10 min, the development of copper-induced cell death was observed during additional 1 h in a dose-dependent manner. Addition of a synthetic peptide (KTNMKHMA) corresponding to the neurotoxic sequence in human PrP, prior to the addition of copper, effectively blocked both calcium influx and cell death induced by copper. Lastly, a possible mechanism of peptide action and future applications of this peptide in the protection of plant roots from metal toxicity or in favour of phytoremediation processes are discussed

Cell suspension culture has rapidly become an alternative source of taxol, an anticancer compound. To investigate the role of DNA methylation in the cultural course of Taxus chinensis cells, analyses of 18S rRNA gene sequences of cultured T. chinensis cells and related species were conducted. The phylogenetic analysis of 18S rRNA gene sequences indicated that HG-1 (the cultured T. chinensis cells), like T. mairei (the natural variety of T. chinensis), should be a new variety of T. chinensis, and cell culture can change the 18S rRNA gene sequence at the level of species despite 18S rRNA is the most conserved gene. The analyses of the CpG and TpG+CpA relative abundance and GC content of the 18S rRNA gene sequences made clear that DNA methylation contributed to changes of the 18S rRNA gene sequence of HG-1 at the level of species, which can make HG-1 to become a new variety of T. chinensis.

It is well known that Paramecium species including green paramecia (Paramecium bursaria) migrate towards the anode when exposed to an electric field in a medium. This type of a cellular movement is known as galvanotaxis. Our previous study revealed that an electric stimulus given to P. bursaria is converted to a galvanotactic cellular movement by involvement of T-type calcium channel on the plasma membrane [Aonuma et al. (2007), Z. Naturforsch. 62 c, 93 - 102]. This phenomenon has attracted the attention of bioengineers in the fields of biorobotics or micro-robotics in order to develop electrically controllable micromachineries. Here, we demonstrate the galvanotactic controls of the cellular migration of P. bursaria in capillary tubes (diameter, 1 - 2 mm; length, 30 - 240 mm). Since the Paramecium cells take up particles of various sizes, we attempted to use the electrically stimulated cells of P. bursaria as the vehicle for transportation of micro-particles in the capillary system. By using apo-symbiotic cells of P. bursaria obtained after forced removal of symbiotic algae, the uptake of the particles could be maximized and visualized. Then, electrically controlled transportations of particle-filled apo-symbiotic P. bursaria cells were manifested. The particles transported by electrically controlled cells (varying in size from nm to μm levels) included re-introduced green algae, fluorescence-labeled polystyrene beads, magnetic microspheres, emerald green fluorescent protein (EmGFP)-labeled cells of E. coli, Indian ink, and crystals of zeolite (hydrated aluminosilicate minerals with a micro-porous structure) and some metal oxides. Since the above demonstrations were successful, we concluded that P. bursaria has a potential to be employed as one of the micro-biorobotic devices used in BioMEMS (biological micro-electro-mechanical systems).

In spite of the importance of chemical signals (pheromones) in the reproductive behaviour of lizards, only a few studies have examined the role of specific chemical compounds as sexual signals. The secreted chemicals vary widely between species but whether this variation reflects phylogenetic or environmental differences remains unclear. Based on mass spectra, obtained by GC-MS, we found 40 lipophilic compounds in femoral gland secretions of male green lizards (Lacerta viridis), including several steroids, α-tocopherol, and esters of n-C 16 to n-C 20 carboxylic acids, and minor components such as alcohols between C 12 and C 20 , squalene, three lactones and one ketone. We compared these chemicals with those previously found in other closely related green lizard species, and discussed how phylogenetical differences and/or environmental conditions could be responsible for the differential presence of chemicals in different lizard species.

Six mexicanolide limonoids isolated from the dichloromethane extract of the fruits of Cipadessa fruticosa Blume (Meliaceae) were evaluated against Spodoptera frugiperda (J. E. Smith). Gedunin was used as a positive control. When incorporated into an artificial diet of neonates at 50.0 mg kg -1 , febrifugin A showed 73.3% mortality. All the compounds showed moderate insecticidal activity, except for ruageanin A, when compared with the control. Febrifugin also showed growth inhibition and antifeedant activities (at 100.0 mg kg -1 ). The correlation between the insecticidal activity of the isolated compounds and their chemical structure was discussed.

Acrylamide is an α,β-unsaturated vinyl monomer that causes cytotoxicity due to its alkylating properties. In recent years several proteins have been identified that are alkylated by acrylamide in vivo. This finding might explain the neurotoxic effects of acrylamide in humans. However, the list of potential acrylamide target proteins is far from being complete. In particular, the proteins that mediate the cytotoxicity of acrylamide in cell cultures remained unknown. Here we identify two novel acrylamide target proteins in human cell cultures (Jurkat, HepG2 and Caco-2), adenosine deaminase and thioredoxin

Multidrug resistance caused by the presence and overproduction of ABC transporters makes serious problems in cancer treating. The drugs administered during therapy are pumped outside the cell using the energy obtained from ATP hydrolysis. The augmented dosage of drugs to overcome the multidrug resistance is not sufficient. Thus knowledge of the structure of ABC proteins is necessary to understand the rules of their action. It could be also helpful to understand how the multidrug resistance could be overcome. One of the strategies involves the treatment of cancer cells with a mixture of anticancer drugs and inhibitors of ABC transporters. The yeast Saccharomyces cerevisiae, whose PDR pumps are analogues of mammalian MDR proteins responsible for multidrug resistance, is a suitable research model. Biophysical methods with different fluorescent dyes seem to be very suitable for the measurement of the efflux pump activity. This review describes some known inhibitors of ABC proteins and biophysical methods which could be used for measuring the ABC transporters activity.