Volume 57, Issue 9-10

Four new eudesmanolides and two new guaianolides were isolated from the aerial parts of Anthemis carpatica Willd. and their structures elucidated by spectral methods. In addition, seven known sesquiterpene lactones were identified.

The rare lupene derivative named resinone has only been isolated before from Fluorensia resinosa. We now report the isolation of this compound from the bark of the new recently described Acacia cedilloi (Fabaceae), and the revision of its structure to 16β-hydroxylup-20(29)-en-3-one, based on NMR and MS spectral data. The detailed 1 H and 13 C NMR assignments of resinone and its acetate achieved by 1D and 2D NMR experiments (including DEPT, COSY, HMQC and HMBC) are reported. In addition, the study of A. cedilloi and A. gaumeri afforded the known related lupenes lupeol and lupenone, the acyclic squalene, the sterols β-sitosterol, stigmasta-7,22-dien-3β-ol (spinasterol) and stigmasta-5,22,25-trien-3β-ol (22-dehydroclerosterol) as well as α-tocopherol and β-carotene.

From the hexane extract of the bark of the stems of Senna racemosa (syn. Cassia racemosa) a new dihydroanthracenone derivative, named racemochrysone, was isolated. Its structure was established as 8,9-dihydroxy-3-methoxy-2,2,6-trimethyl-(2H)-anthracen-1-one based on spectroscopical data, mainly 1D and 2D NMR experiments. In addition β-sitosterol, stigmasterol, chrysophanol and physcion were obtained. From the leaves extracts the piperidine alkaloid cassine and the hexitol pinitol were obtained.

The new alkaloids 7-,9-diangeloylplatynecine (1) and 8-episarracine N-oxide (2), were isolated and identified from the roots of Senecio macedonicus. Another one, 8-epineosarracine was detected by GC/MS analyses of the crude alkaloid mixture. The cytotoxicity and biological activity of the alkaloids were tested on normal murine spleen lymphocytes and P3U1 mouse myeloma.

From a methanolic extract of the leaves of Andira inermis (Fabaceae), andirol A and B, two compounds with a novel type of a rotenoid-related skeleton and andinermol, a new 2-aryl-3-hydroxymethyl-benzofuran could be isolated. Characterisation and structure elucidation of these compounds was achieved on the basis of their spectral data. In addition, the in vitro activities of the isolated compounds against both the chloroquine-sensitive strain PoW and the chloroquine-resistant clone Dd2 of Plasmodium falciparum have been evaluated.

The chemical composition of the essential oils obtained by hydrodistillation of roots, stems with leaves and inflorescences of Valeriana italica Lam. and Valeriana tuberosa L. were studied by GC/MS. Seventy-three and fourty-one constituents were identified from each plant, respectively. The major constituent of the oil obtained from the roots of V. italica was isolated and identified as 15-acetoxyvaleranone. Its stereochemistry and conformation has been studied using NMR spectroscopy and molecular modelling. The oils obtained from V. tuberosa completely lacked the characteristic valerane or kessane sesquiterpenes. Running title: Essential oils of Valeriana italica and V. tuberosa

The composition of essential oil of the leaves of Lavandula stoechas ssp. stoechas, was analyzed by means of capillary GC-MS. The main components of L. stoechas ssp. stoechas oil were pulegone (40.4%), menthol (18.1%), menthone (12.6%). The essential oil of the plant was evaluated for antibacterial and a panel cytotoxic activities.

Muehlenbeckia hastulata (J. E.Sm.) Johnst. used mainly for its abortive properties was found active for oxytoxic and analgesic activities in a biological activity screening (oxytoxic, analgesic, antimicrobial, cytotoxic and xanthine oxidase assay). Epicatechin, emodin-8-glycoside and rutin were isolated from the aerial part and the root of the plant.

A Lactobacillus delbrueckii subsp. bulgaricus HP1 strain with high exopolysaccharide activity was selected from among 40 strains of lactic acid bacteria, isolated from kefir grains. By associating the Lactobacillus delbrueckii subsp. bulgaricus HP1 strain with Streptococcus thermophilus T15, Lactococcus lactis subsp. lactis C15, Lactobacillus helveticus MP12. and Sacharomyces cerevisiae A13, a kefir starter was formed. The associated cultivation of the lactobacteria and yeast had a positive effect on the exopolysaccharide activity of Lactobacillus delbrueckii subsp. bulgaricus HP1. The maximum exopolysaccharide concentration of the starter culture exceeded the one by the Lactobacillus delbrueckii subsp. bulgaricus HP1 monoculture by approximately 1.7 times, and the time needed to reach the maximum concentration (824.3 mg exopolysacharides/l) was shortened by 6 h. The monomer composition of the exopolysaccharides from the kefir starter culture was represented by glucose and galactose in a 1.0:0.94 ratio, which proves that the polymer synthesized is kefiran.

Quantification of the flavonoids in yellow lupin (Lupinus luteus; Leguminosae) seedlings revealed that a flavone glucoside, 7-O-β-(2-O-β-rhamnosyl)glucosyl-4′,5,7-trihydroxyflavone (apigenine 7-O-β-neohesperidoside), is rich in the epicotyl and cotyledon. In hypocotyls and roots, 8-C-β-glucosyl-4′,5,7-trihydroxyisoflavone (genistein 8-C-β-glucoside) was a predominant flavonoid constituent. The roles of the localized flavonoids are briefly discussed relating to defense against biotic and abiotic external stresses.

The genus Satureja is represented by fifteen species of which five are endemic and Satureja pilosa and S. icarica have recently been found as new records for Turkey. Aerial parts of the Satureja pilosa, S. icarica, S. boissieri and S. coerulea collected from different localities in Turkey were subjected to hydrodistillation to yield essential oils which were subsequently analysed by GC and GC/MS. The main constituents of the oils were identified, and both antibacterial and antifungal bioassays were applied. Carvacrol (59.2%, 44.8%, 42.1%) was the main component in the oils of S. icarica, S. boissieri and S. pilosa, respectively. The oil of S. coerulea contained β-caryophyllene (10.6%) and caryophyllene oxide (8.0%) as main constituents.

In order to assess the role of oxidative stress in the cytotoxicity of natural hydroxyanthraquinones, we compared rhein, emodin, danthron, chrysophanol, and carminic acid, and a series of model quinones with available values of single-electron reduction midpoint potential at pH 7.0 (E 1 7 ), with respect to their reactivity in the single-electron enzymatic reduction, and their mammalian cell toxicity. The toxicity of model uinones to the bovine leukemia virus-transformed lamb kidney fibroblasts (line FLK), and HL-60, a human promyelocytic leukemia cell line, increased with an increase in their E 1 7. A close parallelism was found between the reactivity of hydroxyanthraquinones and model quinones with single-electron transferring flavoenzymes ferredoxin: NADP + reductase and NADPH: cytochrome P-450 reductase, and their cytotoxicity. This points to the importance of oxidative stress in the toxicity of hydroxyanthraquinones in these cell lines, which was further evidenced by the protective effects of desferrioxamine and the antioxidant N,N′-diphenyl-p-phenylene diamine, by the potentiating effects of 1,3-bis-(2-chloroethyl)-1-nitrosourea, and an increase in lipid peroxidation.

Curcumin removed turmeric oleoresin (CRTO) was extracted with hexane and concentrated to get turmeric oil, and that was fractionated using silica gel column chromatography to obtain three fractions. These fractions were analyzed by GC and GC-MS. Turmeric oil contained aromatic turmerone (31.32%), turmerone (15.08%) and curlone (9.7%), whereas fractions III has aromatic turmerone (44.5%), curlone (19.22%) and turmerone (10.88%) as major compounds. Also, oxygenated compounds (5,6,8-10) were enriched in fraction III. Turmeric oil and its fractions were tested for antioxidant activity using the β-carotene-linoleate model system and the phosphomolybdenum method. The fraction III showed maximum antioxidant capacity. These fractions were also used to determine their protective effect against the mutagenicity of sodium azide by means of the Ames test. All the fractions and turmeric oil exhibited a markedly antimutagenicity but fraction III was the most effective. The antioxidant effects of turmeric oil and its fractions may provide an explanation for their antimutagenic action.

Two-week-old pea (Pisum sativum var. Arkal) plants were subjected to elevated temperature (38 °C/42 °C) in dark for 14−15 h. The effect of heat treatment on light- induced phosphorylation of LHCII and LHCII migration in the thylakoid membranes were investigated. The heat treatment did cause a substantial (more than two fold) increase in the extent of LHCII phosphorylation as compared to the control. Upon separation of appressed and nonappressed thylakoid fractions by digitonin treatment, the heat-treated samples showed a decrease in LHCII-related polypeptides from the grana stack (appressed region) over the control. Further, a small increase in the intensity of these (LHCII-related) bands was detected in stromal thylakoid fraction (non-appressed membranes). This suggests an enhanced extent of migration of phosphorylated LHCII from appressed to non-appressed regions due to in vivo heat treatment of pea plants. We also isolated the LHCII from control and heat treated (42 °C) pea seedlings. Analysis of CD spectra revealed a 5D6 nm blue shift in the 638 nm negative peak in heat treated samples suggesting alteration in the organization of Chl b in the LHCII macro-aggregates. These results suggest that in vivo heat stress not only alters the extent of migration of LHCII to stromal region, but also affects the light harvesting mechanism by LHCII associated with the grana region.

In the present study membrane fatty acids were analyzed to find a link between the biosynthesis inhibition of very-long-chain fatty acids and the phytotoxic effects of herbicidal chloroacetamides. Accordingly,we have isolated membranes of cucumber seedlings (Cucumis sativus) by two-phase partitioning and analyzed their fatty acid content. Saturated VLCFAs ranging from C20 to C26 were found in high amounts (22%) in the plasma membrane fraction. Nonmodified VLCFAs were predominantly present in phospholipids, while saturated 2-hydroxylated VLCFAs were identified in cerebrosides. Treatment of intact seedlings with chloroacetamides markedly reduced the VLCFA content in the plasma membrane. This result could be specified by fatty-acid labeling using [14C]malonate as a substrate for fatty acid elongation. De novo incorporation of VLCFAs into the plasma membrane and into microsomal membranes, respectively, was severely impaired by chloroacetamides with I50 values between 10 to 100 nm. These results confirm the previous finding that chloroacetamides inhibit VLCFA biosynthesis localized in the microsomes (Böger et al., Pest Manage. Sci. 56, 497D508, 2000). The direct consequence of this inhibition is a strong decrease of VLCFAs required as constituents of the plasma membrane and the substitution by shorter acyl chains. Apparently, physical properties and function of the plasma membrane are affected eventually leading to death of the plant.

We have found that Copper(II) ions at about equimolar Cu 2+ /photosystem II (PS II) reaction center proportions stimulate oxygen evolution nearly twofold. This high affinity Cubinding site is different from the binding sites of Mn and Ca ions. The analysis of the Cu 2+ content in PS II preparations isolated from wild-type tobacco and a tobacco mutant deficient in light-harvesting complex suggests that Cu 2+ may be a native component of PS II and may take part in the oxygen evolution process. At higher concentrations, Cu 2+ ions inhibit oxygen evolution and quench fluorescence.

A mutant of the methylotrophic yeast Hansenula polymorpha with constitutive alcohol oxidase (AOX) and peroxisome biosynthesis was obtained after UV treatment followed by cell plating on a medium containing methanol and 2-deoxy-D-glucose (DOG). DOG-resistant colonies of mutants were insensitive to catabolic repression by glucose and methanol. A selection procedure is described that allows the isolation of a mutant exhibiting a constitutive phenotype of AOX involved in methanol utilization. Furthermore, additional features of the constitutive presence of peroxisomes are demonstrated. 562 DOG-resistant colonies were tested, 24 of them demonstrating constitutive AOX formation. Based on quantitative analysis, one of the strains − DOG-13 was selected and its growth, biochemical and ultrastructural characteristics were examined. Its specific enzyme activity when cultivated on a yeast nitrogen base + 1% glucose (YNB + 1% Glucose) was found to reach 145 nmol.min −1 .mg −1 protein (compared to zero of the parent strain) after he 20 th hour of cultivation. This was confirmed by fine-structure analysis, showing typical peroxisomes, which number and size increased with the enzyme activity. This study demonstrates a constitutive AOX and peroxisome biosynthesis by the mutant strain H. polymorpha DOG-13 obtained.

Detoxification of an antifungal monoterpene terpinolene (1) by the plant pathogenic fungus Botrytis cinerea afforded hydroxlyated metabolites 2,3-dihydro-3β,6β-dihydroxy-terpinolene (2) (39%) and 2,3-dihydro-1α,3α-dihydroxy-terpinolene (3) (20%), respectively. Terpinolene showed good levels of antifungal activity while both the metabolites were inactive against another plant pathogenic fungus Cladosporium herbarum.

Elicitors are molecules which can induce the activation of plant defence responses. Elicitor activity of intercellular wash fluid from Russian wheat aphid, Diuraphis noxia (Mordvilko) infested resistant (cv Tugela DN), and susceptible (cv Tugela), wheat (Triticum aestivum L.), was investigated. Known Russian wheat aphid resistance related responses such as peroxidase and β-1,3-glucanase activities were used as parameters of elicitor activity. The intercellular wash fluid from infested resistant plants contains high elicitor activity while that from infested susceptible plants contains no or very little elicitor activity. After applying C-18 reverse phase and concanavalin A Sepharose chromatography, elicitor active glycoproteins were isolated from the intercellular wash fluid of Russian wheat aphid infested resistant wheat. The elicitor-active glycoproteins separated into three polypeptides during sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isolated glycoproteins elicited peroxidase activity to higher levels in resistant than in susceptible cultivars. It was evident that the glycoproteins were probably a general elicitor of plant origin. Information gained from these studies is valuable for the development of plant activators to enhance the defence responses of plants.

The EtOAc soluble constituents of the unripe fruits of Ginkgo biloba showed motility inhibition followed by lysis of zoospores of the phytopathogenic Aphanomyces cochlioides. We purified 22:1-ω 7 -anacardic acid (1), 24:1-ω 9 -anacardic acid (2) and 22:0-anacardic acid (3), together with other related compounds, 21:1-ω 7 -cardol (4) and 21:1-ω 7 -cardanol (5) from the crude extracts of Ginkgo fruits. Amongst them, compound 1 was a major active agent in quality and quantity, and showed potent motility inhibition (98% in 30 min) followed by lysis (55% in 3 h) of the zoospores at 1 × 10 −7 m. The 2-O-methyl derivative (1−c) of 1 displayed antibacterial activity against Bacillus subtilis, but practically inactive to Escherichia coli. A brief study on structure-activity relationships revealed that a carboxyl group on the aromatic ring and an unsaturated side chain in the anacardic acid derivative are important for strong motility inhibitory and lytic activities against the zoospore

A xanthine oxidase enzyme electrode (xanthine oxidase immobilized on electrochemically modified graphite and conveniently coated with gelatine electrode working surface) for quantitative analysis of xanthine is proposed. The detection of thus developed electrochemical system is based on the electroreduction of hydrogen peroxide generated in enzyme layer and offered l-ascorbic and uric acid reducing interference effect on the substrate determination. At a working potential −50 mV (vs. Ag/AgCl) the detection limit of 4.5 μm and the linearity of the amperometric signal up to substrate concentration of about 40 μm were found. At that working potential, the electrode is practically inert towards l-ascorbic- and uric acid present. The response time did not exceed 2 min.

This work describes the ability of living Trichomonas vaginalis to hydrolyze extracellular ATP (164.0 ± 13.9 nmol Pi / h × 10 7 cells). This ecto-enzyme was stimulated by ZnCl 2 , CaCl 2 and MgCl 2 , was insensitive to several ATPase and phosphatase inhibitors and was able to hydrolyze several nucleotides besides ATP. The activity was linear with cell density and with time for at least 60 min. The optimum pH for the T. vaginalis ecto-ATPase lies in the alkaline range. ᴅ-galactose, known to be involved in adhesion of T. vaginalis to host cells, stimulated this enzyme by more than 90%. A comparison between two strains of T. vaginalis showed that the ecto-ATPase activity of a fresh isolate was twice as much as that of a strain axenically maintained in culture, through daily passages, for several years. The results suggest a possible role for this ecto-ATPase in adhesion of T. vaginalis to host cells and in its pathogenicity.

Upstream of the mouse 45S pre-ribosomal RNA promoter there are regions that are involved in enhancement of pre-rRNA transcription, origin of replication and promotion of amplification. We report that in different mouse strains and cell lines the enhancer region, which overlaps with the origin of replication, is hypo-methylated. Contrary to that the amplification- promoting sequences 1 and 2, identified upstream in the intergenic spacer, are hypermethylated. Hybridization results also suggest that amplification-promoting sequence 1 is repeated in the genome.

Pharmacological induction of low deoxyribonucleoside triphosphate (dNTP) levels in virus-infected cells could result in an increased antiviral effectiveness of some selective antiviral nucleoside analogues. That could be exploited as a new combined strategy in the treatment of herpes virus infections. From this point of view the alteration of antiherpes activity of acyclovir (ACV) in combination with mizoribine (N′-[β-d-ribofuranosyl]-5-hydroxyimidazole-4-carboxamide) (MZR), an inhibitor which lowers the intracellular pool of dGTP, was studied. MZR applied alone at non-toxic concentrations had no effect on herpes simplex virus type 1 (HSV-1) replication in human embryonic skin-muscle fibroblasts (HESMF). The combination of MZR and ACV acts synergistically, as measured by the virus yield assay in the above mentioned system. The potentiating effect of MZR on the anti-HSV-1 activity of ACV was reversed by guanosine (Guo). In this case dGTP could be considered as the “key metabolite” responsible for the higher effectivity of the combination of drugs.

Silylated ethanolic extract of two propolis samples from Kazan and Marmaris regions in Turkey were investigated by capillary GC-MS. The compounds were characterized by comparison with library searches. Twenty four compounds from Kazan samples were identified, eight of them were new for propolis. Eighteen compounds from Marmaris samples were identified, two of them were new for propolis.

The response of the two most abundant cockchafer species in central Europe, Melolontha hippocastani and M. melolontha, towards phenol, mixtures of phenol with the leaf alcohol (Z)-3-hexen-1-ol and the known cockchafer pheromones, 1,4-benzoquinone (M. hippocastani) and toluquinone (M. melolontha), was investigated in the field. During the swarming period at dusk, phenol attracted males of both species, and enhanced the known attraction of cockchafer males towards (Z)-3-hexen-1-ol. A mixture of phenol plus (Z)-3-hexen-1-ol was less attractive for M. hippocastani males than a mixture of (Z)-3-hexen-1-ol plus 1,4- benzoquinone, whereas phenol plus (Z)-3-hexen-1-ol attracted as many M. melolontha males as a mixture of (Z)-3-hexen-1-ol plus toluquinone. In both species three component mixtures containing phenol, (Z)-3-hexen-1-ol, and the respective benzoquinone did not capture more males than two component mixtures consisting of only (Z)-3-hexen-1-ol and the benzoquinone. A possible role of phenol as another cockchafer sex pheromone component is discussed.

A detailed chemical analysis of a Philippine marine sponge Smenospongia sp. has been performed. This study yielded four new metabolites, 5-bromo-l-tryptophan (1), 5-bromoabrine (2), 5,6-dibromoabrine (3) and 5-bromoindole-3-acetic acid (4). The pyrroloiminoquinone alkaloid, makaluvamine O (5) as well as 5,6-dibromotryptamine (6), aureol (7) and furospinulosin 1 (8) were also isolated. Although 1 and 4 have been synthesized previously, this is the first report on the isolation of these compounds from a natural source. The furanosesterterpene furospinulosin 1 (8) was obtained for the first time from the genus Smenospongia. The structures of all compounds were established by spectroscopic methods (UV, IR, 1D and 2D NMR, MS, [α] ᴅ ). The cytotoxic potential of 1−8 was evaluated in a panel of isogenic HCT-116 human colon tumor cell lines.

A tetrahydroxyanthrone derivative, resistomycin, was isolated from the culture broth of Streptomyces sulphureus and a similar polyphenolic dianthraquinone, hypericin, was isolated from an extract of Hypericum perforatum L. as modulators for apoptosis. Resistomycin inhibited apoptosis induced by actinomycin D (AD) with or without acceleration by colcemid (CL) in human megakaryoblastic leukemia CMK-7 cells. IC 50 for inhibition against AD-induced apoptosis was about 0.5 μm and IC 50 for inhibition against AD plus CL-induced apoptosis was about 1 μm. CL alone induced weak apoptosis in cells, which was enhanced by resistomycin. Hypericin did not inhibit AD-induced apoptosis and slightly enhanced CLinduced apoptosis. Emodin, corresponding to 1 of 2 anthraquinone units in hypericin, did not show any effect on this apoptotic system. AD-induced apoptosis was inhibited by the antioxidative flavonoid, luteolin (IC 50 45 μm), and a protein kinase C (PKC) inhibitor, staurosporine (IC 50 1.5 μm), but these compounds did not affect the CL-induced apoptosis. Hypericin and resistomycin scavenged superoxide anion radicals at the same rate as luteolin. PKC in CMK-7 cells was inhibited by hypericin and luteolin, but not significantly inhibited by resistomycin. This result suggests that the inhibition of AD-induced apoptosis by resistomycin is at least partly correlated with its antioxidative activity, and that the enhancement of CLinduced apoptosis by this compound depends upon the lack of PKC inhibitory activity. Though the mechanism is not clear, the enhancement of the CL-induced apoptosis might be hindered by PKC inhibition in the case of hypericin and luteolin.

Experimental results indicate a significant decrease in the potential difference (PD) and in the short-circuit current (Isc) after the application of proparacaine to isolated toad skin, which may reflect an inhibition of the active transport of ions. This finding was explained on the basis of the results obtained from membrane models incubated with proparacaine. These consisted of human erythrocytes, isolated unsealed human erythrocyte membranes (IUM), phospholipid multilayers built-up of dimyristoylphosphatidylcholine (DMPC) and dimyristoylphosphatidylethanolamine (DMPE), representatives of phospholipid classes located in the outer and inner monolayers of the human erythrocyte membrane, respectively, and in large unilamellar vesicles (LUV) of DMPC. X-ray diffraction showed that proparacaine interaction with DMPC and DMPE bilayers perturbed both structures, especially DMPC. This result, confirmed by fluorescence spectroscopy of DMPC LUV at 18 °C, demonstrated that the local anesthetic (LA) could interact with the lipid moiety of cell membranes. However, effects observed by scanning electron microscopy (SEM) of human erythrocytes and by fluorescence spectroscopy of IUM might also imply proparacaine-protein interactions. Thus, the LA may alter epithelial sodium channels through interaction with the lipid matrix and with channel protein residues.

To evaluate the effect of galactose metabolic disorders on the brain Na + ,K + -ATPase in suckling rats. Separate preincubations of various concentrations (1-16 mᴍ) of the compounds galactose-1-phosphate (Gal-1-P) and galactitol (galtol) with whole brain homogenates at 37 °C for 1 h resulted in a dose dependent inhibition of the enzyme whereas the pure enzyme (from porcine cerebral cortex) was stimulated. Glucose-1-phosphate (Glu-1-P) or galactose (Gal) stimulated both rat brain Na + ,K + -ATPase and pure enzyme. A mixture of Gal-1-P (2 mm), galtol (2 mᴍ) and Gal (4 mᴍ), concentrations commonly found in untreated patients with classical galactosemia, caused a 35% (p < 0.001) rat brain enzyme inhibition. Additionally, incubation of a mixture of galtol (2 mᴍ) and Gal (1 mᴍ), which is usually observed in galactokinase deficient patients, resulted in a 25% (p < 0.001) brain enzyme inactivation. It is suggested that: a) The indirect inhibition of the brain Na + ,K + -ATPase by Gal-1-P should be due to the presence of the epimer Gal and phosphate and that the pure enzyme direct activation by Gal-1-P and Glu-1-P to the presence of phosphate only. b) The observed brain Na + ,K + -ATPase inhibitions in the presence of toxic concentrations of Gal-1-P and/ or galtol could modulate the neural excitability, the metabolic energy production and the catecholaminergic and serotoninergic system.

In pollen, flavonoids are usually found as glycosides and in particular, flavonol 3-O-diglycosides. However, in members of the Myrtaceae, subfamily Leptospermoideae, the rare flavone aglycone tricetin, along with other flavonoid aglycones including 3-O-methyl quercetin and luteolin, have been found to comprise a significant portion of the constituent flavonoids.

The molecular structure of diosgenone, a natural steroidal sapogenin, closely related to diosgenin and isolated from Solanum nudum, was solved by single crystal X-ray diffractometry at 120 K and refined by full-matrix least-squares to an agreement factor, R1 = 0.054. It crystallizes in the monoclinic space group P2 1 , with a = 15.1870(4) Å , b = 7.2710(2) Å , c = 21.2840(6) Å , β= 99.251(1) °, and four molecules in the unit cell (Z = 4). The results constitute the first structural report on a steroidal sapogenin from the diosgenin group.

The objective of this study was to examine the effect of Cr(III) (chromium chloride) and Cr(VI) (potassium dichromate) on RNA and DNA-chromium adducts formation in isolated nucleic acids and isolated pig lymphocytes. The incubation of cells with potassium dichromate and chromium chloride at concentrations of 10 and 100 μm results in binding of a 1.2-1.9 fold greater number of chromium atoms to nuclear DNA than to total cellular RNA. The incubation of total cellular RNA and nuclear DNA isolated from lymphocytes with CrCl 3 and K 2 Cr 2 O 7 yielded a binding of 1.1-1.6 fold more of Cr atoms to RNA than to DNA. The number of chromium atoms bound to nucleic acids is higher after incubation with K 2 Cr 2 O 7 than with CrCl 3 in both experimental systems.

Coordination isomeric diastereomeric Cr 3+ complexes of the pyoverdin of Pseudomonas aeruginosa ATCC 15692 could be separated by chromatography and characterized by spectroscopic methods.

This paper describes a comparative study using different chromatographic supports (fully N-acetylated chitin, chitin and silica gel) to separate the flavonoids swertisin and 2″-O-rhamnosylswertisin from Aleurites moluccana. The results show that the flavonoids have apparently been separated by the hydrogen bond between the stationary phase (chitin and chitin-100) and flavonoids under the conditions studied.

A modified, rapid and inexpensive method for preparation of mitochondrial DNA (mtDNA), suitable for molecular analysis is proposed. It comprises batch cultivation of Saccharomyces cerevisiae strain NBIMCC 583 on a simple nutrient medium at 28 °C; permeabialization of cells from late exponential growth phase with cetyltrimethylamonnium bromide, mechanical disintegration of the cell wall; preparation of a mitochondrial fraction and subsequent isolation and purification of mtDNA. The amount and the purity of the obtained mtDNA have been checked and its application for molecular analysis proven. The main advantages of the proposed procedure for isolation of mtDNA are introduction of simple nutrient medium, replacement of the enzymatic lysis of the cell wall by the cheaper mechanical one, avoidance of ultracentrifugation steps and use of harmful chemical substances.

A novel compound, lepidolide 1, was isolated from the fruiting bodies of the Basidiomycete Russula lepida. Its structure was established by spectroscopic and chemical means.