Volume 56, Issue 7-8

Unspecific biological effects of chemically diverse solvents strikingly reveal the unifying motif of oxidant toxicity both in higher organisms and in aerobic bacteria. In a few spectacular cases, solvent metabolites with oxidant properties were demonstrated, which however cannot explain extrahepatic toxicity, e.g. in muscle and nerve cells. A common source of solvent-inducible oxidants, by contrast, is suggested to be located in mitochondria or, more general, in membranes where the respiratory chain operates. Orderly respiration depends on membrane integrity, which is invariably compromised by exposure to most solvents and many other lipophils. In rat mitochondria, toluene-induced membrane derangement has been directly implicated with superoxide production, resulting from autoxidation of the membrane-located respiratory redox-cycler ubisemiquinone. A related mechanism may occur in bacteria: Exposure of Escherichia coli to lipophils such as ethanol, tetralin, indole, chlorpromazine and procaine, or to heat shock, induces anti-oxidant proteins, which are reliable indicators of increased oxidant levels. Although many molecular details remain to be elucidated, this review documents that oxidant toxicity of lipophilic compounds is a common physiological phenomenon correlated with derangement of membranes where respiratory processes take place. Subjective consequences of acute oxidant injury are probably the hangover from alcohol and nicotine consumption, and the sudden death from recreational solvent abuse. Suggestions concerning oxidants as major contributors to ageing remain unchallenged

The alkaloids chelerythrine, norchelerythrine, oxyavicine, canthine-6-one. 4,5-dihydrocanthin-6-one, and γ-fagarine were isolated from Zanthoxylum dimorphophyllum bark, together with two coumarins, scoparone and dimoxylin. This latter is a novel compound whose structure was elucidated on the basis of its spectral data

A new polyene pigment, melanocrocin, has been isolated either from fruit bodies or myce­lial cultures of the subterranean fungus Melanogaster broomeianus. The structure of the pig­ment was determined by spectroscopic methods and chemical transformations. Melanocrocin is the N-acyl derivative of ʟ-phenylalanine methyl ester with a polyolefinic carboxylic acid

A new flavonoid, 2,3-trans-5,2′-dihydroxy-7,8-dimethoxy-dihydroflavonol-3-O-acetate, was isolated from the farinose coating on the lower leave surface of the fern, Notholaena sulphurea. The 2,3-cis diastereoisomer was isolated as a co-constituent. This novel acylated flavonoid is characteristic for the chemotype of N. sulphurea exhibiting yellow frond exudate. Its orrurrence underlines the affiliation of the species with the genus Notholaena

The structures of a new eudesmane sesquiterpene, lauradiol, and a new secoeudesmane, azoridione, have been determined by spectroscopic methods. These compounds and the known sesquiterpenic alcohols, clovanediol and caryophyllenol II, have been isolated from the aerial parts of Laurus azorica

Chemical investigation of the Bulgarian species Tanacetum, parthenium, T. millefolium, T. achilleifolium, T.corymbosum and T. macrophyllum afforded in addition to 24 known sesquiterpene lactones a new 12, 8-eudesmanolide 22. Besides, four known highly oxigenated terpenoids and a new keto-diol 30 of the rare iphionane skeleton were also isolated. The structures were elucidated on the basis of their spectral properties. The accumulation of the different sesquiterpene lactones in the studied species and there classification is discussed

We report here an updated summary about iridoid composition of a series from the genus Scrophularia which have been investigated until now from a phytochemistry point of view. In addition a list is included about iridoids isolated in our laboratory from different plant parts of Scrophularia scorodonia L.,which are compared with iridoids from some species of the Scrophularia genus. The present study may serve as a current information to researchers working on phytochemistry and pharmacological aspects from the Scrophularia genus and possibly to serve as a new starting point for future investigations

The detailed investigation of a methanolic extract of aerial parts of Achillea pannonica SCHEELE. within a chemotaxonomic study led to the isolation of 6 flavonoid glycosides. Besides rutin, apigenin-7-O-glucopyranoside, luteolin-7-O-glucopyranoside, apigenin-7-O-rutinoside and acacetin-7-O-rutinoside, an unusual flavondiglucoside was isolated. Its structure was established by UV, 1 HNMR and 13 C NMR spectroscopic methods including 2D-NMR techniques and ESI-MS as luteolin-7,4′-O-β-diglucoside. This substance is reported for the first time in the genus Achillea. Chemotaxonomic aspects are discussed briefly

A new hydroxycinnamoyl polyamine derivative, N,N′,N″-triferuloylspermidine (= (E)-N-(4-aminobutyI)-3,3′,3″-tris(4-hydroxy-3-methoxyphenyl)-N,N′,N″-(butane-1,4-diyl)tris [prop-2-enamide]) (1) was detected in the H 2 O /MeOH extract of pollen from Hippeastrum × hortorum. The compound was identified by on-line-coupled high-performance liquid chromatography and atmospheric-pressure chemical-ionization mass spectrometry (HPLC-UV(DAD)/ APCI-MS and MS/MS). The structure was proven by comparing the HPLC/MS data after UV-induced (E) ⇄ (Z) photoisomerization and catalytic hydrogenation of the natural compound and the synthetic reference compound. This is the first report of a triferuloylspermidine in nature

Terpene composition of needle and cortical oleoresin from lateral shoots were analyzed by GC/MS for four Silver fir (Abies alba Mill.) populations scattered in natural species range in Albania. More than sixty compounds were detected in the needle oleoresin, which was characterized by a high content of α-pinene, camphene, β-pinene, limonene and bornyl acetate. Three monoterpenes, α-pinene, β-pinene and limonene, and two sesquiterpenes, β-caryophyllene and germacrene D, comprised the majority of cortical oleoresin. The terpene composition differences among the populations that led to the recognition of two chemo-types. The needle oleoresin from the provinces of Puka, Bulqiza and Llogara were characterised by high amounts of β-pinene, camphene and α-pinene and low amounts of limonene, while that from Drenova had high amounts of β-pinene and limonene. A similar pattern was found in the cortical oleoresin with the exception of camphene that was a minor contributor. Geographical and seasonal variation between the populations was, also, investigated. Multi­variate analysis of both needle and cortical oleoresin separated Drenova (southeastern population) from the other sites. When both major monoterpenes and sesquiterpenes were considered four chemical profiles could be attributed. Based on their chemical profiles, the populations can be divided into two groups: Populations with high content of β-pinene and α-pinene but a low content of limonene (Puka, Bulqiza and Llogara), typical of most of A. alba populations in all its distribution range. Population with a high content of limonene and a moderate content of β-pinene and α-pinene (Drenova)

Pyridinochelin, a novel tetradentate catecholate-type siderophore, has been designed on the basis of the active analog enterobactin and was then synthesized. Growth promotion tests indicate that this synthetic siderophore feeds various pathogenic bacteria most effectively with iron even though it lacks one catecholate group compared to enterobactin. The superposition of the mentioned siderophore structures suggests that the structure of the skeleton connecting the catecholate groups might be an important factor for the iron transport

A strain of Pseudomonas aeruginosa isolated from a polluted soil was found to produce an extracellular bioemulsifier when cultivated on hexadecane as sole carbon source. The emulsifier was precipitated with acetone and redissolved in sterile water. Dodecane, crude oil and kerosene were found to be good substrates for emulsification by the bioemulsifier. Growth and bioemulsifier production reached the optimal levels on the fourth and fifth day, respectively. Emulsifying activity was observed over a pH range of 3.5 to 10.0 with a maximum at pH 7.0. The activity of the bioemulsifier was heat stable up to 70 °C while about 50 percent of its activity was retained at 100 °C. The components of the bioemulsifier were determined, it was found to contain carbohydrate, protein and lipid. The protein complex was precipitated with ammonium sulphate and fractionated on a Sephadex G-100. Gel electrophoresis of the bioemulsifier showed a single band whose molecular weight was estimated as 14,322 Da. The bioemulsifier was classified as a peptidoglycolipid. Certain strains of P. aeruginosa produce peptidoglycolipid in place of rhamnolipid

Catalytic activity of catalase (CAT, EC 1.11.1.6), immobilized on carbon black NORIT and soot PM-100, with respect to decomposition of dibenzoyl peroxide (BPO) in non-aque-ous media (acetonitrile and tetrachloromethane), was investigated with a quantitative UV-spectrophotometrical approach. Progress of the above reaction was controlled by selected kinetic parameters: the apparent Michaelis constant (K m app ), the specific rate constant (K sp ), the activation energy (E a ), the maximum reaction rate (V max ), and the Arrhenius’ pre-exponential factor (Z 0 ). Conclusions on the tentative mechanism of the catalytic process observed were drawn from the calculated values of the Gibbs energy of activation (ΔG*), the enthalpy of activation (ΔH*), and entropy of activation (ΔS*)

Enantiomers of triaziflam and structurally related diaminotriazines were synthesized and their herbicidal mode of action was investigated. The compounds caused light and dark-dependent effects in multiple test systems including heterotrophic cleaver and photoautotrophic algal cell suspensions, the Hill reaction of isolated thylakoids and germinating cress seeds. Dose response experiments revealed that the (S)-enantiomers of the compounds preferentially inhibited photosystem II electron transport (PET) and algae growth with efficacies similar to that of the herbicide atrazine. In contrast, the (R)-enantiomers of the diaminotriazines were up to 100 times more potent inhibitors of growth in cleaver cell suspensions and cress seedlings in the dark than the (S)-enantiomers. The most active compound, the (R)-enantiomer of triaziflam, inhibited shoot and root elongation of cress and maize seedlings at concentrations below 1 μm. The meristematic root tips swelled into a club shape which is typical for the action of mitotic disrupter herbicides and cellulose biosynthesis inhibitors. Microscopic examination using histochemical techniques revealed that triaziflam (R)-enantiomer blocks cell division in maize root tips 4 h after treatment. The chromosomes proceeded to a condensed state of prometaphase but were unable to progress further in the mitotic cycle. Disruption of mitosis was accompanied by a loss of spindle and phragmoplast micotubule arrays. Concomitantly, cortical microtubules decreased which could lead to iso-diametric cell growth and consequently to root swelling. In addition, a decline in cellulose deposition in cell walls was found 24 h after treatment. Compared to the (R)-form, triaziflam (S)-enantiomer was clearly less active. The results suggest that triaziflam and related diaminotriazines affect enantioselectively multiple sites of action which include PET inhibitory activity, mitotic disruption by inhibiting microtubule formation and inhibition of cellulose synthesis

Phytochemical survey of stems and leaves of the South Brazilian endemic Raulinoa echinata Cowan, Rutaceae led to the isolation of five limonoid derivatives: the widespread limonin, limonexic acid, kihadalactone B, a methoxylated limonexic acid derivative and a degraded limonoid structurally related to fraxinellone. The two latter compounds have been isolated for the first time. These compounds displayed weak inhibitory activity when assayed in vitro against trypomastigote forms of Trypanosoma cruzi. In this paper, the isolation, structure elucidation and bioactivity of these compounds are reported

The repellence of Aristolochia aff. orbicularis root, a native of Xochipala, Guerrero, Mexico, to the corn borer Sitophilus zeamais (Coleoptera) was investigated. The essential oil was isolated from the aromatic root and its repellent effect was assessed. About 40 components of the oil were identified using gas chromatography-mass spectrometry and other spectroscopic methods. The repellence of the roots, the oil and the chromatography fractions were also evaluated. Some fractions had a higher repellence than the total oil

Susceptibility of the nitrogen-fixing soybean symbiont Bradyrhizobium japonicum to inducible plant defense metabolites such as phytoalexin and H 2 O 2 , was investigated. On the wild-type strain USDA 110 the soybean phytoalexin, glyceollin, showed bacteriostatic activity. Viable bacteria isolated from intact nodules were adapted to glyceollin. H 2 O 2 in physio­logical concentrations did not affect wild-type bacteria. B. japonicum mutants defective in the biosynthesis of cyclic β-(1→3)-(1→6)-glucans showed higher susceptibility to both phyto­alexin and H 2 O 2

Chloroplast structure and function is known to alter during foliar senescence. Besides, the alterations in the structural organisation of thylakoid membranes changes in the steady state levels of thylakoid membrane proteins occur due to leaf ageing. We monitored temporal changes in some of the specific proteins of thylakoid membrane protein complexes by western blotting in the Cucumis sativus cotyledons as a function of the cotyledon age. We observed that the levels of D1 and D2 proteins of photosystem II started declining at the early stages of senescence of Cucumis cotyledons and continued to decline with the progress of cotyledon age. Similarly the level of Cyt f of Cyt b 6 /f complex declined rapidly with progress of senescence in these cotyledons. The reaction centre proteins of photosystem I were relatively found to be more stable than that of photosystem II reaction centre proteins reflecting possibly the disorganisation of photosystem II prior to photosystem I. The 33 kDa extrinsic protein (MSP) of oxygen evolving complex, the LHCII apoprotein and the β-subunit of ATPsynthase showed the declined levels with the progress of cotyledon age. However, the extents of loss of these proteins were not as high as the reaction centre proteins of photosystem II and the Cyt f. These results provide that during senescence, proteins of thylakoid membranes degrade in a specific temporal sequence and thereby affect the temporal photo­chemical functions in Cucumis sativus cotyledons

2′,3′-Dihydroxy-4,4′-dimethoxychalcone (1) and 2′,3′,4-trihydroxy-4′-methoxy-chalcone, two new chalcones, were isolated from propolis from El Salvador. The compounds showed significant antibacterial ana antifunfag activity and moderate toxicity to Artemia salina nauplii

Halobates is the only insect genus with representatives in the open ocean. How adults find one another at sea has long been an intriguing issue. Since chemical communications have been demonstrated in a related marine veliid Trochopus, and laboratory bioassays indicated behavioral differences between males and females when insect extracts were presented, we carried out similar studies on Halobates. Analyses of surface lipid constituents of female and male Halobates hawaiiensis revealed marked differences. Palmitic and oleic acid, major constituents in the male extracts, were absent in the female extract, whereas nonacosenol, dominating the female extracts, was not detected in the male extracts. Analyses of nymphal extracts indicated an intermediate chemical profile. Surface waxes of all insect stages investigated showed nonacosanol and isononacosanol to be main components. “Headspace” analyses of airborne chemicals showed high levels of 4-hydroxy-4-methyl-2-pentanone and benzal­dehyde from the male, whereas benzyl alcohol was the main component in the female mixture

From the aerial parts of Maytenus disticha, we have isolated 9β-benzoyloxy-1α,2α,6β,8α,15- penta-acetoxy-dihydro-β-agarofuran (1) and from seeds of Maytenus boaria 9β-furoyloxy-1α, 6β, 8α-triacetoxy-dihydro-β-agarofuran (2). These compounds and their MeOH and hexane/ethyl acetate (1:1 v/v) extracts were evaluated for their effects on the fall armyworm (Spodoptera frugiperda). Toosendanin, a commercial insecticide derived from Melia azedarach was used as a positive control. When tested for activity using neonate larvae in a nochoice artificial diet bioassays, the agarofurans 1, 2 and toosendanin as well as the MeOH and hexane/EtOAc extracts caused significant growth inhibitory effects with GC 50 of 7.55; 3.84; 1.75; 14.0 and 7.3 ppm at 7 days, respectively. Compounds 1 and 2 caused 100% larval mortality at 25 and 15 ppm, respectively. MeOH and hexane/EtOAc extracts caused 100% larval mortality at 25.0 ppm, respectively, they also increased the development time of surviving larvae and a significant delay for the time of pupation and adult emergence. These compounds showed comparable potency of activity with toosendanin. Acute toxicity against adults of S. frugiperda was also found, for hexane/EtOAc extract and 2 had the most potent activity with LD 50 value of 4.7 and 1.9 ppm, respectively. MeOH extract, hexane/EtOAc extract, 1 and 2 caused acetylcholinesterase inhibition with 78.0, 89.2, 79.3 and 100% inhibition at 15.0 ppm, respectively. Therefore, the furoyloxy agarofuran may be responsible for the insecticidal activity of these plants

The interaction of the local anesthetic dibucaine with the isolated toad skin and membrane models is described. The latter consisted of human erythrocytes, isolated unsealed human erythrocyte membranes (IUM), large unilamellar vesicles (LUV) of dimyristoylphosphati-dylcholine (DMPC) and phospholipid multilayers built-up of DMPC and dimyristoylphos-phatidylethanolamine (DMPE), representative of phospholipid classes located in the outer and inner monolayers of the human erythrocyte membrane, respectively. Results indicate a significant decrease in the potential difference (PD) and in the short-circuit current (Isc) after the application of dibucaine in toad skin, which may be interpreted as reflecting inhibition of the active transport of ions. This finding might be explained on the basis of the results ob­ tained from fluorescence spectroscopy and X-ray diffraction studies on membrane models. In fact, dibucaine induced structural perturbations in IUM, DMPC LUV and phospholipid multilayers. Scanning electron microscopy revealed that dibucaine induced erythrocyte stomatocytosis. According to the bilayer couple hypothesis an echinocytic type of shape change would have been expected given the preferential interaction of dibucaine with DMPC. Although it is still premature to define the molecular mechanism of action of dibucaine, the experimental results confirm the important role played by the phospholipid bilayers in the association of the anesthetic with cell membranes

The effects were studied of dodecyltrimethylammonium chloride (DTAC), dodecyltrimethylammonium bromide (DTAB) and dodecyltrimethylammonium iodide (DTAI) on thermo­tropic phase behaviour of phosphatidylcholine bilayers, as well as on 1 H NMR and 31 P NMR spectra, in the presence of diphenyltin dichloride (DPhT) and triphenyltin chloride (TPhT). The obtained results indicate that in the presence of the surfactant studied the interaction of phenyltin compounds with model membranes was changed and the changes depended on the kind of the counterion. The surfactants studied (especially DTAC) decrease the ability of phenyltin compounds to induce structural changes in the bilayer. It is suggested that DTAB, and especially DTAC, prevent DPhT induced interdigitated phase formation as well as formation of an inverted hexagonal phase (H II ) in the case of TPhT/DPPC liposomes

The possible involvement of opioid system in the regulation of hemolymph glucose level in the fresh water crab Oziotelphusa senex senex Fabricius, was investigated. Opioid agonist and antagonist was also used in addition to methionine-enkephalin itself. Injection of the opioid, methionine-enkephalin and FK 33-824 significantly elevated hemolymph glucose level. In contrast, injection of naloxone in to crab resulted in decrease in hemolymph glucose level. Injection of naloxone prior to injection of methionine-enkephalin blocked the hyperglycemic action of methionine-enkephalin. Injection of methionine-enkephalin, FK 33824 and naloxone produced no significant effect on hemolymph glucose level in eyestalk-less crab. The alterations in the intact crab hemolymph glucose level hypothesised to be due to stimulation of release of hyperglycemic hormone during methionine-enkephalin and FK 33824 treatment and blocking of release of hyperglycemic hormone during naloxone treatment from the eyestalks of crab Oziotelphusa senex senex

In this study we investigated relationships between redox properties and biodurability of crocidolite asbestos fibres and three different man-made vitreous fibres (MMVF): traditional stone wool fibres (MMVF 21), glass fibres (MMVF 11) and refractory ceramic fibres (RCF). Each fibre type was incubated up to 22 weeks in four different incubation media: gamble solution (GS) pH 5.0 and pH 7.4, representing blood plasma without proteins, and surfactant­ like solution (SLS) pH 5.0 and pH 7.4. During incubation time aliquots of incubation mixtures were removed and analysed in a biochemical model reaction, mimicking activated phagocytes. In addition, changes of fibre morphology and chemical composition were examined using SEM-and EDX-technology. In the presence of crocidolite asbestos fibres and MMVF 21 the formation of OH-radicals according to the Haber-Weiss sequence could be demonstrated, whereas MMVF 11 and RCF showed no reactivity. Crocidolite asbestos fibres exhibited a significant higher activity com­pared with the stone wool fibres at the onset of incubation. The oxidative capacities of these fibre types were shown to depend on both specific surface area and iron content. The oxidative potentials of crocidolite asbestos fibres as well as MMVF 21 were not constant during incubation over several weeks in each incubation medium. The reactivities showed sinoidal curves including reactivities much higher than those at the onset of incubation time. These irregular changes of oxidative capacity may be explained by changes of the redox state of fibre surface-complexed iron. Furthermore our results showed clear differences between incubation of fibres in GS and SLS, respectively, indicating that phospholipids play an important part in fibre dissolution behaviour and oxidative reactivity. In conclusion we suggest, that biodurability testing procedures should not exclusively concentrate on dissolution rates of fibres. They should include fibre characteristics concerning known pathogenic mechanisms to evaluate the real toxic potential of the fibre type looking at. Secondly we suggest, that phospholipids should be constituents of incubation liquids used for standardised fibre biodurability test procedures thus representing more realistic incubation conditions

CCl 4 -induced liver damage was modeled in monolayer cultures of rat primary hepatocytes with a focus on involvement of covalent binding of CCl 4 metabolites to cell components and/or peroxidative damage as the cause of injury. (1) Covalent binding of 14 C-labeled metabolites was detected in hepatocytes immediately after exposure to CCl 4 . (2) Low oxygen partial pressure increased the reductive metabolism of CCl 4 and thus covalent binding. (3) [ 14 C]-CCl 4 was bound to lipids and to proteins throughout subcellular fractions. Binding occurred preferentially to triacylglycerols and phospholipids, with phosphatidylcholine containing the highest amount of label. (4) The lipid peroxidation potency of CCl 4 revealed subtle differences compared to other peroxidative substances, viz., ADP-Fe 3+ and cumol hydroperoxide, respectively. (5) CCl 4 , but not the other peroxidative substances, decreased the rate of triacylglycerol secretion as very low density lipoproteins. (6) The anti-oxidant vitamin E (α-tocopherol) blocked lipid peroxidation, but not covalent binding, and secretion of lipoproteins remained inhibited. (7) The radical scavenger piperonyl butoxide prevented CCl 4 -induced lipid peroxidation as well as covalent bind­ing of CCI 4 metabolites to cell components, and also restored lipoprotein metabolism. The results confirm that covalent binding of the CCl 3 * radical to cell components initiates the inhibition of lipoprotein secretion and thus steatosis, whereas reaction with oxygen, to form CCI 3 *-OO*, initiates lipid peroxidation. The two processes are independent of each other, and the extent to which either process occurs depends on partial oxygen pressure. The former process may result in adduct formation and, ultimately, cancer initiation, whereas the latter results in loss of calcium homeostasis and, ultimately, apoptosis and cell death

To assess the lethal doses of gamma radiation and corresponding apoptotic response in new established human melanoma cell lines we exposed exponentially growing cultures to 8- 100 Gy gamma radiation. The apoptosis and cell survival were determined by trypan blue exclusion, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) reaction, agarose gel electrophoresis, colony forming assay, and long-term survival assay. The maximal DNA fragmentation 3 days after irradiation was observed in cultures irradiated with 20 Gy (36.9% TUNEL positive cells). The cultures irradiated with 50 and 100 Gy contained 18.7% and 16.4% TUNEL positive cells, respectively. Cultures exposed to 8 and 20 Gy gamma radiation recovered by week 3-4. Lethally irradiated (50 and 100 Gy) cultures which contained less apoptotic cells by day 3 died by week 5. A detectable increase in melanoma cell pigmentation after irradiation was also observed. The survival of human melanoma cell cultures after exposure to gamma radiation does not correlate with the level of apoptotic cells by day 3. At high radiation doses (> 50 Gy) when the radiation induced cell pigmentation is not inhibited the processes of apoptotic DNA fragmentation might be preferentially inactivated

The aim of the present work is to study the chemical composition of Turkish propolis. Propolis samples were collected from different regions of Turkey (Bursa, Erzurum-Askale, Gumushane-Sogutagil and Trabzon-Caglayan) in 1999. Ethanol extracts of propolis (EEP) were prepared for chemical analysis, using gas chromatograph coupled with mass spectrometry (GC-MS). Our findings show that propolis samples from Trabzon and Gumushane region have a similar chemical composition. In both samples aromatic acids, aliphatic acids and their esters, and also ketone derivatives are the main compound groups. The chemical composition of the single sample that was collected from Erzurum region shows a very different pattern than the other two samples. In this propolis, the main compounds are aromatic acid esters and alcohols. However, it contains a high amount of amino acids compared to the other samples. The other samples collected from three different region of Bursa City are rich with flavavones, aromatic acids and their esters, terpenoids, flavones and ketones