Volume 57, Issue 11-12

Melampodium divaricatum is a medicinal plant, which occurs in Central America. In a recent paper we reported the occurrence of acylated 2-hydroxy thymol glycosides as main constituents in this plant. This paper deals with the isolation of two new 2,5-dihydroxythymol ester derivatives. The formerly reported sesquiterpene lactone mikanokryptin was not found in our plant material.

Two new phenylpropanoid glycosides (2′-O-acetylplantamajoside and 2′-O, 6″-O-diacetylplantamajoside), a new iridoid glycoside (10-O-(cinnamoyl)-6′-O-(desacetylalpinosidyl)-catalpol), the two known iridoid glycosides globularin and isoscrophularioside, and the known phenylpropanoid glycoside platamajoside were isolated from the methanolic extract of the underground parts of Wulfenia carinthiaca. Structure elucidations were based on high-resolution mass spectrometry and extensive 1-D and 2-D NMR spectroscopy.

The investigation of a dichloromethane extract of flower heads of a Hungarian taxon of the Achillea millefolium group led to the isolation of three flavonoid aglycones, one triterpene, one germacranolide and five guaianolides. Their structures were elucidated by UV-VIS, EI- and CI-MS, 1 H NMR and 13 C NMR spectroscopic methods as well as by 2D-NMR studies and by selective 1D-NOE experiments. Besides apigenin, luteolin and centaureidin, β-sitosterol, 3β-hydroxy-11α,13-dihydro-costunolide, desacetylmatricarin, leucodin, achillin, 8α-angeloxy-leucodin and 8α-angeloxy-achillin were isolated. Both latter substances are reported here for the first time. Their NMR data were compared with those of the other guaianolides. The stereochemistry of 3β-hydroxy-11α,13-dihydro-costunolide was discussed and compared with data of the literature.

The infusion of the aerial parts of Turnera diffusa was phytochemically examined. Chromatographic procedures led to the isolation of a new flavone glycoside, five known flavonoids and p-arbutin. Structures were determined by 1D- and 2D NMR experiments, as well as ES-MS and UV spectra.

The alkaloids norchelerythrine, magnoflorine and (-)(S)-O-methylbalfourodinium cation were isolated from Zanthoxylum scandens bark collected in Vietnam, together with the flavanone glycoside hesperidin and the phenylpropanoids (E)-O-geranylconiferyl alcohol and (E)-O-geranylconiferyl alcohol (9Z, 12Z)-linoleate. This latter is a novel compound whose structure was elucidated on the basis of its spectral data and confirmed by chemical correlation.

The hydro-distilled volatile oil of the Cinnamomum zeylanicum (C. zeylanicum) buds was analyzed using GC and GC-MS for the first time. Thirty-four compounds representing ≈ 98% of the oil was characterized. It consists of terpene hydrocarbons (78%) and oxygenated terpenoids (9%). α-Bergamotene (27.38%) and α-copaene (23.05%) are found to be the major compounds. A comparison of the chemical composition of the oil was made with that of flowers and fruits.

A transformed root culture of Cichorium intybus L. (Asteraceae) was found to produce sesquiterpene lactones of guaiane and germacrane type. Lactucopicrin, 8-desoxylactucin and three sesquiterpene lactone glycosides: crepidiaside B, sonchuside A and ixerisoside D were isolated from the roots. The yield of 8-desoxylactucin reached 0.03 g l -1 at the early stationary phase of the culture.

From the leaves of Microbiota decussata (Cupressaceae) biflavones: cupressuflavone, amentoflavone and 7-O-methylamentoflavone were isolated and identified. The amount of cupressuflavone in Microbiota decussata and xCupressocyparis leylandii (Leyland cypress) (Cupressaceae) was determined by HPLC (1.82% and 0.83%, respectively). The chemical composition of essential oils from bark and leaves of Microbiota decussata was established by GC-MS (GC-FID) analysis. As a major component thujopsene (39.2% and 45.9%, respectively) was identified. Wiridiflorol (3.0%) and τ-muurolol (0.3%) were present only in leaves but globulol (1.5%) exclusively in bark. The content of essential oils in M. decussata was high - 5.4% in bark and 12.6% in leaves. The essential oils from M. decussata and xC. leylandii were bioassayed towards different fungi of the genus Fusarium. Leyland cypress essential oil at 2% concentration fully inhibited the growth of all fungi.

5-(2′-oxoheptadecyl)-resorcinol (1) and 5-(2′-oxononadecyl)-resorcinol (2) were isolated from fermentations of an imperfect basidiomycete. The structures of the compounds were determined by spectroscopic techniques. Both compounds exhibit cytotoxic effects against the human colon tumor cell lines COLO-320, DLD-1 and HT-29 and the human promyeloid leukemia cell line HL-60, the human leukemia T cell JURKAT, the human hepatocellular carcinoma cell line HEP-G2 as well as the J774 mouse macrophage cell line. The compounds induce morphological and physiological differentiation of HL-60 cells into granulocytes, which subsequently die by apoptosis. Both compounds show no antibacterial and antifungal activity.

The effect of 2-benzylamino-1,3,5-triazines on photosynthetic electron transport (PET) was measured with thylakoids isolated from atrazine-resistant, wild-type Chenopodium album, and spinach to find novel 1,3,5-triazine herbicides bearing a strong PET inhibition. The PET inhibition assay with Chenopodium (wild-type and resistant), yielded a resistance ratio (R/ W = I 50 (resistant)/I 50 (wild-type)) of 324 for atrazine while for benzylamino-1,3,5-triazine derivatives of diamino-1,3,5-triazines a R/W of 11 to 160 was found. The compounds having a benzylamino group at one of the amino groups in the diamino-1,3,5-triazines have a resistant ratio down to one half to 1/30 of the atrazine value. The average resistance ratio of 21 benzylamino derivatives of monoamino-1,3,5-triazines was found to be about 4.0. The inhibition of 21 benzylamino-1,3,5-triazines assayed with atrazine-resistant Chenopodium thylakoids, indicated by pI 50 (R) -values, correlated well with the PET inhibition pI 50 (W) of wildtype thylakoids from Chenopodium.

Antibacterial bioassay guided fractionation of acetone extracts of Astragalus brachystachys resulted in isolation of sclareol and two related labdane-type diterpenoids, 14R-epoxysclareol and 6β-hydroxysclareol. The antibacterial activity of the isolated compounds was measured and it was deduced that the epoxidation at the double bond of sclareol or hydroxylation at C-6 decreased the activity of the resulting compounds. Salvigenin (5-hydroxy-4′,6,7-trimethoxyflavone) was also separated from this plant for the first time.

Different extracts from 11 West African plants traditionally used against malaria in Ghana were tested against both the chloroquine-sensitive strain PoW and the chloroquine-resistant clone Dd2 of Plasmodium falciparum. Due to the promising in vitro activity of the lipophilic extract [IC 50 : 10.5 μg/ml (PoW); 13.1 μg/ml (Dd2)], Microglossa pyrifolia (Lam.) Kuntze (Asteraceae) was chosen for further phytochemical investigation. From active fractions 13 compounds were isolated; their structures were established on the basis of spectroscopic methods. 1-Acetyl-6E-geranylgeraniol-19-oic acid and sinapyl diangelate represent new natural compounds. The two diterpenes E-phytol [IC 50 : 8.5 μм (PoW); 11.5 μм (Dd2)], and 6Egeranylgeraniol- 19-oic acid [IC 50 : 12.9 μм (PoW); 15.6 μм (Dd2)] proved to be the most active constituents in our test system.

Five annonaceous acetogenins, rolliniastatin-1 (1), rolliniastatin-2 (2), laherradurin (3), squamocin (4), annonacin (5), and rotenone as a reference, differing in their NADH oxidase inhibition activity, have been evaluated for antifeedant, insecticidal, trypanocidal and cytotoxic effects on insect, mammalian and tumor cells. All the test compounds were toxic to Leptinotarsa decemlineata, demonstrated selective cytotoxicity to insect Sf9 cells and a panel of tumor cell lines with the multidrug-resistant SW480 (P-glycoprotein + , Pgp + ) being the most sensitive one. Compounds 1, 2, 4, and rotenone had post-ingestive effects against Spodoptera littoralis larvae while 1, 4, 5, and rotenone were active against Trypanosoma cruzi. Based on their biochemical properties (inhibition of the mitochondrial NADH oxidase activity), the in vivo effects of these compounds on S. littoralis and their cytotoxic effects on Sf9 and tumor cells were more predictable than their effect on T. cruzi and mammalian cells.

Sporopollenin from the pollen of Typha angustifolia L. was exposed to a series of 36 subsequent acidic methanolysis procedures. The remaining decomposition products were investigated using several spectroscopic methods including Fourier transform infrared spectroscopy (FT-IR), solid state 13 C nuclear magnetic resonance spectroscopy ( 13 C-CPMAS-NMR) and X-ray photoelectron spectrometry (XPS). Substantial weight losses of the sporopollenin material occur after each acidic methanolysis step, while FT-IR and 13 C-CPMAS-NMR spectra display no noticeable differences after 12, 24 and 36 steps. These findings are interpreted as a hint that the sporopollenin polymer has a uniform composition, i.e. relatively small monomer moieties of similar primary structure are present. Moreover, the weight losses account for the presence of substantial amounts of ether linkages in the sporopollenin polymer.

A novel Nostoc commune-polysaccharide (NPS)-degrading enzyme with a molecular mass of 128.5 kDa was purified from Paenibacillus glycanilyticus DS-1. The optimum pH and temperature of the enzyme activity were 5.5 and 35 °C, respectively. The enzyme completely degraded NPS to oligosaccharides, ranging from tetra to hexasaccharides and could degrade the xylan weakly whereas xanthan, gellan, cellulose, curdlan and p-nitrophenyl-β-ᴅ-xylopyranoside were not degraded. Homology analysis of the N-terminal amino acid sequence of the NPS-degrading enzyme against the PIR and SWISS-PROT databases indicated that the sequence was not homologous to any other polysaccharide-degrading enzyme.

The decomposition of 4-chloroaniline (4-ClA), used as a model for water pollutants, was studied by ozonolysis as well as by γ-rays in the presence of ozone under comparable conditions. The degradation process was followed by absorption spectroscopy and by HPLC-method as well. Depending on the ozone concentration (mg O 3 /min) introduced into the aqueous solution the substrate is decomposed to a mixture of carboxylic acids, which can be entirely degradated by prolonged treatment. The combined processing of 4-ClA by γ-irradiation in the presence of ozone proved to lead even to more efficient degradation of the substrate. Some primary reaction steps are briefly discussed.

The natural naphthopyranones paepalantine (1), paepalantine-9O-β-ᴅ-glucopyranoside (2) and paepalantine-9-O-β-ᴅ-allopyranosyl-(1→6)-O-β-ᴅ-glucopyranoside (3) were separated in a preparative scale from the ethanolic extract of the capitula of Paepalanthus bromelioides by high-speed counter-current chromatography (HSCCC). The solvent system used was composed of water-ethanol-ethyl acetate-hexane (10:4 : 10:4, v/v/v/v). This technique led to the separation of the three different naphthopyranone glycosides in pure form in approximately 7 hours. Paepalantine showed a good antioxidant activity when assayed by the DPPH radical spectrophotometric assay.

The brominated pyrrolo[2,3-b]indole deformylflustrabromine was isolated as a new natural product from the bryozoan Flustra foliacea, collected in the North Sea. Deformylflustrabromine appears to be the missing link in the biosynthetic sequence from flustrabromine to flustraminol A. Flustramines A, D, and dihydroflustramine C were determined as other major constituents of the investigated sample. Deformylflustrabromine is cytotoxic against the human colon cancer cell line HCT-116 (IC 50 5.8 μм).

The usefulness of phosphotungstate reagent for vitamin C determination in tissue homogenates has been confirmed. An optimal homogenization medium was selected: 1.8 м solution of HPO 3 in 1.3 м CH 3 COOH. With this medium the analytical curve (at 700 nm) demonstrated the right linearity, correlation and recovery coefficients were appropriately high (0.999 and 99.8%) and the values of intraserial and interserial variation coefficient were low (< 5% and < 10%, respectively). It makes this method sensitive, easily repeatable, and useful for vitamin C determination in animal and human tissues, including neoplastic ones.

We studied antioxidant activity of six neuroleptics (chlorpromazine, levomepromazine, promethazine, trifluoperazine and thioridazine) and two antidepressants (imipramine and amitriptyline) in the range of concentration of 10 −7 −10 −4 м. We applied luminol-dependent chemiluminescence to test the ability of these drugs to scavenge the biologically relevant oxygen-derived species: hydroxyl radical, superoxide radical, hypochlorous acid in vitro. We found that the phenothiazines were powerful scavengers of hydroxyl and superoxide radicals. Chlorprothixene, amitriptyline and imipramine had no scavenge activity to the superoxide radical. All drugs showed a moderate scavenger effect on hypochloric anion.

Kinetics and mechanism of hydrolysis of acetylthiocholine by the enzyme butyrylcholine esterase was studied. The spectrophotometric Ellman’s method and potentiometric pH-stat method were used for continuous determination of the actual concentration of the products thiocholine and acetic acid in the reaction mixture. The validity of the Michaelis-Menten (Briggs-Haldane) equation in the whole course of the reaction under used conditions was proved. The corresponding kinetics parameters (V m and K M ) were calculated from the obtained dependences of concentration of thiocholine or acetic acid vs. time and compared. From this comparison the deciding kinetic role of the step producing thiocholine was derived. The values of initial molar concentration of the enzyme and of the rate constants of the kinetic model were estimated.

Vipoxin from the venom of Vipera ammodytes meridionalis is an unique neurotoxic complex between a toxic phospholipase A2 and a highly homologous non-toxic protein inhibitor. It is an example of evolution of a catalytic and toxic function into inhibitory and non-toxic one. The activity of the V. ammodytes meridionalis toxin is 1.7 times higher than that of the closely related (92% sequence identity) neurotoxic complex RV4/RV7 from the venom of Vipera russelli formosensis. The enhanced enzymatic activity of vipoxin is attributed to limited structural changes, in particular to the substitutions G54R and Q78K in the PLA2 subunit of the complex and to the T54R substitution in the inhibitor. Oleyloxyethylphosphocholine, aristolochic acid and vitamin E suppressed the enzymatic activity of vipoxin and its isolated PLA2 subunit. These compounds influence inflammatory processes in which PLA2 is implicated. The peptide Lys-Ala-Ile-Tyr-Ser, which is an integral part of the PLA2 components of the two neurotoxic complexes from V. ammodytes meridionalis and V. russelli formosensis (sequence 70-74) activated vipoxin increasing its PLA2 activity by 23%. This is in contrast to the inhibitory effect of the respective pentapeptides with 70Ð-74 sequences on other group II PLA2s. Surprisingly, the same peptide inhibited 46% of the V. russelli formosensis PLA2 activity. The limited changes in the structure of the two highly homologous neurotoxins lead to considerable differences in their interaction with native peptides.

The steady-state and time-resolved fluorescence properties of the multitryptophan minimal subunit CaeSS2 from Carcinus aestuarii hemocyanin have been studied with the aim of probing the environment of the fluorophores within the protein matrix. Subunit a of Panulirus interruptus hemocyanin, whose X-ray structure is known, has been also studied. The results are compared with those collected with other two monomeric fractions (CaeSS1, CaeSS3) produced by dissociation of the native, oligomeric protein as well as with those of the hexameric aggregate. Three classes of tryptophan residues can be singled out by a combination of fluorescence quenching and lifetime measurements on the holo-Hc (the copper containing, oxygen binding form) and the apo-Hc (the copper-free derivative). One class of tryptophans is exposed to the protein surface. Some of these residues are proposed to be involved in the intersubunit interactions in CaeSS1 and CaeSS3 fractions whereas in CaeSS2 the protein matrix masks them. This suggests the occurrence of conformational rearrangements after detachment of the subunit from the native aggregate, which could explain the inability of CaeSS2 to reassociate. A second class of tryptophan has been correlatively assigned, by comparison with the results obtained with Panulirus interruptus hemocyanin, to residues in close proximity to the active site. The third class includes buried, active site-distant, residues.

Three natural flavonols compounds have been isolated from the ethyl acetate fraction of Scurrula ferruginea Danser (Loranthaceae). Besides quercetin and quercitrin, an unusual flavonol glycoside 4″-O-acetylquercitrin was isolated. Structures were determined using spectroscopic methods including UV, NMR and HRMS-EI. The incidence of 4″-O-acetylquercitrin, not previously reported in the Loranthaceae, is discussed. Cytotoxic evaluation on four human cancer cell lines showed quercetin to be the most active with IC 50 of 35 μм on U251 (human glioblastoma cells).