Stimulatory effects of silibinin and silicristin from the milk thistle Silybum marianum on kidney cells.

The biochemical influence of flavonolignans from the milk thistle Silybum marianum has been tested on kidney cells of African green monkeys. Two nonmalignant cell lines were selected, with the focus of the work on the fibroblast-like Vero line. Proliferation rate, biosynthesis of protein and DNA, and the activity of the enzyme lactate dehydrogenase (as a measure of the cellular metabolic activity) were chosen as parameters for the effect of the flavonolignans.

Formation of 4,4-dialkoxycyclohexa-2,5-dienone N-(thiol-S-yl)imine during reaction of 4-alkoxynitrosobenzenes with thiols in alcoholic solvents.

During the interaction of nitrosoarenes with glutathione in aqueous media, intermediate generation of a highly resonance-stabilized sulfenamide cation has been repeatedly suggested. Most intermediates and end products could be explained by reactions of this sulfenamide cation with different nucleophiles such as excess thiol, solvent water, and metabolically produced arylamine. The present paper presents evidence for adduct formation of the sulfenamide cation with solvent alcohol at neutral pH.

Additional pathways of S-conjugate formation during interaction of 4-nitrosophenetole with glutathione.

The rapid reactions of nitrosoarenes with cellular SH groups have proved to be main metabolic conversions during detoxication. Interactions of the phenacetin metabolite 4-nitrosophenetole with glutathione have been investigated in detail during the last years, revealing a complex pattern of products depending on the stoichiometry of the reactants and reaction conditions. Eight metabolites have been identified hitherto, and the present work extends this medley by six additional products.

Isolation and characterization of dolichol-linked oligosaccharides from Haloferax volcanii.

Biosynthesis of procaryotic glycoproteins has been studied in some detail only in the extreme halophile Halobacterium halobium. To extend these studies for a moderate halophile, dolichol phosphate-linked oligosaccharides were isolated and characterized from Haloferax volcanii. Mannosyl (beta 1-->4)galactosyl phosphodolichol could be characterized as a main component by GC/MS permethylation analysis, mass spectrometry and 1H-NMR-spectroscopy.

Biotransformation of the fungal toxin fomannoxin by conifer cell cultures.

Fomannoxin [(+/-)-5-Formyl-2-isopropenyl-2,3-dihydrobenzofurane] is a phytotoxic secondary metabolite, which is produced by the forest pathogenic basidiomycete Heterobasidion annosum during the infection process. Fomannoxin shows growth-inhibiting effects on callus and suspension cultures of conifer cells. By investigating the interaction of the phytotoxin with Pinus sylvestris cells a detoxification of fomannoxin was detected, presumably as a defense reaction of the plant cells.

Influence of the Gloeophyllum metabolite oosponol and some synthetic analogues on protein and RNA synthesis in target cells.

Oosponol [4-(hydroxyacetyl)-8-hydroxy-1H-2-benzopyran-1-one], a toxic metabolite of the basidiomycete Gloeophyllum abietinum, and some synthetic analogues were studied to clarify the molecular basis of their fungicidal, bactericidal, and phytotoxic effects. The antibiotic activity was due to a strong inhibition of RNA and protein synthesis in target cells.

Chemical reactivity of the toxin oosponol from Gloeophyllum abietinum with nucleophilic agents.

It is shown that contrary to most isocoumarins the antibiotic compound oosponol from the fungus Gloeophyllum abietinum reacts instantaneously with nucleophilic agents like thiol compounds. The reason for this high reactivity is due to the vinylogous acid anhydride character of the compound which is produced by a single oxidation step of the non toxic biological precursor oospoglycol. One must assume that reactions of oosponol with HS-groups of polypeptides form the basis for its toxicity.

Secondary fungal metabolites and their biological activities, V. Investigations concerning the induction of the biosynthesis of toxic secondary metabolites in basidiomycetes.

In cultures of the basidiomycetes Heterobasidion annosum, Gloeophyllum abietinum or Armillaria ostoyae, the biosynthesis of some of their toxic secondary metabolites is enhanced up to 400-fold when they grow in the presence of an antagonist. This stimulation is induced before any cell contact occurs. The "inducing signals" are not macromolecules, polypeptides or constituents of the cell membranes, but the same toxins which are synthesized already in monocultures in very low concentrations.

Secondary fungal metabolites and their biological activities, IV. Synthesis of compounds with structural similarities to the toxic metabolites of the pathogenic fungus Heterobasidion annosum and investigation of their antibiotic activities.

A series of synthetic analogues of fomannoxin and fomajorin S, the toxic metabolites of the basidiomycete Heterobasidion annosum, was prepared in order to investigate which partial structures of the molecules are responsible for their biological activities. Of the compounds synthesized the five indane-2-acid derivatives 5-acetylindane-2-carboxylic acid (2), (+/-)5-formylindane-2-carboxylic acid (3), (+/-)indane-2,5-dicarboxylic acid (4), (+/-)formyl-2-methylindane-2-carboxylic acid (7) and 5-acetyl-indane-2,2-dicarboxylic acid (10) and 4-(2'-ethylbutyloxy)benzaldehyde (18) have not yet been described. Different biological test systems were employed to investigate the antibiotic activities of the synthesized analogues.

Secondary fungal metabolites and their biological activities, III. Further metabolites from dual cultures of the antagonistic basidiomycetes Heterobasidion annosum and Gloeophyllum abietinum.

In addition to a preceding publication (Sonnenbichler, J., Bliestle, I.M.

[Side reactions in peptide synthesis. V. O-sulfonation of serine and threonine during removal of pmc- and mtr-protecting groups from arginine residues in fmoc-solid phase synthesis].

A novel side reaction in Fmoc-solid-phase synthesis, which occurs during removal of protecting groups and detachment from the resin, was elucidated by investigations on model peptides: During the cleavage of Pmc- or Mtr-protecting groups from arginine residues by trifluoroacetic acid in peptides with O-tert-butyl-protected aliphatic hydroxyamino acids, peptides containing O3-sulfo-serine and O3-sulfo-threonine are formed as side-products in high yields, if suitable scavengers are absent. Subsequent to their isolation and purification, the structures of these peptide sulfuric acid mono-esters could unequivocally be proven by chemical and spectroscopic (MS, NMR, IR) methods.

Secondary fungal metabolites and their biological activities, II. Occurrence of antibiotic compounds in cultures of Armillaria ostoyae growing in the presence of an antagonistic fungus or host plant cells.

We found that in the presence of host plant cells or some antagonistic fungi, the highly forest-pathogenic basidiomycete Armillaria ostoyae is strongly stimulated to produce a series of toxic secondary metabolites which are capable of inhibiting the growth of the antagonist or of killing the plant cells still before cell contact. The chemical structures of the metabolites have been identified, of which two of them are new compounds. The time dependence and sites of synthesis in the mycelium have been determined in order to lay the foundation for future studies concerning the induction mechanism for the synthesis of the toxins.

Di-myo-inositol-1,1'-phosphate: a new inositol phosphate isolated from Pyrococcus woesei.

A new inositol derivative could be isolated from the Archaeum Pyrococcus woesei and identified as di-myo-inositol-1,1'-phosphate by 1H, 31P NMR spectroscopy, mass spectrometry and thin layer chromatography. In P. woesei, this inositol phosphate represents the dominant counterion of K+ which ranges from 500 to 600 mM.

Activation and detoxication of aminophenols. III. Synthesis and structural elucidation of various glutathione addition products to 1,4-benzoquinone.

1. Four thioethers of 1,4-hydroquinone with glutathione (GSH) were prepared from 1,4-benzoquinone and characterized by 1H-n.m.

Activation and detoxication of aminophenols. II. Synthesis and structural elucidation of various thiol addition products of 1,4-benzoquinoneimine and N-acetyl-1,4-benzoquinoneimine.

1. Nine thioethers of 4-aminophenol with beta-hydroxyethylmercaptan, ranging from mono- to tetra-substituted thioadducts, were prepared from synthetic 1,4-benzoquinoneimine and characterized by 1H-n.m.

Secondary fungal metabolites and their biological activities, I. Isolation of antibiotic compounds from cultures of Heterobasidion annosum synthesized in the presence of antagonistic fungi or host plant cells.

Heterobasidion annosum (Syn. Fomes annosus), one of the most pathogenic basidiomycetes in conifer forests, produces a series of new metabolites specifically in the presence of antagonistic fungi or some plant cells. These "ecological metabolites" have been isolated and chemically characterized.

Pharmacokinetics and biotransformation of diethylene glycol and ethylene glycol in the rat.

1. 14C-Diethylene glycol (DEG), administered orally to rats at 1, 5, and 10 ml/kg, gave elimination half-lives of 6, 6, and 10 h, respectively, from urinary excretion data. Half-logarithmic plots of urinary 14C excretion rates versus time indicated zero-order elimination for the first 9 and 18 h after oral doses of 5 and 10 ml of 14C-DEG/kg, respectively.

Studies on the stability and decomposition of the Hagedorn-oxime HLö 7 in aqueous solution.

HLö 7, (pyridinium, 1-[[[4-(aminoarbonyl)pyridinio]methoxy]methyl] -2,4-bis- [(hydroxyimino)methyl] diiodide) has been shown to be efficacious in soman poisoning of mice even in the absence of atropine. To assess possible risks involved in the administration of HLö 7 its degradation products were analyzed at pH 2.5 and pH 7.

Wedelolactone and coumestan derivatives as new antihepatotoxic and antiphlogistic principles.

For the study of structure-activity relationships, the antihepatotoxic wedelolactone (7-methoxy-5,11,12-trihydroxy-coumestan) and 6 coumestan derivatives were synthesized by the application of a modified method of Wanzlich. An evaluation of the biological characteristics of the synthetic compounds and acuminatin from Musa acuminata showed that most of the wedelolactone derivatives significantly protected primary cultured liver cells from the toxicity of CCl4, galactosamine (Galc), and phalloidin, and strongly inhibited the activity of 5-lipoxygenase in porcine leukocytes. The hepatocyte protective activity was dependent on the C-7 substitution with pharmacological efficacy decreasing in the following order: EtO greater than MeO greater than OH greater than CH3(CH2)9.

[Determination of T2-times of tumor and muscle tissue by nuclear magnetic resonance tomography and resonance spectroscopy--results of a comparative study].

In 13 patients the T2 values of muscular and various tumor tissues was determined by MR under in-vivo conditions. The tumors were confirmed by surgery. In 5 cases there was a neurinoma of the acoustic nerve, in 3 cases a lateral neck cyst, a granuloma of the larynx and some other pathological processes.

Two-dimensional electrophoresis of yeast histones on cellogel strips and polyacrylamide gels.

For a quick analytical identification of histones a two-dimensional electrophoretic system has been developed. First the proteins are separated on cellulose acetate strips in alkaline buffer. Then they are reelectrophoresed in a second dimension on polyacrylamide gels either with sodium dodecyl sulfate or in the presence of urea at pH 2.