Josef Reiner

Aldehydic lipid peroxidation products derived from linoleic acid

Lipid peroxidation (LPO) processes observed in diseases connected with inflammation involve mainly linoleic acid. Its primary LPO products, 9-hydroperoxy-10,12-octadecadienoic acid (9-HPODE) and 13-hydroperoxy-9,11-octadecadienoic acid (13-HPODE), decompose in multistep degradation reactions. These reactions were investigated in model studies: decomposition of either 9-HPODE or 13-HPODE by Fe(2+) catalyzed air oxidation generates (with the exception of corresponding hydroxy and oxo derivatives) identical products in often nearly equal amounts, pointing to a common intermediate. Pairs of carbonyl compounds were recognized by reacting the oxidation mixtures with pentafluorobenzylhydroxylamine. Even if a pure lipid hydroperoxide is subjected to decomposition a great variety of products is generated, since primary products suffer further transformations. Therefore pure primarily decomposition products of HPODEs were exposed to stirring in air with or without addition of iron ions. Thus we observed that primary products containing the structural element R-CH=CH-CH=CH-CH=O add water and then they are cleaved by retroaldol reactions. 2,4-Decadienal is degraded in the absence of iron ions to 2-butenal, hexanal and 5-oxodecanal. Small amounts of buten-1,4-dial were also detected. Addition of m-chloroperbenzoic acid transforms 2,4-decadienal to 4-hydroxy-2-nonenal. 4,5-Epoxy-2-decenal, synthetically available by treatment of 2,4-decadienal with dimethyldioxirane, is hydrolyzed to 4,5-dihydroxy-2-decenal.

Anionische rutheniumcluster als katalysatoren bei der hydrosilylierung von kohlendioxid

Abstract The cluster anion [HRu 3 (CO) 11 ] - was found to catalyse the synthesis of silyl formates from carbon dioxide and hydrosilanes under mild conditions with high catalytic turnovers. The isolation of the anion [HRu 3 (CO) 10 (SiEt 3 ) 2 ] suggests that the activation of the hydrosilane molecule on the ruthenium cluster is the initiating step of the catalytic process.

(+)-neo-olivil from roots of Urtica dioica

Abstract The all- trans configuration of (+)-neo-olivil from Urtica dioica was established by NMR-spectroscopy. After transforming it to (−)-epipinoresinol and (−)-pinoresinol with trimethylorthoformate and H 2 SO 4 the absolute configuration was determined as 7 R ,7′ R ,8 S ,8′ S .

Three Saponins, a Steroid, and a Flavanol Glycoside from Achyrantes aspera

Summary. Three bisdesmosidic saponins, 20-hydroxyecdysone, and quercetin-3-O-β-D-galactoside were isolated from the methanol extract of the aerial parts of Achyranthes aspera L. (Amaranthaceae). Their structures were established on the basis of NMR spectroscopic analysis; the complete 1H and 13C assignments of the compounds were achieved by means of 2D NMR studies.

Katalytische Hydrierung und Hydrokupplung von Acetessigsäureamiden und -estern mit dem Clusteranion [H3Ru4(CO)12]− als Katalysator

Abstract The cluster anion [H 3 Ru 4 (CO) 12 ] ′ was found to catalyze the hydrogenation of the β-keto function in acetacetic amides and esters. The reaction of acetacetic amides yields the corresponding β-hydroxy derivatives, whereas acetacetic esters are converted in a consecutive coupling step into new diester derivatives. In the case of benzyl acetacetate both the hydrogenation and the hydrocoupling products were obtained.

Profiles of strongly polar and less polar acids obtained from human blood, plasma and serum by two-step ultrafiltration.

A two-step ultrafiltration method combined with anion-exchange chromatography is described for the separation of lipophilic and strongly lipophobic acids occurring in human blood, serum and plasma. After treatment with diazomethane, the acid fractions are separated further by gas chromatography. The acids were identified by their mass spectra. Profiles obtained from the strongly acidic fraction of blood samples of healthy individuals are characterized by main peaks corresponding to organic phosphoric acid esters. The peaks are absent in plasma and serum.

Harn-steroidprofile hirsuter frauen

Abstract Urine steroid profiles of hirsute women Steroid profiles of women suffering from idiopathic hirsutism show in more than 50% of the cases a 10–100 fold increase in the excretion of dehydroepiandrosterone (DHEA) compared with normal values. The excretion of DHEA was reduced much more than that of other 17-ketosteroids if the adrenals (NNR) were suppressed by dexamethasone (DXM). Within one week they reached values at the compound noise level of the gas chromatograms. If the ovaries were stimulated with human chorionic gonadotropin during continued suppression of the NNR with DXM no increase of DHEA could be detected.

10-Hydroxystearic acid--identified after homogenization of tissue--is derived from bacteria.

10-Hydroxystearic acid seems to be widely distributed in nature: Bacteria generate it by hydroxylation of oleic acid, but it was found also as constituent of plants, in cancer cell cultures and in mammalian tissue homogenates. Investigation of 10-hydroxystearic acid, obtained from mammalian tissue homogenates, revealed its identity with that of bacteria. Thus not 10-hydroxystearic acid is widely distributed in nature but its producers: bacteria. When biological material is processed in aqueous media, lipases are activated, these cleave membrane phospholipids. Thus liberated oleic acid is the substrate for widespread bacteria which are introduced into the media when the work up procedure is done in not sterile surrounding. The bacteria transform then oleic acid to 10R-hydroxystearic acid.

NMR-spektroskopische und massenspektrometrische Untersuchung der Struktur und Lösungsgleichgewichte von Hydroxyethylaminotoluchinonen

SummaryThe constitution of hydroxyethylaminotoluquinones have been assigned by means of modern NMR-techniques. The solution equilibria constants have been determined by recording1H-NMR spectra at different temperatures. The reaction of compounds2a1 and2c1 with acetic anhydride leads to the corresponding acetyl derivatives with quinone skeleton. The mass spectra of2a1–c1 are discussed on basis of the fragmentation pattern.