Jindřich Vokoun

Determination of fatty acids in algae by capillary gas chromatography—mass spectrometry

Abstract Capillary gas chromatography and mass spectrometry were used to determine fatty acids in algae of the genera Chlorella and Scenedesmus , and in the blue-green alga Spirulina platensis . Most algae studied were cultivated autotrophically; Chlorella kessleri was also cultivated heterotrophically. In addition to commonly occurring fatty acids in green and blue-green algae, further acids, not previously described in these organisms, were detected. The novel features of these fatty acids were the branching position, cyclopropane ring, number and position of double bonds and chain length.

Analysis of psychotropic compounds in fungi of the genus psilocybe by reversed-phase high-performance liquid chromatography

Abstract High-performance liquid chromatography (HPLC) was used for the analysis of the minor consistuents psilocybin and psilocin in fungi of the genus Psilocybe. The separation and determination of these compounds was carried out on a stationary phase of LiChrosorb RP-18. The analytical column (A) and semipreparative column (B) were eluted isocratically with water—ethanol—acetic acid (79.2:20:0.8) at flow-rates of 20 ml/h (A) and 180 ml/h (B). The compounds were detected with a UV detector at 267 nm and a fluorometric detector (excitation, 280 nm; emission, 360 nm). The UV detection limit of psilocybin was 20–40 ng (267 nm) and several ng could be detected fluorometrically. The identity of the compounds was verified by HPLC and thin-layer chromatography and by mass spectrometry and UV spectroscopy. The compounds were determined by means of a direct calibration method and by means of the method of internal normalization. The standard deviation of the determination was ±3.4% (relative). The above methods were used to determine these compounds in extracts of fruit bodies of two species of the genus Psilocybe growing at various places in Czechoslovakia, and found to contain 0.25–1.15% of psilocybin and 0.02–0.16% psilocin per dry mass.

Separation of four isomers of lysergic acid α-hydroxyethylamide by liquid chromatography and their spectroscopic identification

Abstract A method is described for the separation of four isomers of lysergic acid α-hydroxyethlamide and its decomposition products ergine and erginine using LiC-hrosorb NH 2 as the stationary phase and isocratic elution. The substances under study were determined by 13 C and 1 H NMR and mass spectroscopy. The relative proportions of individual isomers of lysergic acid α-hydroxyethylamide, ergine and erginine in the fermentation medium are assumed to result from chemical equilibrium reactions. The method is reproducible and suitable for kinetic studies of the isomerization and degradation of lysergic acid α-hydroxyethylamide.

2,2′-Dimethoxy-4a,4a′-dehydrorugulosin (Rugulin), a minor metabolite fromPenicillium rugulosum

A new metabolite was isolated from the culture ofPenicillium rugulosum and its structure was determined from physico-chemical data. Accompanying metabolites skyrin and rugulosin were characterized by UV, IR, CD, mass and NMR spectra.

Liquid chromatography of semisynthetic ergot preparations : I. Nicergoline

Abstract An impurity in medical nicergoline preparations was identified as its 5′-chloro analogue by 1 H, 13C NMR and mass spectrometry. Liquid chromatography can readily be applied to a study of the reaction mixtures arising during the synthesis of nicergoline.

7-Deoxy-13-dihydrodaunomycinone in cultures ofStreptomyces coeruleorubidus

Abstract7-Deoxy-13-dihydrodaunomycinone was isolated from three strains ofStreptomyces coeruleorubidus. Its production was found to rise at the end of cultivation and to be stimulated by lowered aeration intensity.

Mass Spectrometry Determination of Some Natural Clavines and Lysergic Acid Derivatives

Summary The mass spectra of 18 natural clavines and lysergic acid derivatives are listed. The molecular peaks, when present, and some characteristic fragment peaks facilitate a quick identification of ergot alkaloids.

Isolation, characterization and biological activities of verotetrone from a mutant strain ofStreptomyces aureofaciens

A new metabolite denoted as verotetrone was isolated from the mycelium of the mutant strainStreptomyces aureofaciens NMG-2. Interpretations of physical data concerning verotetrone and its triacetate and, the determination of its degradation product indicate that verotetrone belongs to pretetramide-type metabolites. Verotetrone exhibits neither antibacterial nor antifungal activity.In vitro it inhibits the synthesis of nucleic acids as well as proteins in Ehrlich ascites carcinoma cells. Both verotetrone and its triacetate interferein vivo with the metabolism of tumour and lymphoid cells, exhibiting antitumour or immunosuppressive activity. This activity, which is more intense with verotetrone than with its triacetate, is detectable in a dose which is already toxic in some animals.