Borje Wickberg

Mutagens in larger fungi: I. Forty-eight species screened for mutagenic activity in the Salmonella/microsome assay

Specimens of large fungi (mushrooms) were screened for mutagenic activity by the Salmonella/microsome assay, with strains TA98, TA2637 and TA100. Our of 48 species tested, 37 exhibited a significant but for the most part weak activity. The activity observed in the presence of S9 mix was typically between 0 and 50% of that without, and in no case was the activity increased in the presence of microsomal enzymes. Six metabolites reported to occur in some of the species included in this investigation were also tested. Significant mutagenic activity was found with isovelleral (5) from Lactarius sp., agaritine (3) from Agaricus bisporus and related sp. and beta-nitraminoalanine (7) from Agaricus silvaticus. Isovelleral may be a major mutagen in some of the sharp-tasting and mutagenic Russulaceae sp. A. bisporus (cultivated specimen) was weakly mutagenic toward all three strains of S. typhimurium, used, and agaritine was weakly active toward TA2637 alone. This implies that this fungus might contain other mutagenic material as well. beta-Nitraminoalanine was not found in the particular collection of A. silvaticus tested here. The mutagenicity observed for the fungus in this work may therefore be due to other metabolites. Even though many species found to be mutagenic are used as food, it seems premature to make specific recommendations about eventual health risks. Further information is needed about the chemistry and toxicology of the active compounds as well as about the effects of various methods used in preparing mushrooms for food.

New sesquiterpenes in a proposed russulaceae chemical defense system

In addition to already known sesquiterpene aldehydes, the lactaranes piperdial 1 and piperalol 2 were isolated from extracts of Lactarius piperatus, L. torminosus and Russula queletii (larger fungi).

Isolation and structure of coprine, a novel physiologically active cyclopropanone derivative from Coprinus atramentarius and its synthesis via 1-aminocyclopropanol

Coprine, the ‘antabuse’-like principle of the inky cap mushroom Coprinus atramentarius has been isolated; its structure, which includes a cyclopropanone equivalent, has been determined and it has been synthesised from 1-hydroxycyclopropylammonium chloride via the unstable 1-aminocyclopropanol.

Velutinal esters of lactarius vellereus and L. Necator. The preparation of free velutinal.

Esters of the pentacyclic sesquiterpene velutinal have been isolated from Lactarius species, and converted to the free alcohol by base-catalyzed transesterfication in EtOH/EtO-.

A facile synthesis of 1,4-diketones

1,4-Diketones may conveniently be synthesized by the addition of 2-methylcyclopropenyllithium to N-methoxy-N-methylcarboxamides followed by hydrolysis of intermediate cyclopropyl ketone adducts on silica gel. The new method has been applied to the synthesis of cis-jasmone.

Electroreduction of organic compounds. IV: Electrochemical reduction of mono- and bis-dithiobenzoate esters in the presence of bi- or monofunctional electrophiles

Reduction de dithiobenzoate de methyle et du bis-dithiobenzoate de propanedithiol-1,3 en presence de dimesylate de propanediol-1,3 ou de iodomethane

Isolation and structure of coprine, the in vivo aldehyde dehydrogenase inhibitor in Coprinus atramentarius; syntheses of coprine and related cyclopropanone derivatives

The disulphiram-like principle of the inky cap mushroom Coprinus atramentarius has been identified as N5-(1-hydroxycyclopropyl)-L-glutamine (coprine)(1). Coprine (1) and several analogous compounds have been synthesised by N-acylation of the unstable 1-aminocyclopropanol, generated in situ from 1-hydroxycyclopropyl-ammonium chloride (6). The lower 1-alkoxycyclopropylamines are stable, distillable compounds which can be N-acylated. Many of the 1-aminocyclopropanol derivatives synthesised have the same physiological activity as coprine.

A total synthesis of (+)-isovelleral. The absolute configuration of the russulaceae sesquiterpenes

(+)-Isovelleral, an antibiotic and antifeedant sesquiterpene dialdehyde from Basidiomycetes, has been synthesised via a diastereoselective intramolecular Diels–Alder cyclisation of a chiral intermediate derived from D-ribonolactone.

Isolation and structure determination of a novel phorbol derivative in an intramolecular diester macrolide

Three proteinkinase C-agonizing macrolides, formed by esterification of the novel phorbol derivative 11,18-dehydro-4,12-dideoxy-16-hydroxyphorbol with dicarboxylic acids, that differ only in the state of oxidation of a phenyl residue, were isolated from the dried leaves of Pycnocoma cornuta Muell. (Euphorbiaceae), and their structures were determined by n.m.r. studies.

The mechanism of the thermal rearrangement of the marasmane sesquiterpene (+)-isovelleral. Cyclopropane ring closure via an intramolecular ene reaction

The reversible thermal conversion of the fungal sesquiterpene Isovelleral (2) into (1) is a unique Intramolecular ene reaction proceeding via the bicyclic enol (3), which is demonstrated by kinetic studies, deuterium incorporation, and the trapping of (3).