The aerial parts of Artemisia iwayomogi afforded, in addition to already known terpenes, eleven new eudesmanolides whereas four new guaianolides were found in A. gmelinii. No sesquiterpene lactones were detected in the aerial parts of A. santolinifolia which afforded two new nerolidol derivatives besides several other already known compounds. From A. caerulescens var. cretacea six eudesmanolide...

Bicyclic chloro-, bromo- and iodo-γ-lactones with dimethylcyclohexane rings were used as substrates for bioconversion by several fungal strains (Fusarium, Botrytis and Beauveria). Most of the selected microorganisms transformed these lactones by hydrolytic dehalogenation into the new compound cis-2-hydroxy-4,6-dimethyl-9-oxabicyclo[4.3.0]- nonan-8-one, mainly the (-)-isomer. When iodo-γ-lactone...

The implementation of light-driven catalytic processes in biocatalysis opens a golden window opportunities. We hereby report the merging photocatalytic C?C bond formation with enzymatic asymmetric reduction for direct conversion simple aldehydes and acrylates or unsaturated carboxylic acids into chiral ?-lactones. Tetrabutylammonium decatungstate (TBADT) is employed as photocatalyst to trigger ...

A wide variety of organisms communicate via the chemical channel using small molecules. A structural feature quite often found is the lactone motif. In the present paper, the current knowledge on such lactones will be described, concentrating on the structure, chemistry, function, biosynthesis and synthesis of these compounds. Lactone semiochemicals from insects, vertebrates and bacteria, which...

Chemical components of the acetone and watery extract of Ambrosia artemisiifolia (LINNAEUS, 1753) plant, and the two identified lactones in the acetone extract: the ambrosin and dihydroambrosin, was tested for genotoxicity activities. The genotoxicity of the extract was tested on the eukaryotic model system Drosophila melanogaster using the sex-linked recessive lethal test (SLRL test). The resu...

Our previous works showed that extracts and fractions from Polymnia sonchifolia had presented an inhibitory activity on growth and aflatoxin production by Aspergillus flavus in non-cytotoxic concentrations. In this work, report results on the in vitro cytotoxicity of subfractions and of a mixture of sesquiterpenes lactones from Polymnia sonchifolia on Vero cells. The cytotoxicity was assayed th...

Four new eudesmanolides and two new guaianolides were isolated from the aerial parts of Anthemis carpatica Willd. and their structures elucidated by spectral methods. In addition, seven known sesquiterpene lactones were identified.

A constitutive peptide lactonase from Actinoplanes missouriensis hydrolyzed echinomycin, stendomycin, thiostrepton, vernamycin B, staphylomycin S, and etamycin. An induced lactonase hydrolyzed actinomycin but not the other peptide lactones.

A sequence involving dihydroxylation and acid induced fragmentation of silene generated silacyclohexenes represents the key step in a concise synthetic route to beta-hydroxy-delta-lactones.

Unsaturated eight-membered lactones undergo decarboxylative and non-decarboxylative transannular Ireland-Claisen rearrangement reactions, to give substituted vinylcyclobutanes. A formal synthesis of (±)-grandisol is described.