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The aerial parts of Francoeuria crispa gave, in addition to known sesquiterpene lactones, two new ones. From the polar parts a large amount of two diterpene glycosides derived from ent-kauren-19-oic acid were obtained.

When irradiated at 360 nm, furocoumarins with a hydroperoxide group in a side chain efficiently give rise to a type of DNA damage that can best be explained by a photo-induced generation of hydroxyl radicals from the excited photosensitizers. The observed DNA damage profiles, i.e. the ratios of single-strand breaks, sites of base loss (AP sites) and base modifications sensitive to formamidopyrimidine--DNA glycosylase (FPG protein) and endonuclease III, are similar to the DNA damage profile produced by hydroxyl radicals generated by ionizing radiation or by xanthine and xanthine oxidase in the presence of Fe(III)--EDTA. No such damage is observed with the corresponding furocoumarin alcohols or in the absence of near-UV radiation. The damage caused by the photo-excited hydroperoxides is not influenced by superoxide dismutase (SOD) or catalase or by D2O as solvent. The presence of t-butanol, however, reduces both the formation of single-strand breaks and of base modifications sensitive to FPG protein. The cytotoxicity caused by one of the hydroperoxides in L5178Y mouse lymphoma cells is found to be dependent on the near-UV irradiation and to be much higher than that of the corresponding alcohol. Therefore the new type of photo-induced damage occurs inside cells. Intercalating photosensitizers with an attached hydroperoxide group might represent a novel and versatile class of DNA damaging agents, e.g. for phototherapy.

Reichardia tingitana var. orientalis afforded, in addition to lupeol, taraxasterol, and the corresponding acetates, three sesquiterpene lactones of the guaianolide type including a new glucoside. The structures were elucidated by spectral methods.

Artemisia monosperma afforded four flavonoids, two acetylenes, eight p -hydroxyacetophenone derivatives and three p -coumaric acid derivatives, two of them being new. The structures were elucidated by spectral methods. The flavonoids present are naringenin 7-methyl ether, eriodictyol 7-methyl ether, quercetin 3,7-dimethyl ether and quercetin 7,3′-dimethyl ether.

A reinvestigation of the aerial parts of Pyrethrum santolinoides afforded, in addition to known compounds, four new sesquiterpene lactones, three germacranolides and an eudesmanolide. The structures were elucidated by high field 1H NMR techniques.

Achillea fragrantissima afforded, in addition to several known glaucolides, five new compounds whose structures were elucidated by high field 1 H NMR spectroscopy.

When β-keto-ester1 a was reacted with dimethyl acetylenedicarboxylate ring expansion occurred to give substituted cyclooctadienones.Michael reactions of the title compounds1 with unsaturated ketones gave adducts, some of which underwent further cyclization reactions. A new route to α-tetralone ring system10 via cyclization of the intermediateMichael adduct9 is described.