José María Hernández

Antifungal activity of scopoletin and its differential accumulation in Ulmus pumila and Ulmus campestris cell suspension cultures infected with Ophiostoma ulmi spores

Abstract Inoculation of cell suspension cultures derived from Ulmus pumila , a species resistant to Dutch elm disease (DED) and U. campestris , a susceptible elm, with spores of Ophiostoma ulmi , differentially induced the accumulation of the hydroxycoumarin scopoletin. This coumarin was induced rapidly and accumulated mainly in the medium of the challenged resistant culture. In in vitro bioassays, scopoletin showed a direct antifungal activity against O. ulmi spore germination being more sensitive to this inhibitory activity than mycelial growth. The significance of scopoletin in vivo is also discussed.

Helmanticine, a phenylpropanoid from Thapsia villosa

Abstract Helmanticine, a new phenylpropanoid esterified by angelic and 2,3-dihydroxy-2-methylbutyric acids, was isolated from Thapsia villosa and its full structure established by spectroscopic methods and chemical transformations. Hydrocarbons, 12-nonacosanone, sitosterol and latifolone were also isolated.

Tovarol and other germacrane derivatives from Thapsia villosa

Abstract Four tovarol, two epoxytovarol (= shiromodiol) and one diepoxytovarol esters were the new germacrane esters isolated from the roots of Thapsia villosa var. minor . The structures of these substances were assigned on the basis of spectral data and chemical correlations with shiromodiol. The acid catalysed rearrangement of tavarol yielded 1(10),4-bulgaradiene-8-ol.

Aromatic compounds from Artemisia campestris subsp. Glutinosa

Abstract From the weakly acid fraction of the hexane extract from Artemisia campestris subsp. glutinosa , five new aromatics have been isolated. They hav

Phenylpropanoids and other derivatives from Thapsia villosa

Abstract Five phenylpropanoids related to hemanticine have been obtained from Thapsia villosa roots. We propose for these substances the trivial names isohelmanticine, neohelmanticine, isoneohelmanticine, epoxyhelmanticine and epoxyhelmanticine angelate. All these substances are based on (1S,2R)1-(3-methoxy-4,5-methylenedioxyphenyl)-1,2-propanediol, which is esterified variously by acetic, angelic, epoxyangelic and/or (2R,3S)2,3-dihydroxy-2-methylbutyric acids. We also report three C6-guaianolides and their hydrolysis products. The name thapsivillosin K is proposed for a new guaianolide.

P-hydroxyacetophenone derivatives from Artemisia Campestris ssp. Glutinosa

Abstract The weakly acidic fraction from Artemisia campestris ssp. glutinosa contains five p -hydroxyacetophenone derivatives, which are structurally biogenetically related.

12-hydroxytovarol and derivatives from Thapsia villosa var. minor

Abstract The new germacrane esters 12-angeloyloxy- and 12-hydroxy-8- O -angeloyltovarol and 12-angeloyloxy-8- O -angeloylshiromodiol were isolated from T. villosa var. minor , and their structures established by spectral data and chemical correlations. The terpenoids geranyl acetate, δ-cadinene, γ-cadinene, γ-muurolene, β-caryophyllene and caryophyllene oxide were also isolated from the aerial parts.