Maria De Bernardi

Coatline A and B, two C-glucosyl-α-hydroxydihydrochalcones from Eysenhardtia polystachya

Abstract The first two examples of naturally occurring C -glucosyl-α-hydroxydihydrochalcones have been isolated from Eysenhardtia polystachya , a Mexica

Sesquiterpenes from Lactarius blennius

Abstract Six sesquiterpene lactones were isolated from Lactarius blennius. The structures of two new sesquiterpenes, blennin A and blennin B were determinated by spectroscopic methods and the structure of the seco-compound, blennin C, is revised. The two known furan sesquiterpenes and lactarorufin A were also identified.

The chemistry of lactarius fuliginosus and lactarius picinus

Abstract Intact fruit-bodies of the Basidiomycetes Lactarius fuliginosus and L. picinus have been found to contain the stearic acid ester 4b . When the mushrooms are injured 4b is rapidly converted to the acrid free phenol 4a which is then gradually oxidized to a mxiture of red pigments, benzofuran 9 and chromenes 8 , 10–13 (or 14 ), 15 , 20 and 22 . These chemical transformations are involved in the change of taste and colour of the latex and flesh of the mushrooms. Compounds 4a–b , 8–12 and 20 were obtained also by synthesis.

Fungal metabolites XXVI: The structure of saponaceolides B, C and D, new C-30 terpenoids from Tricholoma saponaceum☆

Abstract The structures of saponaceolides B, C and D, new C-30 terpenoids from Tricholoma saponaceum, have been established, including their absolute configuration. High cytotoxic activity was detected for saponaceolides B and C.

The chemical basis of hot-tasting and yellowing of the mushrooms Lactarius chrysorrheus and L. scrobiculatus

Abstract The chemical background behind yellowing and pungent taste of Lactarius chrysorrheus and L. scrobiculatus has been investigated. The intact fruit bodies originally contain a fatty acid ester of velutinal (i.e. compound 2b and 2a, respectively) as the only sesquiterpenoid. When the fruit bodies are injured the esters are enzymatically converted into sesquiterpene furans, mono- and di-aldehydes, and lactones, which have been isolated and their structures elucidated. These compounds have been submitted to conformational analysis by molecular mechanics and 1H NMR in order to make correct stereochemical assignments. The pungent taste of the fruit bodies of both species is due to a new dialdehyde, chrysorrhedial (9), while a new triene-enolactone (8) is involved in the change of the colour.

Fungal metabolites xxii(: the unprecedented structure of saponaceolide a, a cytotoxic c-30 terpenoid from

Abstract The structure of saponaceolide A, a new cytotoxic C-30 terpenoid from Tricholoma saponaceum has been established by spectroscopic methods, including single crystal X-ray analysis. Its biogenetic origin is discussed.

Flavonols and quinones in stems of aframomum giganteum

Abstract Three rare naturally occurring flavonol 3-methyl ethers have been isolated from stems of Aframomum giganteum : kaempferol 3,7,4′-trimethyl ether, quercetin 3,7,4′-trimethyl ether (ayanin) and quercetin 3,7,3′,4′-tetramethyl ether (retusine). The following compounds have also been isolated: chrysophanol, physcion, 2,6-dimethoxybenzoquinone and β-sitosterol. Phytochemical aspects of the flavonoids occurring in the Zingiberaceae are discussed.

New sesquiterpene hydroxylactones from Lactarius species

Abstract Four γ-hydroxybutenolide sesquiterpenes have been isolated from Lactarius scrobiculatus , L. blennius and L. pallidus . Their structures and absolute stereochemistry were determined by spectral data and by conversion to known compounds.

Furanoeremophilanes and other constituents from Senecio Canescens

Abstract Investigation of the aerial parts and roots of Ecuadorian Senecio canescens afforded in addition to known furanoeremophilanes the first natural furanoeremophilane hydroperoxide and two new cacalohastine derivatives, one of which is a dimer. The volatile fraction was analysed by GC and GC-mass spectrometry.

Structural studies on lactarius sesquiterpenes: structure elucidation of lactarorufins D and E and conformational analysis of lactaran-5-olides

Abstract The structures of lactarorufins D and E, two new sesquiterpenes from Lactarius necator, have been elucidated. Conformational analysis of lactarorufins and blennins is discussed.