Orso Vajna de Pava

Spirolaxine and sporotricale: Two long-chain phthalides produced by Sporotrichum laxum

Abstract Spirolaxine and sporotricale were isolated from cultures of Sporotrichum laxum . The structure of the two metabolites was determined by means of NMR, mass spectrometry and chemical evidence.

Isoxazoline derivatives. Part VI. Regioselectivity in the 1,3-dipolar cycloaddition of nitrile oxides to αβ-unsaturated ketones

1,3-Cycloadditions of nitrile oxides to αβ-unsaturated ketones have been studied. In most cases a mixture of the two regioisomeric 3-substituted 4- and 5-acyl-Δ2-isoxazolines was obtained. The individual compounds were characterised by chemical and/or spectroscopic methods. Effects of steric and electronic factors on the cycloadditions are discussed.

Isolation and structure elucidation of tsugicolines A-D, novel protoilludane sesquiterpenes from Laurilia tsugicola1

Abstract Four novel Sesquiterpenes, tsugicolines A-D ( 1a, 2, 3a, 4 ), have been isolated from still cultures of the fungus Laurilia tsugicola (Basidiomycetae) Their structures were elucidated by means of chemical correlations and NMR studies and the relative configurations were established through a series of NOE difference spectra. The absolute configuration of tsugicoline A 1a (3- epi -illudol-5-one) was determined as 3S,6S,7R,9R,13S by the ‘partial resolution’ method of Horeau Treatment of tsugicoline A 1a with triethylamine in MeOH gave the metabolite 4; a possible mechanism is reported. Tsugicoline A is inactive on bacteria and fungi but inhibits the germination of the water cress Lepidium sativum .

Cyathiformines A–D, new chorismate-derived metabolites from the fungus clitocybe cyathiformis☆

Abstract Cyathiformines A–D, 1, 4a, 5and6a, have been isolated from the Basidiomycetous fungus Clitocybe cyathiformis. Structural determination was based on NMR studies and chemical evidence.

A new strain of Streptomyces: An anthracycline containing a C-glucoside moiety and a chiral decanol

Abstract Two new metabolites have been isolated from strain C57 of Streptomyces and their structure determined on the basis of chemical and NMR evidence.

Isolation and structure elucidation of tsugicolines F-H, novel furosesquiterpenes, and tsugicoline I from the fungus Laurilia tsugicola☆

Abstract Three novel sesquiterpenes of protoilludane origin, tsugicolines F-H (4a–6a), have been isolated from solid cultures of the Basidiomycetae Laurilia tsugicola. Their structures were elucidated by means of chemical correlation and NMR studies; a possible pathway for the formation from the protoilludane derivative tsugicoline A is reported. The furosesquiterpenes 4a and 5a are weakly active on bacteria but inhibited the germination of the water cress Lepidium sativum. A fourth metabolite, the norsesquiterpene tsugicoline I 7, was also isolated from the same fungus.

Phanerosporic acid, a β-resorcylate obtained from Phanerochaete chrysosporium☆

Abstract The structure of phanerosporic acid, a β-resorcylate isolated from cultures of Phanerochaete chrysosporium , has been assigned on the basis of its 1 H and 13 C NMR data and chemical transformations. Its use as a synthon for macrolide synthesis is also described.

Secondary mould metabolites. Part 58. Modifications in basic conditions and Michael additions of the protoilludane sesquiterpene tsugicoline A; some implications for the biogenesis of other sesquiterpenoids produced by Basidiomycetes

The protoilludane sesquiterpene tsugicoline A 1 rearranges at pH 13 into compound 8a with a structure very similar to isolactarane sesquiterpenes and into compound 9a similar to the natural furosesquiterpene tsugicoline H 9c; under different basic conditions compounds 4a, 5, 6a and 7a,b, are formed. In particular, 4a shows the same skeleton of the natural tsugicoline E 4c. Compound 1 reacts with some thiols to give a Michael addition to α,β-conjugated carbonyl system, giving the adducts 10–13. In the case of compounds 12a,b a new tetrahydrothiophene ring is formed. The structures and stereochemistry of the products are discussed with the aid of NMR data; compounds 4a,c, 10 and 12a,b are correlated also with tandem MS studies. The implications of these results on current opinions on the biogenetic pathways of sesquiterpenes of Basidiomycetes are discussed.

Isolation of illudin M, illudinine and shisool from the mushroom Clitocybe phosphorea; biotransformation of perillyl alcohol and aldehyde☆

Abstract The sesquiterpenes illudin M and illudinine, together with the monoterpene 8- p -menthen-7-ol (shisool), were isolated from cultures of the mushroom Clitocybe phosphorea . Shisool was also obtained by biotransformation of (−)-( S )-perillaldehyde and (−)-( S )-perillyl alcohol from the same fungus.

Direct Amination of Naphthazarin, Juglone, and Some Derivatives

Abstract Mono‐ and diamino‐derivatives of naphthazarin, 2‐methoxynaphthazarin, juglone and their methylethers were prepared by reaction with ammonia. The structure of the products was established by NMR studies. Some compounds were tested for cytotoxic activity.