134. Biosynthetic pathways in Daldinia concentrica

Abstract

Various strains of D. concentrica have been studied in laboratory cultures and a series of aromatic metabolites has been isolated, including benzene derivatives with a C, or C, side-chain, such as the chromanone (V) (shown to be derived from acetate or a related compound), and mono-and di-methyl ethers of 1,8-dihydroxynaphthalene. Non-enzymic oxidation of 1,8-dihydroxynaphthalene has also been investigated. The combined evidence suggests that in the fungus the C , , benzene derivatives and 1,8-dihydroxynaphthalene are alternative metabolites of a common acetate-derived precursor, and that alternative metabolic fates of the 1,s-dihydroxynaphthalene are methylation and oxidation, by way of the binaphthyl (I) to polymeric quinones and the perylenequinone (II), as previously described.

New Naphthalene‐Chroman Coupling Products from the Endophytic Fungus, Nodulisporium sp. from Erica arborea

“…The known compounds 7-13 were identified as benzene-1,2,3-triol (7), a decarboxylation product of gallic acid, [19] helicascolide A (8), [18] 1-(2,6-dihydroxyphenyl)butan-1-one (9), 1-(2,6-dihydroxyphenyl)-3-hydroxybutan-1-one (10), [11] 8-methoxynaphthalen-1-ol (11), [11,20] 1,8-dimethoxynaphthalene (12), [11,20] 5-hydroxy-2-methyl-4H-chromen-4-one [11,21] by comparison of their physical and spectroscopic data with those reported in the literature and previously isolated fungal metabolites. [11] …”

The Chemistry and Stereochemistry of Cercosporin

“…High incorporation ratio of radioactivity into Ia suggests that it is produced via the polyketide route in the manner similar to the polycyclic hydroxyquinones. 8 ) The physiological works concerning the photodynamic action of Ia are now in progress. respectively: electron accerelating voltage, 70 eV; chamber temperature, 160~200°C.…”

5, 7‐Dihydroxy‐8‐methoxy‐chroman‐4‐on aus dem Zwiebelwachs von Eucomis comosa

“…-Alle bisher bekannten Naturstoffe aus der Reihe der Chroman-4-one tragen am heterocyclischen Ring einen oder mehrere Substituenten. Die einfachsten unter ihnen, die nur eine Methylgruppe an C(2) tragen, zahlen ihrerseits erst funf Vertreter, die ausschliesslich aus Mikroorganismen isoliert worden sind [ 5 ] . 1 ist somit das erste naturliche Chroman-4-on mitunsubstituiertem heterocyclischem Ring, das zudem aus einer hoheren Pflanze stammt.…”