Metabolites from a Wood-Inhabiting Cup Fungus,Urnula craterium

Abstract

The metabolites produced by the cup fungus Urnula craterium grown in liquid culture were isolated and elucidated by spectral meth'ods.

Studies on the Constituents of Juglans Species. I. Structural Determination of (4S)- and (4R)-4-Hydroxy-.ALPHA.-tetralone Derivatives from the Fruit of Juglans mandshurica MAXIM. var. sieboldiana MAKINO

“…On the other hand, the sign of the weakly negative [2a: De Ϫ0.8 at 341 nm)] and positive [2b: De Ϫ0.8 at 340 nm)] Cotton effects (n→p*) could be interpreted under the assumption that the half-chair form of the cyclohexenone ring is a more stable conformation than the sofa form in the molecular arrangement. 18) From the above CD effects, the absolute configuration at C-4 of 2a and 2b was assigned as S and R, and this conclusion is in agreement with the sign of the optical rotations 2,[4][5][6][7][8][9][10][11][12][13] (Fig. 2).…”

“…The extract was chromatographed on a silica gel column using an n-hexane-AcOEt gradient, and the eluate was separated into thirteen fractions (frs. [1][2][3][4][5][6][7][8][9][10][11][12][13] …”

“…1) with those of 4S-and 4R-configured isosclerone 4,13) and analogous compounds, 9,12,14) the absolute configurations at C-4 in 1a and 1b were determined to be S and R, respectively. This deduction was further supported by application of the exciton chirality method (see Experimental).15) Consequently, the absolute structures of 1a and 1b were concluded to be (4S) [4][5][6][7][8] C-NMR signal at C-1 of 2 was shifted by Ϫ7.8 ppm in comparison with that of 1. These features suggested that 2 was 5-hydroxy-4-methoxy-a-tetralone.…”

“…15) Consequently, the absolute structures of 1a and 1b were concluded to be (4S) [4][5][6][7][8] C-NMR signal at C-1 of 2 was shifted by Ϫ7.8 ppm in comparison with that of 1. These features suggested that 2 was 5-hydroxy-4-methoxy-a-tetralone.…”

Photipyrones A and B, new pyrone derivatives from the plant endophytic fungus Pestalotiopsis photiniae

“…Photinides A-F with unique benzofuranone-derived g-lactone skeleton have been isolated from the extract of Pestalotiopsis photiniae (L461) grown in SA media culture. 5 In contrast, the crude isolate of the same fungus cultivated in rice-media culture in static condition produced two new d-lactone derivatives named photipyrones A (2) and B (3), along with four known analogues namely LL-P880a (1), 16 LL-P880b (4), 17 1 0 -hydroxy-4-methoxy-6-pentyl-2H-pyran-2-one (5), 18 and 1 0 ,2 0 -dihydroxy-4-methoxy-6-pentyl-2H-pyran-2-one (6) 16 ( Figure 1) completely different from photinides A-F from SA media culture. In this note, we will present the isolation, structure elucidation and bioactivities of these compounds.…”