Biosynthesis of Bisorbicillinoid inTrichodermasp. USF-2690; Evidence for the Biosynthetic Pathway,viaSorbicillinol, of Sorbicillin, Bisorbicillinol, Bisorbibutenolide, and…

Abstract

An incorporation study of [1-(13)C] and [1,2-(13)C2] labeled sodium acetates into sorbicillinol 1 established a ring closure system between C-1 and C-6 and the positions that were oxidized and/or methylated on a hexaketide chain. Subsequent investigations, using 13C-labeled 1 prepared from [1-(13)C] labeled sodium acetate, clearly demonstrated that both bisorbicillinol 2 and sorbicillin 6 incorporated 13C-labeled 1 into their carbon skeletons. 13C-labeled bisorbicillinols 2 derived from [1-(13)C]- and [2-(13)C]-labeled sodium acetates clearly indicate that these were on the biosynthetic route from 1 to bisorbibutenolide (bislongiquinolide) 3 and bisorbicillinolide 4 via 2 as a branching point in the fungus.

Oxidative Dearomatization of Phenols: Why, How and What For?

“…Such a proposal does indeed appear quite logical, but proving that an ortho-quinol either follows or precedes its phenolic counterpart during biosynthesis is not a trivial matter. 108 In any event, it is clearly much more reasonable 117 the Mimoun molybdenum complex 118 and PIDA 119 are among some of the reagents that have been used with some success. Which one did we start with?…”

Novel Secondary Metabolites, Spirosorbicillinols A, B, and C, from a Fungus

“…In the course of our screening program for free radical scavengers by detecting the radical scavenging activity of DPPH-radical, 1) we isolated 12 active sorbicillin related compounds [2][3][4][5][6][7][8] from the fermentation broth of Trichoderma sp. USF-2690 and USF-4860 strains, which had been isolated from a soil sample collected in Shizuoka, Japan.…”

“…Compounds 1-3 demonstrated weak efficacy in this assay, in comparison with other sorbicillin related compounds. [2][3][4][5][6][7][8] A possible biosynthetic scheme for the formation of 1-3 is shown in Fig. 6.…”

Novel DPPH Radical Scavengers, Demethylbisorbibutenolide and Trichopyrone, from a Fungus

“…In the course of our screening program for free radical scavengers by detecting the radical scavenging activity of the DPPH radical, 5) we have isolated twelve sorbicillinoids and bisorbicillinoids, [6][7][8][9][10][11][12] including eight novel radical scavengers, from the fermentation broth of Trichoderma sp. USF-2690 strain.…”

“…Compounds 1 and 2 demonstrated weak efficacy in this assay, in comparison with other sorbicillinoids and bisorbicillinoids. [6][7][8][9][10][11][12] The chemical structure of the non-radical termination compound in the DPPH-radical scavenging reaction can provide important information for understanding the DPPH-radical scavenging mechanism. To isolate the reaction product of 2, we next reacted 2 with the DPPH radical in an ethanol solution, and a reaction product (3), was obtained as a reddish-brown powder after purification by reversed-phased MPLC.…”