Two New Coumarins from Talaromyces flavus

Abstract

Two new coumarins, talacoumarins A (1) and B (2), were isolated from the ethyl acetate extract of the wetland soil-derived fungus Talaromyces flavus BYD07-13. Their structures were elucidated by spectroscopic data (NMR, MS) analyses. The absolute configuration of C-12 in 1 was assigned using the modified Mosher's method, whereas that of C-12 in 2 was deduced via the circular dichroism data of its corresponding [Rh2(OCOCF3)4] complex. Compounds 1 and 2 were evaluated for their anti-Aβ42 aggregation, cytotoxic, and antimicrobial activities. The results showed that the two compounds had moderate anti-Aβ42 aggregation activity, and this is the first report on the Aβ42 inhibitory aggregation activity of coumarins.

Three Pairs of New Isopentenyl Dibenzo[b,e]oxepinone Enantiomers from Talaromyces flavus, a Wetland Soil-Derived Fungus

“…On the basis of the exhaustive analysis of 2D NMR data ( 1 H-1 H COSY, HSQC, and HMBC) (Table S5, Supplementary Materials), the planar structure of 5 was established as the known compound, 1,6,10-trihydroxy-8-methyl-2-(3-methyl-2-butenyl)-dibenz[b,e]oxepin-11(6H)-one [7]. The data recorded in CDCl 3 ( 1 H-NMR for 400 MHz, 13 C-NMR for 100 MHz). The letters of a and b mean that these two potons on C-1 are not chemical equivalence.…”

“…Therefore, 4 and 5 can self-interconvert ( Figure 7) and exist as inseparable tautomeric mixtures in Nature. The data recorded in CDCl3 ( 1 H-NMR for 400 MHz, 13 C-NMR for 100 MHz). The letters of a and b mean that these two potons on C-1' are not chemical equivalence.…”

“…In our search for bioactive secondary metabolites from wetland fungi [10][11][12][13][14][15], several interesting molecules also had been isolated from this species [12][13][14][15]. At present, a chemical investigation of metabolites from Talaromyces flavus AHK07-3 was carried out, which led to the isolation of three pairs of new isopentenyl dibenzo [b,e] [b,e]oxepinone, arugosin N (4), and two known compounds 1,6,10-trihydroxy-8-methyl-2-(3-methyl-2-butenyl)-dibenz[b,e]oxepin-11(6H)-one (5) and chrysophanol (6) (Figure 1).…”

Fungi as a source of natural coumarins production

“…, Phellinus sp. , Streptomyces spheroides, Streptomyces niveus (Steffensky et al 2000), Talaromyces flavus (He et al 2014), Trichosporon asahii (Awe et al 2009), and Xylaria sp. YX-28 (Liu et al 2008).…”

New Isocoumarins and Related Metabolites from Talaromyces flavus

“…This genus has been investigated by many researchers since it produces a variety of secondary metabolites, such as cyclic peptides [1], anthraquinones [2], macrolides [3], alkaloids [4], azaphilones [5], polyesters [6], and norsequiterpenes [7]. As part of our search for bioactive metabolites from fungi, the strain of Talaromyces flavus BYD07-13 showed abundant chemical diversity and produced multi-structure categories, including polyesters [8], sequiterpenes [9], coumarins [10], and isocoumarins. Ongoing chemical study of this fungus for the putative biosynthetic precursor (R)-6-hydroxymellein of polyesters has led to the isolation of two new isocoumarin derivatives, talaisocoumarins A (1) and B (2), and three new related metabolites, talaflavuols A-C (3-5) ( Figure 1).…”