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

Abstract

Three pairs of new isopentenyl dibenzo[b,e]oxepinone enantiomers, (+)-(5S, and a new isopentenyl dibenzo [b,e]oxepinone, arugosin N (4), were isolated from a wetland soil-derived fungus Talaromyces flavus, along with two known biosyntheticallyrelated compounds 5 and 6. Among them, arugosin N (4) and 1,6,10-trihydroxy-8-methyl-2-(3-methyl-2-butenyl)-dibenz[b,e]oxepin-11(6H)-one (CAS: 160585-91-1, 5) were obtained as the tautomeric mixtures. The structures of isolated compounds were determined by detailed spectroscopic analysis. In addition, the absolute configurations of these three pairs of new enantiomers were determined by quantum chemical ECD calculations.

Arugosins O-Q, New Fungal Metabolites from the Fungus Xylariaceae sp. Isolated from Leaves of Lansium domesticum (Meliaceae)

“…A second 1,2,3,6tetrasubstituted benzene ring was constructed based on HMBC correlations from ortho coupled aromatic protons at δ 7.33 (1H, d, J = 8.2 Hz, H-8) to two oxygenated aromatic carbons at δ 154.5 (C-6) and 162.7 (C-10), and at δ 6.58 (1H, d, J = 8.2 Hz, H-7) to two quaternary aromatic carbons at δ 124.8 and 113.4, assigned to C-9 and C-11, respectively. These data were supportive of a dibenzo[b,e]oxepinone skeleton [20].…”

“…, and 119.5 (CH-15), five quaternary carbons at δ 147.0 (C-2), 138.4 (C-4), 124.8 (C-9), 113.4 (C-11), and 116.9 (C-13), three oxygenated carbons at δ 154.5 (C-6), 162.7 (C-10), and 162.4 (C-14) as well as a carbonyl and an acetal carbon at δ 197.2 (C-12) and 103.4 (C-5), respectively. These resonances suggested that compound 1 contains two-tetrasubstituted benzene rings as found in arugosin type derivatives, such as arugosin K (4)[20].…”

Active Metabolites from Endolichenic Fungus Talaromyces sp.

“…were isolated from it. The genus Talaromyces was widely found from soil, [3] plants, [4 -5] sponges, [6] tunicate, [7] and also from lichen in our study. The second metabolites produced by Talaromyces, mainly including lactones, peptides, alkaloids, polyketides, steroids, terpenoids, and so on, [8,9] showed biological activities.…”

Sporulosol, a New Ketal from the Fungus Paraconiothyrium sporulosum

“…However, subsequent HPLC-CD analysis of 5 was unsuccessful, possibly due to the poor HPLC and CD behavior of the compound ( Figure S9 ). To our knowledge, fungal natural products including isopestacin, pestacin, pestalachloride A, fimetarone A, and arugosins K−M, have been reported as racemic mixtures of the S and R enantiomers [ 27 , 28 , 29 , 30 , 31 ].…”