New isochaetochromin, an inhibitor of triacylglycerol synthesis in mammalian cells, produced by Penicillium sp. FKI-4942: II. structure elucidation

Abstract

The structure of a new congener of chaetochromin, an inhibitor of triacylglycerol synthesis in CHO-K1 cells produced by Penicillium sp. FKI-4942, was elucidated by spectroscopic methods, including various NMR experiments. Isochaetochromin A 1 has a bis-naphtho-c-pyrone moiety. The Journal of Antibiotics (2012) 1 from the culture broth of Penicillium sp. FKI-4942. These compounds were found to inhibit triacylglycerol synthesis in CHO-K1 cells. The taxonomy of the producing fungus, fermentation, isolation and biological properties of isochaetochromins were described in a previous paper. 2 In this study, the physico-chemical properties and structure elucidation of isochaetochromin A 1 are described.

Bis-naphtho-γ-pyrones from Fungi and Their Bioactivities

“…The absolute configurations of ustilaginoidin A (15) and the congeners from Ustilaginoidea virens were proved to be R, and the congeners of chaetochromin A (1) from Chaetomium spp. were S [9].…”

“…FK I-4942 [14,15] (10) Endophytic fungus Fusarium sp. [3] Twenty-seven asperpyrone-type bis-naphtho-γ-pyrones (Table 2 and Figure 2) with C-10-C-7' or C-10-C-9' or C-6-C-7' or C-6-C-9' linkages have been isolated from the genera Alternaria and Aspergillus.…”

New isochaetochromin, an inhibitor of triacylglycerol synthesis in mammalian cells, produced by Penicillium sp. FKI-4942: I. Taxonomy, fermentation, isolation and biological properties

“…As described in the accompanying paper, 23 these compounds have the same planar bis-naphtho-g-pyrone structure and are different in the stereochemistry of 2/2¢ and 3/3¢ methyl residues and the aS/aR-type axis, although not specified in Figure 1. These subtle differences appeared to affect the TG synthesis, CE synthesis and cytotoxicity in CHO-K1 cells (Table 1).…”

Discovery of a Fungal Multicopper Oxidase That Catalyzes the Regioselective Coupling of a Tricyclic Naphthopyranone To Produce Atropisomers

“…Innature,aromatic compounds,s uch as phenols,b icyclic species (naphthol or coumarin skeletons [1] ), and tricyclic species (naphthopyranone, [2] anthraquinone, [3] or xanthone [4] skeletons) are dimerized to form am yriad of biaryl compounds.These biaryl species can then be used as pigments and bioactive compounds with av ariety of biological activities, such as antimicrobial, cytotoxic, and enzyme-inhibitory activities.T hey have diverse structures, [2,5] including homodimers coupled at the same position [6][7][8][9][10][11][12] or different positions [13] and heterodimers coupled at the same position [14,15] or different positions. [16,17] Furthermore,s ome of these compounds have axial chirality.…”

“…[24] Fungal MCOs are thought to have multiple roles,such as lignin degradation, pigment biosynthesis,s porulation, pathogen interaction, and defense. 10 classified as alaccase because of the high homology observed with fungal laccases,w hich all contain ac ommon, conserved copper-binding motif consisting of ac luster of His,C ys,a nd Met/Leu residues ( Figure 2B). 10 classified as alaccase because of the high homology observed with fungal laccases,w hich all contain ac ommon, conserved copper-binding motif consisting of ac luster of His,C ys,a nd Met/Leu residues ( Figure 2B).…”