Biosynthesis and biogenetic interrelationships of metabolites of the fungus Arthropsistruncata

Abstract

The incorporation of sodium [1-13C]acetate and sodium [1,2-13C2]acetate into a number of polyketide metabolites produced by the fungus Arthropsistruncata has been examined. The location of sodium [1-13C]acetate incorporation into arthropsadiol A (1), cycloarthropsone (2), and arthropsatriol C (3) has been determined by 13C nuclear magnetic resonance spectra of the corresponding diacetate derivatives, and a biosynthetic pathway is proposed to account for the formation of 1–3. Multiple incorporation of sodium [1,2-13C2]acetate into arthropsadiol A (1) leads to a complicated pattern of satellite multiplets in the 13C nmr spectrum of the corresponding diacetate 6 that are interpreted with the aid of 2D-INADEQUATE spectra. A biosynthesis of arthropsolide A (5) is proposed and the absence of 5 and related metabolites in cultures of the Arthropsistruncata fed with 13C-labelled sodium acetate is discussed.

New Bioactive Rosigenin Analogues and Aromatic Polyketide Metabolites from the Freshwater Aquatic Fungus Massarina tunicata

“…Compound 1 is closely related to the known fungal metabolite rosigenin (8) 3 and other previously reported compounds. [4][5][6][7][8][9][10] Although the relative stereochemistry of 1 was provided by the X-ray structure, NOESY data were acquired to assist in stereochemical comparisons with compounds 2-4 (see below). As might be expected for the 3D structure depicted in Figure 1 Compound 2 (massarigenin B) was determined to be an isomer of 1 on the basis of HRFABMS and 13 C NMR data.…”

“…known primarily for production of the macrosphelides. 10 A number of fungal metabolites containing the similar, nitrogen-containing 2-azaspiro [4,5]decane skeleton have been isolated from Drechslera tritici-repentis 9 and from both wild-type and mutant strains of Staphylotrichum coccosporum (spirostaphylotrichins). [12][13][14][15] The numbering system employed for 1-4 is based on that originally reported for 8-9 and for the spirostaphylotrichins.…”

“…Massarigenin A (1): white crystals; mp 169-171 °C; [R]D -5.6°(c 0.26 g/dL; 24 °C; CH3OH); UV (CH3OH) 210 ( 2000); IR 3590, 2928, 1806 (ester group), 1682 (vinyl ether group), 1605, 1275, 1174, 1103, 1027 cm -1 ; EIMS (70 eV) m/z 208 [(M -H2O) + , rel int 9], 193 (36), 175 (15), 152 (25), 140 (32), 125 (29), 105 (29), 91 (32), 84 (100), 77 (34), 55 (66), 43 (56); 1 H NMR data, Table 1; 13 C NMR data, Table 2; HMBC data, Table 3 (7), 123 (5), 107 (4), 95 (4), 82 (100), 67 (4), 54 (14), 43 (15); 1 H NMR data, Table 1; 13 C NMR data, Table 2; selective INEPT data, Table 3; NOESY data (acetone-d6, H-# T H-#) H-4 T H3-12; H-6 T H-10; HRFABMS (NaI/3-NBA matrix) obsd m/z 247.0575, calcd for C11H12O5+Na, 247.0582.…”

Secondary metabolites of fungi from marine habitats

“…166 For the related metabolite arthropsolide A, produced by Arthropsis truncata, it has been proposed that its biogenesis includes the condensation of a pentaketide precursor and malic acid. 167 The unusual tricyclic compound 2106 A (212) was obtained from the culture broth of an unidentified fungus from the mangrove Avicennia marina in Hong Kong, and its structure was established by X-ray diffraction analysis. 168 Protulactones A (213) and B (214) were reported from the fungus Aspergillus sp., isolated from an inter-tidal sediment sample collected in Korea.…”

Toward the Synthesis of (–)-TAN-2483B Lactam Analogues

“…24) (Figure 7). [38][39][40] Studies on spirostaphylotrichine biosynthesiswhich may be extended to other members of this class of compoundssuggest that they are formed by the condensation of a polyketide chain with an unidentified C4 unit, possibly aspartic acid or an intermediate from the citric acid cycle. 38 Furthermore, the configuration of the C-4 alcohol is conserved during epoxide formation and subsequent epoxide opening from C-4 to C-3, so that the desired 3R configuration is obtained.…”