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Five new hybrid peptide-polyketides, curvularides A-E (1-5), were isolated from the endophytic fungus Curvularia geniculata, which was obtained from the limbs of Catunaregam tomentosa. Structure elucidation for curvularides A-E (1-5) was accomplished by analysis of spectroscopic data, as well as by single-crystal X-ray crystallography. Curvularide B (2) exhibited antifungal activity against Candida albicans, and it also showed synergistic activity with a fluconazole drug.

The endophytic mitosporic Dothideomycete sp. LRUB20 was found to produce pyrone derivatives, dothideopyrones A-D (1, 3, 4, and 5), together with seven known compounds, including questin (9), asterric acid (10), methyl asterrate (11), sulochrin (12), and eugenitin (13), 6-hydroxymethyleugenitin (14), and cis, trans-muconic acid (15). Dothideopyrone D (5) and its acetate derivative 6 exhibited moderate cytotoxic activity. This is the first report on a naturally occurring muconic acid, which is commonly known as a biomarker in environments after exposure to benzene and phenol (or derivatives). Interestingly, the LRUB20 fungus could produce muconic acid in relatively high yield (47.8mg/L). The utility of endophytic fungi in the field of white biotechnology is discussed.

isolation and structure elucidation of curvularide A (Ia), B (II), C (Ib), D (III) and E (IV); curvularide B shows promising antifungal activity

Isolation of a broth extract of the endophytic fungus Corynespora cassiicola L36 afforded three compounds, corynesidones A (1) and B (3), and corynether A (5), together with a known diaryl ether 7. Compounds 1, 3, 5, and 7 were relatively non-toxic against cancer cells, and inactive toward normal cell line, MRC-5. Corynesidone B (3) exhibited potent radical scavenging activity in the DPPH assay, whose activity was comparable to ascorbic acid. Based on the ORAC assay, compounds 1, 3, 5, and 7 showed potent antioxidant activity. However, the isolated natural substances and their methylated derivatives (1-8) neither inhibited superoxide anion radical formation in the XXO assay nor suppressed TPA-induced superoxide anion generation in HL-60 cell line. Corynesidone A (1) inhibited aromatase activity with an IC(50) value of 5.30 microM.

3-Nitropropionic acid (3-NPA, 1) was found in extracts of several strains of endophytic fungi. 3-NPA (1) exhibited potent antimycobacterial activity with the minimum inhibition concentration of 3.3 microM, but was inactive against NCI-H187, BC, KB, and Vero cell lines. Endophytes were found to produce high levels of 3-NPA (1), and therefore 3-NPA (1) accumulated in certain plants may be produced by the associated endophytes. 3-NPA (1) may be used as a chemotaxonomic marker for endophytic fungi. The structure of 3-hydroxypropionic acid, a nematicidal agent, should be revised to 3-NPA (1).