Chemical constituents and their anti-inflammatory activity from the fungus, Diaporthe phaseolorum var. caulivora

Secondary metabolites of microbes are widely considered to be one of the best reservoirs for drug discovery from natural sources [1]. D. phaseolorum var. caulivora, which was isolated from Neolitsea daibuensis, was processed through solid-state fermentation, and its solid fermentate showed anti-inflammatory activity based on the preliminary screening.

The solid fermentate of D. phaseolorum var. caulivora was partitioned into the n-BuOH-soluble layer and water-soluble-layer. In our previous study, we have reported six new geranylcyclohexenetriols, phomentrioloxins A-F (1-6), along with seven known compounds, phomentrioloxin (12), peribysin A (13), adenosine (14), mellein (15), de-O-methyldiaporthin (16), palmitic acid (17), and ergosterol peroxide (18) from the n-BuOH-soluble fraction of solid fermentate of D. phaseolorum var. caulivora. Continuing investigation of this fungus led to the isolation of four additional new compounds, including one new pyrone, caulivopyrone (7), one sesquiterpene, caulivobysin (8), two new isobenzofuranones, cauliphthalide A (9), and cauliphthalide B (10), and one compound isolated from nature for the first time, 3-O-desmethyl phomentrioloxin (11) [2]. Phomentrioloxin (12) exhibited NO inhibitory activity with IC₅₀ value of 12.5 ± 2.2 μM and without cytotoxicity.

• References

• 1 Newman DJ, Cragg GM. Natural products as sources of new drugs from 1981 to 2014. J Nat Prod 2016; 79: 629-661
• 2 Southgate EH, Pospech J, Fu J, Holycross DR, Sarlah D. Dearomative dihydroxylation with arenophiles. Nat Chem 2016; 8: 922-928