New Antifungal Pyranoisoflavone from <em>Ficus tikoua </em>Bur.

Abstract

Considering the undesirable attributes of synthetic fungicides and the availability of Ficus<em> </em>species in China, the stem of<em> Ficus tikoua </em>Bur. was investigated. One<strong> </strong>new antifungal pyranoisoflavone, 5,3',4'-trihydroxy-2",2"-dimethylpyrano (5",6":7,8) isoflavone (<strong>1</strong>), together with two known isoflavones, wighteone (<strong>2</strong>) and lupiwighteone (<strong>3</strong>) (with previously reported antifungal activities), were isolated from ethyl acetate extract by bioassay-guided fractionation. Their structures were determined by spectroscopic analysis, such as NMR (¹H-¹H COSY, HMQC, HMBC and NOESY), IR, UV and HRMS, as well as ESI-MSⁿ analyses. The antifungal activities of <strong>1</strong>–<strong>3</strong> against <em>Phytophthora infestans</em> were evaluated by direct spore germination assay, and the IC₅₀ values were 262.442, 198.153 and 90.365 µg·mL⁻¹, respectively.

Keywords

• &lt;em&gt;Ficus tikoua &lt;/em&gt;Bur.
• pyranoisoflavone
• antifungal activity