Isolation and antifungal activities of a pair of isomers of phloroglucinol derivatives from Dryopteris fragrans / 中草药

ABSTRACT

Objective: To study the chemical constituents and antifungal activitiy of phloroglucinol derivatives from Dryopteris fragrans. Methods: The phloroglucinol derivatives were isolated by silica gel column chromatography, Sephadex LH-20 column chromatography, and pre-HPLC. The chemical structures were elucidated on the basis of physicochemical and spectral properties. The antifungal activities against Trichophyton rubrum and Microsporum gypseum were tested by CLSI M38-A2 broth microdilution methods. Results: Two phloroglucinol derivatives were isolated and identified as disflavaspidic acid PB (1) and flavaspidic acid PB (2). The minimum inhibitory concentration (MIC) of compounds 1 and 2 were 13.33 and 1.875 μg/mL against T. rubrum respectively, 10 and 1.325 μg/mL against M. gypseum. Conclusion: Compound 1 is a new compound named disflavaspidic acid PB. Compound 2 is isolated from D. fragrans for the first time. Compounds 1 and 2 are a pair of isomers with promising antifungal activity.