Antifungal Phenols from Woodfordia uniflora Collected in Oman

J Nat Prod. 2020 Jul 24;83(7):2261-2268. doi: 10.1021/acs.jnatprod.0c00395. Epub 2020 Jul 8.

Abstract

Woodfordia uniflora is a flowering shrub unique to the Dhofar region of Oman and is used locally as a sedative and remedy for skin infection. However, no study to date has examined the pharmacological properties of this plant, and studies regarding phytochemicals present in W. uniflora are limited. Herein, phytochemical screening of the extract of W. uniflora was performed using LC/MS. Three new phenolic compounds, (±)-woodfordiamycin (1), woodfordic acid (2), and rhamnetin 3-O-(6″-galloyl)-β-d-glucopyranoside (3), together with 16 known compounds 4-19, were isolated from the antifungal fraction of the extract. The structures of the new compounds were established by NMR and HR-MS data, and their absolute configurations were established using chemical transformations, including Mosher's method, comparison of experimental and calculated electronic circular dichroism data, and gauge-including atomic orbital NMR chemical shift calculations, followed by DP4+ analysis. The isolated compounds (1-19) were tested for antifungal activity against human fungal pathogens Cryptococcus neoformans and Candida albicans. Compounds (±)-1 and 8 showed antifungal activity against C. neoformans, with the lowest minimum inhibitory concentrations of 1.8-1.9 μM, which was ∼10-fold lower than that of the currently available antifungal drug fluconazole, while (±)-1, 8, and 19 showed antifungal activity against C. albicans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antifungal Agents / chemistry
  • Antifungal Agents / isolation & purification*
  • Antifungal Agents / pharmacology*
  • Candida albicans / drug effects
  • Chromatography, Liquid / methods
  • Cryptococcus neoformans / drug effects
  • Microbial Sensitivity Tests
  • Oman
  • Phenols / chemistry
  • Phenols / isolation & purification*
  • Phenols / pharmacology*
  • Spectrum Analysis / methods
  • Woodfordia / chemistry*

Substances

  • Antifungal Agents
  • Phenols