Benzoylcyclopropane Derivatives from Hypoxis hemerocallidea Corms

Planta Med. 2022 Jul;88(8):685-692. doi: 10.1055/a-1540-4978. Epub 2021 Jul 30.

Abstract

Two monobenzoylcyclopropane (hypoxhemerol A (1: ) and hypoxhemeroloside G (2: )) and three dibenzoylcyclopropane (hypoxhemerol B (3: ), hypoxhemeroloside H (4: ), and hypoxhemeroloside I (5: )) derivatives were isolated from the hydro-alcoholic extract of Hypoxis hemerocallidea corms. This is the first instance where benzoylcyclopropane analogs were isolated from any natural source. Structure elucidation was mainly based on 1D- and 2D-NMR and HRESIMS data. The absolute configuration (2R, 4R) of 1: was determined via NOESY NMR and experimental and calculated ECD data analyses. Compounds 1: -5: and 11 recently reported metabolites (hypoxoside, obtuside A, interjectin, acuminoside, curcapicycloside, and hypoxhemerolosides A - F) were screened for in vitro antimicrobial activity against various bacterial and fungal strains. Curcapicycloside and acuminoside exhibited antibacterial activity against Escherichia coli with 78 and 79% inhibition at 20 µg/mL, respectively. Hypoxhemeroloside A showed mild antifungal activity against Cryptococcus neoformans with 63% inhibition at 20 µg/mL.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Antifungal Agents / pharmacology
  • Fungi
  • Hypoxis* / chemistry
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology

Substances

  • Anti-Bacterial Agents
  • Antifungal Agents
  • Plant Extracts