Sulfadiazine Masquerading as a Natural Product from Scilla madeirensis (Scilloideae)

J Nat Prod. 2020 Apr 24;83(4):1305-1308. doi: 10.1021/acs.jnatprod.0c00163. Epub 2020 Mar 25.


The structure of 2,4-(4'-aminobenzenamine)pyrimidine (1), a pyrimidine alkaloid previously isolated from the bulbs of Scilla madeirensis (Asparagaceae, synonym Autonoë madeirensis), has been revised. These conclusions were met via comparison of reported NMR and EIMS data with those obtained from synthetic standards. The corrected structure is the antibiotic sulfadiazine (2), which has likely been isolated as a contaminant from the site of collection. The reported bioactivity of 1 as an α1-adrenoceptor antagonist should instead be ascribed to sulfadiazine. Our findings appear to show another example of an anthropogenic contaminant being identified as a natural product and emphasize the importance of considering the biosynthetic origins of isolated compounds within a phylogenetic context.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Products / analysis
  • Biological Products / chemistry
  • Biological Products / isolation & purification
  • Biological Products / pharmacology*
  • Magnetic Resonance Spectroscopy
  • Molecular Structure
  • Phylogeny
  • Plant Roots / chemistry
  • Pyrimidines / chemistry
  • Pyrimidines / isolation & purification
  • Pyrimidines / pharmacology*
  • Scilla / chemistry*
  • Sulfadiazine / analysis
  • Sulfadiazine / chemistry*
  • Sulfadiazine / isolation & purification
  • Sulfadiazine / pharmacology*


  • Biological Products
  • Pyrimidines
  • Sulfadiazine