sulfonamide vs tetracycline

sulfonamide

noun
  • Any of a group of antibiotics; a sulfa drug 

  • Any amide of a sulfonic acid RS(=O)₂NR'₂ 

tetracycline

noun
  • Any of a large group of antibiotics with the same general structure derived from tetracene with many hydroxyl and other groups. 

  • A yellow crystalline broad-spectrum antibiotic C₂₂H₂₄N₂O₈ produced by streptomyces or synthetically. 

How often have the words sulfonamide and tetracycline occurred in a corpus of books? (source: Google Ngram Viewer )