Which class of plant-derived compounds is typically nitrogen-containing and frequently ends with the suffix '-ine'?

• A. Active components
• B. Glycosides
• C. Alkaloids
• D. Terpenes

Answer: (C)

Nitrogen-containing plant compounds that frequently end with the suffix -ine are alkaloids. Alkaloids are a diverse group of plant secondary metabolites that contain nitrogen, often in a ring, and they tend to have strong pharmacological effects. The -ine ending is a common naming clue you’ll see with many well-known alkaloids, such as morphine, quinine, atropine, caffeine, and nicotine. The other options describe different kinds of plant constituents: glycosides couple a sugar to another molecule and do not inherently require nitrogen, while terpenes are built from isoprene units and are typically hydrocarbon-based or oxygen-containing without nitrogen. So the clue about nitrogen and the -ine suffix points to alkaloids.