Topic overview

Start with the big picture

Secondary metabolites are generally low-molecular-weight compounds produced beyond the core processes that sustain growth and development. Their ecological roles include defense against herbivores and pathogens, attraction of pollinators and seed dispersers, suppression of competing plants, and protection from environmental stress. They occur in particular species, organs, and developmental stages, contributing to extensive chemical diversity. For pharmacognosy, this diversity matters because these compounds can help distinguish and authenticate crude drugs and provide leads for medicines. This opening topic establishes the basic concept and adaptive significance of secondary metabolites; the broader lesson develops their major classes, biosynthesis, production, analysis, and applications.