BIOL 350 Lecture Notes - Lecture 23: Cardiac Glycoside, Allelopathy, Capsaicin
Document Summary
Thorns: modified branches prickles: outgrowths of the epidermis. Secondary metabolites: these compounds interfere with physiological pathways, can be divided in 3 major classes: Mono- and sesquisterpinoids (2 and 3 isoprenes: sources of essential oils, may be released from glandular trichomes, insect repellant and toxins, ex. Pyrethrins (monoterpinoids produced by chrysanthemums insect neurotoxin. Many of these compounds are not toxic to humans, but distasteful to a lot of herbivores. Peppermint, spearmint, basil, oregano, rosemary, sage, savory . May be toxic to vertebrates as well as insects. Disrupt larval development and increase insect mortality (spinach: limonoids produced by citrus. Citronella from lemon rass: cardiac glycosides (ex. Chemical defenses 2: phenols: tannis, furanocoumarins c) Anti-herbivore phenols: tannis: have a bitter taste and found in wine. Toxic to insects: bind to salivary proteins and digestive enzymes resulting in protein inactivation, causing insects to fail to grow and eventually die.
