Steroid and Sterols = Triterpenoids : Steroid and Sterols = Triterpenoids Steroids are known as tetracyclic triterpenoids.
Plants contain a large number of the more than 150 sterols known to occur in nature.
Slide 2 : Unlike the steroid hormones in animals, there is no known role for sterols in plant development.
Some sterols may have a protective function, such as the phytoecdysones, which have a structure similar to the insect inciting hormones.
When ingested by insect herbivores, phytoecdysones disrupt the insect's moulting cycle. Largest and Most Diverse class of Organic Compounds
Tetraterpenes= C40H64 : Tetraterpenes= C40H64 Carotenoids as Lycopene
Bright reddish yellow pigment found in tomatoes and other yellow red fruits , vegetables, such as carrots, watermelons an papaya
Considered most effective against prostrate cancer.
Slide 4 : In the plant, natural rubber occurs as small particles suspended in a milky white emulsion called latex.
Latex production is widespread in plants, with estimates ranging from a few hundred to several thousand species that produce latex in some form. Polyterpenes
Slide 5 : The principal commercial source is Hevea brasiliensis, a tree native to the Amazon rainforest.
Others include the ornamental rubber tree, Ficus elastica, milkweed , Asclepias and Russian dandelion (Taraxacum).
Slide 6 :
Slide 7 : Deterrent to Herbivores
GLYCOSIDES : GLYCOSIDES Sugar molecule condensed with hydroxyl group
Examples
Saponins
Cardiac glycosides
Cyanogenic glycosides
Saponins='soap plants' : Saponins='soap plants' Bitter acid taste and can cause irritation to gastric tract of herbivores serve as anti-feedants.
Saponin glycyrrhizin from licorice (Glyscyrrhiza glabra) has been used in medicines and is sweetner.
Slide 10 : Medigenic acid from alfalfa, Medicago sativa.