Plant Secondary Compounds

Plants produce an array of organic compounds that are not associated with growth and development. These are often called secondary metabolites or plant secondary compounds and are divided into three major groups: terpenoids, alkaloids, and phenylpropanoids. Many play a significant role against herbivory and microbial infection, as attractants for pollinators and seed dispersers, and as allelopathic agents. These ecological functions affect primarily other organisms and have a profound effect on decomposition processes. The polyphenolic compounds range in molecular weight from 500 to 3000 daltons. They readily precipitate proteins through tannin reactions. Two major classes of tannins termed condensed and hydrolyzable tannins are found in higher plants (Fig. 12.11). Condensed tannins, also referred to as proanthocyanidins, are polymers of three-ring flavanols joined with C-C bonds. Hydrolyzable tannins are further grouped into gallotannins and ellagitannins that are composed of gallic acid or hexahydroxydiphenic acid esters, respectively, linked to a sugar moiety. The tanning of leather is an example in which a natural product is protected from microbial attack. The rate of decomposition can be directly related to the content of plant secondary compounds (Fig. 12.12). The ability to precipitate proteins has been hypothesized to be a competitive advantage for those organisms that can utilize the tannin-protein complexes (Kraus et al., 2003).

Worm Farming

Worm Farming

Do You Want To Learn More About Green Living That Can Save You Money? Discover How To Create A Worm Farm From Scratch! Recycling has caught on with a more people as the years go by. Well, now theres another way to recycle that may seem unconventional at first, but it can save you money down the road.

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