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Primary metabolites. Despite the extremely varied characteristics of living organisms , the pathways for generally modifying and synthesizing carbohydrates, proteins , fats , and nucleic acids are essentially the same in all organisms, apart from minor variations .
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Primary metabolites Despite the extremely varied characteristics of living organisms, the pathways for generally modifying and synthesizing carbohydrates, proteins, fats, and nucleic acids are essentially the same in all organisms, apart from minor variations. These processes demonstrate the fundamental unity of all living matter, and are collectively described as primary metabolism, with the compounds involved in the pathways being termed primary metabolites. i.e. CHM411 Secondary metabolites are derived from primary metabolites but the genes and enzymes guiding biosynthesis vary from one organism to the next. Similar compounds occur within genuses and families
Origins of secondary metabolites Threemajor pathways to assembly of C skeleton Key precursors: Phosphoenolpyruvate (PEP) shikimate pathway Acetyl CoA acetate or mevalonate pathways N from amino acids alkaloids
Building blocks (Fig. 2.2) • C1 – methyl groups • C2 – 2 carbon units from acetate pathway • C5 – isoprene • C6C3 - phenylpropanoid • C6C2N – precursor to indole • C4N & C5N – heterocyclic amines
C1: any molecule C2: Fatty acids Long chains on most molecules Polyketides Some aromatic rings C5: Isoprenoids chains & nonarom. rings C6C3: Phenylpropanoids
C1 comes from SAM (S-adenosylmethionine) SAM can attach a methyl group to just about anything Methyls may be attached to C atoms on chains, rings, attached to oxygen (methoxy), attached to nitrogen (N-methyl)
Building blocks (Fig. 2.2) • C1 – methyl groups • C2 – 2 carbon units from acetate pathway • C5 – isoprene • C6C3 - phenylpropanoid • C6C2N – precursor to indole • C4N & C5N – heterocyclic amines
Origins of alkaloids (nitrogen-containing natural products) pyrrolidine piperidine
Identify the building blocks • Most secondary metabolites are assembled from pieces coming from more than one biosynthetic pathway • Can you figure out what the building blocks are in each structure? • Analysis of building blocks helps us understand how the compound was made, what were the precursors?
b-carotene resveratrol linolenic acid
10-p-trans-coumaroyl-1S-dihydromonotropein tetrahydrocannabinol a-bisabolene berberine
Newsweek article on new drug leads from marine bioprospectors • U. Florida - H. Luesch, isolated anticancer drug largazole from cyanobacteria (Symploca) • process known as “bioassay-guided fractionation” thiazoles come from cyclization of cysteine UMD alum Brian Murphy in search of anti-tuberculosis compounds
