Primary and Secondary 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. – Kingdom Plantae – Kingdom Animalia – Kingdom Fungi – Kingdom Bacteria 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 stuff

Primary Metabolites Necessary for basic survival of an organism Used for energy and tissue construction Includes most carbohydrates, amino acids and proteins, lipids, nucleic acids, and some vitamins & cofactors

Secondary Metabolites Resource: Dewick, Medicinal Natural Products, Ch. 2 Are assembled from (pieces of) primary metabolites Are plentiful and diverse in plant-based foods May be more prevalent or unique to certain genus, species, and similar compounds occur within genuses and families Often have vital functions in the source attractants for propagation of species defense against predators signaling May have useful nutritional benefits to humans/other organisms The genes and enzymes guiding biosynthesis vary from one organism to the next.

Origins of secondary metabolites Four major pathways to assembly of C skeleton: acetate shikimate mevalonate (all organisms) DXP (plants, microbes) Key precursors: Phosphoenol pyruvate (PEP)  shikimate pathway Acetyl CoA  acetate or mevalonate pathways N from amino acids  alkaloids

Building blocks (Fig. 2.2) C 1 – methyl groups C 2 – 2 carbon units from acetate pathway C 5 – isoprene C 6 C 3 - phenylpropanoid C 6 C 2 N – precursor to indole C 4 N & C 5 N – heterocyclic amines

C 1 : any molecule C 2 : Fatty acids Long chains on most molecules Polyketides Some aromatic rings C 5 : Isoprenoids chains & nonarom. rings C 6 C 3 : Phenylpropanoids

C 1 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) C 1 – methyl groups C 2 – 2 carbon units from acetate pathway C 5 – isoprene C 6 C 3 - phenylpropanoid C 6 C 2 N – precursor to indole C 4 N & C 5 N – 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?

 -carotene linolenic acidresveratrol  -bisabolene