Transcript primary metabolism

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
Three major pathways to
assembly of C skeleton
Key precursors:
Phosphoenol pyruvate
(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”
UMD alum Brian Murphy in search
of anti-tuberculosis compounds
thiazoles
come from
cyclization
of cysteine
other cool stuff by cyanobacteria...