This document discusses the study of biogenetic pathways and the use of tracer techniques. It explains that determining the biosynthetic pathway of a compound enables understanding of how compounds are produced in a living cell and the relationships between intermediates and products. Understanding biosynthesis is useful for classifying natural product structures, revealing functional relationships, and controlling metabolite formation. The document outlines different types of biosynthetic pathways and provides examples of isotopically labeled compounds used in biosynthetic studies, including methionine, acetic acid, mevalonate, and phenylalanine.

2.  Class: Third Year B. Pharm Sem: VI
 Sub: Natural Product Chemistry
 Chapter No.: 5
Study of Biogenetic
Pathways
General methods to study the biogenetic pathways with special reference to
Tracer Technique and its application in the biogenetic investigations with
suitable examples.
By: Vipul Dhasade
Department of Pharmacognosy

3. 3
Why study the biosynthetic pathway?
 The determination of the biosynthetic pathway enables us to
understand the relationships and dynamic flow of the compounds
that are present in a living cell.
 The objective of the study of a biochemical sequence is to be able to
identify the “intermediates” and the “product.
 An understanding of a biosynthetic sequence can help us identify
the enzymes and genes, understand the relationships among
different organisms (such as symbiosis, plant-insect interactions, etc).
An understanding of biosynthesis is part of a complete understanding
of plant biology, ecology and biodiversity.

4. 4
An understanding of biosynthesis is very useful!
• It enables us to classify the diversity and complexity of natural products
structures.
• It reveals the functional relationships among natural products in a
dynamic context.
• It provides essential information which enables us to control or
manipulate the formation of desired metabolites.
• It opens up possible directions in biotechnology and molecular biology
through the study of enzymes (proteomics) and genomics:
Genomics + Proteomics + Biosynthesis = Metabolonomics

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Some types of biosynthetic pathways:
1. Simple linear process A B C ..... X Y
2
. M
o
d
ifie
dlin
e
a
r p
ro
c
e
s
s
A B Y Z
C D
M N
3. Convergent process A B C
D E
Y
4
. B
r
a
n
c
h
in
g p
r
o
c
e
s
s A B C D .......... Y
E
F
G
5
.
M
e
t
a
b
o
l
i
c
g
r
i
d A B C
D E F
G H Y

6. 6

8. With ref ..to
Tracer
Techniques.

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Examples of isotopically-label compounds used in
biosynthetic studies:
.
.
= 13C or 14C
H3C
S CO2H
NH2
.
methionine
H3C
C
OH
O
D3C
C
OH
O
H3C
C
OH
O
.
.
acetic acid
-O2C OP
CH3
HO
.
mevalonate
2 5
CO2H
NH2
.
phenylalanine
5
2
.
-O2C OP
CH3
HO
D
D
-O2C OP
CH3
HO
D
D
2 5

30. 30