Page 138 - Pharmd general phytochemistry I-Final2024_LEUCTERS

Constituents:
 American podophyllum yields about 2-8%, and Indian podophyllum about 6-12% of

resin. The resins from these two sources are not completely identical.
 American podophyllum resin contains podophyllotoxin (~ 20%), β-peltatin (~10%) and α-

peltatin (~5%), while Indian podophyllum resin contains mainly podophyllotoxin (upto
40%), with only traces of peltatin.

OH OCH3

OO
OO

OO
OO

H3CO OCH3 H3CO OCH3
OR OR

Podophyllotoxin, R = CH3 -Peltatin, R = -H
Demethylpodophyllotoxin, R = -H -Peltatin, R - CH3

Stereochemistry of the Lactone Ring:
 Podophyllotoxin possesses cytotoxic or antitumor activity, but this activity is lost

on mild base treatment. Epimerization, α- to the carbonyl, results in the formation of
the thermodynamically more stable cis fused lactone, rather than the severely strained
trans arrangement of the natural compounds.

OO

O O

trans-fused lactone ring cis(-ifnuascetdivlea)ctone ring
(active)

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