Page 95 - Pharmd general phytochemistry I-Final2024_LEUCTERS

Bufadienolides

Squill & Toad venum Group
• This group of cardio-active agents includes
- The squill glycosides (the scillarins) and
- The toad poison ( Bufotoxin).
• The genin of the squill glycosides differ from those of The
cardenolides in two important aspects:

1- They have a 6-membered doubly unsaturated lactone ring at C-
17.
2- They have at least one double bond in the steroid nucleus.

• Squill glycosides give positive tests for the steroidal moiety
only , as

• They neither contain a 5- membered lactone ring with a -CH2
group
(c.f. cardenolides) or a 2- deoxy sugar in their sugar moiety.

• Squill glycoside or aglycone + acetic anhydride + H2SO4 →
blood red color → bluish green color.

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