Page 164 - phytochemistry I - PharmD Clinical

red blood corpuscles and thus haemoglobin is liberated. So,
saponins are extremely toxic when injected into the blood stream.
However, they are not harmful when taken orally, as they are not
absorbed from the intestinal tract.

Classification:

Two classes are recognised based on the structure of their aglycone
or sapogenin:

a) The steroidal type, having the characteristic four-ringed steroid
nucleus

b) The triterpenoidal type, having a five-ringed structure and is the
most common.

Both types of saponins have the glycosidic linkage at position 3.

Medicinal Importance of Saponins:

1. As precursors in the partial synthesis of cortecoids and the sex
hormones:
• Steroidal saponins are less widely distributed in nature than
tri-terpinoid saponins, but they are of great medicinal and
commercial value.
• The steroidal saponins are structurally related to the synthetic
compounds that have impressive therapeutic significance,
such as the adrenocortecoids and the sex hormones. So, they
suitable precursors in the partial synthesis of these hormones.
• One of the good sources of sapogenins is the rhizome of
various Dioscoria species, the main sapogenin in which is
diosgenin.

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