Page 160 - Pharmacognosy-I (02-06-06-102)

Willow bark

Botanical origin: It consists of the whole or fragmented dried bark

from young branches of Salix alba L., S. daphnoides Vill., S. fragilis L.,
S. purpurea L., and other appropriate Salix species family Salicaceae.

General appearance

• The bark occurs in flexible, elongated, quilled or curved pieces.
• The outer surface is smooth or slightly wrinkled longitudinally and

greenish-yellow in the younger bark to brownish grey in the older
bark.
• The inner surface is smooth or finely striated longitudinally and
white, pale yellow or reddish-brown, depending on the species.
• The fracture is short in the outer part and coarsely fibrous in the
inner region, and is easily split longitudinally.

Chemical constituents

• Phenolic glycosides: including salicin (approximately 1%),
salicortin (up to 4.0%), 2´-O-acetylsalicortin (up to 10%) which
have collectively been designated as “salicylates”.

• Non-saligenin structure-based phenolic compounds: Triandrin,
vimalin.

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