WHO monographs on selected medicinal plants - travolekar.ru

<strong>WHO</strong> <strong>monographs</strong> on selected medicinal plants
Other purity tests
Chemical tests to be established in accordance with national requirements.
Chemical assays
To be established in accordance with national requirements.
Major chemical constituents
Contains organic acids (e.g. citric and quinic acids predominate), phenolic
acids (e.g. chlorogenic and p-coumaric acids). The fruits contain up to 10%
tannins (mostly catechol tannins). The major flavonoids are myricetin and
quercitin glycoside. The primary constituents of interest in cranberry are
the anthocyanins and related compounds based on the anthocyanidins,
cyanidin and peonidin, to which are attached a glucose, arabinose or galactose
sugar at the number 3 carbon, giving a total of 6 anthocyanins. The
galactosides of peonidin and cyanidin predominate, with moderate amounts
of the arabinosides. Also of interest are proanthocyanidins (condensed tannins)
consisting of oligomers of two flavan-3-ols, primarily epicatechin
plus small amounts of epigallocatechin. Cranberry proanthocyanidins contain
a variety of complex linkages, including A-type, B-type and branching
chains. A-type proanthocyanidins have doubly-linked flavan-3-ol units
with both a carbon–oxygen–carbon (C2–O–C7) bond and a carbon–carbon
(C4–C8 or C4–C6) bond (1, 3). Structures of cyanidin, peonidin,
myricetin and proanthocyanidin trimer are presented below.
HO
OH
O +
3
OH
OR
OH
Cyanidin
R = H
Peonidin
R = CH 3
Myricetin
HO
OH
O
O
3 OH
OH
OH
OH
HO
OH
HO
OH
HO
OH
H
O
OH
H
O
OH
H
O
OH
Proanthocyanidin (trimer)
HO
OH
HO
OH
HO
OH
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