2.3. Leaves with fl owers
In the US Pharmacopeia, quantifi cation of hawthorn
leaves includes the determination of C-glycosylated
fl avones in terms of vitexin (the quantity should
be at least 0.6%), and O-glycosylated fl avones in
terms of hyperoside (the quantity should be at least
0.45%). Hereby the method of high-performance
liquid chromatography is used. The detection for the
determination of C-glycosylated fl avons is carried out
on a 4 mm x 10 cm column at the wavelength of 336
nm and a fl ow rate of about 1.0 ml per minute. In the
determination of O-glycosylated fl avons (the term is
taken from the Pharmacopoeia of the USA, but here it is
a matter of fl avonols), the detection is carried out on a 4.6
mm x 25 cm column at the wavelength of 370 nm with a
fl ow rate of 1.5 ml per minute [27].
Quantifi cation of target substances in leaves with
fl owers according to the European Pharmacopoeia and
the Pharmacopoeia of the Republic of Belarus includes
spectrophotometric determination of the quantity of
the sum of fl avonoids in terms of hyperoside. In raw
materials their quantity should be not less than 1.5% at
the wavelength of 405 nm (European Pharmacopoeia)
and 410 nm (the Pharmacopoeia of the Republic of
Belarus) [26, 28].
Apparently, in this case an further investigation is
necessary for compliance with the choice of the analyti-
cal wavelength characteristic of the substances contain-
ing in raw materials.
2.4. Leaves
In the Pharmacopoeia of the Republic of Belarus, for
quantifi cation of active substances in hawthorn leaves,
spectrophotometric determination of the quantity of fl a-
vonoids in terms of rutin (not less than 0.25%) at the
wavelength of 409 nm, and spectrophotometric determi-
nation of the amount of procyanidins in terms of cyanidin
chloride (not less than 5.0%) at the wavelength of 550
nm [28].
In our opinion, the conclusions regarding the objec-
tivity of this methodology can be made only after a deep
study of the chemical composition of this type of raw
materials.
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