Poster presentation
116
STRUCTURE AND BIOLOGICAL ACTIVITY OF
ARABINOGALACTAN OF Ferula tenuisecta
D.Z. Azizov
1
, A.S. Dmitrenok
2
, R.K. Rakhmanberdiyeva
1
1
) S.Yu. Yunusov Institute of the Chemistry of Plant Substances Academy of
sciences of the Republic of Uzbekistan st. Mirzo-Ulugbek, 77, 100170
Tashkent
2) Institute of Organic Chemistry. N.D. Zelinsky RAS, Moscow, Russia
From the aerial part of
Ferula tenuisecta
, arabinogalactan AG-Ften with a molecular
weight of 38 kDa was isolated, consisting of galactose, glucose, arabinose in a ratio of
25:3.3:10.6. Using methylation, GC, GC-MS and
13
C NMR spectroscopy, it was found
that AG-Ften consists of D-Galp residues linked by β-1,6-glycosidic bonds as the main
chain, and the side chain is represented by α-L-Araf, β-D-Galp and 4-O-MeGlcAp. To
determine the type of glycosidic bonds between monosaccharide residues, AG-Ften was
methylated according to method of J. Ciucanu, and F. Kerek, The completeness of
methylation was controlled by IR spectroscopy by the absence of an absorption band at
3400–3200 cm
–1
(OH groups). Permethylate was subjected to methanolysis, the product
of methanolysis was acetylated to give trimethylsilyl derivatives, which were
analyzed
by GC-MS. Analysis of GC/MS data showed that AG-Ften contains T-Araf (14.94%),
1,5-Araf (4.46%), galactose residues consist of terminal T-Galp (5.64%), 1,6-linked
Galp (38.58%), 1,3-linked Galp (6.44%), and 3,6-linked Galp (14.2%). The detection of
2,3,6-tri-O-Me-Glcp (2.71%) is probably associated with the presence of β-GlcpA-4-
OMe-(1→6)-β-Galp-(1→disaccharide fragment in AG-Ften.
13
C NMR of arabinogalactan was taken in the region from 60 to 180 ppm. The
COZY, TOCSY, and ROESY spectra showed the presence of β-galactopyranose (β-
Galp), α-arbinofuranose (α-Araf), and uronic acid β-glucopyranoside (β-GlcpA)
residues as the sugar component of the polysaccharide. Analysis of the HSQC spectrum
revealed a substitution in β-Galp residues at position C-6 (residues A and E) and
positions 3,6 (residues B and C), as well as a part of unsubstituted β-Galp residues
(terminal, I). Two types of α-Araf residues were observed in the polymer: terminal (G
and G') and 5-substituted (H). The β-GlcpA (F) residues turned out to be substituted at
position 4. All conclusions about the substitution in the residues were made on the basis
of
a comparison of the
13
C NMR subspectra of the residues with the spectra of the
starting sugars, taking into account the positive α-effect of substitution. The following is
the
structure of the main
F. tenuisecta
arabinogalactan fragment:
Pharmacological studies have shown that arabinogalactan
has bifidogenic activity
and can be used as part of functional foods.