OLEANOLIC ACID FROM DIPSACUS AZUREUS L.N. Ashurova, A.R. Khurramov, Kh.M. Bobakulov, N.Sh. Ramazonov, N.D. Abdullaev S.Yu. Yunusov Institute of the Chemistry of Plant Substances Academy of sciences of the Republic of Uzbekistan st. Mirzo-Ulugbek, 77, 100170 Tashkent E-mail: ashurova_lola1985@mail.ru The plant
Dipsacus azureus Schrenk (azure hairweed) (fam. Dipsacaceae) is widely
distributed in Europe and some tropical regions of Asia and Africa. In Uzbekistan, it
grows in the mountainous and foothill regions of the Tashkent, Samarkand, Fergana,
Andijan and Surkhandarya regions. Dipsacus species have long been used as traditional
medicine. to their kidney-toning and circulation-simulating activities.
The aerial parts and roots of this
D. azureus Schrenk plant contain large amounts of
saponins. Previous phytochemical examination of
D. azureus roots revealed the
presence of triterpenoids, an alkaloid, coumarins, flavonoids, and triterpene glycosides -
dipsacoside A
4
and dipsacoside B.
The air-dried crushed plant (3kg) was extracted five times at room temperature with
80% ethanol. The extract was concentrated under vacuum, then the saponins were
precipitated with acetone. The precipitate (total saponins) was dried in an oven under
vacuum, the yield was 300 g. Then the alcohol-water extract was evaporated in vacuum,
the residue was diluted with water in a ratio of 1:1 and subjected to liquid-phase
extraction with chloroform and n-butanol. Having distilled off the solvents, 50 g of
chloroform, 120 g of n-butanol and 300 g of sum saponins were obtained.
The sum of saponins was chromatographed on column eluting with silica gel by
chloroform, chloroform-methanol system with increasing polarity. Eluting in the
CHCl
3
–CH
3
OH (100:1–0:1) solvent system, seven F1–F7 fractions were obtained.
Compound
1 was isolated from the F-6 fraction on with column silica gel in the
solvent system (CHCl
3
–CH
3
OH) with a gradient increase in the methanol content from
100:0 to 10:1.
The chemical structures of the isolated compound were determined using the spectral
data of NMR spectroscopy (
1
H,
13
C, HSQC, HMBC, COSY) followed by comparison
with those of the literature data identified as oleanolic acid.
1 Thus, the obtained results showed that compounds 1 were isolated for the first time
from the aerial part of
D. azureus growing in Uzbekistan.