subsequent heating at 100-110°C for 2-3 min. The solvent systems were CHCl :CH OH (10:1, 1), CHCl :CH OH:H O
3
3
3
3
2
13
(70:23.5:2, 2), and C H N:C H :C H OH:H O (3:5:1:3, 3). PMR and C NMRspectra were recorded on Bruker AM-400 and
5
5
6
6
4
9
2
BS-567 (Tesla) spectrometers in C D N. IR spectra were recorded on a UR-20 instrument in KBr. GC was carried out in a
5
5
Chrom-5 instrument (Czech Rep.) in a glass column (1.5 m × 4 mm) packed with Chromaton-super impregnated with 5%
silicone XE-60, column temperature 210°C, vaporizer 230°C, flame-ionization detector at 250°C, He carrier gas, flow rate
50 mL/min. Rotation angles were determined on a SU-2 instrument; melting points, on a Kofler block.
Isolation of Isoprenoids. Ground leaves of A. caucasicus (1 kg) were extracted three times with ethanol (80%) with
heating. The combined extracts were evaporated toan aqueous residue that was worked up three times with CHCl (0.2 L each).
3
The CHCl was evaporated. The aqueous residue was worked up with hot water, filtered, condensed, and chromatographed over
3
a silica-gel column with elution by CHCl and system 1 to afford total isoprenoids, which were separated over a silica-gel
3
column. Compounds were eluted by system 2. Compounds A, B, and C were isolated. The yield of A was 120 mg.
20
Cycloascauloside A (1), C H O , mp 210-215°C (CH OH); [α]
-4° (c 0.1, EtOH), IR spectrum (KBr, ν
,
max
44 72 16
3
D
-1
cm ): 3400-3000 (OH), 3045 (CH -cyclopropane ring).
2
2
PMR spectrum (C D N, δ, ppm, J/Hz): 0.23, 0.50 (2H-19, d, J = 4.2), 0.89, 1.17, 1.23, 1.24, 1.40, 1.57, 1.78 (7 ×
5
5
3
3
3
CH , s), 1.70 (d, J = 6, L-rhamnose CH ), 1.98 (s, Ac CH ), 3.55 (dd, J = 12, J = 5, H-3), 3.69 (sq, J = 3.6, 9.6, 9.6, H-6),
3
3
3
1
2
3
3
3
3
3.83 (t, J = 7, H-24), 4.70 (q, J = J = J = 8, H-16) [12], 4.90 (d, J = 7.6, D-glucose anomeric proton), 5.89 (d, J = 0.9,
1
2
3
L-rhamnose anomeric proton).
Cyclogalegigenin (2). Compound 1 (50 mg) was hydrolyzed by methanolic H SO (10 mL, 25%) at 60°C for 2 h.
2
4
The reaction mixture was diluted with water. The methanol was evaporated. The resulting precipitate was filtered offand dried.
The resulting genin was purified over a column of silica gel with elution by system 2 to afford genin (28 mg), mp 196-197°C
(CH OH), that was identified also by direct TLC comparison with an authentic sample [1].
3
The carbohydrate part of the hydrolysate (after evaporation) contained D-glucose and L-rhamnose according to PC
(system 3). The remaining hydrolysate was reduced with sodium borohydride and acetylated using Ac /Py. The resulting polyol
2
acetates were identified by comparing GC traces with those of authentic samples and detected rhamnite and dulcite acetates in
a 1:1 ratio [5].
Smith decomposition [3] of glycoside (10 mg) also gave cyclogalegigenin [1].
Progenin 3 from 1. Glycoside (40 mg) was saponified with methanolic base (5 mL, 0.5%) at room temperature for
3 h. After the usual work up ofthe reaction products, chromatographyofthe glycoside part over a silica-gel column with elution
23
by system 2 afforded progenin 3 (32 mg), mp 219-221°C (CH OH), [α]
-121.5 ± 0.5° (c 0.5, CH OH).
3
3
D
Enzymatic Hydrolysis of 3. Progenin 3 (15 mg) was dissolved in CH OH, treated with an aqueous solution of
3
rhamnodiastase, and held at 37°C for 12 h. After work up of the reaction products, the genin part contained the aglycon
cyclogalegigenin (2). Rutinose was found in the carbohydrate part using PC and system 3 [7].
Partial Hydrolysis of 3. Progenin 3 (60 mg) was partially hydrolyzed in methanolic H SO (10 mL, 0.25%) at 50°C
2
4
for 1 h. After the usual work up of the reaction products, chromatography over a silica-gel column with elution by system 1
afforded 2 (5 mg), mp 195-196°C (CH OH). Continued elution of the column by system 2 afforded glycoside 4 (18 mg), mp
3
23
238-239°C (system 1), [α]
+44 ± 0.20° (c 0.6, CH OH:CHCl , 1:1) and unreacted starting glycoside (25 mg), mp 210-221°C
3 3
D
23
(system 1), [α]
-121.5° (c 0.26, CH OH:CHCl , 1:1).
3 3
D
REFERENCES
1.
2.
M. D. Alaniya, M. I. Isaev, M. B. Gorovits, E. P. Kemertelidze, and N. K. Abubakirov, Khim. Prir. Soedin., 332
(1983).
M. D. Alaniya, M. I. Isaev, M. B. Gorovits, E. P. Kemertelidze, and N. K. Abubakirov, Khim. Prir. Soedin., 477
(1984).
3.
4.
5.
M. I. Isaev, Khim. Prir. Soedin., 526 (1991).
Abdel-Akher, J. K. Hamilton, R. Montgomery, and F. Smith, J. Am. Chem. Soc., 74, 4972 (1952).
M. M. Benidze, O. D. Dzhikiya, T. A. Pkheidze, E. P. Kemertelidze, and A. S. Shashkov, Khim. Prir. Soedin., 537
(1987).
6.
M. D. Alaniya, N. F. Komissarenko, and E. P. Kemertelidze, Khim. Prir. Soedin., 813 (1976).
447