Helvetica Chimica Acta – Vol. 94 (2011)
1357
equipped with an H flame ionization detector; HP-5 cap. column (30 m ꢁ 0.25 mm ꢁ 0.25 mm; Agilent,
2
USA). Optical rotations: Perkin-Elmer 343 polarimeter. HR-ESI-MS: 9.4 T Q-FT-MS Apex Qe (Bruker
UNITY
1
13
Co.). NMR spectra: Varian
INOVA 600 (599.8 MHz for H and 150.8 MHz for C); the chemical
shifts in d [ppm] scale with Me Si as an internal standard. ESI-QTOF-MS: Synapt MS system (Waters,
4
USA), mass accuracy was maintained using a lock spray with leucine enkephalin for negative-ion mode
ꢀ
(
[M ꢀ H] 554.2615) at a concentration of 200 pg/ml and a flow rate of 50 ml/min as reference. The full
scan data acquisition range was 100 to 1500 Da.
Plant Material. The material was collected from Sanya County of Hainan Province, P. R. China, in
August 2005, and was identified as leaves of Agave sisalana Perr. by Prof. L.-J. Z., Tianjing University of
Traditional Chinese Medicine. Avoucher specimen (No. 040123) has been deposited with the Herbarium
of the Beijing Institute of Radiation Medicine, Beijing.
Extraction and Isolation. The fresh leaves of Agave sisalana Perr. (74.0 kg) were extracted three
times with 50% aq. EtOH at 1208 for 1 h each time (3 ꢁ 200 l). The combined extract was concentrated
under reduced pressure. CC of the extract was performed on macroporous resin (AB-8) and eluted with a
gradient mixture of Me CO/H O (1:9, 1:1, and 8 :2) to give three fractions, Frs. A – C. Fr. B (1120 g) was
2
2
chromatographed on macroporous resin (SP825) and eluted with a gradient mixture of Me CO/H O
2
2
(
(
3 :20, 5 :20, 7:20, and 20 :20) to give four fractions, Frs. B (182 g), B (208 g), B (202 g), and B
1 2 3 4
330 g). A part of Fr. B (208 g) was chromatographed on ODS SiO (50 mm) and eluted with MeOH/
2
2
H O (38 :62, 45 :55, and 70 :30), the part eluted with MeOH/H O (70 :30) was chromatographed on SiO
2
2
2
and eluted with CHCl /MeOH/H O (60 :35 :10; lower phase); combination of Frs. 8 – 11 gave
3
2
compounds 1 (147 mg) and (3b,5a,6a,22a,25R)-22-methoxyfurostane-3,6,26-triyl tris-b-d-glucopyrano-
side (23 mg). A part of Fr. B (310 g) was chromatographed on SiO and eluted with CHCl /MeOH/H O
4
2
3
2
(
70 :25 :10, lower phase); recrystallization yielded cantalasaponin-1 (235 mg). A part of Fr. B (200 g)
2
was chromatographed on ODS SiO (50 mm) and eluted with MeOH/H O (38 :62, 45 :55, and 70 :30).
2
2
The part eluted with MeOH/H O 45 :55 was chromatographed on ODS SiO and eluted with MeOH/
2
2
H O (35 :65, 38 :62, 40 :60, 44 :56, and 70 :30), and polianthoside (46 mg) was obtained from the part
2
that eluted with MeOH/H O 44 :56 by semi-prep. HPLC with MeCN/H O 18 :82. A part of Fr. B (180 g)
2
2
3
was chromatographed on ODS SiO (50 mm) and eluted with Me CO/H O (20 :80, 24 :76, and 50 :50);
2
2
2
the part eluted with Me CO/H O 20 :80 was chromatographed on Sephadex LH-20 and eluted with
2
2
Me CO/H O 50 :50 to afford (E)- and (Z)-2,3,4’,5-tetrahydrostilbene 2-O-b-d-glucopyranosides (46.7
2
2
and 16.3 mg, resp.) were obtained by semi-prep. HPLC with Me CO/H O 23 :77. Fr. C (20 g) was
2
2
chromatographed on SiO2 with a gradient mixture of CHCl /MeOH/H O (100 :20 :5, 70 :30 :10,
3
2
6
5 :35 :10, lower phase) to give five fractions, Frs. C – C . A part of Fr. C (2 g) was chromatographed on
1 5 1
ODS SiO (50 mm) and eluted with MeOH/H O (50 :50, 80 :20, and 100 :0); the second fraction was
2
2
recrystallized to yield compound 2 (13 mg).
Sisalasaponin C ( ¼ (3b,5a,6a,22a,25R)-3,26-Bis[(b-d-glucopyranosyl)oxy]-22-hydroxyfurostan-6-
2
0
1
yl b-d-Glucopyranoside; 1). White amorphous power. [a] ¼ ꢀ40.3 (c ¼ 0.064, pyridine). H- and
D
13
ꢀ
ꢀ
C-NMR: see the Table. ESI-QTOF-MS (neg.): 935.4857 ([M ꢀ H] ), 773.4351 ([M ꢀ H ꢀ 162] ),
ꢀ
ꢀ
6
11.3807 ([M ꢀ H ꢀ 162 ꢀ 162] ), 449.3316 ([M ꢀ H ꢀ 162 ꢀ 162 ꢀ 162] ). HR-ESI-MS (pos.): 959.4861
þ þ
(
[M þ Na] , C H NaO20 ; calc. 959.4828).
45
76
Sisalasaponin D ( ¼ (3b,5a,25R)-12-Oxospirostan-3-yl 6-Deoxy-a-l-mannopyranosyl-(1 ! 4)-b-d-
glucopyranosyl-(1 ! 3)-[b-d-xylopyranosyl-(1 ! 3)-b-d-glucopyranosyl-(1 ! 2)]-b-d-glucopyranosyl-
2
0
1
(
1 ! 4)-b-d-galactopyranoside; 2). White amorphous power. [a] ¼ ꢀ60.4 (c ¼ 0.086, pyridine). H- and
D
1
3
ꢀ
ꢀ
C-NMR: see the Table. ESI-QTOF-MS (neg.): 1355.6251 ([M ꢀ H] ), 1223.5770 ([M ꢀ H ꢀ 132] ),
ꢀ
ꢀ
1
1
1
061.5205 ([M ꢀ H ꢀ 132 ꢀ 162] ), 915.4227 ([M ꢀ H ꢀ 132 ꢀ 162 ꢀ 146] ), 753.3995 ([M ꢀ H ꢀ 132 ꢀ
ꢀ
ꢀ
62 ꢀ 146 ꢀ 162] ), 591.3532 ([M ꢀ H ꢀ 132 ꢀ 162 ꢀ 146 ꢀ 162 ꢀ 162] ), 429.2926 ([M ꢀ H ꢀ 132 ꢀ
ꢀ
þ
þ
32
62 ꢀ 146 ꢀ 162 ꢀ 162 ꢀ 162] ). HR-ESI-MS (pos.): 1379.6148 ([M þ Na] , C H NaO ; calc.
6
2
100
1
379.6090).
Acid Hydrolysis. Compound 1 (2.0 mg) was treated with 1m HCl (dioxane/H O, 1:1, 2 ml) at 1008 for
2
1
.5 h. The mixture was neutralized with Ag CO , and the solvent was thoroughly driven out under N
2
3
2
overnight. The residue was extracted with CHCl and H O. Then, in the monosaccharide mixture, glucose
3
2
from 1 was detected by TLC analysis on a cellulose plate with BuOH/AcOEt/C H N/H O 6 :1:5 :4 and
5
5
2
aniline-o-phthalic acid for detection, comparing with the authentic sample (glucose: Rf 0.46).