556
Vol. 60, No. 4
1
3
to tetramethylsilane (TMS). Mass spectra were recorded on (DMSO-d , 500MHz) and C-NMR (DMSO-d , 125MHz),
6
6
+
JEOL JMS 700 MStation mass spectrometer. Column chroma- Table 1; HR-FAB-MS m/z: 463.1654 [M+H] (Calcd for
tography was carried out with silica gel 60 (0.040–0.063mm, C H O , 463.1604); CD (MeOH, c=0.024): Δε (nm) −23.9
2
3
27 10
Merck), MCI gel CHP20P (75–150μm, Mitsubishi Chemical (290), +4.2 (345).
Industries Co., Ltd.), Sephadex LH20 (Amersham Pharmacia
Farrerol (2): A pale yellow amorphous powder; [α] −21.3°
Biotech) and Chromatorex ODS (30∼50μm, Fuji Silysia (c=0.62, MeOH) (lit. [α] −23° (c=0.1, MeOH); H-NMR
2
1
D
4)
25
D
1
13
Chemical Co., Ltd.). TLC was performed on a precoated sil- (CD OD, 500MHz and C-NMR (CD OD, 125MHz), Table 1;
3
3
ica gel 60 F254 (0.2mm, aluminum sheet, Merck). CD spectra CD (MeOH, c=0.090): Δε (nm) −53.8 (281), +20.8 (341).
were recorded on JASCO J-810 spectropolarimeter. Acid Hydrolysis of 1 A solution of compound 1 (1mg)
Plant Material Fresh aerial parts of D. canescens were in 2N HCl (0.2mL) in a sealed microtube was heated at 70°C
collected in August, 2007 from Daman, Nepal and shade dried for 4h and then the solution was subjected to silica gel TLC
for one month. The specimen was identified by Mr. Kuber along with authentic samples using 10% sulphuric acid as
Jung Malla, Scientic Officer, Department of Plant Resources, a detection reagent. Glucose was detected using develop-
Thapathali, Kathmandu, Nepal. The voucher specimen has ing solvents n-BuOH:AcOH:H O (5:1:4, upper layer) and
2
been deposited at The Kochi Prefectural Makino Botanical CHCl :MeOH:H O (6:4:1). Similarly, farrerol (2) was de-
3
2
Garden, Kochi, Japan.
tected using developing solvent CHCl :MeOH (9:1).
3
Extraction and Isolation The shade dried aerial parts of
D. canescens (492g) were extracted twice with 70% MeOH
Acknowledgement Authors would like to thank the
(3L) and extracts were evaporated under reduced pressure to Ministry of Education, Culture, Sports, Science and
give 70% MeOH extract (148.7g) which was then dissolved Technology (MEXT) of Japan for the scholarship to one of the
in water and subjected to MCI gel CHP20P column eluting authors, Mr. Hari Prasad Devkota.
with water, 40% MeOH, 70% MeOH and 100% MeOH to
give 8 fractions. Fraction 2 (16.3g) was subjected to Sephadex References
LH20 column (MeOH) and then ODS (30% MeOH) to afford
(121mg). Fraction 4 (10g) was subjected to Sephadex LH20
column (MeOH) to give 8 subfractions (4-1–8). Subfraction
-3 (1.9g) was subjected to Sephadex LH20 column and then
ODS column (30% MeOH) to obtain 9 (6mg), 13 (2mg) and
4 (2mg). Fraction 5 (2.5g) was subjected to Sephadex LH20
1) Manandhar N. P., “Plants and People of Nepal,” Timber Press, Inc.,
3
4
1
column (MeOH) to obtain 9 subfractions (5-1–9). The subfrac-
tion 5-5 was then subjected to ODS column (45% MeOH)
to give further 11 subfractions. Subfraction 5-5–6 (151mg)
was subjected to MCI gel CHP20P column (30% MeOH),
5
)
Ulubelen A., Bucker R., Marby T. J., Phytochemistry, 21, 801–803
(1982).
6) Konishi T., Wada S., Kiyosawa S., Yakugaku Zasshi, 113, 670–675
Sephadex LH20 column (CHCl :MeOH=3:1) and then silica
3
gel column (CHCl :MeOH:H O=9:2:0.1) to obtain com-
3
2
pound 1 (36mg). Similarly, subfraction 5-3 (372mg) was ap-
plied on silica gel column eluting with CHCl :MeOH:H O
3
2
(
5
9:1:0.1) to obtain 10 subfractions (5-3-1–10). Subfraction
-3-1 (57mg) was then applied on silica gel column eluting
with hexane:EtOAc (3:1) to obtain 10 (2mg), 11 (3mg), 12
4mg) and 15 (3mg). Subfraction 5-3-2 (73mg) was applied on
silica gel column eluting with hexane:EtOAc (1:2) to obtain
(24mg) and 7 (7mg). Subfraction 5-3-10 (63mg) was ap-
(
5
3
2
(
9:1:0.1) to obtain 8 (17mg). Fraction 6 (6.4g) was subjected
Sephadex LH20 column (MeOH) to afford 8 subfractions
6-1–6-8). Subfraction 6-3 (1.5g) was then applied on silica
(
gel column eluting with CHCl :MeOH:H Oꢀ(9:1:0.1) to
3
2
afford 8 subfractions (6-3-1–8). Subfraction 6-3-1 (462mg)
was applied on silica gel column eluting with hexane:EtOAc
(
6
1:1) to give further 12 subfractions (6-3-1-1–12). Subfraction
-3-1–2 was again applied on silica gel column eluting with
3
2
as 4 (167mg). Fraction 8 (3.8g) was dissolved in MeOH and
filtered to give MeOH soluble and insoluble parts. MeOH
soluble part was then applied on Sephadex LH20 column
(
6
MeOH) and silica gel column (hexane:EtOAc=2:1) to obtain
(75mg).
Farrerol 4′-O-β-D-Glucopyranoside (1):
A pale yellow
amorphous powder; [α]D −36.5° (c=0.66, MeOH); H-NMR
21
1