盘龙参中的两个新二氢菲类

盘龙参中的两个新二氢菲类
刘静;苏雪会;李聪颖;文庆发;李延芳
【摘要】采用硅胶和凝胶柱色谱,以及制备性薄层色谱等多种分离手段,从盘龙参全草中分离得到了2个新的9,10-二氢菲类化合物,运用NMR和MS等波谱技术分别鉴定为4-羟基-2-甲氧基-8-呋喃[4′,5′:7,8]-9,10-二氢菲(1),4-羟基-2-甲氧基-8-{2',2'-二甲基吡喃[5',6':7,8]}-9,10-二氢菲(2).%A phytochemical study on Spiranthes sinensis led to the isolation of two new dihydrophenanthrenes derivatives,4-hydroxy-2-methoxy-8-furano [ 4',5':7,8 ]-9,10-dihydrophenanthrene ( 1 ) and 4-hydroxy-2-methoxy-8-｛ 2',2'-dimethylpyrano [5',6':7,8] ｝-9,10-dihydrophenanthrene (2).Their structures were established by direct interpretation of their spectral data,mainly HRESIMS,1D ( 1 H,13 C NMR) and 2D NMR ( HSQC and HMBC).
【期刊名称】《天然产物研究与开发》
【年(卷),期】2012(024)007
【总页数】4页(P866-868,872)
【关键词】盘龙参;化学成分;9,10-二氢菲
【作者】刘静;苏雪会;李聪颖;文庆发;李延芳
【作者单位】四川大学化学工程学院制药与生物工程系,成都610065;四川大学化学工程学院制药与生物工程系,成都610065;四川大学化学工程学院制药与生物工程系,成都610065;四川大学化学工程学院制药与生物工程系,成都610065;四川大学化学工程学院制药与生物工程系,成都610065
【正文语种】中文
【中图分类】R284.1
Introduction
The traditional Chinese medicine“Panlongcen”is derived from the dried root or whole plant of Spiranthes sinensis(Pers.)Ames，which is an Orchidacea plant distributed in South China and used as a folk medicine in the treatment of fever，cough，hemoptysis，vertigo，and so on ［1］.Previous phytochemical investigations on S.sinensis have yielded homocyclotriucallane，dihydrophenanthrenes and sterols［2-6］.
In the course of our study on cytotoxic secondary metabolites from traditional Chinese medicine，we examined the constituents of S.sinensis and isolated two new dihydrophenanthrenes(Fig.1)from 95%aqueous ethanolic extract of the whole plants.The aim of this paper is to report the isolation and structures elucidation of new compounds.
Experimental
General Procedures
UV spectra were obtained on a UV-2100 UV spectrophotometer(RAYLEIGH Co.Beijing，China).The high resolution mass spectrometric analysis was performed by quadrupole time of flight(Q-TOF)premier spectrometer coupled with an ESI source(Micromass，Simonsway，Manchester，UK).The1H and13C NMR spectra were recorded on Bruker AM-400 spectrometers with TMS as internal standard.The chemical shifts were
reported in ppm using CD3COCD3as solvent.Silica gel (200-300 mesh)for column chromatography and GF254 (10-40 μ)for TLC were supplied by the Qingdao Marine Chemical Inc.China.Spots on TLC were monitored under UV lamp and by heating silica gel plates sprayed with 10%H2SO4in EtOH.Toyopearl HW-40F resin (TOSOH，Japan)and Sephadex LH-20(Merck，Germany)were used for column chromatography.
Plant Material
The whole plants of S.sinensis were purchased from a local herbal medicine store in Hebei Province，China，in August 2009.The plant was identified by comparison with the voucher specimens already deposited at the Herbarium of Institute of Botany，Chinese Academy of Sciences，Beijing(No:00804465，collected on August 27，1976).A voucher specimen(D201001)was deposited at the department of pharmaceutics＆bioengineering，Sichuan University.
Extraction and isolation
The dried whole plants of S.sinensis(5 kg)were powdered and extracted three times at room temperature with 95%EtOH(25 L，each time for 3 days).After concentration in vacuo，the concentrate was taken up in H2O and partitioned successively with PE，EtOAc and n-BuOH(each 3 L×3).The EtOAc-soluble fraction (69 g)was separated by open column chromatography (40×300 mm，300 g silica gel)using a step gradient of n-hexane-EtOAc-MeOH(20∶1∶0，2 L;10∶1∶0，2.8 L;5∶1∶0，2.8 L;3∶1∶0，2 L;2∶1∶0，2.8 L;1∶1∶0，2.8 L;1∶2∶0，2 L;1∶5∶0，2L;0∶1∶0，2.8
L;0∶0∶1，6.4 L).The flow rate was ca.50 mL/min.The effluent was
combined to 10 fractions(Fr.A-J)according to TLC patterns(detection at 254 nm，365 nm and at daylight after staining with anisaldehyde-sulphuric acid reagent).The Fr.D(546 mg)were further fractionated on a Sephadex
LH-20 column(18×700 mm，CH2Cl2-MeOH，1∶1)to afford 5
portions(Fr.D1-D5).The Fr.D3(413 mg)was further separated by HW-40F column(18×320 mm，CH2Cl2-MeOH，1∶1)and followed by preparative silica gel TLC(PE∶EtOAc=4∶1)afforded to compound 2(11.2 mg，Rf0.45). Then Fr.D5(36 mg)was further separated by HW-40F column(18×320 mm，CH2Cl2-MeOH，1∶1)and further PTLC(PE∶EtOAc=4∶1)to yield compound 1(14 mg，Rf0.53).
Results and Discussion
Compound 1 was obtained as a yellow amorphous powder.Its molecular formula was established as C17H14O3 according to the molecular ion at
m/z 267.1022［M+ H］+by HR-ESI-MS(calcd.for C17H15O3，［M+H］+ 267.1021).UV(MeOH)λmax:226，278，298 nm which are strikingly similar
to those of 9，10-dihydrophenanthrene derivatives［7］.The1H NMR spectrum (Table 1)indicated one methoxyl group［δH3.77 (3H，s)］，two
o-coupled aromatic protons［δH7.36 (1H，d，J=9.2 Hz)，8.42(1H，d，
J=8.8 Hz)］，two m-coupled aromatic protons［δH6.49(1H，d，J=2.4 Hz)，6.45(1H，d，J=2.4 Hz)］.Two methylene groups attributable to the 9-and 10-protons of a dihydrophenanthrene at 2.96(2H，m)and 2.79(2H，m) are exhibited［8］.The13C NMR spectrum(Table 1) displayed the presence of 12 aromatic carbons［three bearing an oxygen atom(δC153.1，155.3，158.9)］，two methylene carbons(δC30.1，25.6)，and one methoxyl
carbon(δC54.4).Characteristic1H and13C NMR resonances for a furan structure also showed in HSQC spectrum［δH6.98(1H，d，J=2.0 Hz)/δC 105.2，7.79(1H，d，J=2.0 Hz)/δC144.8］.
Comparison of the NMR data of 1 and orchinol，one 9，10-dihydrophenanthrene isolated from this plant previously［3］，suggested that they had the same skeleton and similar substitution pattern，with the exception of the hydroxyl group and furan ring in 1 instead of a methoxyl and a hydroxyl group in orchinol.The HMBC correlations of H-2＇
(δH7.79)and the H-3＇(δH 6.98)protons with the C-8(δC125.5)and C-7(δC 153.1)confirmed that furan ring should be connected to C-
7(oxygenated)and C-8 of the aromatic ring.The cross peaks of H-
3(δH6.49)/C-4(δC155.3)，C-2 (δC158.9);H-1(δH6.45)/C-2(δC158.9)，C-10 (δC30.1);and CH3O(δH3.77)/C-2(δC158.9)in HMBC spectrum aided in establishing the location of the hydroxyl and methoxyl group on the dihydrophenanthrene skeleton.From the foregoing data the structure of 1 was assigned as 4-hydroxy-2-methoxy-8-furano［4＇，5＇∶7，8］-9，10-dihydrophenanthrene.
Compound 2，a yellow amorphous solid，has the molecular formula
C20H20O3as determined by HR-ESI-MS m/z 309.1486(calcd.for C20H21O3，［M+H］+ 309.1491).UV(MeOH)λmax:228，266，297 nm which are strikingly similar to those of 9，10-dihydrophenanthrene derivatives ［7］.The1H and13C NMR data of 2(Table 1)indicated that it is also a 9，
10-dihydrophenanthrene parison of the NMR data of 2 and 1 indicated that they had the same skeleton and substitution
pattern.Extensive analysis of its 1D and 2D NMR data revealed that it appeared a 2，2-dimethyl pyran ring［δH1.39(6H，s)，5.78 and 6.71 (1H each，d，J=10.0 Hz)and δC27.0，74.6，119.2，130.5］.The long-range HMBC correlations of H-3＇/C-8 and H-4＇/C-7，8 helped to confirm the location of 2，2-dimethyl pyran ring.From the above analysis，compound 2 was given the structure 4-hydroxy-2-methoxy-8-{2＇，2＇-dimethylpyrano［5＇，6＇∶7，8］}-9，10-dihydrophenanthrene.
Fig.1 Structures of compounds 1 and 2
Table 1 1H and13C NMR spectroscopic data of compounds 1 and 2(in
CD3COCD3，δ in ppm)1 2 No.δH δC HMBC(H→C) δH δC HMBC(H→C) 1 6.45(d，2.4) 105.2 4a，3，2，10 6.39(d，2.4) 104.8 4，4a，3，2，10 2 -158.9 - - 158.6 -3 6.49(d，2.4) 100.8 4，4a，2，1 6.44(d，2.4) 100.7 4，4a，2，1 4 -155.3 - 155.1 -4a - 114.9 - - 114.9 -5a - 127.9 - - 126.2 -5 8.42(d，8.8) 124.8 7，4a，5a 8.15(d，8.8) 128.7 7，4a，8a 6 7.36(d，9.2) 107.9 8，7，5a 6.64(d，8.8) 113.4 8，7，5a 7 -153.1 - - 151.1 -2.96(m) 25.6 8，5a，
8a，10a，10 2.75(m) 24.0 8，5a，8a，10a，10 10 2.79(m) 30.1 1，4a，10a，9 2.68(m) 30.1 1，4a，8a，10a，9 10a - 130.0 - - 140.4 -2＇ 7.79(d，2.0) 144.8 8，7，3＇ - 74.6 -3＇ 6.98(d，2.0) 105.2 8，7，2＇ 5.78(d，10.0) 130.5 8，2＇，7＇，8＇4＇ - 125.5 - 6.71(d，10.0) 119.2 8，7，2＇，7＇，8＇，8a 5＇ - 153.1 - - 117.7 -6＇ - - - - 151.1 -7＇ - - - 1.39(s) 27.0 4＇，3＇，2＇，8＇8＇ - - - 1.39(s) 27.0 4＇，3＇，2＇，7＇2-OCH3 3.77(s) 54.4 - 3.75(s) 125.5 - - 117.7 -8a - 140.7 - - 133.5 -9 8 -54.4 2 Acknowledgements
Financial support by the ChengDa special research scholarships of China
for Jing Liu and NMR measurements afforded by the Centre of Testing＆Analysis，Sichuan University are gratefully acknowledged.
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