APP下载

盘龙参中的两个新二氢菲类

2012-12-22苏雪会李聪颖文庆发李延芳

天然产物研究与开发 2012年7期
关键词:工程系盘龙四川大学

刘 静,苏雪会,李聪颖,文庆发,李延芳

四川大学化学工程学院制药与生物工程系,成都610065

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 C17H14O3according 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)/δC105.2,7.79(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'(δH6.98)protons with the C-8(δC125.5)and C-7(δC153.1)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 derivative.Comparison 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.

Table 1 1H and13C NMR spectroscopic data of compounds 1 and 2(in CD3COCD3,δ in ppm)

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.

1 Zhong Hua Ben Cao(中华本草),2nd ed.,Shanghai Scientific&Technical Publishers,Shanghai,1999,8:755-757.

2 Tezuka Y,Nagashima K,Hirano H,et al.Spiranthesol,A dinerpc dihydrophen antherne from the root of Spiranthes sinensis (PERS.)Amoena(M.BIEBERSON)HARA.Chem Pharm Bull,1989,37:1667-1669.

3 Tezuka Y,Ueda M,Kikuchi T,et al.Studies on the constituents of Orchidaceous Plants.VIII.Constituents of Spiranthes sinensis(PERS.)AMES var.Amoena(M.B IEBERSON) HARA.Isolation and Structure of Spiranthol-A,Spiranthol-B,and Spiranthol-A,New Isopentenyldihydrophen anthrenes. Chem Pharm Bull,1989,37:3195-3199.

4 Tezuka Y,Li J,Hirano H,et al.Studies on the constituents of Orchidaceous Plants.IX.Constituents of Spiranthes sinensis (PERS.)AMES var Amoena(M.BIEBERSON)HARA. Structures of Spiranthesol,Spiranthoquinone,Spiranthol-C,and Spirasineol-B,New Isopentenyldi hydrophen anthrenes. Chem Pharm Bull,1990,38:629-635.

5 Lin Y,Huang R,Don M,et al.Dihydrophenanthrenes from Spiranthes sinensis.J Nat Prod,2000,12:1608-1610.

6 Lin YL,Wang WY,Kuo YH,et al.Homocyclotirucallan and Two Dihydrophenanthrenes from Spiranthes sinensis.Chem Pharm Bull,2001,49:1098-1101.

7 Majumder PL,Datta N.Structure of oxoflavidin,a 9,10-dihydrophenanthropyrone from Coelogyne elata.Phytochemistry,1984,23:671-673.

8 Letcher RM,Nhamo LRM.Chemical constituents of the combretaceae.Part III.Substituted phenanthrenes,9,10-dihydrophenanthrenes,and bibenzyls from the heartwood of Combretum psidioides.J Chem Soc,Perkin Trans,1,1972,1: 2941-2946.

猜你喜欢

工程系盘龙四川大学
【献礼北京科技大学70周年校庆】 步履铿锵卅五载,砥砺奋进谱华章——北科大机械工程学院物流工程系发展历程回顾与展望
四川大学西航港实验小学
云南省昆明市盘龙区盘龙小学五(5)萤火虫中队
新见四川大学博物馆藏敦煌古藏文写经《十万颂大圣般若波罗密多经》考论
武汉盘龙广场银兴影城
聚焦“教室照明”
盘龙糕
盘龙护佛(一石二座)
百年精诚 誉从信来——走进四川大学华西眼视光之一
一只会哭的猫