Ž .Fitoterapia 71 2000 420]424

A new secoiridoid glycoside from Loniceraangustifolia

Devi Prasada,U, Vijay Juyalb, Rajdev Singha,Virendra Singhc, Geeta Pant a, Mohan S.M. Rawata

aDepartment of Chemistry, H.N.B. Garhwal Uni ersity, Srinagar Garhwal-246 174, Indiab ( )Department of Pharmaceutical Sciences, S.B.S. P.G. Institute of Biomedical Sciences and

Research, Balawala, Dehradun, IndiacChemistry Di ision, Forest Research Institute, New Forest, Dehradun-248 006, India

Received 24 December 1999; accepted 26 January 2000

Abstract

Ž .A new secoiridoid glycoside, 69-O-b-apiofuranosylsweroside 1 , together with the knowncompounds sweroside, loganin, b-sitosterol, oleanolic acid, ursolic acid and methyl-4-hydroxybenzoate have been identified from the leaves of Lonicera angustifolia. The structure of thenew compound has been elucidated on the basis of spectroscopic and chemical evidence.Q 2000 Elsevier Science B.V. All rights reserved.

Keywords: Lonicera angustifolia; Secoiridoids; 69-O-b-Apiofuranosylsweroside; Triterpenes

1. Introduction

Ž .Lonicera Caprifoliaceae is a genus of erect climbing or scrambling shrubdistributed chiefly in the sub-tropical and temperate regions of the NorthernHemisphere. Approximately 40 species are found in India and some exotics arecultivated for ornamental purpose. Lonicera species are medicinally important,

U Corresponding author. Present address: Directorate of Research Indian Council of ForestryResearch and Education, New Forest, Dehra Dun-248 006, India. Tel: q91-135-754776; Fax: q91-135-754776

Ž .E-mail address: joharia@jcfre.up.nic.in D. Prasad .

0367-326Xr00r$ - see front matter Q 2000 Elsevier Science B.V. All rights reserved.Ž .PII: S 0 3 6 7 - 3 2 6 X 0 0 0 0 1 4 9 - 0

( )D. Prasad et al. r Fitoterapia 71 2000 420]424 421

used in indigenous system of medicine as an antipyretic, stomachic and diureticw xand in dysentery 1 .

Different species of Lonicera have been chemically investigated and variousiridoids, bisiridoids, sulfur containing monoterpenoids, alkaloid glucosides, triter-penoid saponins, coumarin glycosides and flavone glycosides have been isolatedw x2]15 . Iridoid and secoiridoid glycosides have been reported to possess hypoten-

w xsive, sedative, antipyretic, antitussive and tonic activities 6,7 and are involved inw xthe biosynthesis of alkaloids of medicinal importance 16]18 . The present commu-

nication deals with the isolation and identification of six known metabolites,loganin, sweroside, b-sitosterol, oleanolic acid, ursolic acid and methyl-4-hydroxy

Ž .benzoate, and a new compound, 69-O-b-apiofuranosylsweroside 1 from the leavesof Lonicera angustifolia Wall.

2. Results and discussion

A chloroform extract of leaves of L. angustifolia on repeated column chro-

( )D. Prasad et al. r Fitoterapia 71 2000 420]424422

matography over silica gel yielded b-sitosterol, oleanolic acid, ursolic acid andmethyl-4-hydroxy benzoate. From the ethyl acetate soluble fraction, 69-O-b-

Ž . Ž . Ž .apiofuranosylsweroside 1 , sweroside 2 and loganin 3 were isolated. Swerosideand loganin were identified by comparison of their physical constants and spectral

Ž1 13 . w xdata H- and C-NMR with literature 19]21 .69-O-b-Apiofuranosylsweroside, a colourless crystalline solid, showed molecular

w xq Ž .ion peak at mrz 491 M q H HRFABMS at 491.17, calculated for C H O .21 30 131 w xThe H-NMR spectrum of 1 was strongly reminiscent of that recorded 20 for

sweroside and in addition contained signals for an apiofuranose moiety. The13C-NMR spectra of 1 showed the presence of 21 carbon atoms, the DEPTspectrum revealing the presence of 13 methine, six methylene and two quarternarycarbon atoms. The 1H- and 13C-NMR resonances were confirmed by 1H] 1HCOSY and HMQC experiments. Acetylation of 1 with a mixture of acetic anhy-dride and pyridine gave the hexaacetate, in the 1H-NMR spectrum of which signals

Ždue to six alcoholic acetoxyl groups were observed d 1.07, 2.0, 2.04, 2.05, 2.09 and.2.11 . On the basis of above mentioned spectral data, 1 was presumed to have the

structure in which sweroside is substituted by an apiofuranose group at C-69 of thesugar. This suggestion was supported by a close similarity of 13C-NMR spectrum of1 with that of sweroside except for the signal due to apiofuranose moiety. On acidichydrolysis, compound 1 gave glucose and apiofuranose. The 1H-NMR spectrum of

Ž .compound 1 exhibited a doublet at d 4.66 J s 8 Hz for the anomeric proton ofb-linked glucose. A doublet at d 4.98 was corroborated for the anomeric proton ofapiofuranose. The location of the apiofuranose group was presumed to be at C-69from the 13C-NMR resonance of C-69, resonating at d 68.5. On the basis of thesefindings, the structure of compound 1 was elucidated as 69-O-b-apiofuranosyls-weroside.

3. Experimental

3.1. Plant material

The leaves of L. angustifolia were collected from Chopta, Tungnath, U.P., India,during September 1999. The plant was identified by Dr. L.R. Dangwal, Department

Ž .of Botany, H.N.B. Garhwal University, India. A voucher specimen No. 3251 isdeposited in the herbarium of Botany Department, H.N.B. Garhwal University,India.

3.2. Extraction and isolation

Ž .Air dried leaves of L. angustifolia 1 kg were exhaustively defatted with lightŽpetroleum ether and then extracted with hot 90% EtOH. The resulting extract 250

.g was dissolved in water and subjected to solvent partition with CHCl and EtOAc3Ž . Ž .to give CHCl fraction 35.0 g and EtOAc fraction 40.1 g after evaporation of3

solvents. The CHCl fraction, on repeated Si-gel CC eluting with C H ]EtOAc3 6 6

( )D. Prasad et al. r Fitoterapia 71 2000 420]424 423

Ž .with increasing content of EtOAc, afforded b-sitosterol 130 mg , oleanolic acidŽ . Ž . Ž .170 mg , ursolic acid 95 mg and methyl-4-hydroxybenzoate 106 mg . The EtOAcfraction, on repeated Si-gel CC eluting with CHCl ]MeOH with increasing amount3

Ž . Ž .of MeOH, afforded 69-O-b-apiofuranosylsweroside 40 mg , sweroside 60 mg andŽ .loganin 83 mg .

Ž . w x20 Ž69-O-b-Apiofuranosylsweroside 1 . Colourless crystalline solid, a y 2048 cD. Ž . Ž .0.015, MeOH ; UV max MeOH : 242 log « 1.01 nm; FABMS: m r z 513

w xq w xq 1 Ž .M q Na , 491 M q H , 197, 175, 91, 57; H-NMR CD OD, 400 MHz : d 5.453Ž . Ž . Ž . Ž1H, d, J 1.2 Hz, H-1 , 7.59 1H, d, J 2.4 Hz, H-3 , 3.13 1H, m, H-5 , 1.73 2H, m,

. Ž . Ž . Ž . ŽH-6 , 4.4 2H, m, H-7 , 5.54 1H, m, H-8 , 2.71 1H, m, H-9 , 5.33 1H, dd, J 2.0,. Ž . Ž .16.8 Hz, H-10a , 5.27 1H, dd, J 2.0, 9.0 Hz, H-10b , 4.66 1H, d, J 8.0 Hz, H-19 ,

Ž . Ž . Ž .3.20 1H, dd, J 8.0, 8.8 Hz, H-29 , 3.72 1H, t, J 8.8 Hz, H-39 , 3.30 1H, m, H-49 ,Ž . Ž . Ž3.46 1H, m, H-59 , 3.63 1H, dd, J 12.0, 6.0 Hz, H-69a , 4.01 1H, d, J 12.0, 6.4 Hz,. Ž . Ž . ŽH-69b , 4.99 1H, d, J 4.0 Hz, H-10 , 3.90 1H, d, J 4.0 Hz, H-20 , 3.96 1H, d, J 10

. Ž . Ž . 13 ŽHz, H-40a , 3.76 1H, d, J 10 Hz, H-40b , 3.56 2H, brs, H-50 ; C-NMR CD OD,3. Ž . Ž100 MHz and multiplicity of the signal given by DEPT : d 98.11 d, C-1 , 153.8 d,

. Ž . Ž . Ž . Ž . Ž . ŽC-3 , 105.9 s, C-4 , 28.4 d, C-5 , 25.8 t, C-6 , 69.6 t, C-7 , 133.2 d, C-8 , 43.8 d,

. Ž . Ž . Ž . Ž . Ž .C-9 , 120.9 t, C-10 , 168.4 s, C-11 , 99.7 d, C-19 , 74.6 d, C-29 , 77.7 d, C-39 ,Ž . Ž . Ž . Ž . Ž . Ž71.4 d, C-49 , 77.7 d, C-59 , 68.5 t, C-69 , 110.9 d, C-10 , 77.1 d, C-20 , 80.4 s,. Ž . Ž . Ž .C-30 , 74.9 t, C-40 , 65.4 t, C-50 . Peracetate of 1 Ac O-py, 18 h at 608C -FABMS:2

w xq w xq 1 Žm r z 765 M q Na , 743 M q H , 259, 139, 97, 43; H-NMR 400 MHz,. Ž . Ž . Ž .CDCl : d 5.31 1H, brs, H-1 , 7.56 1H, d, J 2.4 Hz, H-3 , 2.86 1H, m, H-5 , 1.713

Ž . Ž . Ž . Ž . Ž2H, m, H-6 , 4.45 2H, m, H-7 , 5.48 1H, m, H-8 , 2.68 1H, m, H-9 , 5.34 1H,. Ž . Žbrdd, J 2.0, 8.8 Hz, H-10a , 5.27 1H, dd, J 2.0, 9.4 Hz, H-10b , 4.92 1H, d, J 8.0

. Ž . Ž . Ž .Hz, H-19 , 3.58 1H, m, H-29 , 5.24 1H, t, J 10.0 Hz, H-39 , 4.96 1H, m, H-49 , 4.32Ž . Ž . Ž . Ž . ŽH-69a , 3.75 H-69b , 4.98 1H, d, J 2.4 Hz, H-10 , 4.46 1H, H-20 , 4.23 1H, d, J

. Ž . Ž .10.0 Hz, H-40a , 4.14 1H, d, J 10.0 Hz, H-40b , 4.73 1H, d, J 12.0 Hz, H-50a ,Ž . Ž4.58 1H, d, J 12.0 Hz, H-50b , 2.11, 2.09, 2.05, 2.04, 2.01, 1.97 each 3H, s,

.6 = OAc .Ž . w x20 Ž .Sweroside 2 . Amorphous powder, a y 2378 c 0.020, water ; UV maxD

Ž . Ž . 1 Ž . ŽMeOH : 244 log « 3.91 nm; H-NMR CD OD, 400 MHz : d 5.43 1H, d, J 1.23. Ž . Ž . Ž .Hz, H-1 , 7.56 1H, d, J 2.4 Hz, H-3 , 3.11 1H, m, H-5 , 1.71 2H, m, H-6 , 4.41

Ž . Ž . Ž . Ž2H, m, H-7 , 5.56 1H, m, H-8 , 2.72 1H, m, H-9 , 5.33 1H, dd, J 2.0, 16.8 Hz,. Ž . Ž . ŽH-10a , 5.25 1H, dd, J 2.0, 9.0 Hz, H-10b , 4.63 1H, d, J 8.0 Hz, H-19 , 3.22 1H,

. Ž . Ž . Ždd, J 8.0, 8.8 Hz, H-29 , 3.71 1H, t, J 8.8 Hz, H-39 , 3.31 1H, m, H-49 , 3.44 1H,. Ž . Ž .m, H-59 , 3.65 1H, dd, J 12.0, 6.0 Hz, H-69a , 4.02 1H, d, J 12.0, 6.4 Hz, H-69b ;

13 Ž . Ž . Ž . Ž . Ž .C-NMR CD OD, 100 MHz : 98.1 C-1 , 154.3 C-3 , 105.3 C-4 , 27.3 C-5 , 25.13Ž . Ž . Ž . Ž . Ž . Ž . Ž .C-6 , 70.1 C-7 , 132.1 C-8 , 42.6 C-9 , 121.2 C-10 , 169.7 C-11 , 99.4 C-19 , 73.7Ž . Ž . Ž . Ž . Ž .C-29 , 76.2 C-39 , 70.2 C-49 , 72.1 C-59 , 61.0 C-69 .

Ž . w x20 Ž . Ž .Loganin 3 . MP 220]2228C; a y 82.78 c 0.015, water ; UV max MeOH :DŽ . 1 Ž . Ž .237 log « 4.03 nm; H-NMR CD OD, 400 MHz : d 5.26 1H, d, J 4.4 Hz, H-1 ,3Ž . Ž . Ž . Ž .7.38 1H, s, H-3 , 3.09 1H, m, H-5 , 1.62 1H, m, H-6a , 2.03 1H, m, H-6b , 4.04

Ž . Ž . Ž . Ž1H, t, J 4.4 Hz, H-7 , 1.87 1H, m, H-8 , 2.23 1H, m, H-9 , 1.07 3H, d, J 6.8 Hz,. Ž . Ž .H-10 , 4.64 1H, d, J 8.0 Hz, H-19 , 3.17-3.39 4H, m, H-29, H-39, H-49, H-59 , 3.66

Ž . Ž . 131H, dd, J 11.8, 6.0 Hz, H-69a , 3.89 1H, dd, J 11.8, 5.2 Hz, H-69b ; C-NMR

( )D. Prasad et al. r Fitoterapia 71 2000 420]424424

Ž . Ž . Ž . Ž . Ž . Ž .CD OD, 100 MHz : d 97.7 C-1 , 152.1 C-3 , 114.1 C-4 , 32.2 C-5 , 42.6 C-6 ,3Ž . Ž . Ž . Ž . Ž . Ž . Ž .74.7 C-7 , 42.2 C-8 , 46.6 C-9 , 13.4 C-10 , 169.6 C-11 , 99.9 C-19 , 75.1 C-29 ,Ž . Ž . Ž . Ž .78.3 C-39 , 71.6 C-49 , 78.0 C-59 , 62.1 C-69 .

Acknowledgements

The authors are thankful to Dr. L.R. Dangwal, Department of Botany, H.N.B.Garhwal University, Srinagar Garhwal for identification of the plant sample andMr. Sanjay Juyal, NMRrMRI Division, All India Institute of Medical Sciences,New Delhi, India for recording of NMR spectra.

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