3‐O‐Methylquercetin Glucosides from Ophioglossum pedunculosum and Inhibition of Lipopolysaccharide‐Induced Nitric Oxide Production in RAW 264.7 Macrophages

The three new 3‐O‐methylquercetin glucosides 1 – 3 , together with three known congeners and 3‐O‐methylquercetin, were isolated from the fern Ophioglossum pedunculosum (quercetin=2‐(3,4‐dihydroxyphenyl)‐3,5,7‐trihydroxy‐4H‐1‐benzopyran‐4‐one). The new compounds were identified on the basis of spectroscopic analysis as 5′‐isoprenyl‐3‐O‐methylquercetin 4′,7‐di‐β‐D ‐glucopyranoside ( 1 ), 3‐O‐methylquercetin 4′‐β‐D ‐glucopyranoside 7‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranoside] ( 2 ), and 3‐O‐methylquercetin 7‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranoside] ( 3 ). The effect of the isolated compounds on lipopolysaccharide (LPS)‐induced NO production was evaluated. The inhibitory activity of 3‐O‐methylquercetin derivatives decreased markedly with the increasing number of glucosyl groups in the structures.     

Phenylethyl Glycosides from Digitalis lanata

Three new phenylethyl glycosides, 3′′′′‐O‐methylmaxoside (=2‐(3,4‐dihydroxyphenyl)ethyl O‐β‐D ‐glucopyranosyl‐(1→3)‐O‐[β‐D ‐glucopyranosyl‐(1→6)]‐4‐O‐(E)‐feruloyl‐β‐D ‐glucopyranoside; 1 ), digilanatosides A (=2‐(3,4‐dihydroxyphenyl)ethyl O‐6‐O‐(E)‐sinapoyl‐β‐D ‐glucopyranosyl‐(1→3)‐4‐O‐(E)‐caffeoyl‐β‐D ‐glucopyranoside; 2 ), and digilanatoside B (=2‐(3,4‐dihydroxyphenyl)ethyl O‐6‐O‐(E)‐p‐coumaroyl‐β‐D ‐glucopyranosyl‐(1→3)‐4‐O‐(E)‐caffeoyl‐β‐D ‐glucopyranoside; 3 ) were isolated from the aerial parts of Digitalis lanata, along with two known phenylethyl glycosides, purpureaside A and maxoside, a phenylpropanoid glucose ester, 1‐O‐(E)‐feruloyl‐β‐glucopyranose, a benzoquinolethanoid glucoside, cornoside, a cardenolide, lanatoside C, a furostane‐type steroidal saponin, purpureagitoside, and a disaccharide, sucrose. Their structures were elucidated on the basis of spectroscopic evidence (1D‐ and 2D‐NMR, and HR‐MALDI‐MS).     

Phenyl and Phenylethyl Glycosides from Picrorhiza scrophulariiflora

Three new phenyl glycosides, scrophenoside A ( 1 ), B ( 2 ), and C ( 3 ), and two new phenylethyl glycosides, scroside D ( 4 ) and scroside E ( 5 ), were isolated from the stem of Picrorhiza scrophulariiflora Pennell (Scrophularlaceae), besides five known compounds. On the basis of spectroscopic evidence, the structures of the new compounds were elucidated as 4‐acetyl‐2‐methoxyphenyl 6‐O‐[4‐(β‐D ‐glucopyranosyloxy)vanilloyl]‐β‐D ‐glucopyranoside ( 1 ), 4‐acetylphenyl 6‐O‐[(E)‐p‐coumaroyl]‐β‐D ‐glucopyranoside ( 2 ), 4‐[(1R)‐ and (1S)‐1‐hydroxyethyl]‐2‐methoxyphenyl β‐D ‐glucopyranoside ( 3a and 3b , resp.), 2‐(3,4‐dihydroxyphenyl)ethyl O‐β‐D ‐glucopyranosyl‐(1→3)‐4‐O‐[(E)‐feruloyl]‐β‐D ‐glucopyranoside ( 4 ), and 2‐(3,4‐dihydroxyphenyl)ethyl O‐β‐D ‐glucopyranosyl‐(1→3)‐6‐O‐[(E)‐feruloyl]‐β‐D ‐glucopyranoside ( 5 ).     

Chemical Constituents from Myrsine africana L.

Three new compounds, myrsinoside A (=2,4‐dihydroxy‐6‐methylphenyl β‐D ‐(6′‐galloyl)glucopyranoside; 1 ), myrsinoside B (2,4‐dihydroxy‐6‐methylphenyl β‐D ‐glucopyranoside; 2 ), and (3β,16α,20α)‐3,16,28‐trihydroxyolean‐12‐en‐29‐oic acid 3‐{O‐β‐D ‐glucopyranosyl‐(1→2)‐O‐[β‐D ‐glucopyranosyl‐(1→4)]‐α‐L ‐arabinopyranoside} ( 3 ), along with four known compounds, were isolated from the stems of Myrsine africana L. The structures of these new compounds were elucidated on the basis of spectroscopic analysis, including 1D‐ and 2D‐NMR and ESI‐MS techniques, and chemical methods.     

Seven New Acyl Glycosides from Erycibe obtusifolia

Seven new acyl glycosides, benzyl 5‐O‐vanilloyl‐β‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 1 ), 4‐hydroxy‐3‐methoxyphenyl 5‐O‐syringoyl‐β‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 2 ), isopentyl 5‐O‐syringoyl‐β‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 3 ), 3,4,5‐trimethoxyphenyl 5‐O‐sinapoyl‐β‐d ‐apiofuranosyl‐(1→6)‐β‐d ‐glucopyranoside ( 4 ), 6‐methoxy‐7‐[(6‐O‐sinapoyl‐β‐d ‐glucopyranosyl)oxy]coumarin ( 5 ), 6‐methoxy‐7‐[(2‐O‐sinapoyl‐β‐d ‐glucopyranosyl)oxy]coumarin ( 6 ), and isopentyl β‐d ‐apiofuranosyl‐(1→6)‐[5‐O‐syringoyl‐β‐d ‐apiofuranosyl‐(1→2)]‐β‐d ‐glucopyranoside ( 7 ), were isolated from Chinese folk herb Erycibe obtusifolia. Their structures were elucidated on the basis of extensive spectroscopic analysis, including UV, IR, MS, and 1D‐ and 2D‐NMR techniques. Further, these compounds were evaluated against HCT‐8 (human colon carcinoma), Bel‐7402 (human liver carcinoma), BGC‐823 (human stomach carcinoma), A549 (human lung carcinoma), and A2780 (human ovarian carcinoma) cell lines, however, none of them exhibited a significant bioactivity (IC₅₀ > 10 μm ).     

Revised structures of avenacosides A and B and a new sulfated saponin from Avena sativa L.

The revised structures of avenacosides A and B and a new sulfated steroidal saponin isolated from grains of Avena sativa L. were elucidated. Their structures and complete NMR assignments are based on 1D and 2D NMR studies and identified as nuatigenin 3‐O‐{α‐l ‐rhamnopyranosyl‐(1→2)‐[β‐D‐glucopyranosyl‐(1→4)]‐β‐d ‐glucopyranoside}‐26‐O‐β‐d ‐glucopyranoside (1), nuatigenin 3‐O‐{α‐l ‐rhamnopyranosyl‐(1→2)‐[β‐d ‐glucopyranosyl‐(1→3)‐β‐d ‐glucopyranosyl‐(1→4)]‐β‐d ‐glucopyranoside}‐26‐O‐β‐d ‐glucopyranoside (2), and nuatigenin 3‐O‐{α‐l ‐rhamnopyranosyl‐(1→2)‐[β‐d ‐6‐O‐sulfoglucopyranosyl‐(1→4)]‐β‐d ‐glucopyranoside}‐26‐O‐β‐d ‐glucopyranoside (3). Copyright © 2012 John Wiley & Sons, Ltd.     

Phenylethanoid Glycosides from the Roots of Digitalis ciliata Trautv.

Three new phenylethanoid glycosides, named digicilisides A – C ( 1  –  3 , resp.), have been isolated from the roots of Digitalis ciliata, along with five known phenylethanoid glycosides. The structures of 1  –  3 were identified as 2‐(4‐hydroxy‐3‐methoxyphenyl)ethyl β‐d ‐glucopyranosyl‐(1→3)‐[α‐l ‐rhamnopyranosyl‐(1→6)]‐4‐O‐[(E)‐feruloyl]‐β‐d ‐glucopyranoside ( 1 ), 2‐(3,4‐dihydroxyphenyl)ethyl α‐l ‐arabinopyranosyl‐(1→2)‐[β‐d ‐glucopyranosyl‐(1→3)]‐[α‐l ‐rhamnopyranosyl‐(1→6)]‐4‐O‐[(E)‐feruloyl]‐β‐d ‐glucopyranoside ( 2 ), and 2‐(3,4‐dihydroxyphenyl)ethyl β‐d ‐glucopyranosyl‐(1→3)‐{6‐O‐[(E)‐feruloyl]‐β‐d ‐glucopyranosyl‐(1→6)}‐4‐O‐[(E)‐caffeoyl]‐β‐d ‐glucopyranoside ( 3 ).     

Two New Triterpene Saponins from Acanthophyllum laxiusculum

Two new triterpene glycosides, 1 and 2 , together with three known ones, were isolated from roots of Acanthophyllum laxiusculum Schiman ‐Czeika . The structures of the new compounds were established by extensive 1D‐ and 2D‐NMR spectroscopic experiments and MS analyses as 23‐O‐β‐D ‐galactopyranosylgypsogenic acid 28‐O‐{β‐D ‐glucopyranosyl‐(1→2)‐6‐O‐[4‐carboxy‐3‐hydroxy‐3‐methyl‐1‐oxobutyl]‐β‐D ‐glucopyranosyl‐(1→6)}‐[β‐D ‐glucopyranosyl‐(1→3)]‐β‐D ‐galactopyranosyl ester ( 1 ) and gypsogenic acid 28‐O‐{β‐D ‐glucopyranosyl‐(1→2)‐6‐O‐[4‐carboxy‐3‐hydroxy‐3‐methyl‐1‐oxobutyl]‐β‐D ‐glucopyranosyl‐(1→6)}‐[β‐D ‐glucopyranosyl‐(1→3)]‐β‐D ‐galactopyranosyl ester ( 2 ).     

New Cycloartane and Flavonol Glycosides from Corchorus depressus

Two new monodesmosidic cycloartane triterpene glycosides, depressosides E and F, and two new flavonol glycosides, depressonol A and B, were isolated from the butanol‐soluble part of the EtOH extract of Corchorus depressus L . The structures of the new compounds were elucidated as (22R,24S)‐22,25‐epoxy‐9,19‐cyclolanostane‐3β,16β,24‐triol 3‐[α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranoside] ( 1 ), (22R,24S)‐22,25‐epoxy‐9,19‐cyclolanostane‐3β,16β,24‐triol 3‐[α‐D ‐glucopyranosyl‐(1→3)‐β‐D ‐glucopyranoside] ( 2 ), kaempferol 3‐[β‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside] 7‐[α‐L ‐arabinofuranoside] ( 4 ), and kaempferol 3‐[β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐galactopyranoside] 7‐[α‐L ‐arabinofuranoside] ( 5 ) on the basis of chemical evidence and detailed spectroscopic studies.     

New Isoflavone C‐Glycosides from Pueraria lobata

Three new isoflavone C‐glycosides, along with two known isoflavone O‐glycosides, were isolated from the roots of Pueraria lobata (Willd .) Ohwi . The structures of the new compounds were elucidated as 4′,7‐dihydroxy‐3′‐methoxyisoflavone 8‐C‐[β‐d‐ glucopyranosyl‐(1→6)]‐β‐d‐ glucopyranoside ( 1 ), 4′,7‐dihydroxy‐3′‐methoxyisoflavone 8‐C‐[β‐d‐ apiofuranosyl‐(1→6)]‐β‐d‐ glucopyranoside ( 2 ), and 8‐C‐β‐d‐ glucopyranosyl‐4′,7‐dihydroxy‐3′‐methoxyisoflavone 4′‐O‐β‐d‐ glucopyranoside ( 3 ) on the basis of spectroscopic methods, especially 2D‐NMR and MS analyses. The known compounds isolated were identified by comparison of their physical and spectroscopic data with those reported in the literature.     

Five New Medicagenic Acid Saponins from Muraltia ononidifolia

Five new triterpene saponins 1 – 5 were isolated from the roots of Muraltia ononidifolia E. Mey along with the two known saponins 3‐O‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid 28‐[O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester and 3‐O‐(β‐D ‐glucopyranosyl)medicagenic acid 28‐[O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester (medicagenic acid=(4α,2β,3β)‐2,3‐dihydroxyolean‐12‐ene‐23,28‐dioic acid). Their structures were elucidated mainly by spectroscopic experiments, including 2D‐NMR techniques, as 3‐O‐(β‐D ‐glucopyranosyl)medicagenic acid 28‐[O‐β‐ D ‐apiofuranosyl‐(1→3)‐O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester ( 1 ), 3‐O‐(β‐D ‐glucopyranosyl)medicagenic acid 28‐{[O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐[β‐D ‐apiofuranosyl‐(1→3)]‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl} ester ( 2 ), 3‐O‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid 28‐{O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐[β‐D ‐apiofuranosyl‐(1→3)]‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl} ester ( 3 ), 3‐O‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid 28‐[O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester ( 4 ), and 3‐O‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid ( 5 ).     

Bidesmosidic Oleanane Saponins from Xerospermum noronhianum

Three new oleanane‐type triterpenoid saponins, 3‐O‐(α‐L ‐rhamnopyranosyl(1→2)‐β‐D ‐fucopyranosyl)‐28‐O‐{[α‐L ‐rhamnopyranosyl(1→2)] [β‐D ‐fucopyranosyl(1→6)]‐β‐D ‐glucopyranosyl} oleanolic acid ( 1 ), 3‐O‐[α‐L ‐rhamnopyranosyl(1→3)‐β‐D ‐fucopyranosyl]‐28‐O‐[α‐L ‐rhamnopyranosyl(1→4)‐β‐D ‐glucopyranosyl] oleanolic acid ( 2 ), and 3‐O‐{α‐L ‐rhamnopyranosyl(1→2)‐[3′,4′‐diacetoxy‐β‐D ‐fucopyranosyl]}‐28‐O‐[α‐L ‐rhamnopyranosyl(1→2)‐β‐D ‐glucopyranosyl] oleanolic acid ( 3 ) have been isolated from the stems of Xerospermum noronhianum. The structures of the saponins were determined as a series of bidesmosidic oleanane saponins based on spectral evidence. The anticholinesterase activity of the saponins 1 – 3 was also evaluated.     

Steroidal Saponins from Disporopsis pernyi

Four new steroidal saponins, named disporosides A–D ( 1 – 4 ), corresponding to (3β,25R)‐3‐[(β‐D ‐glucopyranosyl‐(1→2)‐[β‐D ‐glucopyranosyl‐(1→6)]‐β‐D ‐glucopyranosyl)oxy]‐5β‐spirostan ( 1 ), (3β,25R)‐3‐[(β‐D ‐glucopyranosyl‐(1→2)‐[6‐O‐hexadecanoyl‐β‐D ‐glucopyranosyl‐(1→6)]‐β‐D ‐glucopyranosyl)oxy]‐5β‐spirostan ( 2 ), (3β,22R,25R)‐26‐[(β‐D ‐glucopyranosyl)oxy]‐3‐[(β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl)oxy]‐5β‐furostan ( 3 ), and (3β,22R,25R)‐26‐[(β‐D ‐glucopyranosyl)oxy]‐3‐[(β‐D ‐glucopyranosyl‐(1→2)‐[β‐D ‐glucopyranosyl‐(1→6)]‐β‐D ‐glucopyranosyl)oxy]‐5β‐furostan ( 4 ), have been isolated from the fresh rhizomes of Disporopsis pernyi, together with the three known compounds Ys‐I, agavoside B, and (3β,25R)‐3‐[(β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranosyl)oxy]‐5α‐spirostan‐12‐one. Their structures were elucidated by spectroscopic analyses, chemical transformations (acid hydrolysis), and comparison with literature data.     

Two New Kaempferol Glycosides from Androsace umbellata

Two new kaempferol glycosides, 5‐hydroxy‐2‐(4‐hydroxyphenyl)‐4‐oxo‐7‐(α‐L ‐rhamnopyranosyloxy)‐4H‐chromen‐3‐yl 2‐O‐acetyl‐3‐O‐β‐D ‐glucopyranosyl‐α‐L ‐rhamnopyranoside ( 1 ) and 5‐hydroxy‐2‐(4‐hydroxyphenyl)‐4‐oxo‐7‐(α‐L ‐rhamnopyranosyloxy)‐4H‐chromen‐3‐yl β‐D ‐glucopyranosyl‐(1→2)‐6‐O‐[(2E)‐3‐(4‐hydroxyphenyl)prop‐2‐enoyl]‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranoside ( 2 ), along with ten known compounds, were isolated from the 95% EtOH extract of the whole plant of Androsace umbellata. The structures of the new glycosides were determined on the basis of detailed spectroscopic analyses, including 1D‐ and 2D‐NMR, MS, and chemical methods.     

New Antifungal Terpenoid Glycosides from Alibertia edulis (Rubiaceae)

Phytochemical investigation from the stems of Alibertia edulis led to the isolation and identification of a new iridoid 6β‐hydroxy‐7‐epigardoside methyl ester ( 1 ) and a new saponin 3β‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)‐O‐β‐D ‐glucopyranosyl‐(1→2)‐O‐β‐D ‐glucopyranosyl]‐28‐O‐β‐D ‐glucopyranoside pomolate ( 2 ), along with three known compounds, shanzhiside methyl ester ( 3 ), ixoside ( 4 ), and 3,4,5‐trimethoxyphenyl 1‐O‐β‐D ‐apiofuranosyl‐(1→6)‐O‐β‐D ‐glucopyranoside ( 5 ). The structures of 1 and 2 were established on the basis of their spectroscopic data. Iridoid 1 and saponin 2 exhibited moderate inhibitory activities against Candida albicans and C. krusei in a dilution assay.     

Three New ent‐Kaurane Diterpenoids from Siegesbeckia pubescens

Three new ent‐kaurane glucopyranosides, 2‐O‐[β‐D ‐apiofuranosyl‐(1→3)‐2‐O‐isovaleryl‐β‐D ‐glucopyranosyl]‐4‐epi‐atractyligenin ( 1 ), 2‐O‐[β‐D ‐apiofuranosyl‐(1→3)‐2‐O‐isovaleryl‐β‐D ‐glucopyranosyl]atractyligenin ( 2 ), and 2‐O‐[β‐D ‐apiofuranosyl‐(1→3)‐2‐O‐(3‐methylpentanoyl)‐β‐D ‐glucopyranosyl]‐4‐epi‐atractyligenin ( 3 ), along with 2‐O‐(2‐O‐isovaleryl‐β‐D ‐glucopyranosyl)‐4‐epi‐atractyligenin ( 4 ), were isolated for the first time from the aerial parts of Siegesbeckia pubescens. The structures were established by extensive spectroscopic analyses including 1D ‐ and 2D ‐NMR (HSQC, HMBC, and ROESY), and HR‐ESI‐MS, and by comparison with published data.     

New Triterpenoid and Ergostane Glycosides from the Leaves of Hydrocotyle umbellata L.

Two new triterpenoid glycosides, together with two new ergostane glycosides, umbellatosides A–D ( 1 – 4 , resp.), have been isolated from the leaves of Hydrocotyle umbellata L. Their structures were established by 2D‐NMR spectroscopic techniques (¹H,¹H‐COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry as 3β,22β‐dihydroxy‐3‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐glucuronopyranosyl]olean‐12‐en‐28‐oic acid 28‐O‐β‐D ‐glucopyranosyl ester ( 1 ), 3‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐glucuronopyranosyl]oleanolic acid 28‐O‐β‐D ‐glucopyranosyl ester ( 2 ), (3β,11α,26)‐ergosta‐5,24(28)‐diene‐3,11,26‐triol 3‐O‐(β‐D ‐glucopyranosyl)‐11‐O‐(α‐L ‐rhamnopyranosyl)‐26‐O‐β‐D ‐glucopyranoside ( 3 ), and (3β,11α,21,26)‐ergosta‐5,24(28)‐diene‐3,11,21,26‐tetrol 3‐O‐(β‐D ‐glucopyranosyl)‐11‐O‐(α‐L ‐rhamnopyranosyl)‐26‐O‐β‐D ‐glucopyranoside ( 4 ).     

Four New Lariciresinol‐Based Lignan Glycosides from the Roots of Rhus javanica var. roxburghiana

The four new lariciresinol‐based lignan glycosides, (?)‐lariciresinol 4′‐(6″‐O‐feruloyl‐β‐D ‐glucopyranoside) ( 1 ), (?)‐lariciresinol 4′‐(4″,6″‐di‐O‐feruloyl‐β‐D ‐glucopyranoside) ( 2 ), 5,5′‐dimethoxylariciresinol 4′‐(4″,6″‐di‐O‐feruloyl)‐β‐D ‐glucopyranoside) ( 3 ), and 4‐O‐[α‐(1,2‐dihydroxyethyl)syringyl]‐5,5′‐dimethoxylariciresinol 4′‐(4″,6″‐di‐O‐feruloyl‐β‐D ‐glucopyranoside) ( 4 ), together with two known ones, lariciresinol 4′‐β‐D ‐glucopyranoside) ( 5 ) and tortoside B ( 6 ), were isolated from the BuOH extract of Rhus javanica var. roxburghiana roots, and their structures were established by means of various spectroscopic techniques.     

Three New Triterpene Saponins from Bolbostemma paniculatum

Two novel noroleanane saponins, tubeimoside A ( 1 ) and tubeimoside B ( 2 ), and a new dammarane triterpene saponin, tubeimoside C ( 3 ), together with two known compounds, 4 and 5 , were isolated from the bulbs of Bolbostemma paniculatum (Maxim .) Franquet . Compound 4 was found in this genus for the first time. Based on spectroscopic methods, including IR, NMR (DEPT, COSY, HMQC, HMBC, and TOCSY), and MS experiments, and chemical reactions, the structures of the new compounds were elucidated as 3β‐[β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyloxy]‐2β,23‐dihydroxy‐28‐norolean‐12‐en‐16‐one ( 1 ), 3β‐[β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyloxy]‐2β,23‐dihydroxy‐28‐norolean‐12‐en‐22‐one ( 2 ), (3β,7β)‐7,18,20‐trihydroxydammar‐24‐en‐3‐yl 2‐O‐α‐L ‐arabinopyranosyl‐β‐D ‐glucopyranoside ( 3 ).     

Tensioactive Compounds from the Aquatic Plant Ranunculus fluitans L. (Ranunculaceae)

In the search for the cause for the formation of persistent foam in the Rhine River below the Rhine Fall at Schaffhausen, an investigation of the tensioactive principles from the aquatic plant Ranunculus fluitans L. (Ranunculaceae) was carried out. Two new (see 1 and 2 ) and four known bisdesmosidic triterpene saponins (see 4 – 6 ) were isolated along with the two known diacylglycerol galactosides 7 and 8 . The saponin structures were established by the identification of the aglycon and sugar moieties by HPLC and chiral capillary zone electrophoresis (CZE), ion‐spray LC/MS and extensive 1‐ and 2D homo‐ and heteronuclear NMR spectroscopy. The structures of the new oleanane‐type saponins were identified as 3‐O‐[β‐D ‐glucopyranosyl‐(1→3)‐α‐L ‐arabinopyranosyl]‐28‐O‐[α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl]hederagenin ( 1 ) and 3‐O‐[β‐D ‐glucopyranosyl‐(1→3)‐β‐D ‐glucopyranosyl]oleanolic acid [α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl] ester ( 2 ). LC/MS Studies of tensioactive fractions revealed the presence of additional glycoglycerolipids.