Furostane‐Type Steroidal Saponins from the Roots of Chlorophytum borivilianum

Four new furostanol steroid saponins, borivilianosides A–D ( 1 – 4 , resp.), corresponding to (3β,5α,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐hydroxyfurostan‐3‐yl O‐β‐D ‐xylopyranosyl‐(1→3)‐O‐β‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐galactopyranoside ( 1 ), (3β,5α,22R,25R)‐ 26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurostan‐3‐yl O‐β‐D ‐xylopyranosyl‐(1→3)‐O‐β‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐galactopyranoside ( 2 ), (3β,5α,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurostan‐3‐yl O‐β‐D ‐xylopyranosyl‐(1→3)‐O‐[β‐D ‐glucopyranosyl‐(1→2)]‐O‐β‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside ( 3 ), and (3β,5α,25R)‐26‐(β‐D ‐glucopyranosyloxy)furost‐20(22)‐en‐3‐yl O‐β‐D ‐xylopyranosyl‐(1→3)‐O‐[β‐D ‐glucopyranosyl‐(1→2)]‐O‐β‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside ( 4 ), together with the known tribuluside A and (3β,5α,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐22‐methoxyfurostan‐3‐yl O‐β‐D ‐xylopyranosyl‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐O‐β‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐galactopyranoside were isolated from the dried roots of Chlorophytum borivilianum Sant and Fern . Their structures were elucidated by 2D ‐NMR analyses (COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry.     

New Glycosides from Salvia moorcroftiana (Lamiaceae)

From the MeOH extract of Salvia moorcroftiana Wall. (Lamiaceae), four new compounds, the two flavonoid glycosides genkwanin 4′‐[O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐galactopyranoside] ( 1 ) and genkwanin 4′‐[O‐α‐L ‐arabinopyranosyl‐(1→3)‐α‐L ‐rhamnopyranoside] ( 2 ), and the two benzene derivatives 4‐hydroxy‐2‐isopropyl‐5‐methylphenyl O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐glucopyranoside ( 3 ) and nonyl 4‐hydroxybenzoate ( 4 ), were isolated in addition to two known compounds. The structures of all new compounds were determined by 1D and 2D homonuclear and heteronuclear NMR spectroscopy and by comparison with published data.     

Three New Kaempferol Glycosides from Cardamine leucantha

Three new kaempferol glycosides, kaempferol 3‐O‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐galactopyranosyl‐7‐O‐α‐L ‐rhamnopyranoside ( 1 ), kaempferol 3‐O‐β‐D ‐galactopyranosyl‐7‐O‐β‐D ‐glucopyranosyl‐(1→3)‐α‐L ‐rhamnopyranoside ( 2 ), and kaempferol 3‐O‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐galactopyranosyl‐7‐O‐β‐D ‐glucopyranosyl‐(1→3)‐α‐L ‐rhamnopyranoside ( 3 ), were isolated from the whole herbs of Cardamine leucantha, along with three known kaempferol glycosides, kaempferol 7‐O‐α‐L ‐rhamnopyranoside, kaempferitrin, and kaempferol 3‐O‐β‐D ‐galactopyranosyl‐7‐O‐α‐L ‐rhamnopyranoside. Their structures were elucidated on the basis of spectroscopic methods.     

Flavonoid Glycosides from the Leaves of Machilus philippinensis

Thirteen flavonoid glycosides ( 1‐7 , 11‐13 , 15 , 17 , and 18 ) were isolated from the EtOH extract of the leaves of Machilus philippinensis. Of these, kaempferol 3‐O‐(2‐O‐β‐D ‐apiofuranosyl)‐α‐L ‐rhamnopyranoside ( 1 ) and kaempferol 3‐O‐(2‐O‐β‐D ‐apiofuranosyl)‐a‐L ‐arabinofuranoside ( 2 ) are new natural products. By application of HPLC‐SPE‐NMR hyphenated technique, five additional flavonol glycosides were characterized ( 8‐10 , 14 , and 16 ). Their structures were elucidated based on spectroscopic analysis. Of these, quercetin 3‐O‐(6‐O‐α‐L ‐rhamnopyranosyl)‐β‐D ‐galactopyranoside ( 5 ) and kaempferol 3‐O‐α‐L ‐arabinopyranoside ( 15 ) showed moderate inhibitory activity against α‐glucosidase type IV from Bacillus stearothermophilus with the IC₅₀ values of 19.5 and 19.0 μM, respectively.     

New Minor Spirostane Glycosides from Ypsilandra thibetica

A further phytochemical investigation on the whole plants of Ypsilandra thibetica yielded three new spirostane glycosides, named ypsilandrosides M–O ( 1 – 3 ). Their structures were established as (3β,11α,25R)‐3,11‐dihydroxyspirost‐5‐en‐12‐one 3‐{O‐α‐L ‐rhanmopyranosyl‐(1→4)‐O‐L ‐rhanmopyranosyl‐(1→4)‐O‐[α‐L ‐rhanmopyranosyl‐(1→2)]‐β‐D ‐glucopyranoside} ( 1 ), (3β,7β,25R)‐spirost‐5‐ene‐3,7‐diol 3‐{O‐α‐L ‐rhanmopyranosyl‐(1→4)‐O‐α‐L ‐rhanmopyranosyl‐(1→4)‐O‐[α‐L ‐rhanmopyranosyl‐(1→2)]‐β‐D ‐glucopyranoside} ( 2 ), and (3β,7α,25R)‐spirost‐5‐ene‐3,7,17‐triol 3‐{O‐α‐L ‐rhanmopyranosyl‐(1→4)‐O‐α‐L ‐rhanmopyranosyl‐(1→4)‐O‐[α‐L ‐rhanmopyranosyl‐(1→2)]‐β‐D ‐glucopyranoside} ( 3 ) by means of a combination of MS, 1D‐ and 2D‐NMR spectroscopic methods, and chemical degradation. Among them, compound 3 is the first pennogenin (=(3β,25R)‐spirost‐5‐ene‐3,17‐diol) saponin whose aglycone contains an OH group at C(7). Compounds 1 – 3 were evaluated for the inhibition of the growth of five tumor cell lines, but all of them proved to be inactive.     

Flavonol Glycosides with α‐Glucosidase Inhibitory Activities and New Flavone C‐Diosides from the Leaves of Machilus konishii

Seventeen flavonoids, five of which are flavone C‐diosides, 1 – 5 , were isolated from the BuOH‐ and AcOEt‐soluble fractions of the leaf extract of Machilus konishii. Among 1 – 5 , apigenin 6‐C‐β‐D ‐xylopyranosyl‐2″‐O‐β‐D ‐glucopyranoside ( 2 ), apigenin 8‐C‐α‐L ‐arabinopyranosyl‐2″‐O‐β‐D ‐glucopyranoside ( 4 ), and apigenin 8‐C‐β‐D ‐xylopyranosyl‐2″‐O‐β‐D ‐glucopyranoside ( 5 ) are new. Both 4 and 5 are present as rotamer pairs. The structures of the new compounds were elucidated on the basis of NMR‐spectroscopic analyses and MS data. In addition, the ¹H‐ and ¹³C‐NMR data of apigenin 6‐C‐α‐L ‐arabinopyranosyl‐2″‐O‐β‐D ‐glucopyranoside ( 3 ) were assigned for the first time. The isolated compounds were assayed against α‐glucosidase (type IV from Bacillus stearothermophilus). Kaempferol 3‐O‐(2‐β‐D ‐apiofuranosyl)‐α‐L ‐rhamnopyranoside ( 12 ) was found to possess the best inhibitory activity with an IC₅₀ value of 29.3 μM .     

New Furostanol Glycosides from the Roots of Digitalis ciliata Trautv.

Three new furostanol glycosides, named ciliatasides A, B, and C ( 1 – 3 , resp.), have been isolated from the roots of Digitalis ciliata, along with two known furostanol glycosides. The structures of the new compounds were identified as (2α,3β,5α,14β,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐2‐hydroxyfurost‐20(22)‐en‐3‐yl β‐D ‐glucopyranosyl‐(1→2)‐[β‐D ‐glucopyranosyl‐(1→3)]‐β‐D ‐galactopyranoside ( 1 ), (2α,3β,5α,14β,22R)‐26‐(β‐D ‐glucopyranosyloxy)‐2‐hydroxy‐22‐methoxyfurost‐25(27)‐en‐3‐yl β‐D ‐galactopyranosyl‐(1→2)‐[β‐D ‐xylopyranosyl‐(1→3)]‐β‐D ‐glucopyranosyl‐(1→4)‐β‐D ‐galactopyranoside ( 2 ), and (2α,3β,5α,14β,22R,25R)‐26‐(β‐D ‐glucopyranosyloxy)‐2,22‐dihydroxyfurostan‐3‐yl β‐D ‐glucopyranosyl‐(1→2)‐[β‐D ‐glucopyranosyl‐(1→3)]‐β‐D ‐galactopyranoside ( 3 ).     

Three New Triterpenoid Saponins from Ardisia crenata

Three new triterpenoid saponins, ardisicrenoside I ( 1 ), ardisicrenoside J ( 2 ), and ardisicrenoside M ( 3 ), along with eight known compounds, were isolated from the roots of Ardisia crenata Sims . Their structures were elucidated as 16α‐hydroxy‐30,30‐dimethoxy‐3β‐O‐{β‐D ‐xylopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl‐(1→4)‐[β‐D ‐glucopyranosyl‐(1→2)]‐α‐L ‐arabinopyranosyl}‐13β,28‐epoxyoleanane ( 1 ), 16α‐hydroxy‐30,30‐dimethoxy‐3β‐O‐{α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl‐(1→4)‐[β‐D ‐glucopyranosyl‐(1→2)]‐α‐L ‐arabinopyranosyl}‐13β,28‐epoxyoleanane ( 2 ), 30,30‐dimethoxy‐16‐oxo‐3β‐O‐{β‐D ‐xylopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl‐(1→4)‐[β‐D ‐glucopyranosyl‐(1→2)]‐α‐L ‐arabinopyranosyl}‐13β,28‐epoxyoleanane ( 3 ), ardisiacrispin A ( 4 ), ardisiacrispin B ( 5 ), ardisicrenoside B ( 6 ), ardisicrenoside A ( 7 ), ardisicrenoside H ( 8 ), ardisicrenoside G ( 9 ), cyclamiretin A‐3β‐O‐β‐D ‐xylopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl‐(1→4)‐α‐L ‐arabinopyranoside ( 10 ), and cyclamiretin A‐3β‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl‐(1→4)‐α‐L ‐arabinopyranoside ( 11 ) by means of chemical and spectral analysis, and their cytotoxicities were evaluated in vitro.     

Two new acylated flavonoid glycosides from Morina nepalensis var. alba Hand.‐Mazz.

From the whole plant of Morina nepalensis var. alba Hand.‐Mazz., two new acylated flavonoid glycosides ( 1 and 2 ), together with four known flavonoid glycosides ( 3–6 ), were isolated. Their structures were determined to be quercetin 3‐O‐[2″′‐O‐(E)‐caffeoyl]‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐galactopyranoside (monepalin A, 1 ), quercetin 3‐O‐[2″′‐O‐(E)‐caffeoyl]‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranoside (monepalin B, 2 ), quercetin 3‐O‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐galactopyranoside (rumarin, 3 ), quercetin 3‐O‐β‐D ‐galactopyranoside ( 4 ), quercetin 3‐O‐β‐D ‐glucopyranoside ( 5 ) and apigenin 4^′‐O‐β‐D ‐glucopyranoside ( 6 ). Their structures were determined on the basis of chemical and spectroscopic evidence. Complete assignments of the ¹H and ¹³C NMR spectra of all compounds were achieved from the 2D NMR spectra, including H–H COSY, HMQC, HMBC and 2D HMQC‐TOCSY spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

Two New Homo‐aro‐cholestane Glycosides and a New Cholestane Glycoside from the Roots and Rhizomes of Paris polyphylla var. pseudothibetica

Two new homo‐aro‐cholestane glycosides and a new cholestane glycoside, along with three known saponins, were isolated from the 95% EtOH extract of the roots and rhizomes of Paris polyphylla var. pseudothibetica. The structures of the new compounds were elucidated as 3β‐O‐{α‐L ‐rhamnopyranosyl‐(1→4)‐α‐L ‐rhamnopyranosyl‐(1→4)‐[α‐L ‐rhamnopyranosyl‐(1→2)]}‐β‐D ‐glucopyranosylhomo‐aro‐cholest‐5‐ene‐26‐O‐β‐D ‐glucopyranoside (parispseudoside A, 1 ), 3β‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐glucopyranosylhomo‐aro‐cholest‐5‐ene‐26‐O‐β‐D ‐glucopyranoside (parispseudoside B, 2 ), and (25R)‐3β‐O‐{α‐L ‐rhamnopyranosyl‐(1→4)‐α‐L ‐rhamnopyranosyl‐(1→4)‐[α‐L ‐rhamnopyranosyl‐(1→2)]}‐β‐D ‐glucopyranosyl‐cholesta‐5,17(20)‐diene‐16,22‐dione‐26‐O‐β‐D ‐glucopyranoside (parispseudoside C, 3 ) by spectroscopic methods, including 1D‐ and 2D‐NMR, and MS experiments, as well as chemical evidences.     

Diterpene Glycosides from the Dry Fronds of Conyza japonica

Phytochemical investigation of the 95% EtOH extract of the dry fronds of Conyza japonica (Thunb .) Less. resulted in the isolation of three new labdane diterpene glycosides, (3β,13S)‐13‐O‐α‐L ‐rhamnopyranosyllabda‐8(17),14‐dien‐3‐yl α‐L ‐rhamnopyranoside ( 1 ), (3β,13S)‐13‐O‐α‐L ‐rhamnopyranosyllabda‐8(17),14‐diene‐3‐yl 2‐O‐acetyl‐α‐L ‐rhamnopyranoside ( 2 ), and (3β,13S)‐13‐O‐α‐L ‐rhamnopyranosylabda‐8(17),14‐dien‐3‐yl 6‐O‐acetyl‐β‐D ‐glucopyranosyl‐(1→2)‐α‐L ‐rhamnopyranoside ( 3 ), together with their aglycone, (13S)‐labda‐8(17),14‐diene‐3,13‐diol ( 4 ). Their structures were characterized by spectroscopic analyses and chemical correlations, including 1D‐ and 2D‐NMR, and HR‐ESI‐MS. Furthermore, compounds 1 – 3 appeared to be promising as active agents against the tested pathogen fungi and oral pathogens as they possessed moderate cytotoxic properties.     

Unusual Nortriterpenoid Saponins from Stauntonia chinensis

Four new saponins, yemuosides YM₁₇–YM₂₀ ( 1 – 4 , resp.), were isolated from the rattan of Stauntonia chinensis DC. (Lardizabalaceae) along with a known saponin, nipponoside D ( 5 ). Their structures were elucidated by spectroscopic analysis and chemical evidence as 20,30‐dihydroxy‐29‐noroleanolic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 1 ), 20,29‐dihydroxy‐30‐noroleanolic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 2 ), 29‐hydroxy‐30‐norolean‐20(21)‐enolic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 3 ), 29‐hydroxyoleanolic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 4 ), and 23,29‐dihydroxyoleanolic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1→4)‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl ester ( 5 ). Yemuoside YM₁₇–YM₁₉ ( 1 – 3 , resp.) contain novel unusual nortriterpene aglycones.     

DOSY NMR applied to analysis of flavonoid glycosides from Bidens sulphurea

2D DOSY ¹H NMR has proved to be a useful technique in the identification of the molecular skeleton of the four major compounds of ethyl acetate extract of aerial parts of Bidens sulphurea (Asteraceae). The combination of this technique with HPLC, mass spectrometry and other NMR techniques enabled the identification of four flavonoid glycosides: quercetin‐3‐O‐β‐D ‐galactopyranoside, quercetin‐3‐O‐β‐D ‐glycopyranoside, quercetin‐3‐O‐α‐L ‐arabinofuranoside and quercetin‐3‐O‐β‐D ‐rhamnopyranoside. Copyright © 2009 John Wiley & Sons, Ltd.     

Flavonoid Constituents from Spiraea brahuica

Sparins A–C ( 1 – 3 , resp.), three new flavonoids, were isolated from the CHCl₃ subfraction of the EtOH extract of the whole plant of Spiraea brahuica, along with 3′,7‐di‐O‐methylquercetin ( 4 ) and luteolin 7‐β‐D ‐glucopyranoside ( 5 ), reported for the first time from this species. The structures of the new compounds were elucidated by spectroscopic techniques including MS and 2D‐NMR spectroscopy.     

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.     

Flavonol Glycosides and Cytotoxic Triterpenoids from Alphitonia Philippinensis

Three new flavonol glycosides, namely, isorhamnetin 3‐O‐(6″‐O‐(Z)‐p‐coumaroyl)‐β‐D ‐glucopyranoside ( 1 ), quercetin 3‐O‐α‐L ‐rhamnopyranosyl(1 → 2)‐α‐L ‐arabinopyranosyl(1 → 2)‐α‐L ‐rhamnopyranoside ( 2 ), and quercetin 3‐O‐α‐L ‐arabinopyranosyl(1 → 2)‐α‐L ‐rhamnopyranoside ( 3 ), were isolated from the stems of Alphitonia philippinensis. Their structures were established by spectral analysis. In addition, NMR data were assigned for ceanothenic acid ( 11 ). Some of the isolated triterpenoids and flavonoid glycosides showed cytotoxicity against human PC‐3 cells and hepatoma HA22T cells, and inhibition of replication on herpes simplex virus type‐1.     

Clintoniosides A – C,New Polyhydroxylated Spirostanol Glycosides from the Rhizomes of Clintonia udensis

Phytochemical analyses were carried out on the rhizomes of Clintonia udensis (Liliaceae) with particular attention paid to the steroidal glycoside constituents, resulting in the isolation of three new polyhydroxylated spirostanol glycosides, named clintonioside A ( 1 ), B ( 2 ), and C ( 3 ). On the basis of their spectroscopic data, including 2D‐NMR spectroscopy, in combination with acetylation and hydrolytic cleavage, the structures of 1 – 3 were determined to be (1β,3β,23S,24S,25R)‐1,23,24‐trihydroxyspirost‐5‐en‐3‐yl O‐β‐D ‐glucopyranosyl‐(1→4)‐O‐[α‐L ‐rhamnopyranosyl‐(1→2)]‐β‐D ‐glucopyranoside ( 1 ), (1β,3β,23S,24S)‐3,21,23,24‐tetrahydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐α‐L ‐rhamnopyranosyl‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐β‐D ‐glucopyranoside ( 2 ), and (1β,3β,23S,24S)‐21‐(acetyloxy)‐24‐[(6‐deoxy‐β‐D ‐gulopyranosyl)oxy]‐3,23‐dihydroxyspirosta‐5,25(27)‐dien‐1‐yl O‐α‐L ‐rhamnopyranosyl‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐β‐D ‐glucopyranoside ( 3 ).     

New Phenolic Compounds from the Roots of Lentil (Lens culinaris)

While lentil (Lens culinaris) seeds are phytochemically well characterized, very little is known about secondary metabolites from lentil roots. Our research on lentil roots led to isolation of five phenolic compounds and five group B soyasaponins. Their structures were established using NMR spectroscopy and mass spectrometry. Four phenolics have not been hitherto described in the literature: 4‐O‐β‐d ‐glucopyranosyl‐2‐methoxybenzoic acid, (αS)‐4,4′‐di‐O‐β‐d ‐glucopyranosyl‐α,2′‐dihydroxydihydrochalcone, (αS)‐4′‐O‐β‐d ‐glucopyranosyl‐α,2′,4‐trihydroxydihydrochalcone, and keto‐2‐hydroxyglycitein. The DPPH^? radical‐scavenging activity of the purified phenolic compounds was additionally evaluated.     

Studies towards a Conjugate Vaccine for Anthrax: Synthesis of the Tetrasaccharide Side Chain of the Bacillus anthracis Exosporium

The first synthesis of β‐L ‐glycoside 17 of the tetrasaccharide β‐Ant‐(1 → 3)‐α‐L ‐Rhap‐(1 → 3)‐α‐L ‐Rhap‐(1 → 2)‐L ‐Rhap is described (Schemes 1–3). Its spacer can be functionalized to make it amenable to conjugation to proteins by different conjugation methods. The synthesis was performed in a stepwise manner starting from the aglycon‐bearing terminal saccharide with thioglycosides as glycosyl donors. To attach the upstream terminal anthrose residue, the assembled linker‐equipped trisaccharide was glycosylated with ethyl 4‐azido‐3‐O‐benzyl‐2‐O‐(bromoacetyl)‐4,6‐dideoxy‐1‐thio‐β‐D ‐glucopyranoside ( 11 ). Further functionalization of the tetrasaccharide thus obtained, followed by deprotection gave the target substance 17 . Synthesis of substructures of 17 equipped with the same spacer, namely β‐L ‐Rhap‐1‐O‐(CH₂)₅COOMe ( 21 ), α‐L ‐Rhap‐(1 → 2)‐β‐L ‐Rhap‐1‐O‐(CH₂)₅COOMe ( 22 ), and α‐L ‐Rhap‐(1 → 3)‐α‐L ‐Rhap‐(1 → 2)‐β‐L ‐Rhap‐1‐O‐(CH₂)₅COOMe ( 23 ), is also described (Scheme 4).     

Three New Medicagenic Acid Saponins from Polygala micrantha Guill. & Perr.

Three new medicagenic acid saponins, micranthosides A–C ( 1 – 3 ), were isolated from the roots of Polygala micrantha Guill . & Perr ., along with six known presenegenin saponins. Their structures were elucidated on the basis of extensive 1D‐ and 2D‐NMR experiments (¹H, ¹³C, DEPT, COSY, TOCSY, NOESY, HSQC, and HMBC) and mass spectrometry as 3‐O‐β‐D ‐glucopyranosylmedicagenic acid 28‐[O‐β‐D ‐galactopyranosyl‐(1→4)‐O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐fucopyranosyl] ester ( 1 ), 3‐O‐β‐D ‐glucopyranosylmedicagenic acid 28‐[O‐6‐O‐acetyl‐β‐D ‐galactopyranosyl‐(1→4)‐O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐fucopyranosyl] ester ( 2 ), and 3‐O‐{O‐β‐D ‐glucopyranosyl‐(1→3)‐O‐[β‐D ‐glucopyranosyl‐(1→6)]‐β‐D ‐glucopyranosyl}medicagenic acid 28‐{O‐β‐D ‐apiofuranosyl‐(1→3)‐O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐[β‐D ‐apiofuranosyl‐(1→3)]‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐fucopyranosyl} ester ( 3 ). Compounds 1 – 3 were evaluated against HCT 116 and HT‐29 human colon cancer cells, but they did not show any cytotoxicity.