Ursane‐Type Triterpene Saponins from Zygophyllum geslini

Four new ursane‐based triterpene glycosides, compounds 1 – 4 , as well as the known glycosides zygophylosides E, G, and H, and 3‐O‐(β‐D ‐quinovopyranosyl)quinovic acid 28‐(O‐β‐D ‐glucopyranosyl) ester, were isolated from the BuOH‐soluble fraction of the MeOH/H₂O 7 : 3 extracts of Zygophyllum geslini (roots or aerial parts). Their structures were established mainly by 1D‐ and 2D‐NMR techniques, in combination with HR‐MS analysis and acid hydrolysis.     

C21 Steroidal Glycosides from Cynanchum wilfordii

Eight new C₂₁ steroidal glycosides, named wilfosides A–H ( 1 – 8 , resp.), along with one known compound wilfoside KIN ( 9 ), were isolated from the roots of Cynanchum wilfordii. The structures of the new glycosides were determined on the basis of spectroscopic analysis, including 1D‐ and 2D‐NMR, and ESI‐MS techniques, as well as by comparison of the spectral data with those of related compounds.     

Water‐Soluble Constituents from the Liverwort Marchantia polymorpha

Four new glycosides, the bibenzyl glycoside α,β‐dihydrostilbene‐2,4′,5‐triol 2,5‐di‐(β‐D ‐glucopyranoside) ( 1 ), the shikimic acid glycoside shikimic acid 4‐(β‐D ‐xylopyranoside) ( 2 ), and two phenylethanoid glycosides 2‐(3,4‐dihydroxyphenyl)ethyl O‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐allopyranoside ( 3 ) and 2‐(3,4‐dihydroxyphenyl)ethyl O‐β‐D ‐xylopyranosyl‐(1→6)‐β‐D ‐allopyranoside ( 4 ), together with three known aromatic glycosides were isolated from the H₂O‐soluble fraction of the EtOH extract of the liverwort Marchantia polymorpha. Their structures were elucidated on the basis of chemical and spectroscopic evidences.     

Five New Aromatic Glycosides from Carthamus tinctorius

Five new aromatic glycosides, 1 – 5 , named as carthamosides B₄–B₈, together with three known compounds, 4′‐(hydroxyphenacyl)‐β‐D ‐glucopyranoside ( 6 ), benzyl‐O‐α‐L ‐rhamnopyranosyl‐(1→6)‐β‐D ‐glucopyranoside ( 7 ), and 4‐(methoxybenzyl)‐O‐β‐D ‐glucopyranoside ( 8 ), have been isolated from the air‐dried flower of Carthamus tinctorius. Their structures were identified on the basis of chemical and spectroscopic methods.     

Five New Cycloartane‐Type Triterpenoid Saponins from Nervilia fordii

Five new cycloartane glycosides, nervisides D–H ( 1 – 5 ), were isolated from the AcOEt‐ and H₂O‐soluble portions of the 90% EtOH extract of the aerial part of the plant Nervilia fordii. The structures of the isolated glycosides were elucidated by extensive spectroscopic analysis including HR‐ESI‐MS and NMR data. The isolated nervisides D–H were evaluated for the cytotoxic activity in vitro against human‐tumor cell lines (CNE, Hep‐2 and HepG2) with the MTT method.     

Two New Disulfated Triterpenoids from Zygophyllum fabago

From the aerial parts of Zygophyllum fabago, two new monosodium salts of sulfated derivatives of ursolic acid, along with two known quinovic acid glycosides were isolated. The structures of the new compounds were determined as (3β,4α)‐3,23,30‐trihydroxyurs‐20‐en‐28‐al 3,23‐di(sulfate) sodium salt (1 : 1) ( 1 ) and of (3β,4α)‐3,23,28‐trihydroxyurs‐20‐en‐30‐yl β‐D ‐glucopyranoside 3,23‐di(sulfate) sodium salt (1 : 1) ( 2 ) with the molecular formula C₃₀H₄₇NaO₁₀S₂ and C₃₆H₅₉NaO₁₅S₂, respectively. The structures of the known compounds were 3‐O‐(2‐O‐sulfo‐β‐D ‐quinovopyranosyl)quinovic acid 28‐β‐D ‐glucopyranosyl ester ( 3 ) and 3‐O‐(β‐D ‐glucopyranosyl)quinovic acid 28‐β‐D ‐glucopyranosyl ester ( 4 ) (quinovic acid=(3β)‐3‐hydroxyurs‐12‐ene‐27,28‐dioic acid). The structures of all these compounds were determined by using 1D‐ and 2D‐NMR spectroscopic techniques.     

8‐(3,3‐Dimethylallyl)‐Substituted Flavonoid Glycosides from the Aerial Parts of Epimedium koreanum

Ten 8‐(3,3‐dimethylallyl)‐substituted flavonoid glycosides, including the four new flavonol glycosides 1 and 3 – 5 and the new flavanonol glycoside 2 , besides five known flavonol glycosides, were isolated from the aerial parts of Epimedium koreanum Nakai . Their structures were determined by spectroscopic methods, including UV, IR, 1D‐ and 2D‐NMR, ESI‐MSⁿ, HR‐ESI‐MS, and circular dichroism (CD) experiments.     

Sesquiterpenoids and Lignans from Ligularia virgaurea spp. oligocephala

From the BuOH extract of the whole plant of Ligularia virgaurea spp. oligocephala, a series of sesquiterpenes, sesquiterpene glycosides, and lignan glycosides were isolated, including the three new compounds (1α)‐1‐hydroxy‐8‐oxo‐eremophila‐6,9‐dien‐12‐oic acid ( 1 ), 8‐[(β‐D ‐glucopyranosyl)oxy]eremophila‐1(10),8,11‐trien‐2‐one ( 2 ), and 4‐[(β‐D ‐glucopyranosyl)oxy]pinoresinol ( 4 ). Their structures were elucidated by 1D‐ and 2D‐NMR as well as HR‐ESI‐MS analyses, and by comparison of the spectroscopic data with those reported for structurally related compounds.     

Flavonoids Isolated from Heat‐Processed Epimedium koreanum and Their Anti‐HIV‐1 Activities

Systematic phytochemical investigation on heat‐processed Epimedium koreanum led to the isolation of 13 flavonoids, including five new prenyl‐flavonol glycosides, koreanosides A–E ( 1 – 5 , resp.). Their structures were elucidated on the basis of detailed analysis of the 1D‐ and 2D‐NMR spectroscopic data and chemical reactions. Apigenin ( 11 ) exhibited moderate anti‐HIV‐1 activity with an EC₅₀ value of 12.8±3.27 μg/ml.     

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.     

Iridoid and Phenylethyl Glycosides from Globularia sintenisii

A new iridoid glycoside, sintenoside ( 1 ) and two new phenylethyl glycosides, globusintenoside (=2‐(3,4‐dihydroxyphenyl)ethyl‐O‐6‐O‐feruloyl‐β‐D ‐glucopyranosyl‐(1→4)‐α‐L ‐rhamnopyranosyl‐(1→3)‐4‐O‐caffeoyl‐β‐D ‐glucopyranoside; 2 ) and 3′′′‐O‐methylcrenatoside (=1,2‐O‐[2‐(3,4‐dihydroxyphenyl)ethan‐1,2‐diyl]‐3‐O‐α‐L ‐4‐O‐feruloyl‐rhamnopyranosyl‐β‐D ‐glucopyranose; 3 ) were isolated from the underground parts of Globularia sintenisii, along with three known iridoid glycosides, lytanthosalin, globularin, catalpol, and six known phenylethyl glycosides, verbascoside, isoverbascoside, leucoscepthoside A, plantainoside C, martynoside, and isocrenatoside. The structure elucidation of the isolated compounds was performed by spectroscopic methods (MS and 1D and 2D NMR).     

Addition of Electrophilic Radicals to 2‐Benzyloxyglycals: Synthesis and Functionalization of Fluorinated α‐C‐Glycosides and Derivatives

A new method for the synthesis of fluorinated α‐C‐glycosides is described. The reactions between highly electrophilic radicals (fluorinated or unfluorinated) and a 2‐benzyloxyglucal or galactal provide 2‐keto‐D ‐arabino‐ or 2‐keto‐D ‐lyxo‐hexopyranosides through an addition/fragmentation process. Sodium borohydride mediated or Meerwein–Ponndorf–Verley (MPV) reduction of these compounds provides α‐C‐glycosides that feature appropriate anchoring groups for further synthetic elaboration. The presence of CF₂CO₂iPr or CF₂Br groups at the pseudo‐anomeric position allows efficient reduction/olefination or Br/Li‐exchange/nucleophilic‐addition sequences. These transformations open the way for the synthesis of fluorinated C‐glycosidic analogues of glycoconjugates.     

Five New Steroidal Glycosides from Caralluma dalzielii

Five new pregnane glycosides, caradalzielosides A–E ( 1 – 5 ), were isolated from the aerial parts of Caralluma dalzielii. Their structures were elucidated by extensive 1D‐ and 2D‐NMR spectroscopic analysis as well as by HR‐FAB‐MS experiments.     

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.     

Steroidal saponins and pregnane glycosides from Smilax microphylla

Six steroidal saponins and two pregnane glycosides were isolated from the BuOH subfraction of 70% EtOH extract of Smilax microphylla C.H.Wright, among them two were new compounds (1 and 7). Pregnane glycosides were firstly isolated from the genus Smilax (Smilacaceae). Structures of the new compounds were determined on the basis of HR‐ESI‐MS, 1D and 2D NMR spectroscopic analysis. Copyright © 2012 John Wiley & Sons, Ltd.     

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 ).     

Three New Polyoxypregnane Glycosides from Marsdenia tenacissima

Three new polyoxypregnane glycosides, marsdenosides I–K ( 1 – 3 ), were isolated from the stem of Marsdenia tenacissima. The structures were elucidated on the basis of in‐depth spectroscopic analyses, and by means of chemical evidence. Marsdenoside I ( = (3β,5α,11α,12β,14β,17α,20R)‐3‐[(2,6‐dideoxy‐4‐O‐(6‐deoxy‐3‐O‐methyl‐β‐D ‐allopyranosyl)‐3‐O‐methyl‐β‐D ‐arabino‐hexopyranosyl)oxy]‐8,20 : 11,20‐diepoxypregnane‐12,14‐diol; 1 ) is the first C₂₁ steroidal glycoside with a rigid cage. Also, the isolation of 1 demonstrated that tenacigenin A ( 1a ) is a true natural product as well, rather than an artifact.     

Iridoid Glycosides from Hedyotis corymbosa

Three new iridoid glycosides, hedycorysides A–C ( 1 – 3 , resp.), were isolated from the whole plant of Hedyotis corymbosa (Linn .) Lam ., along with four known compounds. Their structures were elucidated by extensive 1D‐ and 2D‐NMR analysis, as well as by HR‐ESI‐MS experiments. The three new compounds are the first benzoylated geniposide derivatives from Hedyotis.     

A Catalytic and Stereoselective Glycosylation with β‐Glycosyl Fluorides

A catalytic and stereoselective glycosylation of several glycosyl acceptors with β‐D ‐glycosyl fluoride was successfully performed in the presence of a catalytic amount of trityl tetrakis(pentafluorophenyl)borate (TrB(C₆F₅)₄) or trifluoromethanesulfonic acid (TfOH). When TrB(C₆F₅)₄ was used as a catalyst in the solvent pivalonitrile/(trifluoromethyl)benzene 1 : 5, the glycosylation proceeded smoothly to afford the glycosides in high yields with high β‐D ‐stereoselectivities (see Table 3). Further, the glycosylation by the armed‐disarmed strategy in the presence of this catalyst was established (see Table 4). Similarly, glycosylation catalyzed by the strong protic acid TfOH afforded the corresponding β‐D ‐glycosides in good‐to‐excellent yields on treating β‐D ‐ glycosyl fluorides having a 2‐O‐benzoyl group with various glycosyl acceptors including thioglycosides (see Tables 6 and 7).     

New Antioxidant Phenolic Glucosides from Viburnum dilatatum

Chemical investigation of the fruits of Viburnum dilatatum Thunb. resulted in the isolation and characterization of four new phenolic glycosides, jiamiziosides A–D ( 1 – 4 ), together with five known compounds. Their structures were established by spectroscopic means and by comparison with the literature values. The antioxidant activities of the new isolates were determined against 2,2‐diphenyl‐1‐picrylhydrazyl (=2,2‐diphenyl‐1‐(2,4,6‐trinitrophenyl)hydrazinyl; DPPH) and superoxide radicals. Among the compounds tested, jiamizioside C ( 3 ) possesses the most potent inhibitory scavenging effect on DPPH and superoxide radicals with IC₅₀ values of 16.8 and 17.8 μM , respectively.