Two new phenolic glycosides from the aerial parts of Androsace umbellata

Two new phenolic glycosides, 2-hydroxy-4-O-β-D-glucopyranosylphenylacetic acid methyl acetate （1） and 2-hydroxy-4-O-β-D- glucopyranosylphenylacetic acid （2） were isolated from the aerial parts ofAndrosace umbellata. Their structures were elucidated by spectral techniques. C 2009 Wen Cai Ye. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

Anti-acetylcholinesterase activity of the aglycones of phenolic glycosides isolated from Leonurus japonicus

Objective: To find the genuine structure with anti-acetylcholinesterase(anti-ACh E) from the phenolic glycosides abundant in Leonurus japonicus(Lamiaceae). The assay for antiACh E activity is often used to lead anti-Alzheimer's drugs.Methods: The five phenolic glycosides, tiliroside, leonurusoside C, 2’’’-syringoylrutin,rutin, and lavanduliofolioside were isolated from L. japonicus. The activities of the glycosides were relatively low. Seven compounds including p-coumaric acid, caffeic acid, hydroxytyrosol, salidroside, syringic acid, kaempferol, and quercetin, which are produced by the hydrolysis of the five glycosides, were also assayed for anti-ACh E activity.Results: Of those seven compounds, the five compounds other than salidroside and syringic acid exhibited potent anti-ACh E activities. In particular, the IC_(50)s of caffeic acid and quercetin were(1.05 ± 0.19) and(3.58 ± 0.02) mg/m L, respectively. Rutin was the most abundant flavonoid in the extract(9.18 mg/g as measured by HPLC).Conclusion: The substances with potent anti-ACh E were caffeic acid, quercetin, pcoumaric acid, kaempferol, and hydroxytyrosol that can be produced from their glycosides.

Phenolic glycosides from Boschniakia himalaica

Two new phenylethanoid glycosides,himalosides A（1） and B（2）,were isolated from the whole plant of Boschniakia himalaica, together with four known compounds.Their structures were elucidated on the basis of spectral and chemical evidences.Himaloside A（1） and（＋）-lariciresinol 4＇-O-β-D-glucopyranoside（4） exhibited antibacterial activity with the MIC values at 50 and 25μg/mL against Staphylococcus aureus and S.epidermidis,respectively.

Phenolic glycosides from the stems of Homalium stenophyllum

The phytochemical investigation of the stems of Homalium stenophyllum afforded seven new phenolic glycosides(1-5 and 8-9)and two known compounds(6 and 7).Their structures were elucidated by comprehensive analyses of NMR spectroscopic,mass spectrometric data and chemical hydrolysis.Additionally,their anti-inflammatory activities against the NO production in LPS-induced macrophages were evaluated.

A novel phenylpropanoid glycosides and a new derivation of phenolic glycoside from Paris Polyphylla var. yunnanensis

A novel phenylpropanoid glycosides 1, named parispolyside E and a novel derivation of phenolic glycoside 2, named parispolyside G, as well as two known flavonoid glycosides were isolated from the rhizome of Paris polyphylla var. yunnanensis. Their structures were elucidaed by spectroscopic methods.

Minor antifungal aromatic glycosides from the roots of Gentiana rigescens(Gentianaceae)

Two new phenolic glycosides, 2,3-dihydroxybenzoic acid methyl ester 3-O-β-o-glucopyranosyl-（1-6）-β-D-glucopyranoside （1） and 2,5-dihydroxylbenzofuran 5-O-β-D-xylopyranosyl-（1-6）-O-β-D-glucopyranoside （2）, were isolated as the minor chemical constituents from the roots of Gentiana rigescens, along with 15 known compounds. Their structures were elucidated by detailed spectroscopic analysis, including 1D, 2D NMR and chemical method. All of these compounds were isolated for the first time from the title plant. Moreover, compounds 1 and 2 were tested for the antifungal activities on three plant pathogens Peronophythora litchi, Glomerella cingulata, and Glorosprium musarum.

Two New Phenolic Constituents from the Stems of Euphorbia griffithii

Phytochemical studies on MeOH extract of stems of Euphorbia griffithii led to the isolation of one new hydrolyzable tannin dimer,corilagiffithiin(1)and one new galloyl-glucoside(2),alongside six known ones(3-8).Their structures and absolute configurations were determined by in depth spectroscopic analyses and comparison of their 1D NMR and MS data with literature reported values.Configurations of sugar moieties were determined by acidic hydrolysis and subsequent GC analysis of their corresponding trimethylsilylated l-cysteine adduct.At a concentration of 50μM,compounds 1-3 showed no anti-inflammatory activities.

A phenolic glycoside from Fagopyrum dibotrys (D.Don) Hara

A new phenolic constituent along with five known compounds were isolated from Fagopyrum dibotrys (D.Don) Hara. The new compound was characterized as 1,3-dimethoxy-2-O-β-xylo-pyranosyl-5-O-β-glucopyranosyl-benzene, by spectroscopic analysis and enzymatic hydrolysis.

Synthesis of the Acetate of a New Phenolic Glycoside,Anacardoside,from Semecarpus anacardium and its Diastereomer

the acetate of a novel phenolic glycoside, 1-O-beta-D-glucopyranosyl-( 1-->6)-beta-D-glucopyranosyloxy-3-hydroxy-5-methylbenzene anacardoside, from the fruits of Semecarpus anacardium, and its diastereomer were first synthesized using Koenigs-Knorr method from D-glucose through six steps with total yields 33% and 16% respectively.

Chemical constituents from Schisandra sphenanthera

The chemical constituents of the stems of Schisandra sphenanthera are described for the first time. This investigation has resulted in the isolation of a new phenolic glycoside （1）, along with seven known compounds. The structure of 1 was assigned by using spectroscopic techniques, including 2D NMR spectra.

Chemical Constituents from the Stems of Ecdysanthera rosea

One new eudesmane sesquiterpenoid(1)named ecdysantherol A and two new benzene derivatives ecdysantherols B(2)and C(3),together with five known benzene derivatives(4–8)were isolated from the stems of Ecdysanthera rosea.The structures of the new compounds were elucidated by extensive spectroscopic methods and X-ray diffraction.The known compounds were identified by the comparison of their spectroscopic data with reported literature data.Compound 1 showed moderate antibacterial activity against the Providensia smartii with MIC value of 12.5 lg/mL.

Regioselective Acylation of 2＇- or 3＇-Hydroxyl Group in Salicin： Hemisynthesis of Acylated Salicins

Salicin-based phenolic glycosides（PGs） are important defensive substances against herbivore feeding and have good bioactivities. In this work, a novel approach for the synthesis of salicin-based PGs has been developed, by which PGs of 2＇-O-acetylsaliein（5a）, 3＇-O-acetylsalicin（gb） and 3＇-O-benzoylsalicin（Sd） were hemisynthesized. The effects of acylation reagent, solvent and temperature on the regioselective acylation of 2＇- or 3＇-hydroxyl groups of salicin mediated by dibutyltin oxide were investigated. The optimal conditions under which the best regioselectivity reached for 5a-5d were discovered, respectively. Moreover, a tentative tin-oxygen coordination mechanism was put forward to explain the different regioselectivities shown under different conditions.