New phenolic glycosides from the stems and leaves of Casearia multinervosa

Four phenolic glycosides (1-4), including two new ones (3 and 4), have been isolated from the stems of Casearia multinervosa and identified as arbutin (1), 4-O-E-caffeoylarbutin (2), 4-O-E-coumaroylarbutin (3) and 4-O-E-feruloylarbutin (4), respectively. In addition, the two known phenolic glycosides (1 and 2) were also isolated from the leaves. Structures were elucidated on the basis of spectroscopic evidence. Compounds 1-4 were tested for cytotoxicity against the P388 mouse lympholytic cell line by an ATP Lite-M assay method and showed mild to moderate activity.     

New glycosides from the rhizomes of Tacca chantrieri

Five new glycosides, which are classified into two bisdesmosidic pseudofurostanol glycosides (1, 2), two new ergostanol glycosides (3, 4), and a new phenolic glycoside (5), were isolated from the rhizomes of Tacca chantrieri. The structures of 1-5 were determined on the basis of extensive spectroscopic analysis, including that of two-dimensional (2D) NMR data, as well as hydrolytic cleavage followed by spectroscopic and chromatographic analyses.     

Three new phenolic glycosides from the caulis of Millettia speciosa

Three new phenolic glycosides, millettiaspecosides A--C (1-3), were isolated from the caulis of Millettia speciosa along with three known phenolic glycosides, khaephuoside B (4), seguinoside K (5), albibrissinoside B (6). Their structures were established by spectroscopic methods. The spectral analysis permitted correct assignments for (1)H and (13)C NMR data of compounds 4 and 5.     

Phenolic compounds of mountain tea from the Balkans: LC/DAD/ESI/MSn profile and content

Twenty-one samples of Sideritis species (S. scardica, S. raeseri, S. taurica, S. syriaca and S. perfoliata) from various locations on the Balkan Peninsula were evaluated for their chemical constituents. Chemical analyses were focused on secondary metabolites, particularly phenolic compounds, which have several roles in the plant physiological processes and have demonstrated significant health beneficial effects. The occurrence of hydroxycinnamic acids, phenylethanoid glycosides and flavonoids has been investigated in taxonomically related taxa of the genus Sideritis. A systematic method for phenolic compounds identification was developed using tandem mass spectrometry coupled to high performance liquid chromatography with diode array detection. Scanning for precursor ions of commonly found phenolics in Sideritis species using LC/MS11 with an ion trap instrument permitted the specific determination of hydroxycinnamic acid derivatives, and phenylethanoid and flavonoid glycosides. Further characterization of each phenolic compound was performed using MS/MS product-ion analysis and common-neutral-loss analysis. This on-line technique allowed identification of three hydroxycinnamic acid derivatives, eight phenylethanoid glycosides, and twenty-four flavonoid glycosides. All the taxa analysed produced very similar phenolic patterns characterized by the presence of 5-caffeoylquinic acid, lavandulifolioside, verbascoside, hypolaetin 7-O-[6'-O-acetyl]-allosyl(1-->2)glucoside, apigenin 7-(4"-p-coumaroylglucoside), 4'-O-methylisoscutellarein 7-O-[6'-O-acetyl]-allosyl(1-->2)glucoside, and minor amounts of isoverbascoside, apigenin 7-O-allosyl(1-->2)glucoside, isoscutellarein 7-O-allosyl-(1-->2)-[6"-O-acetyl]-glucoside, hypolaetin 7-O-allosyl-(1-->2)-[6"-O-acetyl]-glucoside and 4'-O-methylhypolaetin 7-O-[6'-O-acetyl]-allosyl-(1-->2)-[6"-O-acetyl]-glucoside. These results show that the investigated species are systematically very closely related. Phenylethanoid glycosides and flavonoid acetylglycosides are dominant and constitute 90% of the total phenolic compounds compared with hydroxycinnamic acid and flavonoid 7-O-glycosides. Principal component analysis (PCA) was performed for the nature and content of the different compounds to be correlated to the particular Sideritis species and also to the locations.     

Phenolic glycosides from Lindera fruticosa root and their inhibitory activity on osteoclast differentiation

Two new compounds were found in the phenolic glycosides isolated from the roots of Lindera fruticosa: 5-O-[beta-D-apiofuranosyl-(1'-->2')-O-beta-D-xylopyranosyl]gentisic acid-7,5'-ester (3), named linderofruticoside A; and 5-O-[beta-D-apiofuranosyl-(1'-->3')-O-beta-D-xylopyranosyl]gentisic acid methyl ester (4), linderofruticoside B. Two previously known phenolic glycosides were also identified: beta-D-(3,4-disinapoyl)fructofuranosyl-alpha-D-(6-sinapoyl)glucopyranoside (1) and beta-D-(3-sinapoyl)fructofuranosyl-alpha-D-(6-sinapoyl)glucopyranoside (2). Compounds 1 and 2 inhibited osteoclast differentiation in a dose-dependent manner at concentrations higher than 1.04 microM and 0.132 microM, respectively.     

Iridoid and phenolic glycosides from the roots of Prismatomeris connata

A new phenolic glycoside, 1-O-[beta-D-glucopyranoyl-(1-->6)-beta-D-glucopyranosyl]-3,4,5-trimethoxyphenol, named prismaconnatoside (1), together with one known phenolic glycoside (2) and four aspruloside type iridoid glycosides (3-6) were isolated from the roots of Prismatomeris connata. Their structures were determined by spectroscopic and spectrometric methods. Based on the results, along with those from other studies, iridoids were suggested to be chemical markers to distinguish between P. connata and P. tetrandra, two species that are confused in traditional Chinese medicine.     

Phenolic compounds from Anaphalis aureo-punctata

From the ethanolic extract of the whole plant of Anaphalis aureo-punctata, a new acylated flavonoid glycoside 3-O-kaempferol-3-O-acetyl-6-O-(p-coumaroyl)-β-D-glucopyranoside (1), and five known phenolic compounds 3-O-kaempferol-6- O- ( p-coumaroyl )-β-D-glucopyranoside ( 2 ), kaempferol-3- O-β-D-glucopyranoside 3,6-(4′-hydroxystyryl)-4-methoxy-2-pyrone (4), 2H-pyran-2-one, 6-[ 2-( 4-(β-D-glucopyranosyloxy ) phenyl ) ethenyl ]-4-methoxy-( E ) (5) and 4-hydroxy-3-methoxycinnamic hexacosyl ester (6) were isolated. Their structures were established by spectral methods (UV, IR, MS, 1D, 2D-NMR). The flavonoid glycosides, 1, 2 and 3 showed markedly inhibited oxidative DNA strand breaks induced by Fenton reaction and NADH/PMS in a concentration-dependent manner.     

Two new acylated flavanone glycosides from the leaves and branches of Phyllanthus emblica

Two new acylated flavanone glycosides, (S)-eriodictyol 7-O-(6"-O-trans-p-coumaroyl)-beta-D-glucopyranoside (1) and (S)-eriodictyol 7-O-(6"-O-galloyl)-beta-D-glucopyranoside (2) were isolated from the leaves and branches of Phyllanthus emblica together with a new phenolic glycoside, 2-(2-methylbutyryl)phloroglucinol 1-O-(6"-O-beta-D-apiofuranosyl)-beta-D-glucopyranoside (3), as well as 22 known compounds. Their structures were determined by spectral and chemical methods.     

Two New Phenolic Glycosides from Magnolia rostrata

For a long time Magnolia rostrata has been used as a substitute of Magnolia officinalis which is a precious traditional Chinese medicine1. The aqueous constituents of M. rostrata have not been studied2. During our studies on the n-Bu-OH extract, two new phenolic glycosides (Figure 1) were isolated. Here, we report their structural elucidation. Compound 1, white amorphous powder, mp 180-182°C exhibited a molecular formula C21H30O11 based on its quasi-molecular ion peak at m/z 457 [M-H]- …     

Two new phenolic glycosides from Viscum articulatum

Two new phenolic glycosides, 1-O-benzyl-[5-O-benzoyl-beta-D-apiofuranosyl (1-->2)]-beta-D-glucopyranoside (1), and 4;-hydroxy-7,3;-dimethoxyflavan-5-O- beta-D-gluco-pyranoside (2), together with nine known flavanones 3 - 11, have been isolated from the dried whole plants of Viscum articulatum.Their structures were identified by extensive spectral analysis, especially 2D NMR techniques. Compound 9 showed weak anti-HIV-1 activity.     

Phenolic glycosides from Pyrola japonica

Five new phenolic glycosides, 2-beta-D-glucopyranosyloxy-5-hydroxyphenylacetic acid methyl ester (4), 4-hydroxy-2-[3-hydroxy-3-methylbutyl]-5-methylphenyl beta-D-glucopyranoside (5), 4-hydroxy-2-[(E)-4-hydroxy-3-methyl-2-butenyl]-5-methylphenyl beta-D-glucopyranoside (7), 4-hydroxy-2-[(2E,6Z)-8-beta-D-glucopyranosyloxy-3,7-dimethylocta-2,6-dien-1-yl]-5-methylphenyl beta-D-glucopyranoside (8), and 2,7-dimethyl-1,4-dihydronaphthalene-5,8-diol 5-O-beta-D-xylopyranosyl(1-->6)-beta-D-glucopyranoside (10), were isolated from the whole plants of Pyrola japonica (Pyrolaceae), together with androsin, (-)-syringaresinol glucoside, homoarbutin, pirolatin, hyperin, monotropein and chimaphilin.     

Screening non-colored phenolics in red wines using liquid chromatography/ultraviolet and mass spectrometry/mass spectrometry libraries

Liquid chromatography/ultraviolet (LC/UV) and mass spectrometry/mass spectrometry (MS/MS) libraries containing 39 phenolic compounds were established by coupling a LC and an ion trap MS with an electrospray ionization (ESI) source, operated in negative ion mode. As a result, the deprotonated [M-H]- molecule was observed for all the analyzed compounds. Using MS/MS hydroxybenzoic acid and hydroxycinnamic acids showed a loss of CO2 and production of a [M-H-44]- fragment and as expected, the UV spectra of these two compounds were affected by their chemical structures. For flavonol and flavonol glycosides, the spectra of their glycosides and aglycones produced deprotonated [M-H]- and [A-H]- species, respectively, and their UV spectra each presented two major absorption peaks. The UV spectra and MS/MS data of flavan-3-ols and stilbenes were also investigated. Using the optimized LC/MS/MS analytical conditions, the phenolic extracts from six representative wine samples were analyzed and 31 phenolic compounds were detected, 26 of which were identified by searching the LC/UV and MS/MS libraries. Finally, the presence of phenolic compounds was confirmed in different wine samples using the LC/UV and LC/MS/MS libraries.     

Chemical constituents of Bacopa procumbens

Phytochemical investigation of Bacopa procumbens afforded two new phenolic glycosides 1 and 2, for the first time, along with 12 known compounds 3-14. Structures of these compounds were established based on spectral and chemical evidences.     

Novel phenolic glycoside dimer and trimer from the whole herb of Pyrola rotundifolia

From the water-soluble constituents of the whole herb of Pyrola rotundifolia (Pyrolaceae), one novel phenolic glycoside dimer, pyrolaside A (1), and one novel phenolic glycoside trimer, pyrolaside B (2), together with two known phenolic glycosides homoarbutin (3) and isohomoarbutin (4), were isolated. The structures were elucidated by spectroscopic analysis and confirmed with chemical degradation. In vitro tests for antimicrobial activity showed pyrolaside B (2) to possess significant activity against two Gram-positive organisms, Staphylococcus aureus and Micrococcus luteus.     

Rhyncosides A-F, phenolic constituents from the Chinese mangrove plant Bruguiera sexangula var. rhynchopetala

Chemical investigation on the stem of a Chinese mangrove plant Bruguiera sexangula var. rhynchopetala (Rhizophoraceae) resulted in the isolation and characterization of four new phenolic glycosides rhyncosides A-D (1-4), and two new lignan derivatives namely rhyncosides E-F (5-6), along with twelve known phenolic constituents. Their structures were determined by extensive spectroscopic data analyses.     

Phenolic constituents from Ephedra nebrodensis

Two new phenolic glycosides, 4-hydroxy-3-(3-methyl-2-butenyl)phenyl beta-D-glucopyranoside (nebrodenside A) and O-coumaric acid beta-D-allopyranoside (nebrodenside B), were isolated from the aerial parts of Ephedra nebrodensis. In addition, O-coumaric acid glucoside, (-)-epicatechin, and (-)-ephedrine were also isolated. The structures were deduced from extensive 1D and 2DNMR spectroscopy (1H, 13C, DQF-COSY, TOCSY, GHSQC, GHMQC, ROESY) as well as mass spectrometry (EI and HR-MALDI). (-)-Epicatechin showed weak antiviral activity against Influenza A virus and very weak cytotoxicity against MDCK cells.     

On the chemical constituents of Dipsacus asper

Bioassay-guided fractionation of 95% EtOH extract from the roots of Dipsacus asper lead to the isolation of some phenolic acids (caffeic acid, 2,6-dihydroxycinnamic acid, vanillic acid, 2'-O-caffeoyl-D-glucopyranoside ester, and caffeoylquinic acid) as the major active components, and five new iridoid glucoside dimers (1-5) and one new iridoid glucoside monomer (6), other known iridoid glycosides loganin, cantleyoside, triplostoside A, lisianthioside, 6'-O-beta-D-apiofuranosyl sweroside, as well as triterpenoids oleanic acid and akebiasaponin D. The structures of new compounds 1-6 were determined as dipsanosides C (1), D (2), E (3), F (4), G (5), and 3'-O-beta-D-glucopyranosyl sweroside (6) by spectroscopic, including 1D and 2D NMR techniques, and chemical methods.     

Phenolic constituents of Cassia seeds and antibacterial effect of some naphthalenes and anthraquinones on methicillin-resistant Staphylococcus aureus.

Thirteen phenolic glycosides including six new compounds were isolated from seeds of Cassia tora (Leguminosae). The structures of the new compounds, rubrofusarin triglucoside (7), nor-rubrofusarin gentiobioside (9), demethylflavasperone gentiobioside (10), torachrysone gentiobioside (11), torachrysone tetraglucoside (12) and torachrysone apioglucoside (13), were elucidated on the basis of spectroscopic and chemical evidence. The effects of the phenolic glycosides, their aglycones and several other compounds structurally related to them on Escherichia coli K12, Pseudomonas aeruginosa PAO1 and some strains of Staphylococcus aureus were then examined. Among them, torachrysone (15), toralactone (16), aloe-emodin (18), rhein (19) and emodin (20) showed noticeable antibacterial effects on four strains of methicillin-resistant Staphylococcus aureus with a minimum inhibitory concentration of 2-64 micrograms/ml. On the other hand, the phenolic compounds tested did not show strong antibacterial effects on E. coli and P. aeruginosa.     

New phenolic glycosides from the seeds of Cucurbita moschata

Five new phenolic glycosides, cucurbitosides A-E (1-5), were isolated from the seeds of Cucurbita moschata. Their structures were elucidated as 2-(4-hydroxy)phenylethanol 4-O-(5-O-benzoyl)-beta-D-apiofuranosyl(1-->2)-beta-D-glucopyranoside (1), 2-(4-hydroxyphenyl)ethanol 4-O-[5-O-(4-hydroxy)benzoyl]-beta-D-apiofuranosyl(1-->2)-beta-D-glucopyranoside (2), 4-hydroxybenzyl alcohol 4-O-(5-O-benzoyl)-beta-D-apiofuranosyl(1-->2)-beta-D-glucopyranoside (3), 4-hydroxybenzyl alcohol 4-O-[5-O-(4-hydroxy)benzoyl]-beta-D-apiofuranosyl(1-->2)-beta-D-glucopyranoside (4) and 4-hydroxyphenyl 5-O-benzoyl-beta-D-apiofuranosyl(1-->2)-beta-D-glucopyranoside (5) on the basis of spectroscopic analysis and chemical evidence.     

Cypellogins A, B and C, acylated flavonol glycosides from Eucalyptus cypellocarpa

Three new acylated flavonol glycosides, cypellogins A (1), B (2) and C (3), along with eight known phenolic compounds, were isolated from the dried leaves of Eucalyptus cypellocarpa, and their structures were elucidated using spectroscopic methods, including 2D NMR experiments and chemical evidence.