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.     

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.     

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.     

Phenolic Compounds from the Twigs of Gardenia jasminoides and their Antibacterial Activity

Chemistry of Natural Compounds - Eight phenolic compounds (1–8), including two new compounds (1 and 2), were isolated from the twigs of Gardenia jasminoides. Their structures were determined...     

New phenolic constituents from the fruit juice of Phyllanthus emblica

Six new phenolic constituents, L-malic acid 2-O- (1), mucic acid 2-O- (5), mucic acid 1,4-lactone 2-O- (6), 5-O- (8), 3-O- (10), and 3,5-di-O- (11) gallates, were isolated from the fruit juice of Phyllanthus emblica together with their methyl esters (2-4, 7, 9), and their structures were determined by spectral and chemical methods. Compounds 5, 6, and 8, the major phenolic constituents of the juice, were present as an equilibrium mixture in aqueous solution.     

Oplopanphesides A-C, three new phenolic glycosides from the root barks of Oplopanax horridus

Three new phenolic glycosides, named oplopanphesides A-C (1-3), have been isolated from the root barks of Oplopanax horridus. Their structures were elucidated by a combination of spectroscopic analyses, including 1D- and 2D-NMR techniques. These phenolic glycosides possess a novel feature in their sugar moieties that a 3-hydroxy-3-methylglutaryl moiety was connected with C-6 of the β-D-glucopyranosyl group. Those compounds showed no cytotoxic effects against human cancer cell lines (MDA-231 and MCF-7) by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method.     

Analysis of phenolic acids by non-aqueous capillary electrophoresis after electrokinetic supercharging

Electrokinetic supercharging (EKS), a new and powerful on-line preconcentration method for capillary electrophoresis, was utilized in non-aqueous capillary electrophoresis (NACE) to enhance the sensitivity of phenolic acids. The buffer acidity and concentration, leader and terminator length and electrokinetic injection time were optimised, with the optimum conditions being: a background electrolyte of 40 mM Tris-acetic acid (pH 7.9), hydrodynamic injection of 50 mM ammonium chloride (22 s, 0.5 psi) as leader, electrokinetic injection of the sample (180 s, -10 kV), hydrodynamic injection of 20 mM CHES (32 s, 0.5 psi) as terminator, before application of the separation voltage (-25 kV). Under these conditions the sensitivity was enhanced between 1333 and 3440 times when compared to a normal hydrodynamic injection with the sample volume <3% of the capillary volume. Detection limits for the seven phenolic acids were in the range of 0.22-0.51 ng/mL and EKS was found to be 3.6-7.9 times more sensitive than large-volume sample stacking and anion selective exhaustive injection for the same seven phenolic acids.     

Phenolic constituents from the rhizomes of Dryopteris crassirhizoma

A new phenolic glycoside, dryopteroside (1), was isolated from the rhizomes of Dryopteris crassirhizoma (Dryopteridaceae), together with five known compounds, 4beta-carboxymethyl-(-)-epicatechin (2), isobiflorin (3), biflorin (4), 1-beta-D-glucopyranosyloxy-3-methoxy-5-hydroxybenzene (5) and (+)-catechin-6-C-beta-D-glucopyranoside (6). The new compound was elucidated to be 1-butanoyl-3-C-beta-D-glucopyranosyl-5-methyl-phloroglucinyl-6-O-beta-D-glucopyranoside (1) by chemical and various spectroscopic analyses. The known compounds 2-6 were first reported from the genus Dryopteris.     

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.     

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.     

Chemical constituents from Pseudolarix kaempferi

A novel degraded triterpenoid isopseudolaritone A (1) and one new oligosaccharide, 1-O-isopropyl-6-O-[2-O-methyl-alpha-L-rhamnopyranosyl(1 --> 6)]-beta-D-glucopyranose (2), two new artefacts, 9-O-formacyl cedrusin (5) and 9,9'-O-diformacyl cedrusin (6), as well as 12 known phenolic Compounds (3-4, 7 16), were isolated from the root bark of Pseudolarix kaempferi. Their structures were elucidated mainly by spectroscopic methods.     

Dihydrophenanthrenes from Bletilla formosana

Three new dihydrophenanthrenes, 4-methoxy-9,10-dihydrophenanthrene-1,2,7-triol (1), 1-(4-hydroxybenzyl)-4,7-dimethoxy-9,10-dihydrophenanthrene-2-ol (2), and 1,3,6-tri(4-hydroxybenzyl)-4-methoxydihydrophenanthrene-2,7-diol (3) together with seven known phenanthrene derivatives, six known flavonoids, a bibenzyl and three phenolic compounds were isolated from the whole plant of Bletilla formosana. Their structures were elucidated by spectroscopic, mainly 2D NMR spectrometry and chemical methods.     

萘并萘醌酚醛树脂的合成和光致变色性质

通过6-氯-5,12-萘并萘醌(1)与酚醛树脂经亲棱取代,一步合成制备具有光致变色性的酚醛树脂(3)。在苯溶液中,光致变色聚合物(3)与光致变色化合物6-{4-[2-(4-羟基苯基)异丙基]苯氧基}-5,12-萘并萘醌(2)有相似的光致变色行为。但是,在聚合物(3)中,由于苯基处于聚合物骨架中不易迁移,使聚合物(3)的变色速度较化合物(2)明显减慢,化合物(2)的光异构化速度常数是聚合物(3)的3倍。同时发现溶剂对聚合物(3)的光诱导trans-ana异构化反应速度有明显影响,在氯仿中的反应速度常数约为在苯中的2倍。     

Detection, characterization and identification of phenolic acids in Danshen using high-performance liquid chromatography with diode array detection and electrospray ionization mass spectrometry

By using HPLC-diode array detection-electrospray ion trap tandem mass spectrometry (HPLC-DAD-ESI-MS(n)) in negative ion mode, we have analyzed the fragmentation pathways of 11 phenolic acids which were isolated from Danshen. Then the extract of Danshen was analyzed, and a total of 42 phenolic acids, including sixteen new minor constituents, were identified or tentatively identified for the first time. A new solid-phase extraction (SPE) method, new HPLC separation method, new liquid chromatography (LC)-MS and LC-MS(n) (n=3-5) data and proposed fragmentation pathways, LC retention time for phenolic acids are reported.     

Triterpenoids and phenolics from the fruiting bodies of Inonotus hispidus and their activations of melanogenesis and tyrosinase

Two new 24-methyl lanostane triterpenoids,hispindic acids A and B(1 and 2),and a new phenolic compound,hispinine(7),along with nine known compounds(3-6,and 8-12),were isolated from the fruiting bodies of Inonotus hispidus.Their structures were elucidated based on the extensive analysis of spectroscopic data(NMR and HRMS).Hispindic acid A(1) possesses an unusual formyl group at C-30.Compounds 1,3-4,and 8 showed stronger activate abilities of melanogenesis and tyrosinase in B16 melanoma cells than those of positive control,8-methoxypsoralen,at 50 μmol/L     

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.     

Antioxidant activities, total phenolics and HPLC analyses of the phenolic compounds of extracts from common Mediterranean plants

In this study, the total phenolic amounts and antioxidant activities of plant extracts obtained from some common Mediterranean plant species collected from different places in Jordan were determined. The phenolic constituents of these extracts were also determined using HPLC. The total phenolic amounts ranged from 52.8 to 876.9 mg GAE per 100 g dry material. The antioxidant activities were evaluated according to the 2,2-diphenyl-1-picrylhydrazyl radical scavenger method. Sage (Salvia officinalis) showed the highest antioxidant activity (91%), while the lowest (11.3%) was seen in parsley (Petroselinum crispum). A strong correlation (r = 0.85) between antioxidant activity and total phenolic content was found. The phenolic compounds identified by HPLC were gallic acid, protocatechuic acid, catechin, gentisic acid, chlorogenic acid, vanillic acid, syringic acid, caffeic acid, epicatechin and benzoic acid. All the investigated plants contain gallic acid, whose phenolic content ranged from 0.4 to 37.8 mg per 100 g, catechin (0.3-339.9 mg per 100 g), protocatechuic acid (0.3-41.9 mg per 100 g) and gentisic acid (0.3-35.8 mg per 100 g), while caffeic acid (0.3-2.6 mg per 100 g) was detected in six species only. These natural plant phenolics could thus be a good source of antioxidants for applications in food.     

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.     

A new depsidone from Usnea diffracta

A new depsidone,diffractione A(1),as well as six known phenolic compounds(2-7)were isolated from Usnea diffracta.Their structures were ducidated by ID and 2D NMR spectroscopy together with HRESIMS analysis.All components were obtained for the first time from U.diffracta.     

Phenolic constituents of licorice. III. Structures of glicoricone and licofuranone, and inhibitory effects of licorice constituents on monoamine oxidase

Two new phenolic compounds, glicoricone (3) and licofuranone (4), were isolated from a species of licorice brought from the northwestern region of China, and their structures were assigned. Among the twelve licorice constituents examined for the inhibition of monoamine oxidase (MAO), six compounds, 3, 4, genistein (6), licopyranocoumarin (7), licocoumarone (14) and glycyrrhisoflavone (15), inhibited the enzyme with the IC50 (concentration required for 50% inhibition of the enzyme activity) values of 6.0 x 10(-5)-1.4 x 10(-4) M. Glycyrrhizin (1) also inhibited MAO with the IC50 value of 1.6 x 10(-4) M.