High performance liquid chromatography-electrospray lonization MS-MS analysis ofForsythia koreana fruits, leaves, and stems. Enhancement of the efficiency of extraction of arctigenin by use of supercritical-fluid extraction

Recovery Effect of a Rutin-Enriched Fraction Prepared From Forsythia koreana Flowers on Alloxan-Induced Pancreatic Islets in Zebrafish Larvae (Danio rerio)

A simple method to prepare a high-content rutin fraction from Forsythia koreana flowers (HRFK) is described. Rutin, isolated for the first time from the flowers, was identified from spectroscopic data including nuclear magnetic resonance, mass spectrometry, and infrared. As a result of HPLC quantitative analysis, the content of rutin was found to be 80.0 ± 0.02% in HRFK. Our previous study reported that F koreana MeOH extract (FK) significantly recovered alloxan-induced pancreatic islets in zebrafish. However, HRFK as well as rutin exhibited an enhanced anti-diabetic effect compared to FK in our latest experiments. In conclusion, HRFK, as well as rutin and FK, have potential as anti-diabetic agents.

A review on the structure and pharmacological activity of phenylethanoid glycosides

Phenylethanoid glycosides (PhGs) are compounds made of phenylethyl alcohol, caffeic acid and glycosyl moieties. The first published references about phenylethanoid glycosides concerned the isolation of echinacoside from Echinaceu ungustifolia (Asteraceae) in 1950 and verbascoside from Verbascum sinuatum (Scrophulariaceae) in 1963. Over the past 60 years, many compounds with these structural characteristics have been isolated from natural sources, and most of these compounds possess significant bioactivities, including antibacterial, antitumor, antiviral, anti-inflammatory, neuro-protective, antioxidant, hepatoprotective, and immunomodulatory activities, among others. In this review, we will summarize the phenylethanoid glycosides described in recent papers and list all the compounds that have been isolated over the past few decades. We will also attempt to present and assess recent studies about the separation, extraction, determination, and pharmacological activity of the excellent natural components, phenylethanoid glycosides.

Lignans From Forsythia x Intermedia Leaves and Flowers Attenuate the Pro-inflammatory Function of Leukocytes and Their Interaction With Endothelial Cells

Aim of the study: Taking into account that overactivated leukocytes are an important factor in the development of many chronic diseases, we investigated the activity of phytochemically characterized (HPLC-DAD-MSⁿ) extracts from forsythia leaves and flowers on the pro- and anti-inflammatory functions of leukocytes (effects on IL-1β, IL-8, TNF-α, and TGFβ release) and their adherence to endothelial cells. Using bio-guided fractionation, we isolated the active compounds and determined their biological activity, and we included the positive control quercetin. Methods: The effect on IL-1β, TNF-α, IL-8, and TGF-α production by leukocytes was measured by enzyme-linked immunosorbent assay (ELISA). The surface expression of adhesion molecules was analyzed with flow cytometry, and the neutrophil attachment to the endothelial cells was assessed fluorimetrically. The effects on p38MAPK, ERK1/2 and JNK phosphorylation were determined using western blots. Results: Leaf extracts had the effect of decreasing TNF-α production in neutrophils and monocyte/macrophage cells. The bio-guided fractionation led to the isolation of the following lignan aglycones: (+)-pinoresinol, (+)-epipinoresinol, (-)-matairesinol, (+)-phillygenin, and (-)-arctigenin. Only phillygenin was able to stimulate the anti-inflammatory function of macrophages by inducing TGF-β release and IL-10 receptor surface expression. Arctigenin, phillygenin, and a metabolite produced by the gut microbiota, enterolactone, decreased TNF-α and IL-1β production and neutrophil adhesion to endothelial cells, probably by attenuating the p38 and ERK kinase pathways. Conclusion:Forsythia x intermedia is a valuable source of active lignans, which may be potential candidates for treating inflammatory diseases that are associated with the excessive production of cytokines such as TNF-α and IL-1β.

Use of compressed fluids for sample preparation: Food applications

This review attempts to provide an updated overview (including works published till June 2006) on the latest applications of compressed fluids as sample preparation techniques for food analysis. After a general review of the principles of supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE; also called accelerated solvent extraction, ASE or subcritical water extraction, SWE, when water is employed as extraction solvent), the principal applications of such techniques in the mentioned fields of food and natural products are described, discussing their main advantages and drawbacks.

Characterization of phenolic compounds in the fruits of Forsythia suspensa by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry

Phenolic compounds are the major bioactive constituents of Forsythia suspensa, an important Chinese herbal medicine used for the treatment of various infectious diseases. Fragmentation behaviors of the phenolic compounds in F. suspensa were investigated by using a high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS(n)) method. For common phenylethanoid glycosides, the loss of the caffeoyl moiety was the first fragmentation step, then sequential losses of rhamnose, hexose and water were observed in further fragmentations. If a substituent group presented in the beta position, the fragmentation was triggered by initial loss of a substituent group to form structures such as suspensaside A. Then it underwent the common fragmentation pathways as mentioned above, or eliminated characteristic residues of masses 134 or 152 Da, respectively. The latter pathway is reported here for the first time. The fragmentation behaviors of furofuran lignans displayed a typical cleavage of the tetrahydrofuran ring. However, the presence of a hydroxyl group at C-1 led to the successive loss of 30 Da. Neutral loss of CO(2) and benzyl cleavage were characteristic for lignans with a 2,3-dibenzylbutyrolactone skeleton. A neutral loss of 30 Da was also observed in the fragmentation pattern of flavonols. These fragmentation rules were implemented to analyze phenolic compounds in the fruits of F. suspensa. A total of 51 compounds, including 24 phenylethanoid glycosides, 21 lignans and 6 flavonols, were identified or tentatively characterized based on their retention times, UV spectra and MS fragmentation patterns.

Chromatographic analysis of lignans

Methods and procedures for analysis of lignans in trees and other plants are reviewed. The importance of cautious sample handling and pretreatment procedures to avoid contamination, loss of sample, and unwanted chemical reactions is discussed. Sequential extraction with a non-polar solvent followed by extraction with acetone or ethanol is recommended to separate the lignans from the plant matrix. An additional step of acid, alkaline, or enzymatic hydrolysis may be necessary for some plant matrixes. Flash chromatography is a convenient method for preparative separation and isolation of pure lignans from raw extracts. TLC is very suitable for qualitative screening of extracts and for monitoring of lignan isolation and purification steps. Trimethylsilyl ethers of lignans can be separated and quantified by GC even in the case of complex mixtures of lignans and other polyphenols, and the lignans can be identified by GC-MS in a routine manner. HPLC on reversed-phase columns is especially suited for analysis of lignans and their metabolites in biological matrixes. The recent development of HPLC-electrospray ionisation (ESI)-iontrap MS (MS(n)) and corresponding techniques with high sensitivity and selectivity has proven valuable in lignan analysis. Lignan enantiomers can be separated on chiral HPLC columns.

A preparative isolation and purification of arctigenin and matairesinol fromForsythia koreana by centrifugal partition chromatography

Centrifugal partition chromatography was applied to separate arctigenin and matairesinol from Forsythia koreana extract with a two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (5:5:5:5 v/v). Using this method, arctigenin and matairesinol were successfully separated from partially purified F. koreana extracts in only one step. The purities of isolated compounds were determined to be over 90% by HPLC analysis.