OBJECTIVEIn situ, real timely and dynamically monitoring the processes of theaflavin (TF), curcumin (Cur) and cyanidin (Cy) binding to human whole saliva (WS) surface has been investigated by surface plasmon resonance (SPR) technique at the molecular level.

METHODSThe affinity between pigments and WS, association rate constant (k(a)), dissociation rate constant (k(d)), association equilibrium constant (K(A)) and dissociation equilibrium constant (K(D)) of pigments binding on WS surface had been determined by SPR and the Langmuir model as well as the Freundlich model. The data were analyzed by one-way ANOVA and SNK-q test.

RESULTSThere were significant differences among TF, Cur and Cy in k(a), k(d), K(A) and K(D) (P<0.05). Our results showed that the adsorption isotherm of pigments on WS surface could be better described by the Freundlich model than the Langmuir model. The pigments adsorption on WS surface was dominant by specific interactions, such as hydrogen bonding. The affinity of pigments to WS were TF> Cur>Cy (P<0.05), as evidenced by the rate constants and equilibrium constants.

CONCLUSIONCompared with Cur and Cy, TF shows much higher adsorption capacity on WS surface, suggesting the importance of the hydroxyl group in pigment/protein interactions.

Adsorption ; Anthocyanins ; Biflavonoids ; Catechin ; Curcumin ; Humans ; Saliva ; Surface Plasmon Resonance

Animals ; Atherosclerosis ; prevention & control ; Biflavonoids ; pharmacology ; Catechin ; pharmacology ; Grape Seed Extract ; pharmacology ; Humans ; Proanthocyanidins ; pharmacology

OBJECTIVETo explore the driving force of the oral astringency produced by the interaction of theaflavin (TF) and epigallocatechin-3-gallate (EGCG) to human salivary a-amylase(HSA).

METHODSThe constants of the rate, equilibrium of reaction (k(a), k(d), K(A), and K(D)) and Langmuir, Freundlich adsorption isotherm (K(L), K(f), and Mm) were determined by surface plasmon resonance (SPR) technique and adsorption kinetics.

RESULTSBoth of Langmuir and Freundlich models could be used for describing the binding processes of TF and EGCG onto HSA surfaces, and there were no significant differences of the correlation coefficient of determination between these two models (P > 0.05). The constants of adsorption isotherm, the rate and equilibrium constants of the association for TF were higher than those of EGCG (P < 0.05). The rate and equilibrium constants of the dissociation for TF were lower than those of EGCG (P < 0.05). The affinity of TF to HSA was higher than that of EGCG.

CONCLUSIONThe sorely oral astringency is much easily produced by TF from the black tea rather than EGCG from the green tea. The driving force of the oral astringency is attributed to the hydrogen bonds of hydroxyl groups and hydrophobic interaction of galloyl groups in polyphenolic structures.

Adsorption ; Animals ; Antioxidants ; Biflavonoids ; Catechin ; analogs & derivatives ; Cercopithecus aethiops ; Humans ; Salivary alpha-Amylases ; Tea ; alpha-Amylases

To explore new biflavones, 7-hydroxy-8-hydroxymethyl-4'-methoxyisoflavone (1), (5, 7-dihydroxyflavone-8-yl)-(7'-hydroxy-4"-methoxyisoflavone-8'-yl)methane (2), bis(7-hydroxy-4'-methoxyflavone-8-yl) methane (3), bis(3', 5'-diisopropyl-7, 4'-dihydroxy-isoflavone-8-yl)methane (4), and bis(7-hydroxy-isoflavone-8-yl) methane (5) were designed and synthesized from chrysin, formononetin, 7, 4'-dihydroxy-3', 5'-diisopropyl-isoflavone and 7-hydroxy-isoflavone. Their structures were identified with IR, 1H NMR, 13C NMR and elemental analysis. The binding of 1-5 with DNA was studied with fluorescent spectroscopy. Compounds 2-5 showed higher binding affinity with DNA than 1. According to the Stern-Volmer equation, the binding constants of 2, 3 were determined at 35 degrees C and 25 degrees C respectively, they were Kq2 (25 degrees C) = 1.95 x 10(4) Lx mol(-1) and Kq2 (35 degrees C) = 1.67 x 10(4) L x mol(-1); Kq3 (25 degrees C) = 1.89 x 10(4) L x mol(-1) and Kq3 (35 degrees C) = 1.58 x 10(4) L x mol(-1). The quenching mechanism of 2, 3 was suggested as static quenching.
Biflavonoids ; chemical synthesis ; chemistry ; DNA ; chemistry ; Flavonoids ; chemical synthesis ; chemistry ; Molecular Structure

BACKGROUND AND OBJECTIVES: Glutaraldehyde (GA) has been used as a representative method of tissue preservation in cardiovascular surgery. However, GA has showed limited durability including calcification, mechanical failure and toxicity. To overcome those unsolved problems, we analyzed the crosslinking differences of primary amines, GA and genipin in their mechanical and biochemical properties with a single or double crosslinking agent for clinical application. MATERIALS AND METHODS: Samples were divided into 3 groups; control, single crosslinking fixation and double crosslinking fixation after decellurarization using bovine pericardium. For analysis of the biochemical and mechanical properties of each crosslinking method, tensile strength, percentage strain, thermal stability, resistance to pronase, nynhydrin and cytotoxicity test were studied. RESULTS: Combined hexamethylene diamine and suberic acid in the carbodiimide hydrochloride/N-hydroxysucinimide solution (EDC/NHS) after decellurarization, tensile strength and strain percentage were not statistically significant compared to the single crosslinking treated groups (p>0.05). Tissue crosslinking stability was weak in single treatment of diphenylphosphoryl azide, suberic acid, low concentration of EDC, hexamethylene diamine and procyanidin groups, but thermal stability and resistance to the pronase and ninhydrin were markedly increased in concentrated EDC/NHS or after combined double treatment with low concentration of GA or genipin (p<0.001). CONCLUSION: Single or double crosslinking with low concentration of carbodiimide, diphenylphosphonyl azide, procyanidin, suberic acid and hexane diamine were not as effective in mechanical, biochemical, cytotoxic and crosslinking properties compared to GA or genipin fixation, but their mechanical and chemical properties were much improved when combined with low concentrations of GA or genipin in the double crosslinking process.
Amines ; Azides ; Biflavonoids ; Bioprosthesis ; Caprylates ; Catechin ; Dicarboxylic Acids ; Glutaral ; Iridoids ; Ninhydrin ; Pericardium ; Proanthocyanidins ; Pronase ; Sprains and Strains ; Tensile Strength ; Tissue Preservation

OBJECTIVETo establish a HPLC-DAD model for the simultaneous determination of two selaginellins (selaginellin and selaginellin B) and four biflavones (amentoflavone, sequoiaflavone, hinokiflavone and isocryptomerin) contained in 10 batches of Selaginella tamariscina and 12 batches of S. pulvinata produced in different areas.

METHODThe analysis was performed on a Waters Cosmosil C18 column (4.6 mm x 250 mm, 5 microm) eluted with acetonitril-0.1% formic acid as mobile phase in a linear gradient mode. The detection wavelength was set at 280, 337 nm. The flow rate was kept at 1.0 mL x min(-1), and the column temperature was 30 degrees C.

RESULTThe six active constituents showed significant different in content. Amentoflavone in S. tamariscina contains (5. 628-9. 184 mg x g(-1)) is more than that contained in S. pulvinata (0.823-7.131 mg x g(-1)), while selaginellin in S. pulvinata (0.123-0.593 mg x g(-1)) is more than that contained in S. tamariscina (0.067-0.133 mg x g(-1)). All the calibration curves showed good linear correlation coefficients (r > 0.9997) over the wide test ranges.

CONCLUSIONThe developed HPLC-DAD method is simple, sensitive and accurate and has the good repeatability in separation, which is available for the quality control of S. tamariscina and S. pulvinata.

Biflavonoids ; chemistry ; Biphenyl Compounds ; chemistry ; Chromatography, High Pressure Liquid ; methods ; Cyclohexanones ; chemistry ; Flavones ; chemistry ; Flavonoids ; chemistry ; Selaginellaceae ; chemistry

OBJECTIVE: To investigate the protective effect of procyanidin B2 (PCB2) on the intestinal barrier and against enteritis in mice with trinitrobenzene sulphonic acid (TNBS)-induced colitis and explore the possible mechanism. METHODS: A mouse model of TNBS-induced colitis was established in male Balb/c mice aged 6-8 weeks. The successfully established mouse models were randomly divided into PCB2 treatment group (=10) and model group (=10) and were treated with daily intragastric administration of PCB2 (100 mg/kg, 0.2 mL) and 0.2 mL normal saline, respectively. After 4 weeks, the disease symptoms, intestinal inflammation, intestinal mucosal cell barrier function and the changes in PI3K/AKT signaling were evaluated using HE staining, immunofluorescence assay and Western blotting. RESULTS: The disease activity index of the mice was significantly lower and the mean body weight was significantly greater in PCB2 group than in the model group in the 3rd and 4th weeks of intervention ( < 0.05). The levels of colonic inflammation and intestinal mucosal inflammatory mediators IL-1β and TNF-α were significantly lower while IL-10 was significantly higher in PCB2 group than in the model group ( < 0.05). Compared with those in the model group, the mice in PCB2 treatment group showed a significantly lower positive rate of bacterial translocation in the mesenteric lymph nodes and a lower thiocyanate-dextran permeability of the intestinal mucosa ( < 0.05). Western blotting showed that PCB2 treatment significantly increased the expressions of claudin-1 and ZO-1 ( < 0.05) and significantly lowered the expression levels of p-PI3K and p-AKT in the intestinal mucosa as compared with those in the model group ( < 0.05). CONCLUSIONS PCB2 suppresses intestinal inflammation and protects intestinal mucosal functions and structural integrity by inhibiting intestinal PI3K/AKT signaling pathway, suggesting the potential of PCB2 as a new drug for Crohn's disease.
Animals ; Biflavonoids ; Catechin ; Colitis ; chemically induced ; Colon ; Enteritis ; Intestinal Mucosa ; Male ; Mice ; Phosphatidylinositol 3-Kinases ; Proanthocyanidins ; Trinitrobenzenesulfonic Acid

OBJECTIVETo investigate the role of β-catenin and caspase-3 in amentoflavone-induced apoptosis of human colorectal cancer SW480 cells.

METHODSMTT assay was used to detect the viability of SW480 cells exposed to amentoflavone, and flow cytometry was employed to assess the cell apoptosis. Western blotting was performed to determine the protein expressions of β-catenin and caspase-3 in the exposed cells.

RESULTSAmentoflavone dose-dependently inhibited the viability of SW480 cells, and a high concentration of amentoflavone (150 µmol/L) obviously induced apoptosis of the cells. Amentoflavone exposure caused significantly increased expression of caspase-3 and suppressed β-catenin expression in the cells.

CONCLUSIONAmentoflavone-induced apoptosis in SW480 human colorectal cancer cells is associated with altered expressions of β-catenin and caspase-3.

Apoptosis ; Biflavonoids ; pharmacology ; Caspase 3 ; metabolism ; Cell Line, Tumor ; drug effects ; Colorectal Neoplasms ; pathology ; Humans ; beta Catenin ; metabolism

OBJECTIVETo establish a method to analyze HPLC fingerprint characteristics of 10 plants from Selaginella.

METHODHPLC was applied for establishment of fingerprints, which were used to evaluate and distinguish the different species of Selaginella.

RESULTThe different species from Selaginella showed different HPLC fingerprint characteristic. The samples of the same species but collected in different period, different environment or different locations showed certain difference in fingerprints

CONCLUSION2 important mutual fingerprint peaks were found in the 10 plants of Selaginella species and 5 peaks can be used as "main fingerprint peaks". The dates of these peaks can used for assessment of phylogenetic relation among species and evaluation of quality.

Biflavonoids ; analysis ; China ; Chromatography, High Pressure Liquid ; methods ; Plants, Medicinal ; chemistry ; classification ; Selaginellaceae ; chemistry ; classification ; Species Specificity

AIMTo investigate the chemical constituents of the secondary metabolites of the roots of Daphne genkwa.

METHODSThe roots of D. genkwa were extracted with 95% ethanol at 60-70 degrees C for 7 days to obtain the crude extract. The crude extract was purified by silica gel and Sephadex LH-20 column chromatography as well as the HPLC techniques. The structures of the isolates were elucidated by combined spectroscopic methods including 1D and 2D NMR, MS, UV, IR and CD.

RESULTSThree new biflavonoids were isolated from the ethanol extract of the roots of D. genkwa and their structures were identified as daphnodorin H-3-methyl ether (1), daphnodorin H-3"-methyl ether (2) and daphnodorin G-3"-methyl ether (3).

CONCLUSIONCompounds 1, 2 and 3 are three new biflavonoids.

Biflavonoids ; chemistry ; isolation & purification ; Daphne ; chemistry ; Ethanol ; Molecular Conformation ; Molecular Structure ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry