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PubMed1996

[Relationship between nutritional composition and anatomical parameters in sorghum (Sorghum bicolor L. Moench)].

Nutritional and chemical parameters with significant differences (P = 0.5) among 10 varieties of sorghum and rates observed in them were as follow: lipids (2.76 to 3.75%), raw fiber (60.0 to 64.7%) protein (9.01 to 11.43%), no nitrogen extract 977.65 to 83.07%), starch (60.5 to 64.20%), tannin (2.50 to 10.16 mg/g), and total calories (380 to 4000 Kcal). Ash content with value of 1.17 to 1.91% protein digestibility (23.8 to 38.8%) and "in situ" starch (54.4 to 66.6%) were not statistically different. When correlation indexes were determined between results of chemical analysis, it was obtained follow positive correlation having significance: carbohydrates with total calories and fat with fiber. The main negative correlations were: fat and fiber with carbohydrates, fiber with calories, and digestibility "In vitro" of protein with tannin. In order to obtain equivalent analytical tests to substitute an anatomic determination for a chemical one, or vice versa, and make easy the selection of varieties for different use, and the adequate process for sorghum grain, were obtained correlations between chemical data of this study and compared to anatomic features determined in a previous analysis with same samples (1), it was found 19 significant coefficients from which 8 were positives and 11 negatives. The main correlations with capacity of analytical substitution were: size of starch grain of cornea endosperm-starch amount; size of protein body of flour-like endosperm-digestibility "in vitro" and "in situ" of protein; length of cell of flour like endosperm-starch amount; length and broad of aleurona cells-fiber content. The major negative correlations were: size of starch grain of cornea and flour-like endosperm ash; size of protein body of cornea endosper-starch amount; length and broad of aleurona cells-carbohydrates and total calories.

Edible Grain↗
PubMed1998

[Densitometric method for parallel measurement of rosmarinic and caffeic acids in plant samples].

In the last few years, the role of free radicals in the promotion of cell aging and tumour growth has focused attention on phenolic compounds. Rosmarinic acid (RA) and caffeic acid (CA), as major components of tannins, commonly occur together in many species of the Lamiaceae. A TLC-densitometric method was introduced for the parallel determination of RA and CA. Experiments were performed to establish the optimal measurement parameters related to the excitation wavelength, colour stability, linearity of the calibration curves, sensitivity and reproducibility. In the wavelength range 290-330 nm, it was found that the emission peak areas exhibit a maximum at 325 nm. Therefore, the densitometric evaluations of these tannins were made at 325 nm. The two compounds behaved very similarly as regards colour stability. The changes during the 3 hours of observation were not strong, as reflected by coefficients of variation of 8.20% for RA and 5.40% for CA. The calibration plots demonstrating the relation between the spotted amount and the measured peak area were found to include 2 intersecting linear sections, in the intervals 0-0.40 microgram and 0.40-1.20 micrograms for RA and 0-0.08 microgram and 0.08-0.30 microgram for CA. The correlation coefficients ranging between 0.991 and 0.998. The lower limits of detection were 1 ng for RA and 0.1 ng for CA. The reproducibility proved to be very good: the 10 times repeated densitometric estimation of the same spot yielded a coefficient of variation of 0.34% for RA and 0.36 for CA. The application of TLC permits utilization of the fluorescence of both phenols, often without the need for prior purification. This fluorescence measurement makes the detection extremely sensitive. The densitometric quantification allows the routine analysis of many samples in a short time with reasonable accuracy. The practical application of the elaborated method will be demonstrated on the leaves of 5 Salvia species. The results are shown in table I.

Antioxidants↗
PubMed2006

New phenolic constituents from Balanophora polyandra with radical-scavenging activity.

The 80% acetone extract of Balanophora polyandra Griff. (Balanophoraceae) was found to exhibit high radical-scavenging activity (SC(50)=14.48 mug/ml) towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals. Further chemical investigation led the isolation of two new hydrolysable tannins, balapolyphorins A (1) and B (2), together with 20 known phenolic compounds (3-22). Their structures were established by detailed spectroscopic analysis, and the radical-scavenging properties of all isolated compounds were determined by DPPH assay.

Acetone↗
PubMed1984

In vitro interaction of neuroleptics and tricylic antidepressants with coffee, tea, and gallotannic acid.

The in vitro interaction of selected drugs with coffee, tea, gallic acid, and gallotannic acid was examined by mixing solutions of drug with each of these four preparations. Results of these experiments indicate that significant precipitation occurs for a variety of agents, including several phenothiazines, amitriptyline, haloperidol, imipramine, and loxapine. The strong complex which is formed between these drugs and tannins is probably the basis of the interaction of these drugs with coffee and tea. Although precipitates did occur with a number of neuroleptics, two members of this drug class, thiothixene and molindone, failed to interact with the solutions used.

Antidepressive Agents, Tricyclic↗
PubMed2004

Mitochondrial dysfunction as an early event in the process of apoptosis induced by woodfordin I in human leukemia K562 cells.

Tannins are a group of widely distributed plant polyphenols, some of which are beneficial to health because of their chemopreventive activities. In the present study, we investigated the effects and action mechanisms of woodfordin I, a macrocyclic ellagitannin dimer, on human chronic myelogenous leukemia (CML) K562 cells. The results showed that woodfordin I was able to suppress the proliferation and induce apoptosis in K562 cells. Apoptosis was evaluated by cytomorphology, internucleosomal DNA fragmentation, and externalization of phosphatidylserine. Woodfordin I treatment caused a rapid and sustained loss of mitochondrial transmembrane potential (MMP), transient generation of reactive oxygen species (ROS), transient elevation of intracellular Ca2+ concentration, and cytosolic accumulation of cytochrome c. The activation of caspase-9 and 3, but not caspase-8, was also demonstrated, indicating that the apoptotic signaling triggered by woodfordin I was mediated through the intrinsic mitochondria-dependent pathway. Western blot and immunofluorescence analysis revealed that the anti-apoptotic Bcl-2 and Bcl-xL levels were downregulated, together with the pro-apoptotic Bax protein. Significantly, woodfordin I-induced apoptosis was associated with a decline in the levels of c-Abl, Bcr-Abl, and cellular protein tyrosine phosphorylation. Considering the consequence of all the events in the process of woodfordin I-induced apoptosis, the mitochondrial dysfunction is directly responsible for the pro-apoptotic effects on K562 cells. Furthermore, because CML is a malignancy of pleuripotent hematopoietic cells caused by the dysregulated tyrosine kinase activity of Bcr-Abl, these findings suggest that woodfordin I may be a potential lead compound against CML.

Apoptosis↗
PubMed1999

Induction of apoptosis by penta-O-galloyl-beta-D-glucose through activation of caspase-3 in human leukemia HL-60 cells.

Penta-O-galloyl-beta-D-glucose is structurally related to (-)-epigallocatechin gallate and is isolated from hydrolyzed tannin. Penta-O-galloyl-beta-D-glucose can inhibit tumor promotion by teleocidin. We investigated the effects of penta-O-galloyl-beta-D-glucose and various tea polyphenols on cell viability in human leukemia HL-60 cells. In this study, we demonstrated that penta-O-galloyl-beta-D-glucose was able to induce apoptosis in a concentration- and time-dependent manner; however, other polyphenols were less effective. We further investigated the molecular mechanisms of penta-O-galloyl-beta-D-glucose-induced apoptosis. Treatment with penta-O-galloyl-beta-D-glucose caused induction of caspase-3/CPP32 activity in dose- and time-dependent manner, but not caspase-1 activity, and induced the degradation of poly-(ADP-ribose) polymerase. Pretreatment with acetyl-Asp-Glu-Val-Asp-aldehyde (Ac-DEVD-CHO) and Z-Val-Ala-Asp-fluoromethyl-ketone (Z-VAD-FMK) inhibited penta-O-galloyl-beta-D-glucose-induced DNA fragmentation. Furthermore, treatment with penta-O-galloyl-beta-D-glucose (50 microM) caused a rapid loss of mitochondrial transmembrane potential, release of mitochondrial cytochrome c into cytosol, and subsequent induction of procaspase-9 processing. Our results indicate that penta-O-galloyl-beta-D-glucose allows caspase-activated deoxyribonuclease to enter the nucleus and degrade chromosomal DNA, and induces DFF-45 (DNA fragmentation factor) degradation. These results lead to a working hypothesis that penta-O-galloyl-beta-D-glucose-induced apoptosis is triggered by the release of cytochrome c into the cytosol, procaspase-9 processing, activation of caspase-3, degradation of poly-(ADP-ribose) polymerase, and DNA fragmentation caused by the caspase-activated deoxyribonuclease through the digestion of DFF-45. The induction of apoptosis by penta-O-galloyl-beta-D-glucose may provide a pivotal mechanism for its cancer chemopreventive action.

Acridine Orange↗
PubMed2002

Two ellagitannins from Punica granatum heartwood.

In the course of studies on polyphenol metabolism in Punica granatum heartwood two new ellagitannins, diellagic acid rhamnosyl (1-->4) glucopyranoside and 5-O-galloylpunicacortein D were isolated and characterized together with four known tannin metabolites, punicacortein D, punicalin, punicalagin and 2-O-galloylpunicalin. Structures of the isolated compounds were established by chromatography, chemical degradation, UV and 1D/ 2D 1H/13C NMR spectroscopy.

Ellagic Acid↗
PubMed2003

Caffeoyl sugar esters and an ellagitannin from Rubus sanctus.

The new natural caffeoyl esters, 3,6-di-O-caffeoyl-(alpha/beta)-glucose and 1-O-caffeoyl-beta-xylose, together with the hitherto unknown natural tannin, 2,3-O-hexahydroxydiphenoyl-4,6-O-sanguisorboyl-(alpha/beta)-glucose, have been isolated from the aqueous alcohol aerial part extract of Rubus sanctus. Establishment of all structures was based on the chemical and spectral evidence, including ESI-MS and 2D NMR.

Caffeic Acids↗
PubMed1997

Binding nature and denaturation of protein during interaction with galloylglucose.

Analysis of insoluble complexes between tetragalloylglucose and proteins following a series of successive washes with buffer indicated (1) heterogeneity of binding between galloylglucose and protein and (2) irreversible denaturation of protein during interaction with galloylglucose. Relatively large amounts of tetragalloylglucose were removed by initial washes, indicating weak, low affinity binding, whereas smaller amounts removed by subsequent washes suggest bonds with a higher affinity. Although the maximum number of bindings sites, calculated per 10,000 M(r) of protein, was similar for BSA, myoglobin and lysozyme, the proportion of these sites that appeared to have high affinity, varied from 8 to 29%. The low proportion of strongly binding sites in lysozyme explains its relatively low tannin-complexing ability. Solubility decrease in protein during successive washing and decrease in the beta-glucosidase activity indicate that irreversible denaturation of protein occurs, which progresses with an increase in the incubation time with galloylglucose and galloylglucose/protein molar ratio in the mixture. Relative affinity of galloylglucose is directly related to the ability to cause irreversible denaturation.

Hydrolyzable Tannins↗
PubMed1998

Production of macrocyclic ellagitannin oligomers by Oenothera laciniata callus cultures.

Callus cultures of Oenothera laciniata grown on LS agar medium supplemented with IAA and kinetin produced large amounts of the macrocyclic ellagitannin dimer, oenothein B, and a trimer, oenothein A, accompanied with related monomeric hydrolysable tannins. The content of the main compound oenothein B (65 mg/g dry wt) in calli cultured on modified LS medium containing 10 mM NH4+ and 5 mM NO3- was nearly two times higher than that in intact leaves.

Biopolymers↗
PubMed2002

Antiherpes simplex virus type 2 activity of casuarinin from the bark of Terminalia arjuna Linn.

Casuarinin, a hydrolyzable tannin isolated from the bark of Terminalia arjuna Linn. (Combretaceae), was investigated for its antiviral activity on herpes simplex type 2 (HSV-2) in vitro. Results showed that the IC(50) of casuarinin in XTT and plaque reduction assays were 3.6+/-0.9 and 1.5+/-0.2 microM, respectively. The 50% cytotoxic concentration for cell growth (CC(50)) was 89+/-1 microM. Thus, the selectivity index (SI) (ratio of CC(50) to IC(50)) of casuarinin was 25 and 59 for XTT and plaque reduction assays, respectively. Casuarinin continued to exhibit antiviral activity even added 12 h after infection. During the attachment assay, casuarinin was shown to prevent the attachment of HSV-2 to cells. Furthermore, casuarinin also exhibited an activity in inhibiting the viral penetration. Interestingly, casuarinin was virucidal at a concentration of 25 microM, reducing viral titers up to 100,000-fold. This study concludes that casuarinin possesses anti-herpesvirus activity in inhibiting viral attachment and penetration, and also disturbing the late event(s) of infection.

Animals↗
PubMed2003

Transcriptional suppression of the HIV promoter by natural compounds.

Tannins and lignins are natural compounds contained in plants such as tea leaves. Previously, we demonstrated that tannic acid represses 12-o-tetra-decanoyl phorbol-13-acetate (TPA)-induced human immunodeficiency virus (HIV) promoter activity. Furthermore, we demonstrated that a 30-bp element located just downstream of the NF-kappaB element in the HIV promoter responds negatively to tannic acid. However, the kinds of molecules responsible for this suppressive effect have remained unknown, because tannic acid is a mixture of various galloylglucoses. Here, we examined structure-defined natural compounds for HIV promoter-suppressive effects. We found that ellagitannins suppress TPA-induced HIV promoter activity to the same extent as tannic acid. 3-phenylcoumarins, isoflavone and chalcones have more suppressive effects than ellagitannins. On the other hand, other flavonoids and acetogenins have no suppressive effect. 3-phenylcoumarins and chalcones showed no suppressive effect on the cytomegalovirus (CMV) promoter, suggesting that they act specifically on the HIV promoter. These results suggest that 3-phenylcoumarin or chalcone compounds could be used to develop novel anti-HIV drugs with an action targeted at HIV promoter activity.

Anti-HIV Agents↗
PubMed2001

Camelliin B induced apoptosis in HeLa cell line.

Gordonia axillaris (Roxb.) Dietrich (Theaceae) is a native to Taiwan and the leaves have been used as an astringent folk medicine. Camelliin B (CB), a macrocyclic hydrolyzable tannin, was isolated from G. axillaris and showed cytotoxic effects in human carcinoma cells. Among the target cells (SKHep-1, Ha-22T, DU-145, AGS, and HeLa), the cervical carcinoma cell line, HeLa, was more sensitive to CB than were Chang normal liver cells and primary-cultured normal gingival and cervical fibroblasts. Furthermore, the cytotoxic effects of CB showed dose-dependency at 3.2-100.0 microg/ml in HeLa for 1,24,48, and 72 h and with an IC(50) value of 46.3 microg/ml for 48 h. However, the IC(50) value of CB in primary-cultured normal cervical fibroblasts was 108.0 microg/ml. Therefore, the selectivity shown by CB was ascribed to the difference in growth speed between normal and tumor cells. HeLa cells and primary-cultured normal cervical fibroblasts were treated with 50.0 and 100.0 microg/ml CB for 48 h, respectively, and exhibited chromatin condensation, indicating the occurrence of apoptosis. Flow cytometric analysis demonstrated the presence of apoptotic cells with low DNA content, a decrease of cell population at the G(1) phase, and a concomitant increase of cell population at the G(2)/M phase. CB also caused DNA fragmentation and inhibited PARP degradation in HeLa cells. However, CB did not significantly inhibit Bcl-2 expression in HeLa cells at 50.0 microg/ml, only at 100.0 microg/ml for 48 h. These results suggest that CB induced apoptosis, without direct inhibition of Bcl-2 expression in HeLa cells.

Antineoplastic Agents, Phytogenic↗
PubMed1999

Antitumor activity of four macrocyclic ellagitannins from Cuphea hyssopifolia.

We evaluated the antitumor activities of four macrocyclic hydrolyzable tannin dimers, cuphiin D1, cuphiin D2, oenothein B and woodfordin C isolated from Cuphea hyssopifolia (Lythraceae). All significantly inhibited the growth of the human carcinoma cell lines KB, HeLa, DU-145, Hep 3B, and the leukemia cell line HL-60, and showed less cytotoxicity than adriamycin against a normal cell line (WISH). All four compounds inhibited the viability of S-180 tumor cells in an in vitro assay and an in vivo S-180 tumor-bearing ICR mice model. Oenothein B demonstrated the greatest cytotoxicity (IC50 = 11.4 microg/ml) against S-180 tumor cells in culture, while cuphiin D1 resulted in the greatest increase in survival on S-180 tumor-bearing mice (%ILS = 84.1%). Our findings suggest that the antitumor effects of these compounds are not only related to their cytotoxicity on carcinoma cell lines, but also depended on a host-mediated mechanism; they may therefore have potential for antitumor applications.

Animals↗
PubMed2002

First observation of solution structures of bradykinin-penta-O-galloyl-D-glucopyranose complexes as determined by NMR and simulated annealing.

Polyphenols (tannins) are known for their high propensity to precipitate proteins. They bind most strongly to proteins with a high proline content. Understanding the mechanism of this association is of prime interest because this interaction might induce protein conformational changes that may modify their biological activity. To investigate the interaction, an NMR study was carried out on the binding of a representative polyphenol, penta-O-galloyl-D-glucopyranose, to a nonapeptide hormone, bradykinin (BDK), where proline accounts for 30% of residues. Series of 1D and 2D-NMR experiments were performed. For the first time, a three-dimensional structure of complexes was determined using 2D-NMR experiments and molecular modeling. These structure calculations are a potent tool to understand how the association arises. They clearly show that the interaction is a complex phenomenon where several parameters are involved. The PGG/BDK complexes are formed by multiple weak interactions between peptide side chains and galloyl rings. Proline and arginine are good anchoring points and the glycine gives a certain flexibility in the peptide backbone that allows the polyphenol to approach and interact. Therefore, it is not only the hydrophobic stackings between galloyl rings and proline and hydrogen bonding involving arginine and aromatic rings which are important. The residue sequence and the side chain steric bulk also intervene.

Bradykinin↗
PubMed2001

Evolution of ellagitannins in Spanish, French, and American oak woods during natural seasoning and toasting.

The evolution of tannins in Spanish oak heartwood of Quercus robur L., Quercus petraea Liebl.,Quercus pyrenaica Wild., and Quercus faginea Lam. was studied in relation to the processing of wood in barrel cooperage. Their evolution was compared with that of French oak of Q. robur (Limousin, France) and Q. petraea (Allier, France) and American oak of Quercus alba L. (Missouri), which are habitually used in cooperage. Two stages of process were researched: the seasoning of woods during 3 years in natural conditions and toasting. Total phenol and total ellagitannin contents and optical density at 420 nm of wood extracts were determined. The ellagitannins roburins A-E, grandinin, vescalagin, and castalagin were identified and quantified by HPLC, and the molecular weight distribution of ellagitannins was calculated by GPC. During the seasoning process the different ellagitannin concentrations decreased according to the duration of this process and in the same way as those in French and American woods. The toasting process also had an important influence on the ellagitannin composition of wood. Roburins A-E, grandinin, vescalagin, and castalagin decreased during this process in the Spanish wood species, in the same proportion as in the French and American ones. Also, the seasoning and toasting processes lead to qualitative variations in the structure of ellagitannins, especially in the molecular weight distribution, as was evidenced by GPC analysis of their acetylated derivatives.

Chromatography, High Pressure Liquid↗
PubMed2000

Radical scavenging activity of a purple pigment, hordeumin, from uncooked barley bran-fermented broth.

A novel purple pigment called hordeumin, a type of anthocyanin-tannin pigment, was produced from barley bran-fermented broth. The radical scavenging activity of hordeumin was analyzed by using an electron-spin resonance (ESR) spectrometer. The hordeumin scavenged superoxide radical in a concentration-dependent manner. Superoxide dismutase-like activity values were 118 and 195 units/mg for crude and partially purified hordeumin, respectively. The two types of hordeumins also scavenged the DPPH radical. Furthermore, barley bran-fermented filtrate before pigment formation and extract of barley bran also scavenged the DPPH radical. However, the DPPH radical scavenging activity of a filtrate, fermented over a long period, was stronger than that fermented over a short period. Thus, it was considered that radical scavenging activity of hordeumin resulted from barley bran polyphenol such as proanthocyanidins.

Anthocyanins↗
PubMed2001

Phyllanemblinins A-F, new ellagitannins from Phyllanthus emblica.

Six new ellagitannins, phyllanemblinins A-F (1-6), were isolated from Phyllanthus emblica, along with 30 known tannins and related compounds. Their structures were determined by spectral and chemical methods. Phyllanemblinins A (1) and B (2) were confirmed to be ellagitannins having a tetrahydroxybenzofuran dicarboxyl group and a hexahydroxydiphenoyl group, respectively, by chemical synthesis from furosin (8). Phyllanemblinin C (3) has a new acyl group at the glucose 2,4-positions and is structurally related to chebulagic acid. Phyllanemblinins D (4), E (5), and F (6) were found to be positional isomers of neochebuloyl 1(beta)-O-galloylglucose.

Antineoplastic Agents, Phytogenic↗