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PubMed1990

[Gypsum temporary filling material containing HY-agent. The effects of the HY-agent on the dentin].

The effects of the Tannin-Fluoride preparation, called the HY-agent, on dentin substrate were examined by immersion of the dentin previously treated with HY-agent into the calcifying fluid at 37 degrees C. The changes in the nature of the dentin surface and penetration of elements in the dentin were observed. CaF2 was formed on the dentin as a result of a reaction between F, an element of the HY-agent, and Ca which precipitated from the calcifying fluid. This observation was confirmed by means of the X-ray diffraction method. Penetration of F, Zn, Sr and Ca into dentin was confirmed by the use of an electron probe X-ray microanalyser (EPMA). Application of the HY-agent to the dentin for sevendays increased the hardness of the dentin about 10%. Application of the HY-agent to the dentin for sevendays increased the contact angle about 3%. These results suggested that the organic and inorganic matter in dentin can be stabilized effectively both chemically and physically by treatment with an HY-agent.

Calcium Sulfate↗
PubMed1986

[Dehulling of sorghum in grinding mills].

The efficiency of the dehulling process of sorghum grain was studied in a laboratory abrasive stone mill. Residual tannins as tannic acid and cathequin equivalent, as well as color measurements of the product were determined as control parameters of the procedure. Besides, fiber, ash and fat contents as well as other variables were evaluated. Assays were performed at three stone speeds and at different operation times. According to the results obtained, a stone speed of 1,700 rpm and a 12-minute period, are the best operating conditions, while measurements of color of the product constitute the best method for controlling the dehulling process.

Edible Grain↗
PubMed1998

Diet and pemphigus. In pursuit of exogenous factors in pemphigus and fogo selvagem.

Individuals with a genetic predisposition to pemphigus will develop the disease only when one or more additional factors are present. The nature of these factors is as yet unknown, but our starting point was that certain drugs (penicillamine, captopril, and rifampicin) are recognized as such factors. Since some nutrients have chemical compositions similar to these known causative drugs, these nutrients may act similarly and, therefore, nutritional factors should also be suspected. As when drugs are involved, elimination of the inciting ingredients may be crucial for management of the disease. This article discusses the possible role of nutritional ingredients in the disease process of pemphigus, including fruit, leaves, roots, seeds, and even water. Possible causative candidates are thiol, thiocyanate, phenols, and tannins.

Diet↗
PubMed1997

Assessment of bog-body tissue preservation by pyrolysis-gas chromatography/mass spectrometry.

Flash pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) was used to assess the quality and mechanism of protein preservation in the tissue of Iron Age bog bodies from Lindow, UK, and south-eastern Drenthe, The Netherlands. Abundant pyrolysis products of the fresh skin tissue, including 2,5-diketopiperazines of Pro-Gly, Pro-Ala, Pro-Val, Pro-Pro and Hyp, were readily assigned to specific amino acid or dipeptide moieties. Comparison of the pyrolysates of the bog-body tissues with that of modern samples revealed qualitative similarities suggesting good preservation of the collagen and non-collagenous proteins in the ancient tissues. Examination of the pyrolysates of samples of fresh calf skin, which had been treated with various vegetable tanning agents, clearly revealed markers of non-hydrolysable tannins including 1,2-benzenediol, 1,3-benzenediol and 1,2,3-benzenetriol, although chromatographic quality inevitably diminished with increasing functionalization of the compounds. Such markers were not detected in the pyrolysates of the bog-body tissues. Instead 4-isopropenylphenol, a characteristic pyrolysis product of Sphagnum moss, was detected in both solvent-extracted and base-treated samples of tissue. The presence of 4-isopropenylphenol in the pyrolysates of the bog-body tissues provides evidence that their preservation involves reactions of amino acids with sphagnum acid, and possibly other agents derived from the peat. The study constitutes the first chemical characterization of the pyrolysis products of modern and ancient collagen.

Aged↗
PubMed1999

Antiplasmodial activity of selected sudanese medicinal plants with emphasis on Acacia nilotica.

Twenty-two plant organs from eleven plants comprising five families were extracted and screened for antiplasmodial activity in vitro against Plasmodium falciparum 3D7 (chloroquine sensitive) and Dd2 (chloroquine resistant and pyrimethamine sensitive). Fifty nine percent of plant extracts from 22 extracts exerted activity on P. falciparum strain 3D7 with an IC(50) less than 50 microg/mL, whereas 43% of plant extracts showed an IC(50) value within 50 microg/mL on Dd2 strains. Plant extracts from Gardenia lutea, Haplophyllum tuberculatum, Cassia tora, Acacia nilotica and Aristolochia bracteolata possessed IC(50) values less than 5 microg/mL on both tested strains. Bioassay guided fractionation of A. nilotica revealed that the ethyl acetate extract possessed the highest activity (IC(50) = 1.5 microg/mL). Fraction 2 (R(f) = 0.75) prepared by preparative chromatography showed the highest activity on P. falciparum (IC(50) = 1.7 microg/mL). Phytochemical analysis indicated that the most active phase contained terpenoids and tannins and was devoid of alkaloids and saponins. The effect of plant extracts on lymphocyte proliferation showed low toxicity to the human cells. This plant has been subjected to long term clinical trials in folk medicine and is a promising plant.

Acacia↗
PubMed2000

The plant kingdom as a source of anti-ulcer remedies.

Phytogenic agents have traditionally been used by herbalists and indigenous healers for the prevention and treatment of peptic ulcer. This article reviews the anti-acid/anti-peptic, gastro-protective and/or anti-ulcer properties of the most commonly employed herbal medicines and their identified active constituents. Botanical compounds with anti-ulcer activity include flavonoids (i.e. quercetin, naringin, silymarin, anthocyanosides, sophoradin derivatives) saponins (i.e. from Panax japonicus and Kochia scoparia), tannins (i.e. from Linderae umbellatae), gums and mucilages (i.e. gum guar and myrrh). Among herbal drugs, liquorice, aloe gel and capsicum (chilli) have been used extensively and their clinical efficacy documented. Also, ethnomedical systems employ several plant extracts for the treatment of peptic ulcer. Despite progress in conventional chemistry and pharmacology in producing effective drugs, the plant kingdom might provide a useful source of new anti-ulcer compounds for development as pharmaceutical entities or, alternatively, as simple dietary adjuncts to existing therapies.

Aloe↗
PubMed1999

Kinetic analysis of antioxidant capacity of wine.

A competition kinetics procedure for measuring total antioxidant capacity in wine is described. This procedure is based on the "crocin bleaching test" [28] as modified for analyzing the antioxidant capacity of complex mixtures [24]. The antioxidant capacity of white wines ranged from 0.08 to 1.2 mM equivalents of the reference antioxidant (Trolox C), while for red wines values ranging from 6.4 to 41.9 mM have been obtained. Although a correlation exists between antioxidant capacity and total phenol content of wines, due to the variable reactivity of different phenol groups, the analysis of the phenol content provides only a crude indication of the actual antioxidant capacity. The analysis of antioxidant capacity on different polyphenol classes, separated by solid phase extraction, indicated that anthocyanins are the major antioxidants of young red wines, and tannins of old red wines and white wines. Several vintages of the same grape have been analyzed and the expected decrease of antioxidant capacity upon ageing was not observed, although spectrophotometric analysis clearly demonstrated the shift from anthocyanin monomers to polymers. Artificial ageing by stirring under air produced a rapid decrease (30 min) of antioxidant capacity followed by an increase (up to two weeks), but not any significant modification of the spectrophotometric chemical age factor. Since neither natural nor artificial ageing present a clear-cut relationship with a decrease of antioxidant capacity, we could conclude that the a priori assumption that an old wine contains less antioxidant capacity, although popular, is not fully correct.

Air↗
PubMed2004

Solid-state fermentation: a continuous process for fungal tannase production.

Truly continuous solid-state fermentations with operating times of 2-3 weeks were conducted in a prototype bioreactor for the production of fungal (Penicillium glabrum) tannase from a tannin-containing model substrate. Substantial quantities of the enzyme were synthesized throughout the operating periods and (imperfect) steady-state conditions seemed to be achieved soon after start-up of the fermentations. This demonstrated for the first time the possibility of conducting solid-state fermentations in the continuous mode and with a constant noninoculated feed. The operating variables and fermentation conditions in the bioreactor were sufficiently well predicted for the basic reinoculation concept to succeed. However, an incomplete understanding of the microbial mechanisms, the experimental system, and their interaction indicated the need for more research in this novel area of solid-state fermentation.

Bioreactors↗
PubMed1978

Immobilization of Streptomyces flavochromogenes pullulanase on tannic acid and TEAE--cellulose.

Pullulanase was immobilized successfully by simple, inexpensive methods that may be useful for industrial application of this enzyme. A tannin--pullulanase(TP) complex was obtained by addition of tannic acid to the culture filtrate of thermophilic Streptomyces flavochromogenes. TP could be bound to TEAE--cellulose (TTCP). Immobilization in this manner took place with quantitative retention of activity. The immobilized enzymes were stable for more than six months. The optimum temperatures of the native enzyme and TP were both 50 degrees C; that of TTCP was 45 degrees C. In the presence of 5mM Ca2+, the activity of TTCP was increased approximately twofold and the optimum temperature was raised to 50--60 degrees C. Pullulanase was not significantly eluted from TP or TTCP by NaCl solution (0.1--0.5M).

Enzymes, Immobilized↗
PubMed2007

Antigenotoxic activities of crude extracts from Acacia salicina leaves.

For centuries, plants have been used in traditional medicines and there has been recent interest in the chemopreventive properties of compounds derived from plants. In the present study, we investigated the effects of extracts of Acacia salicina leaves on the genotoxicity of benzo[a]pyrene (B(a)P) and nifuroxazide in the SOS Chromotest. Aqueous, total oligomers flavonoids (TOF)-enriched, petroleum ether, chloroform, ethyl acetate, and methanol extracts were prepared from powdered Acacia leaves, and characterized qualitatively for the presence of tannins, flavonoids, and sterols. All the extracts significantly decreased the genotoxicity induced by 1 microg B(a)P (+S9) and 10 microg nifuroxazide (-S9). The TOF-enriched and methanol extracts decreased the SOS response induced by B(a)P to a greater extent, whereas the TOF-enriched and the ethyl acetate extracts exhibited increased activity against the SOS response produced by nifuroxazide. In addition, the aqueous, ethyl acetate, and methanol extracts showed increased activity in scavenging the 1,1-diphenyl- 2-picrylhydrazyl (DPPH) free radical, while 100-300 microg/ml of all the test extracts were active in inhibiting O2-production in a xanthine/xanthine oxidase system. In contrast, only the petroleum ether extract was effective at inhibiting nitroblue tetrazolium reduction by the superoxide radical in a nonenzymatic O2- -generating system. The present study indicates that extracts of A. salicina leaves are a significant source of compounds with antigenotoxic and antioxidant activity (most likely phenolic compounds and sterols), and thus may be useful for chemoprevention.

Acacia↗
PubMed1994

Biochemical studies of some non-conventional sources of proteins. Part 7. Effect of detoxification treatments on the nutritional quality of apricot kernels.

Detoxification of apricot kernels by soaking in distilled water and ammonium hydroxide for 30 h at 47 degrees C decreased the total protein, non-protein nitrogen, total ash, glucose, sucrose, minerals, non-essential amino acids, polar amino acids, acidic amino acids, aromatic amino acids, antinutritional factors, hydrocyanic acid, tannins and phytic acid. On the other hand, removal of toxic and bitter compounds from apricot kernels increased the relative content of crude fibre, starch, total essential amino acids. Higher in-vitro protein digestibility and biological value was also observed. Generally, the detoxified apricot kernels were nutritionally well balanced. Utilization and incorporation of detoxified apricot kernel flours in food products is completely safe from the toxicity point of view.

Amino Acids↗
PubMedDate not supplied

Quantitative analysis of the active components and the by-products of eight dry extracts of Hypericum perforatum L. (St John's Wort).

The major components of eight different batches of commercially available dry extracts of Hypericum perforatum L. were quantified. Hyperforin (1), hypericin (2) and flavonoids, which are considered to play key roles in the treatment of mild and moderate depressive disorders, were determined by HPLC methods. The contents of 1, 2 and flavonoids were found to be in the range of 1.3-3.9%, 0.19-0.30%, and 4.8-11.4%, respectively. Generally extracts contained, besides the so-called active components, a wide variety of by-products which may act partially as co-effectors and affect the technological properties of the extracts. Water-soluble sugars form one of the main groups of these by-products, and a procedure for the purification and quantification of such sugars in H. perforatum using HPLC with refractive index detection has been established. Native fructose, glucose and sucrose, as well as lactose added during the processing of the extracts, were determined. The total sugar content in the dry herbal extracts varied from 19 to 25% by weight. Further, citric acid (0.9-2.3%) and malic acid (2.3-3.1%) were determined by HPLC, tannins (6.2-9.0%) and total ash (4.9-8.4%) were quantified according to the methods described in the European Pharmacopoeia, and the content of the total protein (3.9-8.3%) was estimated by elemental analysis. Thus, 60-70% of the compounds of the H. perforatum dry extracts have been quantified.

Anthracenes↗
PubMedDate not supplied

Chemical identification of the sources of commercial Fructus Chebulae.

Twenty-eight commercial samples of Fructus Chebulae were collected from local herbal markets in Taiwan and were determined to have been derived from Terminalia chebula Retz. and Terminalia chebula Retz. var. parviflora Thwaites, which differ markedly in external appearance. Ten tannin-related constituents [gallic acid (1), chebulic acid (2), punicalagin (4), chebulanin (7), corilagin (8), neochebulinic acid (9), ellagic acid (11), chebulagic acid (12), chebulinic acid (13) and 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (14)] were identified and quantified by HPLC. Samples derived from T. chebula. var. parviflora, which are typically round-shaped, generally contained higher concentrations of 13 and 14 but lower levels of 12 compared with those from T. chebula, which are largely oval-shaped. The ratio of the concentration of 14 to that of 4 may serve as a potential parameter for differentiating samples from the two origins (T. chebula, ratio 0.6 +/- 0.3; T. chebula. var. parviflora, ratio 3.4 +/- 2.2). Levels of the three major bioactive constituents 12-14 were found to provide good references for the quality assessment of Fructus Chebulae. The ratio of the concentration of 12 to that of 14 may offer a guideline for determining quality as well as origin of the drug (lower-grade T. chebula, ratio 12.4 +/- 6.0; medium-grade T. chebula, ratio 8.8 +/- 7.9; higher-grade T. chebula, ratio 3.2 +/- 0.8; T. chebula var. parviflora, ratio 1.6 +/- 0.7).

Carboxylic Acids↗
PubMed2002

Antimicrobial activity of some species of the family Combretaceae.

Forty eight extracts of four plants of the family Combretaceae were screened for antibacterial activity against standard organisms as well as clinical isolates. The extracts in different solvent systems showed high activity against both standard organisms and clinical isolates. Phytochemical screening revealed that the plants were very rich in tannins to which antibacterial activity may be attributed.

Anti-Bacterial Agents↗
PubMed2000

Differential toxicity of leaf litter to dipteran larvae of mosquito developmental sites.

The relative toxicity of leaf litter to nematocerous dipteran larvae characteristic of mosquito developmental sites was investigated. Culicidae, Chironomidae, and Simuliidae taxa originating from alpine hydrosystems were tested together with two laboratory nonindigenous culicid taxa. Bioassays indicate that ingestion of 10-month-old decaying leaves from Alnus glutinosa, Populus nigra, and Quercus robur by larvae is more deleterious for Aedes aegypti, A. albopictus, Culex pipiens, Simulium variegatum, and Chironomus annularius than for A. rusticus. Histopathological observations reveal that the midgut epithelium is the main target organ of the toxic effect of dietary leaf litter, which appears to be stronger than that of previously reported tannic acid. There is a general response of the nematocerous larval midgut epithelium to dietary tannins-phenolic compounds: clear cells of the anterior midgut showing symptoms of intoxication before dark cells of the posterior midgut.

Animals↗
PubMed1997

Risks associated with consumption of herbal teas.

Plants have been used for medicinal purposes for centuries. Health-oriented individuals are turning to herbal teas as alternatives to caffeinated beverages such as coffee, tea, and cocoa and for low-caloric supplements. The popularity of herbal tea consumption has increased significantly during the past two decades in the U.S. Hundreds of different teas made up of varied mixtures of roots, leaves, seeds, barks, or other parts of shrubs, vines, or trees are sold in health food stores. Although chemists have been characterizing toxic plant constituents for over 100 years, toxicological studies of herbal teas have been limited and, therefore, the safety of many of these products is unknown. Plants synthesize secondary metabolites that are not essential in the production of energy and whose role may be in the defense mechanisms as plant toxins to their interactions with other plants, herbivores, and parasites. Pyrrolizidine alkaloids (PAs) were among the first naturally occurring carcinogens identified in plant products, and their presence in herbal teas is a matter of public health significance. Some herbal tea mixtures and single-ingredient herbal teas have been analyzed for toxic/mutagenic potential by bioassay and chromatographic techniques. Numerous human and animal intoxications have been associated with naturally occurring components, including pyrrolizidine alkaloids, tannins, and safrole. Thus, the prevention of human exposure to carcinogens or mutagens present in herbal tea mixture extracts is crucial. Preparation of infusion drinks prepared from plants appears to concentrate biologically active compounds and is a major source of PA poisoning. The quantity and consumption over a long period of time is of major concern. It is recommended that widespread consumption of herbal infusions should be minimized until data on the levels and varieties of carcinogens, mutagens, and toxicants are made available.

Beverages↗
PubMed1983

Iron requirements and bioavailability of dietary iron.

Over the past few decades so much knowledge has been gained about iron needs, dietary iron availability and adequacy that it is now one of the best defined nutrients in these respects. Development of new, accurate methods for the measurement of both the losses of iron from the body and the absorption of iron from the diet has significantly contributed to this situation. Present knowledge of iron needs is summarized. Specific to iron are the much higher needs in women than in men and the great variation in needs between different women due to a marked physiological variation in menstrual iron losses and to the effects of pregnancies. Iron availability is discussed separately for heme and non-heme iron (the major type of food iron). Heme iron in small amounts is, on average, better absorbed than non-heme iron. The absorption of heme iron is influenced very little by the iron status of the subject and by the other food components in the diet with the exception of meat which stimulates absorption. On the other hand, the absorption of non-heme iron is markedly influenced both by the iron status of the subject and a great number of dietary factors. The absorption of iron from the diet is thus determined more by meal composition than by the amount of iron present in the diet. The great variation in absorption between different meals is illustrated and the importance of various factors influencing non-heme iron absorption is also demonstrated. Whilst the mode of food preparation itself influences iron absorption, meat or fish and ascorbic acid are some principal food constituents that enhance absorption of iron. On the other hand, several factors like tannins, phytates, phosphates, soya protein products and various "dietary" fibres have been reported to inhibit non-heme iron absorption. A consideration of the nutritional adequacy of iron high-lights the importance of methods of evaluation, particularly the usefulness of the "bioavailable nutrient density" (BND) approach for different meals; BND for iron represents the amount of iron absorbed per 1'000 kcal (4'180 kJ). The main problem in iron nutrition in Western countries today is that arising from the combination of a low-energy intake, especially in women having the highest iron needs, with a conservation in the choice of meals/meal composition. Provision of bioavailable dietary iron to meet needs has hence not been adjusted to "modern life".

Ascorbic Acid↗
PubMed1984

On the use of plants and plant-derived compounds for the control of schistosomiasis.

The rising costs of chemotherapy and synthetic molluscides have led to an increasing interest in plants which are lethal to the intermediate host of schistosomiasis (bilharzia). Over one thousand species have been tested but only a few have been phytochemically examined. Approximately fifty molluscicidal compounds have so far been isolated from plants, including saponins, terpenoids, flavonoids, naphthoquinones and tannins. The saponins from Phytolacca dodecandra are the most active and have been successfully employed in field tests. The latest results in this area and the problems involved in the use of plants and natural products for the control of schistosomiasis are discussed here.

Animals↗