Tannin crude extract

We have employed two different protocols for the chemical fractionation of GSE obtained from MegaNatural-AZ based on the amounts needed for bioactivity-based assays. Batches of GSE (50 g) were extracted in acetone/water (7 3) under N2 with mechanical agitation for 12 h. The acetone was removed on a rotary evaporator and the aqueous phase was freeze-dried to yield 48 g of tannin crude extract (TCE). TCE was further fractionated following two different methods. 

Tannin crude extract partitioning Cl 8 reverse phase cartridge... 

Fig. 3.6 Tannin crude extract from grape seed separated by normal-phase HPLC with post-coiumn...

Crude GSE can be separated into distinct components from monomer-rich to oligomer- and polymer-rich fractions by solvent extraction followed by chromatography on Toyopearl resin. The pre-fractionation of the tannin crude extract by liquid-liquid extraction with ethyl acetate fractionates the monomers into the organic phase and improves the subsequent fractionation of oligomers and polymers on Toyopearl HW 40 resin. This fractionation technique is easy to operate and... 

A crude extract of Linderae umbellatae exhibited antipeptic and antiulcerogenic activity, and these effects were considered ascribable to the presence of tannins or related compounds. Nine condensed tannins (monomers, dimers, trimers, and tetramers) have been isolated and their antipeptic and antiulcer activity confirmed experimentally (pylorus ligated in rats and stress-induced gastric lesions in mice). 

Tafauma ovala St. Hill (Magnoliaceae) Leaves (Brazil) Chemical analyisis of extract of leaves demonstrated the presence of phytosteroids, saponins, alkaloids and tannins in the crude extract. The leaf extract is commonly considered as antidiabetic remedy. However, pharmacological studies failed to demonstrate the hypoglycemic effect of this plant in normoglycemic, hyperglycemic or alloxan diabetic rats [174]. 

Protein Binding—Tannins, as the name implies, characteristically form complexes with proteins based on multipoint hydrogen bonding, and this feature can be used to detect and remove tannins from crude extracts. A visible protein-tannin precipitate should be formed on addition of the tannin-containing extract to a relatively concentrated (approx 5%) solution of bovine serum albumin (BSA). The amount of BSA either remaining in solution or in the precipitate can be analyzed by various protein determination assays. 

One of the major applications of CPC is the purification of natural products from vegetal extracts (flowers, roots, etc.) or cmde extracts from fermentation broth without previous sample preparation. Hostettmann and coworkers have described many examples of isolation of natural products by CPC. Some flavonoids are, for instance, purified by using solvent systems containing chloroform, some cou-marins by using solvent systems containing HEX and EtOAc, and more polar products, such as tannins, by butanol-based systems. The main interest of this technique lies, however, in the possibility to overload its column so that all the applications of semipreparative chromatography are available. For instance, Menet and Thiebaut have separated 140 mg of an antibiotic from a crude extract of a fermentation broth. Some fractions of up to 95% purity were collected, while the original extract contained only 7% of the molecule of interest. They have also compared the performances of CPC, preparative LC, and hydrodynamic mode CCC. They finally showed that the solvent consumption is the lowest for CPC, while the enrichment is the best. 

The adjuvant activity of saponins has been known for more than 50 years [10]. Commercially available saponins frequently consist of highly heterogeneous preparations of varying composition, sometimes being little more than crude extracts of the bark of the South American soap tree, Quillaja saponaria (Rosaceae), which may be contamined with tannins. The major components, however, are bidesmo-sidic quillaic acid triterpene-saponins [10]. 

Recent investigations have shown that tannins are often responsible for the antitumour activity of crude extracts of some plants, especially those having activity against W 256, S 180 and Lewis Lung tumours. So far, those tannins examined have not shown sufficient activity to warrant preclinical pharmacology [253]. 

Teas, leaf essential oil, leaf oleoresin, eugenol, bark essential oil bark oleoresin, E-cinnamaldehyde, oil-macerated garlic extract, tannins, polymers of flavanols, cassia bark-derived substances, crude extracts of bulbs (Lycoiis chinensis), stems and leaves of (Nandina domestica), (Mahonia fortune ), (Mahonia bealei), stems of Berbeiis thunbergii and stems, leaves and fruits of Camptotheca acuminata, methanol and acetone extracts of 14 plants belonging to different families, Eruca sativa (aerial and root). EOs and methanol extracts of sweet basil Ocimum basilicum L. (Lamiaceae). Ponkan (Citrus mticulata Blanco). Seeds of Zizyphus jujube. 

The next step in sample preparation is to pirrify the crude extract. Plant extracts contain much ballast material, both nonpolar (chlorophylls and waxes) and polar, such as tannins or sugars. Most often liquid-liquid extrac-ti(Mi is used, which takes advantage of solubility differences of hydrophobic substances, which have affinity for nonpolar solvents, and hydrophilic substances, which have an affinity for aqueous solutions. 

Molan, A. L., Duncan, A. J., Barry, T. N. and McNabb, W. C. (2003). Effects of condensed tannins and crude sesquiterpene lactones extracted from chicory on the motility of larvae of deer lungworm and gastrointestinal nematodes . Parasitology International, 52, 209-218. 

Giner-Chavez BI, Van Soest PJ, Robertson JB et al (1997) A method for isolating condensed tannins from crude plant extracts with trivalent ytterbium. J Sci Food Agric 74 359-368... 

The USDA characterized a large number of biomass species for their traditional composition fractions of ash, crude protein, polyphenols, oils and hydrocarbons among others. These fiactions were defined operationally by the USDA botanochemical screening project their sample analysis and fraction partitioning scheme is summarized in Fig. 1. Of interest were extractives, components that can he separated/paititioned from the plant by solvents. The major extractives included various oils, terpenes, fatty acids, unsaponiflables, aromatic compounds, tannins, and quinones. In exceptional cases extractives composed over 15% of the biomass (especially ash) but generally they did not exceed S-10%. 

The effect of kind and amount of commercial tannins and crude wood extracts on phenolic bonding. Holzforschung 30 14-19... 

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