Polyphenols extraction

J (2001) Green tea polyphenol extract attenuates inflammation in interleukin-2-deficient mice, a model of autoimmunity , J Nutr, 131 (7), 2034-9. 

Escribano-Bailon M and Santos-Buelga C. 2003. Polyphenol extraction from foods. In Santos-Buelga C, Williamson G, editors. Methods in Polyphenol Analysis. Cambridge The Royal Society of Chemistry,... 

In studies on hamsters and guinea pigs exposed to aerosols of crude and refined extracts from cotton mill trash and CMD, Kilburn et al (59) has further demonstrated recruitment of PMN beneath the basement membrane and on luminal surfaces of intrapulmonary airways and tracheas. When administered as aerosols or dust, polyphenolic extracts from cotton trash and pure and oxidization-polymerization products of quercetin also recruit PMN from the trachea to terminal bronchioles in hamsters (60). 

Miketova, P. et al., Tandem mass spectrometry studies of green tea catechins. Identification of three minor components in the polyphenolic extract of green tea, J. Mass Spectrom., 35, 860, 2000. 

Escribano-Bailon, M.T. and Santos-Buelga, C., Polyphenol extraction from food. In Methods in Polyphenol Analysis (eds C. Santos-Buelga and G. Williamson), The Royal Society of Chemistry, Cambridge, 2003, p. 1. 

Kirakosyan, A. et al.. Antioxidant capacity of polyphenolic extracts from leaves of Crataegus laevigata and Crataegus monogyna (Hawthorn) subjected to drought and cold stress, J. Agric. Food Chem., 51, 3973, 2003. 

Milk thistle (Silybum marianum) is an annual to biennial plant of the Aster-aceae family. It is native principally to southern Europe and northern Africa. The crude drug consists of the ripe fruits from which the pappus has been removed. Milk thistle fruits contain 15% to 30% proteins. The main active compounds constitute only about 2% to 3% of the dried fruits. The active principle is a mixture of flavolignans called silymarin. Silymarin, a polyphenolic extract isolated from the seeds of milk thistle, is composed mainly of silybin (50 70%), with small amounts of other silybin structural isomers, namely isosilybin, silydianin, and silychristin (Fig. 11) (123-125). The highest concentration of silymarin is found in the ripe fruits (126). Silibinin is the main compound, also considered to be the most active one in several paradigms (127). 

The powdered plant material maximizes polyphenolic extraction because of its high contact area with solvent and easy destruction of biological cell walls. Ethanol may be employed instead of methanol in routine extractions to avoid the toxic properties of methanol. The main advantage of methanol over ethanol is its lower boiling point. 

Filter the aqueous polyphenolic extract with a 0.45-jam PVDF filter and adjust the pH to 7.0 with 5 N NaOH. 

In a polyphenolic extract, anthocyanins can interfere with other polyphenolics such as pro-cyanidins during HPLC analysis and hence should be removed prior to analysis. Anthocyanins from crude polyphenolic extracts can be removed as described in Basic Protocol 2. The ethyl acetate used for elution of phenolic compounds other than anthocyanins is removed using a rotary evaporator at 20°C. The non-anthocyanin polyphenolics are dissolved in deionized distilled water and the pH is adjusted to 7.0 with NaOH as described in Alternate Protocol 2 or the method developed by Oszmianski and Lee (1990a). In the latter method, polyphenolics were fractionated into three groups neutral fraction A (flavanols and other polar phenolics), neutral fraction B (flavonols), and acidic phenolics. Polyphenolic extracts were adjusted to pH 7.0 with NaOH... 

After filtering the mixture of sample and organic solvent, the hose connected from the water aspirator to the flask under the Buchner funnel should first be carefully disconnected before shutting off the water source to prevent possible backflow of tap water into the flask, which would contaminate the sample. Prior to evaporation, the solvent waste reservoir should be empty, clean, and dry. Evaporation should be started slowly at reduced pressure to avoid the boiling over of solvent and samples. If by chance the polyphenolic extract boils over into the waste reservoir, immediately release the applied vacuum and transfer the extract back to the original boiling flask. If this is not satisfactory and contamination is a possibility, extraction should be performed again with a new sample. 

Cao H, Urban JF. Jr., Anderson RA. 2008. Cinnamon polyphenol extract affects immune responses by regulating anti- and proinflammatory and glucose transporter gene expression in mouse macrophages. J Nutr 138 833-840. 

Polyphenolic extract of fenugreek seed acts as a protective agent against ethanol-induced abnormalities in the liver and the effects are comparable with those of a known hepatoprotective agent, silymarin (Kaviarasan and Anuradha, 2007). 

The polyphenol extract from the barley bran (BPE) induced the differentiation of human promyelocytic leukemia HL-60 cells, based on the expression of the differentiation markers such as nitro blue tetrazolium (NBT) reducing activity and a-naphthyl butyrate esterase activity. Prodelphini-din B-3, Tl, T2, and T3 induced 26-40% NBT-positive cells and 22-32% a-naphthyl butyrate esterase-positive cells. Proanthocyanidins might potentiate the retinoic acid (all-frarcs-retinoic acid)-induced granulocytic differentiation and sodium butyrate-induced monocytic differentiation in the HL-60 cells [101]. 

The rapid growth of the pulp and paper industry following World War II coupled with a renewed scientific interest in utilization of bark and wood residues led to investigative programs on bark and wood tannins. The leather industry was continuing to decline in importance, so other alternatives were needed. One of these was replacement of phenol in whole or in part in phenol-formaldehyde adhesive formulations. This work progressed to the point where commercial quantities of polyphenolic extractives were made and sold for adhesive application. Excessive capacity and low petrochemically derived phenol prices in the 1960 s led to the demise of this effort in the United States (2,5). 

The gluing experiments were done with commercially available starch, proteins (casein, glutin) and tannins of mimosa Acacia spp.), Pinus radiatay and quebracho (Schinopsis spp.) and with tannins extracted from the bark of spruce (Picea abies) and common pine (Pinus sylvestris). The extractions were carried out with water or organic solvents under alkali and/or sulphite conditions on a laboratory scale aiming at optimization of yield and polyphenolic extract content. After extraction, the solutions were concentrated under reduced pressure and freeze dried. One pine bark extract was modified with phenol. A summary of the tannin extracts and their properties is given in Table I. 

Chen, C.W., and Ho, C.T., Antioxidant properties of polyphenols extracted from green and black teas, J. Food Lipid, 2, 35 6, 1994. 

Regardless, the reputation of pomegranate as a superfruit is based entirely on its juice and polyphenol extract products, which are typically low in nutrient content, so it s always wise to check the Nutrition Facts panel on your favorite juice brand if nutrients are your goal. 

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