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Tannins leaching from an unprepared driftwood decoration in an aquarium can cause pH lowering and coloring of the water to a tea-like tinge. A way to avoid this is to boil the wood in water several times, discarding the water each time. Using peat as an aquarium substrate can have the same effect. Many hours of boiling the driftwood may need to ...
The ellagitannins are a diverse class of hydrolyzable tannins, a type of polyphenol formed primarily from the oxidative linkage of galloyl groups in 1,2,3,4,6-pentagalloyl glucose. Ellagitannins differ from gallotannins, in that their galloyl groups are linked through C-C bonds, whereas the galloyl groups in gallotannins are linked by depside ...
An astringent (sometimes called adstringent) is a chemical that shrinks or constricts body tissues. The word derives from the Latin adstringere , which means "to bind fast". Astringency , the dry, puckering or numbing mouthfeel caused by the tannins [ 1 ] [ 2 ] in unripe fruits, lets the fruit mature by deterring eating.
For anthocyanidins, precursors of the condensed tannin biosynthesis, dihydroflavonol reductase and leucoanthocyanidin reductase (LAR) are crucial enzymes with subsequent addition of catechin and epicatechin moieties for larger, non-hydrolyzable tannins.
A hydrolysable tannin or pyrogallol-type tannin is a type of tannin that, on heating with hydrochloric or sulfuric acids, yields gallic or ellagic acids. [ 1 ] At the center of a hydrolysable tannin molecule , there is a carbohydrate (usually D-glucose but also cyclitols like quinic or shikimic acids ).
Tannic acid can be applied to woods low in tannin so chemical stains that require tannin content will react. The presence of tannins in the bark of redwood (Sequoia) is a strong natural defense against wildfire, decomposition and infestation by certain insects such as termites. It is found in the seeds, bark, cones, and heartwood.
Even untrained humans can decipher ape communication, including gestures related to grooming and sex, according to a new study published on Jan. 24 in the journal PLOS Biology.
Body language is a type of nonverbal communication in which physical behaviors, as opposed to words, are used to express or convey information. Such behavior includes facial expressions, body posture, gestures, eye movement, touch and the use of space. Although body language is an important part of communication, most of it happens without ...