Quinone extraction from

Weng XC, Gordon MH (1992) Antioxidant activity of quinones extracted from tanshen (Salvia miltiorrhiza Bunge). J Agric Food Chem 40 1331... 

Muralikrishna K, Manoharachary C, Prasad U (1989) Effect of Quinone Extracted from Pyxine pefricola Nyl. on Mitosis in Allium cepa L. Root Meristems. Curr Sci 58 1393... 

Quinones are colored p-benzoquinone, for exanple, is yellow. Many occur naturally and have been used as dyes. Alizarin is a red pigment extracted from the roots of the madder plant. Its preparation from anthracene, a coal tar derivative, in 1868 was a significant step in the development of the synthetic dyestuff industry. 

Oxidative degradation of the o-quinone (429), obtained by chromic acid oxidation of the corresponding benzofuran (extracted from coal... 

The sulfur compound sulfuraphane, extracted from fresh broccoli, has received attention in recent years because of its strong action in inducing synthesis of quinone reductase and glutathione S-transferases that help detoxify xenobiotics and may have significant anticancer activity/... 

If preferred, the crude suspension of quinone obtained from 25 gms. of aniline (see p. 235) may be employed, being saturated with sulphur dioxide until it smells very strongly of the gas. After standing for 2 hours, if it still smells of the gas the liquid is extracted with ether, as above. If the odour of the gas has vanished, the liquid must be resaturated, and so on, until the smell persists for 2 hours. 

A naphthoquinone unit is located at the end of a molecular wire to fit into the pocket (so-called quinone pocket) from which VKi has been extracted. 

The radical-pair state P I is also formed if unreduced reaction centers are excited with a short flash, but it then decays with a time constant of about 200 ps [54,70-74]. The rapid decay of the transient state presumably reflects electron transfer from I to (Fig. 1), because it is prevented if the quinone is already reduced or is extracted from the reaction centers. The transient absorption changes suggest that I is a BPh 7r-radical anion, which interacts with a nearby BChl [75-77], The absorbance changes in a band associated with the BChl decay with somewhat different kinetics from those in bands associated with the BPh or BPh , perhaps because they reflect nuclear motions in the electron carriers or the surrounding protein [75]. The possible role of the BChl in the initial transfer of an electron from P to the BPh will be discussed below. 

There was a time when few naturally-occurring dyes w ere of greater importance than madder because of its extensive use for dyeing bright red shades. The best madder red was dyed in Turkey and, from this, the name Turkey Red ultimately became a general term for all comparatively fast dyeings in this colour. The active mordant dye in madder is Alizarin, extracted from the root of the plant which was cultivated extensively in southern Europe, the Middle East, and Asia. It w as demonstrated by Graebe and Liebermann in 1868 that Alizarin was 1 2 dihydroxyanthra-quinone, (3) ... 

Degradation products of Irganox 1330 have been extracted from irradiated PP samples by refluxing with chloroform for at least 2 h followed by particle-beam LC-MS analysis. The compounds with quinone methide structures, e.g. l,3,5-trimethyl-2,4,6-tris(3, 5, di-tert-butyl-4-hydroxybenzyl)ben-zene were quantified [64]. 

Polyphenols, such as quinones, are major components of many traditional herbal remedies which exhibit several beneficial effects, including antiinflammation. For example, Cuellar et al. [105] investigated the topical antiinflammatory activity of extracts from Cassia angustifolia Vahl. and Rheum palmatum, medicinal plants commonly known for their anthraquinonic content, and used in traditional East Asian medicine against different skin disorders. All the extracts significantly inhibited the edema induced by 12-0-tetradecanoylphorbol-13-acetate (TP A) in both single or multiple applications. 

Ceratocystis ulmi. These sesquiterpenes quinones possess antifungal properties. None of the mansonones was detected by TLC in extracts from healthy U. Americana. Accumulation of mansonones A, C, D and G in... 

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