Rhamnus species

Unripe fruits of many plants contain compounds such as quinines that impart an aversive taste and discourage fruit eaters from consuming them before they are ripe and their seeds are mature and ready for dispersal. Unripe fruit of some Rhamnus species contain emodin, an anthraquinone that deters birds and mammals from feeding. Anthraquinone reduced red-winged blackbird feeding on rice by 84%, and 71% in boat-tailed grackles (Avery etal, 1997). 

Wei, B.L. et al.. In vitro anti-inflammatory effects of quercetin 3-0-methyl ether and other constituents from Rhamnus species, Planta Medica, 61, 745, 2001. 

Emodin (11) and helminthosporin (9) (Fig. 6,1) (see also Chapter 5) are derived from acetate-malonate precursors. An enzyme that provides strict substrate control, emodin 1-0-methyltransferase, was purified 89-fold (Hutchinson, 1986). Chrysophanol (57), found in Rumex (Polygonaceae) and Rhamnus (Rhamnaceae) species, appears to result from folding of the polyketide chain in one arrangement (58), whereas aloesaponarin (59) seems to involve a second form (60) (Fig. 6.13). Both chrysophanol and aloesaponarin occur in the roots of Aloe saponaria (Liliaceae) (Leistner, 1981). Under special conditions, callus cultures of Rhamnus species... 

There is some limited mention of the use of this dyestuff as part of lake pigment recipes, such as that given by Tingry (1804) for a brownish variety of Dutch pink q.v.), based on a berberis extract with yellow berries (dye derived from the unripe berries of Rhamnus species). 

Common English name for several species of Rhamnus and Frangula the berries of which produce both a yellow and a green flavonoid dyestuff. R catharticus L., found in southern Europe, North Afi ica and Asia R. alatemus L., in southern Europe and additionally Frangula alnus Miller (formerly Rhamnus frangula L.), in North Africa, North-west Asia and all of Europe except the Mediterranean. The latter is commonly known as Alder buckthorn. Other dye producing Rhamnus species are found in other parts of Europe. 

Sap green was made from a flavonoid dye extracted from the ripe berries of buckthorn (Rhamnus cathartica L.) and various other Rhamnus species. The related Chinese green and lokao were greens produced by Rhamnus species found in China (see the entry for lokao). 

Yellow lake pigments based on dye derived from Rhamnus species, presumably from those indigenous to the historical territories of Turkey. Bristow (1996b) cites the records of the English firm of Beiger where Turkey berries (from Izmir - formerly Smyrna - or Aleppo) and Persian berries were used for production of Dutch pink (. v.) and brown pink he tentatively identifies the plant source as R. sacatalis, R. amygdalinus and/or R. oleiodes. However, see the entry for Rhamnus for a fuller discussion. 

Verde vessie - literally, bladder green - was synonymous with sap green, a lake pigment traditionally made from dyes derived from the ripe berries of Rhamnus species (though some literature references also indicate the use of woad and blue iris). 

Various Rhamnus species produce a yellow dyestuff, generally extracted from the inrripe berries. These latter are typically referred to in the historical literature as yellow berries, buck-friom (. v.), French berries or Avignon berries (. v.). The dye is in turn used to produce various yellow lake pigments, often called pink in earher docinnentary sources. The term yellow berries was also apphed to the actual pigment produced from these berries, and came to replace the earher term pink (Harley, 1982). For a fuller discussion of the species involved, constituent compounds, substrates and alternative terminology, see the enhy for rhamnus. 

Yellow lake might reasonably be defined as any pigment formed by the deposition of a dyestuff onto a base which gives a yellow compound. Historically a wide range of dyestuffs has been used to produce yellow-coloured lakes, notably those from flavonoid sources such as the bark of Quercus species - oak - and the berries of various Rhamnus species - buckthorn (qqv.) bases such as cuttlefish, aluminium hydroxide, marl, chalk and occasionally lead white and starch were used. 

Emodin is a naturally occurring anthraquinone produced in many species of lichen, fungi, and higher plants (e.g., the genus, Rhamnus). Extracts containing emodin have been used in traditional medicine as herbal laxatives. It has also... 

Sterculia species (stercuiia) Stercuiiaceae (cacao) Cascara sagrada Rhamnus purshianus... 

Rhamnase, found in Rhamnus Frangula and probably other species of Rhamnus, hydrolyzes the glucoside frangulin to rhamnose and emodin. 

The above is a commercial green dyestuff prepared from the bark of various species of Bhamnus Rhamnus uHlis,Rh. chlorophlorus). It consists chiefly of the alumina and lime lakes of the glucoside. 

Persian berry The fruit of any species of buckthorn (Rhamnus). 

Various species of Rhamnus provide an enzyme mixture, commonly... 

C15H10O5. Mr 270.24, orange needles, mp. 223 - 225 °C, uv 430 nm (C2H5OH), soluble in ether, benzene, and hot ethanol. A. is named after the aloe, the concentrated leaf juices of various Aloe species (A. ferox, A. barbadensis, Liliaceae) and occurs additionally in free form and as the corresponding anthrone glycosides in Rhamnus, Rheum, Rumex, and Cassia species. In addition to laxative action it also exhibits an antileukemic effect and is used as starting material for the synthesis of anthracycline antibiotics. 

As typical examples of C. a. amphibine A (type 4) and zizyphine A (type 5) from Zizyphus species as well as frangulanine (type 4) occurring in small amounts in bark and leaves of buckthorn (Rhamnus frangula) are illustrated ... 

The fresh bark of Rhamnus frangula and most Cassia species contains anthrones and not anthraquinones (Leistner, 1985). After storage and extraction, anthraquinones and di-anthrones are isolated but are probably artifacts. Except for a dubious record of acetate-derived anthraquinones in the Scrophulariaceae, these compounds are not yet recorded from orders of plants that produce iridoid monoterpenes (see Chapter 20). 

Anthraquinone glycosides have long been used medicinally as cathartics and laxatives. Plant-derived drugs of this type include aloes Aloe species), cascara sagrada (Rhamnus purshiams), frangula (Rhamnus frangula), rhubarb (Rheum officinale), rumex or yellow dock (Rumex crispus) and senna (Cassia spp.). Many of the commercial preparations (patent medicines) based on these plants are readily available. 

The solvents in Table 170 are suitable for TLC-separation of the constituents of Aloe, Rhamnus and Senna species and also for tinctures and extracts prepared from them [23—26, 108, 114, 142, 143, 178—182, 213]. Solvent I has an especially wide range of application with mixtures of anthraquinone glucosides. Solvent VII is more suitable, however, for the dianthrone glucosides. 

Emodin is found mostly as a rhamnoside in various Rhamnus, Rheum and Cassia species. 

For a fuller discussion of the plant species involved, constituent compounds, substrates and alternative terminology, see the entry for Rhamnus. 

Emodin, l,3,8-trihydroxy-6-methylanthraquinone, is an anthraquinone dye which occurs mostly as a rhatrmoside (see Frangulin) in various Rhamnus, Rheum and Cassia species. It is a major dye component extracted from the bark of Cassia fistula L. Also known as frangula emodin and rheum emodin Merck Index, 1996 Schweppe, 1992). 

Various species of Rhamnus produce a dyestuff, generally extracted from the unripe berries these latter are known as yeUow berries, buckthorn, French berries or Avignon berries. This is the dye used to produce the various yeUow lake pigments called pinks. Harley (1982) states that this term also came to be appHed to the pigment as the term pink fell into disuse. See also Avignon berries, pink and Stil de Grain. 

A yeUow lake colour. It is caUed French as this refers to the berries used in its manufacture, tiiese coming from certain species of Rhamnus (probably R. alatemus and R infectorius) which were... 

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