Juglans Juglone

The toxic influence exerted by Juglans nigra (black walnut) on other plants has been attributed to 5-hydroxy-1,4-naphthoquinone (juglone) (11,31). Hydrojuglone is present in the root bark, leaves, and fruit husks. This compound is not considered toxic, but it is oxidized to the toxic juglone upon exposure to air (51). Rainfall... 

Colaric M, Veberic R, Solar A, Hudina M and Stampar F. 2005. Phenolic acids, syringaldehyde, and juglone in fruits of different cultivars of Juglans regia L. J Agric Food Chem 53(16) 6390-6396. 

Quinone Colors depend on mordant and pH 1. benzoquinone 2. naphthaquinone 3. anthraquinone Carthamine Juglone Alizarin Purpurin Walnut or butternut (Juglans sp.) Rubiaceae family Sorrel (Rumex sp.) Poligonaceae family Forms lake with mordant For 3. pH >7 -> violet-blue pH < 7-> yellow-red AL rose-red Ca bluish-red Zn red-violet Fe black-violet Cr=red brown... 

Juglone (= 5-Hydroxy-1,4- in Cotula (Asteraceae), Cactus (Cactaceae), Argemone (Papaveraceae), Taxodium (Taxodiaceae) spp. Juglans cinerea,J. nigra MLCK, PKA, PKC (a 3)... 

Juglone (= 5-Hydroxv-1,4- Pimelea decora, P simplex (Thymelaeaceae) Juglans cinerea, J. nigra [stem bark], ECMOX (100) (MLCK, PKA,... 

Juglone (5-hydroxy-1,4-naphthoquinone) is a water-soluble yellow pigment that is exuded from leaves, fruits, bark, and roots of black walnut Juglans nigra), English walnut (J. regia), and hickory (Carya ovata) trees, among others. 

The fresh fruit-shell of Juglans regia (English walnut) contains the naphthoquinone constituent juglone, which is mutagenic and possibly carcinogenic. The juglone content of dried shells has not yet been studied adequately. 

Naphthoquinones Juglone (130), Plumbagin Juglans regia HSV Non-specific at [16]... 

Documented effects The leaves and the fruit husks are used to make the preparation Juglon. It is used externally to treat skin tuberculosis and Staphylococcus and Streptococcus lesions. It has antimicrobial and anti-inflanunatory actions and is used to heal wounds. Unsaturated fatty acids from the nuts help to prevent arteriosclerosis (Nuraliev 1989). CUnical studies showed that a water extract of the leaves was effective in treating some forms of skin tuberculosis, tuberculosis lymphadenitis, and tnbercnlosis of the larynx (Altimishev 1991). In experiments with mice, extracts of Juglans regia improved glucose tolerance in hypoglycemic activity screens (Neef et al. 1995). In vitro, an extract of the nuts inhibited the oxidation of hnman plasma and low density hpoproteins (Anderson et al. 2001). Polyphenols and tocopherols, isolated from the nuts, exhibited antioxidative properties (Fukudu et al. 2003 Li et al. 2007). 

Naphthoquinones Juglone (D 8.1) The leachate of Juglans leaves contains 1,4,5-trihydro xy-naphthalene-4-glucoside which after hydrolysis and oxidation yields juglone. Juglone inhibits seed germination and development of many plants... 

Anthraquinones and naphthoquinones are not exclusively formed via the polyketide biosynthetic route. They can also be derived from the shikimate pathway, e.g., the allelopathic naphthoquinone juglone from the walnut tree Juglans regia) and the anthraquinone alizarin from madder root Rubia tinctorium), which was used as purple dye. 

Jose, S. and Gillespie, A.R. (1998) Allelopathy in black walnut (Juglans nigra L.) alley cropping. I. Spatio-temporal variation in soil juglone in a black walnut-corn (Zea mays L.) alley cropping system in the midwestem USA. Plant Soil 103, 191-197... 

Investigation of an antitumour-active fraction of walnut, Juglans nigra, has shown that juglone (LXI) decreased significantly the gain in tumour size of... 

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