Juglone structure

JugJone (Cl Natural Brown 7 Cl 755001 was isolated from the husks of walnuts in 1856. Juglone occurs in walnuts as a glycoside of its reduced form, 1,4,5-trihydroxynaphthalcnc. Its structure is (3),... 

Although the X-ray structure of a Pinl-dipeptide complex implicated covalent catalysis, a lack of nucleophilic assistance in the catalytic pathway can be derived from the covalent modification of parvulins by 5-OH-l,4-naphthoquinone (juglone). A juglone-inactivated E. coli ParlO contains two inhibitor molecules that are covalently bound to the side-chains of Cys41 and Cys69 because of a Michael... 

Other naphthoquinones found in higher plants, for example juglone, which superficially resemble compounds (XXI) and (XXII) in structure utilize several pathways involving shikimic acid-derived precursors (Zenk and Leistner, 1968), although inspection of formulas may indicate their origin by similar routes. 

A group of natural and synthetic dyestuffs based on the naphthoquinone structure (phenolic) have found use in the formation of lake and other pigments. Naphthoquinones are found in the leaves, blossoms, wood, bark, roots and fruit of about 20 different species. Those which are found in pigment use are AUcannin and Alkannan in AUcanet from plant species such as Alkanna lehmannii Tineo (formerly known as Alkanna tinctoria Tausch.), Macrotomia spp., Onosma spp. and juglone in Walnut qq.v.) fiom Juglans spp. 

Quinones group Alkanet Alkannan Alkannin Juglone Walnut For structure, see Quinones group entry. 

In addition to antitumor activity, diospyrin exhibits antileishmanial properties , perhaps by ET . Based on common functionalities (quinone and phenol), diospyrin is structurally related to several other compounds that are physiologically active. The antiviral agent, sakyomicin A, which contains a hexose residue and the juglone skeleton, generates H2O2 after... 

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