Of plumbagin

Sugie, S. et al., Inhibitory effects of plumbagin and jugloneon azoxymethane-induced intestinal carcinogenesis in rats. Cancer Lett., Ill, 111, 1998. 

Fig. 2 Dionaea muscipula (4) shows the prominent blue (vis/A) and red-brown (UV-365 nm/B) A,B zone of plumbagin (Tl) at R, - 0.3 in solvent system I. The hydroplunibagin-4- )-D-glucoside remains al the start.

Fig. 7. Synthesis of plumbagin (24) and a-caryopterone (28) from juglone through retro Diels-Alder reaction...

The identification of plumbagine (42), however, in Triphyophyllum peltatum 31), as well as in Ancistrocladus abbreviatus Airy Shaw 46), co-occurring with the alkaloids, can be interpreted as a strong indirect indication of a polyacetate pathway in the plants. By 1972, Zenk and co-workers had already found that the naphthoquinone 42 is formed from acetate units, albeit in Drosera and Plumbago species 47). A joint biosynthesis of plumbagine (42) and both molecular moieties, for example, of the alkaloid 23 from the same monocyclic precursor 32 seems evident (Scheme 6). 

Sugie, S., Okamoto, K., Rahman, K.M.W., Tanaka, T., Kawai, K., Yamahara, J., and Mori, H., Inhibitory effects of plumbagin and juglone on azoxymethane-induced intestinal carcinogenesis in rats. Cancer Lett., ill, 177-183, 1998. 

NahaUca, J., Nahakova, J., Gemeiner, R, and Balanark, P. 2004. Elicitation of plumbagin by chitin and its release into the medium in Drosophyllum lusctanicum Link. Suspension cultures. Biotechnol. Lett., 20 841-845. 

Durand, R. and M. H. Zenk, Bios3mthesis of plumbagin (1,5-hydroxy-2-methyl-1,4-naphthoquinone) via the acetate pathway in higher plants, Tetrahedron Lett., 3009-3012 (1971). 

Tokunaga T, Takada N, Ueda M (2004) Mechanism of antifeedant activity of plumbagin, a compound concerning the chemical defense in carnivorous plant Tetrahedron Lett 45 7115-7119 Trapp S, Croteau R (2001) Defensive resin biosynthesis in conifers. Annu Rev Plant Physiol Plant Mol Biol 52 689-724... 

Meyer, J.J.M. et al. (2007) Identification of plumbagin epoxide as a germination inhibitory compound through a rapid bioassay on TLC. South Afric. J. Bot. 73, 654-656... 

Sandur, S.K. et ah, Plumbagin (5-hydroxy-2-methyl-1,4-naphthoquinone) suppresses NF-kappa B activation and NF-kappa B-regulated gene products through modulation of p65 and I-kappa-B-alpha kinase activation, leading to potentiation of apoptosis induced by cytokine and chemotherapeutic agent, J. Biol. Chem., 281, 17023, 2006. 

The naphthalene derivatives (171, 172), from Daldinia concentrica (Ascomycetes), were significantly active towards C. elegans (10, 25 (ig/ml) and also showed antimicrobial and cytotoxic activity [6]. Since the black fruiting bodies of D. concentrica are highly melanized, it is likely that these compounds arise from melanin biosynthesis. Some naphthoquinones have been found to inhibit the motility and survival of H. contortus (LI). Plumbagin ( 173) was the most potent (ED 1 ig/ml) followed by 1, 4-naphthoquinone, juglone (174) and 1, 2-naphthoquinone [281]. 

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