Terpene indole alkaloids

Rniz-May E, Galaz-Avalos RM, Loyola-Vargas VM. (2009) Differential secretion and accumulation of terpene indole alkaloids in hairy roots of Catharanthus roseus treated with methyl jasmonate. Mol Biotechnol 41 278-285. 

Terpenes, indole alkaloids Catharanthus roseus infected by phytoplasma 1H NMR and PCAdata analysis 46... 

C4 Geraniol 8- or 9-hydroxylase Terpene indole alkaloids [52]... 

Catharan-thus roseus 71D12 Taberosine 16-hydroxylase Terpene indole alkaloids Vindoline [207]... 

BJ1 Taberosine 19-hydroxylase Terpene indole alkaloids Horhammericine [209]... 

A strong cytotoxic lignan is podophyllotoxin (Fig. 17) irom Podophyllum peltatum or P. hex-andrum (Berberidaceae). Podophyllotoxin has the same mechanism of action as the terpene indole alkaloids vinblastine and vincristine it inhibits cell division by binding to tubulin and preventing its polymerization. This lignan is used as treatment for warts, but is too toxic for systemic application. Derivatives with reduced toxicity are etoposide, etopophos, and tenipo-side. They are prepared semi-synthetically from 4 -demethylpodophyllotoxin and have an inverted stereochemistry at C-4. These changes lead to a new anticancer mechanism, the... 

Fig. 3 Primary precnrsor-end product relationships in alkaloid biosynthesis. Color codes blue, terpene indole alkaloids green, benzophenanthridine alkaloids gray, benzylisoquinoline alkaloids red, quinolizi-dine alkaloids yellow, pyridine alkaloids pink, tropane alkaloids...

Geraniol 10-hydroxylase (CYP76B6) from Catharanthus roseus is a key regulatory enzyme in the synthesis of the terpene indole alkaloid vindoline [51]. Alkaloids such as vincristine and vinblastine (derived from vindoline) are used in modem medicine as anti-neoplastic agents (Fig. 3). 

Biosynthesis of some classes of terpene indole alkaloids is well understood. In certain cases, many of the enzymes that are responsible for biosynthesis have been cloned and mechanistically studied. In other cases, biosynthesis pathway is only proposed based on the results of feeding studies with isotopically labeled substtates and from the structures of isolated biosynthetic intermediates. All terpene indole alkaloids are derived from tryptophan and the iridoid terpene secologanin (Fig. 14.11). Tryptophan decarboxylase, a pyridoxal-dependent enzyme [29], converts tryptophan to tryptamine [30]. The following strictosidine synthase-catalyzed Mannich reaction connects ttyptamine and secologanin to yield strictosidine [31]. The Apocynaceae, Loganiaceae, Rubiaceae, and Nyssaceae families of plants each produce terpene indole alkaloids with dramatically diverse structures [32-34]. The mechanisms and control of... 

FIGURE 14.11 Classes of terpene indole alkaloid derived from strictosidine. 

FIGURE 14.13 Selected targets on David M. C. MacMillan s collective synthesis of terpene indole alkaloids. 

O Connor SE, Maresh JJ. Chemistry and biology of mono-terpene indole alkaloid biosynthesis. Nat. Prod. Rep. 2006 23 532-547. 

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