Heliotropium Indicine

The Borage plant (syn. Forget-me-not) family (Boraginaceae Lindl.) contains L-ornithine (Figure 11 and 15) derived alkaloids, such as indicine-N-oxide in the heliotrope (Heliotropium indicum) and southern hound s tongue Cynoglosum creticum) species (Table 8). Farsam et al. reported on new alkaloids from... 

Boraginaceae Heliotropium indicum Cynoglossum spp. Symphytum officinale Indicine-A-oxide Indicine-A-oxide Acetyl-intermedine Acetyl-lycopsamine... 

Previous work on Heliotropium indicum L. has demonstrated the presence of indicine (26) and acetylindicine (27).12 Plants grown in Bangladesh contained indicine as principal alkaloid, together with heliotrine (28), lasiocarpine (29), echinatine (30), supinine (31), and heleurine (32).13 The N-oxide of indicine (26), also isolated from this species, displayed significant antitumour activity.14 The dried plant material of H. ramosissimum contains 0.58% of alkaloids, the majority of which is heliotrine (28).15... 

A variety of pyrrolizidine alkaloids and their N-oxides have antitumor activity (Wink, 1993b). Herbal material of Senecio vulgaris (Asteraceae) has been used for hundreds of years as a treatment for cancer. The active compounds have been shown to be senecionine (5) and senecionine N-oxide. Indicine N-oxide (16) from Heliotropium indicum (Boraginaceae) has pronounced antitumor activity. Mono-crotaline (8), from several Crotalaria species (Fabaceae), has similar activity (Blasko and Cordell, 1988 Suffness and Cordell, 1985). Alkylation seems to be involved in the antitumor activity. As the A -oxides cannot serve as enamines and hence cannot be directly involved in alkylation, these compounds should only be active to the extent they are converted to the free bases. At least in the case of indicine iV-oxide (16), this does not appear to be the case (Suffness and Cordell, 1985). 

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