Nicandra Withanolides

Insecticidal properties of withanolides were first noticed on components isolated from the Peruvian plant Nicandra physaloides. Nicandrenone (Nic-1) (90), the major component isolated from this plant, was known by its bitter taste and its insecticidal properties. [58-61]... 

During an infestation by larvae of the Egyptian cotton leafworm Spodoptera littoralis (Boisd) in the summer of 1978, it was noticed that shrubs of Physalis peruviana L. (cape gooseberry) were not attacked, whereas other Physalis and Nicandra spp. suffered heavy damage. Asher and co-workers demonstrated that withanolide E (118) and 4(3-hydroxywithanolide E (119), isolated from P. peruviana, as well as several related steroids, had insect antifeedant properties. Further studies on other withanolides showed antifeedant effects and species-specific activity on three insects, S. littoralis (Boisd.) (Lepidoptera), the Mexican bean beetle, Epilachna varivestis Muls. (Coleoptera) and the red flour beetle, Tribolium castaneum (Herbst) [62]. 

Nicandra steroids are closely related to withanolides (Chart I). 

The withanolide having unique structural feature, aromatic ring D, example is nicandrenone (8), only reported from Nicandra physalodes [19, 20]. 

Co-occurrence of lactol-type withasteroids and steroidal alkaloids/glycoalkaloids has been demonstrated in two Solamm spp. S. ciliatum, S. sisymbrifolium). However, there is no report on co-occurrence of these alkaloids and withanolides. In a few taxa even withanolides co-occur surprisingly with different types of tropane alkaloids, i.e., hyoscyamine-type tropanes fowDatura spp., Hyoscyamus niger) or non-hyoscyamine-type tropanes and related alkaloids Nicandra physalodes, Physalis alkekengi, P. peruviana, Withania somnifera) for details see Tables 3.1 and 3.8. 

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