Chemical profiling of camptothecin and methoxy camptothecin in Nothapodytes nimmoniana Grah. (Mabb.) during seed development, seed germination and their effects on seed-borne pathogens

Abstract

Camptothecin, a pyrroloquinoline alkaloid, is one of the most promising anti-cancer drugs. Although this compound has been reported to exist in several species, the highest concentration (about 0.30%) has been reported from Nothapodytes nimmoniana. In this study, we described the dynamics of camptothecin and methoxy camptothecin accumulation during fruit development, seed germination and their role on seed pathogens and seed pests. HPLC analysis revealed camptothecin and methoxy camptothecin content high (0.28%) in stage-3 and decreased in the later stages. Whereas, in the different parts of the fruit, the maximum accumulation in the endosperm (0.46%) of stage-3 followed by the embryo, seed coat, and fruit coat. The pattern of accumulation of both the metabolites were decreasing at the time of seed hydration, early seed germination (0.12%–0.08%) and thereafter it is increasing up to 8-week seedlings (0.08%–0.39%). The growth inhibition of five seed-borne fungal pathogens and fecundity of pulse beetles on chickpea seeds were tested for different concentrations of camptothecin ranging from 0.01 to 10 μg ml−1 for the sensitivity. At 10 μg ml−1 concentration the fungal isolates were severely inhibited. The lowest number of eggs (106) laid was observed on 10 μg ml−1 concentration compared to the control (169). The results showed that camptothecin is found in plants have a role in defense against insect herbivores and pathogens involved in deterrence/antifeedant activity or toxic.