Topotecan and Irinotecan are two widely used anticancer drugs that are produced by using camptothecin as the lead molecule. More than a dozen derivatives and conjugates of camptothecin are under various stages of clinical trials for anti-cancer applications. Camptothecin is the third most in-demand alkaloid that is isolated from the Chinese tree Camptotheca acuminata and the Indian tree Nothapodytes nimmoniana.

Nearly 1,000 tonnes of plant material is required to extract just one tonne of camptothecin. Due to extensive overharvesting to meet the demand, both these plants are now critically endangered. The N. nimmoniana population has declined more than 20 per cent in the last decade alone.

To meet the demand and conserve natural sources, the researchers at IIT-Madras have now developed an alternative method of camptothecin production through a microbial fermentation process.

Highlighting the applications of the research, Smita Srivastava, Associate Professor, Department of Biotechnology, IIT Madras, and the principal investigator of the study, said, “The novelty of the work lies in the fact that unlike other potential microbial strains reported, this strain has been found to show sustainable production even beyond 100 generations. The plan now is to use the isolated novel strain for the development of a microbial fermentation-based sustainable bioprocess for largescale in vitro production of camptothecin, preferably in collaboration with industries.”

Apart from Dr Srivastava, the research team included Prof Suresh Kumar Rayala, Khwajah Mohinudeen, PhD research scholar and Rahul Kanumuri, SRF, Department of Biotechnology, IIT Madras; Prof R Uma Shaanker and KN Soujanya, researcher, School of Ecology and Conservation, University of Agricultural Sciences, GKVK, Bengaluru.

The work was recently published in the reputed peer-reviewed, International Journal of Scientific Reports, a Nature Research Publication.