Patterns of accumulation of camptothecin, an anti-cancer alkaloid in Nothapodytes nimmoniana Graham., in the Western Ghats, India: implications for identifying high-yielding sources of the alkaloid

Abstract

Camptothecin, a monoterpene indole alkaloid, is regarded as one of the most promising anticancer drugs of the twenty-first century. Among the various plant sources, the highest yields of the alkaloid are reported from Nothapodytes nimmoniana (Icacinaceae), a small tree distributed in the Indian subcontinent. Because of the enormous demand for the chemical worldwide, there has been an indiscriminate extraction of the trees from many parts of India, especially from the Western Ghats, a mega-diversity forest range along the western coast of India. Recently the tree has been assigned a vulnerable status. In an effort to conserve the remaining populations of the species and to identify high-yielding sources of the alkaloid, attempts are being initiated in chemically profiling the species. As a first step in this direction, we have attempted to establish the general patterns of accumulation of camptothecin in N. nimmoniana across individuals, plant parts, plant size and sex of plants, in the Western Ghats. Individual trees with as high as 100 per cent greater camptothecin content than hitherto reported have been found. The study indicates the potentiality of further screening populations of N. nimmoniana to identify high-yielding sources that can be used for developing in vitro production systems or for establishing high-yielding clonal populations.