Evaluating Nothapodytes nimmoniana population from three localities of Western Ghats using camptothecin as phytochemical marker and selection of elites using a new-content range chart method

Background: Nothapodytes nimmoniana (Grah.) Mabb. is a high valued medicinal plant endemic to Western Ghats of India, distributed in fragmented populations. The plant is valued for potent anticancer drug camptothecin (CPT). Objective: The study compares and expounds variation in CPT content from leaves and stems of N. nimmoniana obtained from three populations of Western Ghats, India. The study also describes a method for categorizing these populations using content range chart (CRC) method for percent yield of CPT. Materials and Methods: A total of 60 samples were investigated including ten each of leaves and stems from three localities. Micro-extraction method was implemented to extract CPT. reversed phase ultra-performance liquid chromatography photo diode array technique was used to quantify CPT. Results: Leaf samples of an individual collected from Joida, yielded lowest CPT content (0.002 ± 0.000 g/100 g), whereas a stem sample from Amgaon, yielded highest CPT content (0.123 ± 0.006 g/100 g). The findings suggest great variation in individuals producing and accumulating CPT. Using this data along with earlier published work, five categories of CPT yielding plants were made viz. I: Very low: <0.020, II: Low: 0.021-0.039, III: Moderate: 0.040-0.059, IV: High: 0.060-0.079 and V: Very high: >0.080. Based on CPT content in leaves, majority of individuals were under very low category (Ist) and on the other hand stem samples were in ‘II’ category. Besides, very few individuals were observed in category ‘V’. Conclusion: The study expounds use of CRC method for identifying elite population and suggests the need for its conservation.