Search for Camptothecin-yielding Ophiorrhiza species from southern Western Ghats in India: A HPTLC-densitometry study

[Display omitted] ► Forty-four Ophiorrhiza accessions belonging nine species and three varieties. ► Camptothecin (CPT) estimation by HPTLC-densitometry. ► CPT content: O. mungos 0.017–0.050%, O. mungos var. angustifolia 0.013–0.048%. ► CPT contents varied between ecotypes/genotypes of same Ophiorrhiza species/variety. ► Six Ophiorrhiza species and two varieties showed low or non-detectable levels of CPT. Camptothecin (CPT) content in 44 accessions belonging to nine Ophiorrhiza species and three varieties collected from their natural habitats in the Kerala region of Western Ghats were estimated by HPTLC-densitometry. Ophiorrhiza mungos 170.11–503.15 (μg/g, dr. wt.) and O. mungos var. angustifolia 127.86–476.89 (μg/g, dr. wt.) accessions showed the highest CPT contents. O. trichocarpon (19.50–28.31μg/g) and O. pectinata (0.28–38.65μg/g) showed moderate contents of CPT. Among the nine Ophiorrhiza species and three varieties screened O. barberi, O. caudata, O. nairii and O. rugosa var. decumbens showed zero or non-detectable levels of CPT. O. grandiflora (1.07–1.34μg/g), O. eriantha (0.00–0.30μg/g), O. rugosa var. prostrata (0.16μg/g) and O. shendurunii (0.05μg/g) showed only very low contents of CPT. O. mungos var. angustifolia is an established variant and is a small herb which could be relatively easily cultivated or multiplied by tissue culture compared to O. mungos. Significant variations in CPT contents were found between the ecotypes/genotypes of the same Ophiorrhiza species or variety collected from different geographic locations. This revealed the importance of choosing high CPT yielding Ophiorrhiza genotypes or ecotypes for commercial purposes.