The biosynthesis of pharmacologically active compounds in Calophyllum brasiliense seedlings is influenced by calcium and potassium under hydroponic conditions

Background: The influence of soil nutrients on biosynthesis of secondary metabolites from tropical trees has been poorly investigated. Questions: Does the deprival of Ca2+ and K+ influence the production of pharmacologically active compounds in the seedling of Calophyllum brasiliense? Species study: Calophyllum brasiliense Cambess. Study site: Los Tuxtlas, Veracruz, Mexico; November 2005 to November 2009. Methods: The seedlings were obtained from seeds and subjected to different hydroponic treatments: 1) modified Hoagland solution (MHS), 2) MHS-Ca2+, and 3) MHS-K+. Growth, height, foliar biomass, and HPLC analysis were performed after 7 months. Results: Under hydroponic conditions Ca2+ and K+ deficiency induced the mortality of 53 % and 28 % of the seedlings, respectively. The foliar biomass, and plant height of the survivors were also drastically reduced. MHS-K+ treatment induced a 15, 4.2 and 4.3-fold decrease for calanolides B, C, and apetalic acid in the leaves, respectively. MHS-Ca2+ treatment induced a decrease of 4.3, and 2.4-fold for calanolide B, and C, respectively. Conclusion: Ca2+ is essential for survival of C. brasiliense seedlings under hydroponic conditions, Ca2+ and K+ are critical for growth, foliar production, and biosynthesis of apetalic acid, and calanolide B.