Exploring Variability in the Methylxanthine Content within <i>Ilex guayusa</i> Loes: Impact of Soil Conditions, Age, and Sunlight Exposure

The Amazon rainforest is a highly biodiverse region, offering valuable plants for the pharmaceutical, cosmetic, and food industries. Ilex guayusa, from the Ecuadorian Amazon, is rich in methylxanthines, compounds with stimulant effects and health benefits. This study evaluates the variability in the methylxanthine content within I. guayusa under different soil, light, and plant age conditions, aiming to understand how these cultivation variables affect the production of these compounds and how they can be optimized through sustainable agricultural practices. A mixed-level factorial design analyzed leaf samples, considering plant age, soil quality, and light conditions. Using HPLC-UV and LC-MS/MS techniques, the results show that shaded conditions increase methylxanthine accumulation, with caffeine and theobromine concentrations rising with leaf age, while theophylline decreases under light. Soil with high organic matter and nutrients enhanced methylxanthine levels. These findings suggest shade management and optimal harvest timing are key to maximizing methylxanthine production for future industrial applications.