Arginine and Folic Acid Improve Metabolites Content of Tomatillo (Physalis philadelphica) Fruit.

Tomatillo (Physalis philadelphica Lam.) has been interested for its medicinal bioactive compounds, which can be promoted using biostimulants. This study was conducted to evaluate the foliar application of arginine (0, 300, 600, and 900 μM) and folic acid (0, 100, and 200 μM) on the metabolites content and antioxidant activity of tomatillo fruits. Results showed that the combined application of higher concentrations of arginine and folic acid significantly improved the content of acid ascorbic, phenolic compounds, flavonoids, tropane alkaloids (scopolamine and atropine), total alkaloid, physalins, and antioxidant activity of tomatillo fruits. The ascorbic acid content increased by 49.0 and 54.7% under Arg (900 μM) + FA (100 or 200 μM) treatments, respectively, compared to untreated plants. The highest total phenolic and flavonoid contents as well as tropane and total alkaloids were recorded in plants treated with 900 μM Arg + 200 μM FA. The atropine content was higher than the scopolamine content. The physalins content and DPPH radical scavenging capacity of fruits under Arg (900 μM) + FA (100 or 200 μM) treatments increased by 2.1 and 1.7 times, respectively, in comparison to the control. Significant positive correlation coefficients (r = 0.92–0.99) were found between all phytochemical parameters, which indicates that acid ascorbic, phenolic compounds, flavonoids, physalins, and alkaloids are related to the antioxidant activity of tomatillo fruits. Therefore, exogenous application of arginine and folic acid could be considered as a valuable and safe tool to improve the pharmaceutical potential of tomatillo fruits. [ABSTRACT FROM AUTHOR]