Pharmacognostic Specifications, RP-HPLC Analysis of Chlorogenic Acid Content and Antioxidant Activity of Morus alba Linn. Leaves in Thailand

Background: Morus alba Linn. leaves have been widely used as herbal medicine with therapeutics and contain chlorogenic acid as a bioactive phenolic compound. Objective: The present study aimed to conduct the pharmacognostic specifications of M. alba leaves and the method validation for quantification of chlorogenic acid content. Materials and Methods: Macroscopic- and microscopic characteristics, physicochemical parameters combined with quantification of chlorogenic acid in M. alba leaves collected from 15 sources throughout Thailand and their antioxidant activity were reported in this study. Results: The physicochemical parameters of M. alba leaves were determined by indicating water content (7.97 ± 0.35%), loss on drying (4.55 ± 0.21%), total ash (14.38 ± 0.25%), acid-insoluble ash (6.21 ± 0.37%), water-extractive value (16.14 ± 0.50%) and ethanol-extractive value (8.61 ± 0.39%). In addition, the chlorogenic acid contents in M. alba leaves were found to be 0.4159 ± 0.1958 g/100g dry weight. The ethanolic leaf extracts exhibited their antioxidant activity with half-maximal inhibitory concentration (IC₅₀) values (326.09–467.55 μg/mL). Conclusion: This study showed the establishment of pharmacognostic study of M. alba leaves and validation of the reversed-phase high-performance liquid chromatography (RPHPLC) quantitative analysis of their chlorogenic acid contents, which are applicable to be a reference for quality control and standardization of M. alba leaves.