Total Phenolic and Flavonoid Contents and Flavonoid Composition of Flowers and Leaves from the Mexican Medicinal Plant Gymnosperma glutinosum (Spreng.) Less

Objectives: The aim of the present study was to evaluate the total phenolics and flavonoids content of leaves and flowers of Gymnosperma glutinosum (Spreng.) Less., and identify their main chemical constituents.

Materials and Methods: G. glutinosum leaves and flowers were separately extracted with sequential 85, 80, 75, and 70% Methanol. Total phenolic content was determined using the Folin-Ciocalteu assay with gallic acid as standard. Total flavonoid content was evaluated using the aluminum chloride colorimetric method with quercetin as a standard. TLC and HPLC analysis of theextracts were performed, and compounds were identified by retention time and UV spectra in comparison with polyphenolic standards.

Results: Total phenolic content of leaf extracts was 116.7 mg/g GAE (Gallic Acid Equivalents) whereas that of flower extracts was 159.8 mg/g GAE. Total flavonoid content of leaf extracts was 6.7 mg/g QE (Quercetin Equivalents) and that of flower extracts 15.9 mg/g QE. According to TLC and HPLC analysis, chlorogenic acid, astragalin, quercitrin, quercetin, rutin, kaempferol, and vitexin were the main components.

Conclusions: The identified polyphenols, except vitexin, have not yet been reported for G. glutinosum. These compounds might be involved in health benefits attributed to G. glutinosum. The higher content of flavonoids and other polyphenols in the flower extract suggest that G. glutinosum could be more efficient as an herbal remedy when the specimens are flowering, a feature not yet indicated in the Mexican traditional medicine.