Theobroma mariae: Bioactive Compound-Rich Flowers

Abstract

Edible flowers have gained attention as unconventional food sources due to their nutritional and functional properties. This study provides novel information on the chemical composition, cytotoxicity and antiproliferative effects of Theobroma mariae flowers. The objective of this paper was to identify bioactive compounds in its flowers using one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS). The phenolic fraction of the flowers revealed bioactive compounds such as hyperoside, guaijaverin, astragalin, juglalin, and kaempferol. The results confirmed the potential of T. mariae flowers as a source of phenolic compounds, emphasizing their feasibility for possible applications in the development of functional foods. Moreover, the antiproliferative assay demonstrated that the phenolic fraction inhibits cell proliferation (GI₅₀) while presenting low cytotoxicity in both cancer and normal cells.

Keywords: LC-HRMS; Malvaceae; NMR; antiproliferative; citotoxicity; food plant; phenolics compounds.

Figure 1

T. mariae flowers.

Figure 2

(A) Chromatogram of phenolic fraction of T. mariae flowers (190–400 nm). (B) Amplification of the ¹H NMR spectra (5.0–8.6 ppm) for the signals of the compounds identified in the phenolic fraction of T. mariae flowers (500.13 MHz, CD₃OD). Peak numbers correspond to those of Table 1. (2): malic acid e (3) Unknown.

Figure 3

Cytotoxic activity of the phenolic fraction of T. mariae flower on Hep G2 and HUVEC cell lines. (A) IC₅₀ is the concentration at which cell growth is inhibited by 50%. (B) GI₅₀ represents the concentration that reduces cell proliferation by 50% when compared to control cells. (C) LC₅₀ is the concentration at which there is a 50% reduction in the cell population compared to the initial cell count at the start of the treatment.