Phytochemical Analysis and Specific Activities of Bark and Flower Extracts from Four Magnolia Plant Species

Abstract

This study rigorously investigates the bioactive properties and characteristics of extracts derived from the flowers and bark of four distinct Magnolia species: Magnolia champaca, Magnolia denudata, Magnolia grandiflora and Magnolia officinalis. The primary objective is to evaluate the potential application of these extracts in cosmetics and other relevant industries. We used ethanol to extract compounds from these plants and conducted various tests, including spectrophotometry, HPLC, GC-MS, and microbiological analyses. The extracts, particularly rich in polyphenols (55.18 mg GAE/g), displayed significant antioxidant capabilities, with IC 50 values ranging between 9.99 mg/mL and 23.23 mg/mL. We quantified different compounds: phenolic acids (6.259 to 27.883 mg/g dry weight), aglycone flavonoids (61.224 to 135.788 mg/g dw), glycosidic flavonoids (17.265 to 57.961 mg/g dw), and lignans (150.071 to 374.902 mg/g dw). We identified 76 volatile compounds, predominantly oxygenated monoterpenes and sesquiterpene hydrocarbons, which contribute to the antibacterial effectiveness of the extracts. These extracts showed greater inhibitory potential against Gram-negative bacteria than Gram-positive bacteria. The diverse chemical compounds and their demonstrated activities suggest these extracts could be valuable in the cosmetics industry, pharmaceutical industry, or other industries.

Keywords

• plant extracts
• polyphenols
• antioxidant activity
• phenolic compounds
• volatile compounds
• MIC