Anti-Propionibacterium acnes assay-guided purification of brazilin and preparation of brazilin rich extract from Caesalpinia sappan heartwood

Context: Caesalpinia sappan L. (Leguminosae or Fabaceae) heartwood has been used as a coloring agent, with antibacterial activity in food, beverages, cosmetics, and garments. Objectives: To purify brazilin from C. sappan heartwood and use it as a standard marker for the preparation and standardization of an active constituent-rich extract. Material and methods: Crude ethanol extracts of C. sappan heartwood (CSE) were fractionated to isolate brazilin by an anti-P. acnes assay-guided isolation. Quantitative analysis was performed by HPLC. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined by the broth microdilution method. Results and discussion: Brazilin isolated from CSE possessed antibacterial activity against P. acnes with MIC and MBC values of 15.6 and 31.2 μg/mL, respectively. Brazilin was, therefore, used as a standard marker for standardization and preparation of a brazilin rich extract (BRE). BRE was prepared from CSE using a simple one-step purification using a macroporous resin column eluted with 35% v/v ethanol. This method increased the brazilin content in the BRE up to 39.9% w/w. The antibacterial activity of the standardized BRE against acne involved bacteria was higher than for the CSE but lower than brazilin. However, for industrial applications, a large-scale one-step preparation of BRE has more advantages than the use of pure brazilin in terms of convenience and a low-cost production process. Therefore, BRE is considered as a potential coloring agent with antibacterial activity which is used for pharmaceutical, cosmetic, and nutraceutical applications