Microwave-assisted rapid extraction of red dye from Caesalpinia sappan heartwood

Since ancient times Caesalpinia sappan heartwood dye has been well-known for its medicinal and dyeing properties. Isolation of the red dye using both conventional and newly developed microwave method was carried out. The conventional heating of 2 h provided 0.656 +/- 0.049 g of the dye and by microwave heating at 540 W for 20 min, the yield obtained was 0.747 +/- 0.047 g. Both the dyes were found to be the same as evidenced by UV, TLC and HPTLC studies. Antioxidant activity of the dyes was also carried out using DPPH and nitric oxide methods to confirm the similarity in their biological activity. The procedure developed can be used for the fast extraction of the red dye of C. sappan without affecting the nature of the product.