Dracorhodin Content and Selected Bioactivities of Calamus ruber’ Dragon Blood Resin from Different Drying Conditions

Dragon blood resin from the fruit barks of Calamus ruber contains a bioactive compound, dracorhodin, that has many medicinal benefits. The study aimed to investigate the effects of different drying methods on dracorhodin content, cytotoxicity and antioxidant activities of the resin. Hot-air and hot-steam-air drying at 55°C and 60°C were employed in this study. Resin dried with the hot-steam-air drying at 55° was most toxic to Artemia salina (LC50 of 430.61 ppm). Resin dried with hot-steam-air drying at 60°C contained the highest dracorhodin content (4.34%) and was the best at scavenging DPPH• (1,1-diphenyl-2-picrylhydrazyl) (IC50 of 32.73 ppm), cupric ion (TEAC of 63.15 ppm) and ferric ion (TEAC of 8.73 ppm). Resin from the hot-air-drying at 55°C was the best at scavenging ABTS•+ (2,2’-azino-bis (3- ethylbenzothiazoline-6-sulfonic acid)) (TEAC of 469.72 ppm). Drying method and temperature affected the dracorhodin content and IC50 of the resin, respectively.