Bioassay guided purification of cytotoxic natural products from a red alga Dichotomaria obtusata

ABSTRACT Different solvent extracts of Dichotomaria obtusata (J. Ellis & Solander) Lamark, Galaxauraceae, a red algae collected from the coast of Bushehr in the Persain Gulf, was investigated for its cytotoxic properties and chemical constituents. The fresh alga, after extraction with methanol and dichloromethane were combined and partitioned between water, dichloromethane and ethyl acetate. The above fractions were then tested against MOLT-4 (human lymphoblastic leukemia) cancer cell line. The IC50 values of the dichloromethane and ethyl acetate layers of the crude extract were 29.8 ± 3.1 an...