An anthraquinone with diverse biological activities; active against Gram-positive bacteria, including MRSA, M. tuberculosis, and C. botulinum; inhibits proliferation of A549 lung adenocarcinoma cells at 10-30 μM; a phytotoxin that induces necrosis of water hyacinth leaves at ~7 μg/ml; has been used as a cross-linking agent for protein immobilization that retains bacteriostatic activity when immobilized on nonwoven polypropylene fabric