Carbamidocyclophanes A-E, chlorinated paracyclophanes with cytotoxic and antibiotic activity from the Vietnamese cyanobacterium Nostoc sp.

Five new paracyclophanes, carbamidocyclophanes A-E (1-5), characterized by carbamido side chains at a symmetric [7.7]paracyclophane ring, have been isolated from the biomass of the Vietnamese Nostoc sp. CAVN 10. Structure elucidation by spectroscopic methods showed that 1-5 vary in the substitution pattern of the chlorinated butyl side chains. The compounds exhibited cytotoxic activity against MCF-7 (breast cancer cell line) and Fl cells (human amniotic epithelial cell line) and moderate antibacterial activity against the Gram-positive bacterium Staphylococcus aureus.