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.