Merocyclophanes A and B, antiproliferative cyclophanes from the cultured terrestrial Cyanobacterium Nostoc sp.

► Two [7.7]paracyclophanes named merocyclophanes A and B were obtained. ► Both displayed antiproliferative activity against the HT-29 cancer cell line. ► Nostoc sp. (UIC 10062) was obtained from Grand Mere State Park in Michigan. ► Nostoc sp. was classified based on microscopic and 16S rRNA gene sequence analysis.