Semisynthetic studies on the manzamine alkaloids.
Sayed KA, Khalil AA, Yousaf M, Labadie G, Kumar GM, Franzblau SG, Mayer AM, Avery MA, Hamann MT.
Chemical transformation studies were conducted on (-)-8-hydroxymanzamine A ( 1), (-)-manzamine F ( 2), manzamine A ( 3), and (+)-8-hydroxymanzamine A ( 4), isolated from Indo-Pacific Acanthostrongylophora sponges. Thirteen new semisynthetic manzamine derivatives, including four Delta (34,35) manzamines ( 5, 6, 8, and 9) and the unprecedented manzamine derivative 17, are reported. The potent in vitro activities of the obtained semisynthetic manzamines against activated brain microglia and the AIDS opportunistic infection pathogen Mycobacterium tuberculosis are presented.