ACETOGENINS FROM ANNONACEAE .18. RIOCLARIN AND MEMBRANACIN, 2 NEW BIS-TETRAHYDROFURAN ACETOGENINS FROM THE SEEDS OF ROLLINIA-MEMBRANACEA

The fractionation of the cytotoxic MeOH extract of the seeds of Rollinia membranacea (Annonaceae) led to the isolation of two new adjacent bis-tetrahydrofuran acetogenins, rioclarin [1] and membranacin [2], and two other known acetogenins, squamocin [3] and rolliniastatin 1 [4]. In addition to these bioactive acetogenins, a new furofuranic lignan (membrin [5]) and a known one (magnolin [6]), have been obtained. Rioclarin [1] is an original tetrahydroxylated bis-tetrahydrofuran acetogenin. Its structure was established on the basis of ms and 1D and 2D nmr experiments.