ACETOGENINS OF ANNONACEAE .37. RETICULATAIN-1 AND RETICULATAIN-2 WITHRETICULATAMONE - 3 NEW POLYKETIDES FROM THE SEEDS OF ANNONA-RETICULATA

We have isolated four annonaceous acetogenins of identical molecular f ormula C37H68O5 from Annona reticulata seeds. They all belong to the A l type (one tetrahydrofuran ring). Two of them, reticulatain-1 and ret iculatain-2, are new and possess the very rare threo-trans-erythro ste reochemical relationship across the THF ring. The other two, reticulat acin and uvariamicin III, were also isolated and fully characterized s ince uvariamicin III was only reported as a component of a mixture. Fu rthermore, a new acetogenin precursor was extracted and characterized, possessing a single asymmetric center of (S) absolute configuration, as proved by its total synthesis.