Fuente: WIPO "biotechnology" The new 1,2-dithiolo AD4,3-b BDpyrrole derivatives (also designated as Xenorhabdins) of formula (I): Xenorhabdin I: R1 = H, R2 = n-pentyl; Xenorhabdin II: R" = H, R2 = 4-methylpentyl; Xenorhabdin III: R" = H, R2 = n-heptyl; Xenorhabdin IV: R" = CH3, R2 = n-pentyl; Xenorhabdin V: R1 = CH3, R2 = 4-methylpentyl are antibiotics and pesticides. Their bio-syntheses from Xenorhabdus nemtophilus or X. luminescens, and the pharmaceutical and pesticidal formulations containing them have been disclosed. Several xanthydrol and acetate derivates of Xenorhabdins have been prepared.