Jena. A research team at the Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI) in Jena, Germany has developed a new method to produce complex natural products in amoebae. These polyketides include various antibiotics but also olivetolic acid, a precursor of the herbal active ingredient tetrahydrocannabinol (THC). The results were published in Nature Biotechnology.