Daurichromenic 1 acid (DCA) is a meroterpenoid with anti-HIV properties that is produced in young leaves of Rhododendron dauicum. In this study, Iijimi et al. identified a DCA synthase gene. Starting with their previous observations that this enzyme is a stereoselective meroterpenoid oxidocyclase, similar to cannabinoid synthases of Cannabis sativa, the authors looked in a transcriptome database from Rhododendron dauicum for cDNAs encoding cannabinoid-synthase-like proteins. When candidate cDNAs were expressed in a heterologous system (Pichia pastoris), the recombinant enzyme showed DCA synthase activity. The identification of the DCA synthase gene provides an opportunity for semi-synthetic production of this anti-HIV natural product. Plant Physiol.