Diterpenes

Other Names Diterpene, diterpenes, diterpenoids, diterpenos Diterpenes are not alkaloids but non-nitrogenous natural substances composed of four isoprene groups. They are related to the monoterpenes and sesquiterpenes and belong to the terpene group. Diterpenes occur in numerous plants and several essential oils. Some diterpenes regulate plant growth. Termites, sponges (Spongia spongens 1.), and coelenterates contain bioactive diterpenes that have inhibiting effects upon certain bacteria (Buchbauer et al. 1990, 28). There are even sweet-tasting diterpenes, such as the natural sweetening agents in Stevia rebaudiana (Bert.) Hemsl., the leaves of which are used to sweeten mate (cf. Ilex paraguariensis) . The first psychoactive diterpene to be discovered was salvinorin A. It is very likely that there are other psychoactive diterpenes that have not yet been isolated, pharmacologically tested, or chemically described. Some psychoactive alkaloids are diterpene derivatives. Aconitine, the primary active constituent in monkshood (cf. Aconitum ferox, Aconitum napellus), is a diterpene alkaloid. Diterpene alkaloids also occur in Delphinium and Spiraea.

Diterpenes in Psychoactive Plants (from Buchbauer et al. 1990; Rein 1979; supplemented) Stock Plant Distribution Coleus blumei bicyclic diterpenes Coleus spp. forskolin, labdanes, coleones Crocus sativus crocetine (as glycoside) Helichrysum spp. (cf. Helichrysum foetidum) various Jatropha grossidentata jatrophone Lagochilus inebrians lagochiline (diterpene alcohol) Leonotis leonurus various Leonurus sibiricus various Nicotiana sylvestris Spegazz. 2,7, Il-duvatrien-4,6-diol Nicotiana tabacum labdanes or duvanes Nicotiana tomentosiformis Goodspeed labdanes Nicotiana spp.   Petunia patagonica (Spegazz.) Millan various (cf. Petunia violacea)   Piper auritum trans-phytol Salvia divinorum salvinorin A, salvinorin B (clerodanes) Scoparia dulcis labdanediterpenes Taxus baccata 1. (cf. witches' ointments) taxines, taxol Taxus brevifolia Nutt. taxines Taxus canadensis Marsh. taxines Taxus cuspidata Sieb. et Zucco taxines Taxus wallichiana taxines Literature See also the entries for Coleus blumei, Salvia divinorum, and salvinorin A. Buchbauer, Gerhard, Helmut Spreizer, and Gabriele Kiener. 1991. Biologische Wirkungen von Diterpenen. Pharmazie in unserer Zeit 19 (1): 28-37. Reid, W. W. 1979. The diterpenes of the Nicotiana species and N. tabacum cultivars. In The biology and taxonomy of the Solanaceae, ed. J. G. Hawkes, R. N. Lester, and A. Skelding, 273-78. London: Academic Press.