Schimp., spreading earthmoss; Picea abies (L.) H. Karst; Norway spruce; Picea
Schimp., spreading earthmoss; Picea abies (L.) H. Karst; Norway spruce; Picea glauca (Moench) Voss; white spruce; Picea sitchensis (Bongard) Carri e; 1855; Sitka spruce; Pinus banksiana Lamb., jack pine; Pinus contorta Douglas; lodgepole pine; Pinus nigra J.F. Arnold; Austrian pine or black pine; Pinus nigra subsp. laricio (Poiret) Maire; Calabrian pine; Pinus pinaster Aiton; maritime pine; Pinus radiata D. Don; Monterey pine; Pinus taeda L., loblolly pine; Pseudolarix amabilis (N. Nelson) Rehder; golden larch.Plants 2021, 10, 2391. doi/10.3390/plantsmdpi.com/journal/plantsPlants 2021, 10,two of1. Introduction Gymnosperms created a range of physical and HDAC11 review chemical defences against pathogens and herbivores, among which one in the most substantial is definitely the production of terpenoid metabolites [1]. The complicated terpenoid defence mechanisms have persisted all through the lengthy evolutionary history of gymnosperms and their decreasing geographical distribution through the Cenozoic era [5,6], but diversified into frequently species-specific metabolite blends. As an example, structurally connected labdane-type diterpenoids, which include ferruginol and derivative compounds, act as defence metabolites in numerous Cupressaceae species [3,7,8]. On the other hand, diterpene resin acids (DRAs), with each other with mono- and sesqui-terpenes, will be the principal components from the oleoresin defence method inside the Pinaceae species (e.g., conifers), and have been shown to provide an effective barrier against stem-boring weevils and COX-3 list related pathogenic fungi [92]. Diterpenoids from gymnosperms are also vital for their technological makes use of, becoming employed within the production of solvents, flavours, fragrances, pharmaceuticals and a huge choice of bioproducts [1,13], for example, among the many other examples, the anticancer drugs pseudolaric acid B, obtained from the roots from the golden larch (Pseudolarix amabilis) [14], and taxol, extracted from yew (Taxus spp.) [15], as well as cis-abienol, created by balsam fir (Abies balsamea), which can be a molecule of interest for the fragrance sector [16]. The diterpenoids of conifer oleoresin are largely members of three structural groups: the abietanes, the pimaranes, along with the dehydroabietanes, all of that are characterized by tricyclic parent skeletons [2,17]. These diterpenoids are structurally related to the tetracyclic ent-kaurane diterpenes, which consist of the ubiquitous gibberellin (GA) phytohormones. Both the oleoresin diterpenoids of specialized metabolism and the GAs of common metabolism derive in the prevalent non-cyclic diterpenoid precursor geranylgeranyl diphosphate (GGPP). In conifers, among the other gymnosperms, the structural diversity of diterpenoids results from the combined actions of diterpene synthases (DTPSs) and cytochrome P450 monooxygenases (CP450s) [2]. The former enzymes catalyse the cyclization and rearrangement on the precursor molecule GGPP into a range of diterpene olefins, frequently referred to as the neutral components of the oleoresins. Olefins are then functionalized at particular positions by the action of CP450s, by way of a sequential three-step oxidation 1st to the corresponding alcohols, then to aldehydes, and lastly to DRAs [2], for instance abietic, dehydroabietic, isopimaric, levopimaric, neoabietic, palustric, pimaric, and sandaracopimaric acids, which are the key constituents of conifer oleoresins [2,17,18]. The chemical structures from the most-represented diterpenoids in Pinus spp. are reported in Figure S1. Dite.
