Diterpene

About: Diterpene is a research topic. Over the lifetime, 2586 publications have been published within this topic receiving 48162 citations. The topic is also known as: C20 isoprenoids & diterpenes.

Genomic Organization of Plant Terpene Synthases and Molecular Evolutionary Implications

Abstract: Terpenoids are the largest, most diverse class of plant natural products and they play numerous functional roles in primary metabolism and in ecological interactions. The first committed step in the formation of the various terpenoid classes is the transformation of the prenyl diphosphate precursors, geranyl diphosphate, farnesyl diphosphate, and geranylgeranyl diphosphate, to the parent structures of each type catalyzed by the respective monoterpene (C(10)), sesquiterpene (C(15)), and diterpene synthases (C(20)). Over 30 cDNAs encoding plant terpenoid synthases involved in primary and secondary metabolism have been cloned and characterized. Here we describe the isolation and analysis of six genomic clones encoding terpene synthases of conifers, [(-)-pinene (C(10)), (-)-limonene (C(10)), (E)-alpha-bisabolene (C(15)), delta-selinene (C(15)), and abietadiene synthase (C(20)) from Abies grandis and taxadiene synthase (C(20)) from Taxus brevifolia], all of which are involved in natural products biosynthesis. Genome organization (intron number, size, placement and phase, and exon size) of these gymnosperm terpene synthases was compared to eight previously characterized angiosperm terpene synthase genes and to six putative terpene synthase genomic sequences from Arabidopsis thaliana. Three distinct classes of terpene synthase genes were discerned, from which assumed patterns of sequential intron loss and the loss of an unusual internal sequence element suggest that the ancestral terpenoid synthase gene resembled a contemporary conifer diterpene synthase gene in containing at least 12 introns and 13 exons of conserved size. A model presented for the evolutionary history of plant terpene synthases suggests that this superfamily of genes responsible for natural products biosynthesis derived from terpene synthase genes involved in primary metabolism by duplication and divergence in structural and functional specialization. This novel molecular evolutionary approach focused on genes of secondary metabolism may have broad implications for the origins of natural products and for plant phylogenetics in general.

Cyclization Enzymes in the Biosynthesis of Monoterpenes, Sesquiterpenes, and Diterpenes

Abstract: Terpene synthases catalyze the first committed steps in the biosynthesis of monoterpenes, sesquiterpenes, and diterpenes. An overview is presented of the enzymology and mechanism of these terpene synthases, and their molecular cloning, expression, and sequence analysis. Detailed structural and functional evaluation of four representative monoterpene, sesquiterpene, and diterpene synthases is also presented.

Cell Differentiation-Inducing Diterpenes from Andrographis paniculata NEES

Abstract: The methanol extract of the aerial part of Andrographis paniculata Nees showed potent cell differentiation-inducing activity on mouse myeloid leukemia (M1) cells. From the ethyl acetate-soluble fraction of the methanol extract, six new diterpenoids of ent-labdane type, 14-epi-andrographolide (3), isoandrographolide (4), 14-deoxy-12-methoxyandrographolide (7), 12-epi-14-deoxy-12-methoxyandrographolide (8), 14-deoxy-12-hydroxyandrographolide (9) and 14-deoxy-11-hydroxyandrographolide (10) as well as two new diterpene glucosides, 14-deoxy-11,12-didehydroandrographi-side (12) and 6'-acetylneoandrographolide (14), and four new diterpene dimers, bis-andrograpolides A (15), B (16), C (17) and D (18), were isolated along with six known compounds. The structures of the diterpenoids were determined by means of spectral methods. Some of these compounds showed potent cell differentiation-inducing activity towards M1 cells.

Rapid HPLC screening of jasmonate-induced increases in tobacco alkaloids, phenolics, and diterpene glycosides in Nicotiana attenuata

Abstract: A rapid, HPLC-based screening procedure for the main classes of secondary metabolites in Nicotiana attenuata leaves (alkaloids, phenolics, and diterpene glycosides) is reported. In a single step, leaves are extracted in aqueous acidified (0.5% acetic acid) methanol, and the extracted compounds are separated by reversed-phase HPLC with an acidic water/acetonitrile gradient in <30 min. The utility of the method in quantifying changes in the secondary metabolites after methyl jasmonate treatment of the plants, a treatment known to elicit resistance to herbivores in nature, is illustrated. Methyl jasmonate treatment elicited dramatic increases in some secondary metabolites (caffeoylputrescine, nicotine, and diterpene glycosides increased 12.5-, 1.4-, and 1.9-fold, respectively) but left others, such as rutin, unchanged. Such broad-based analytical screens will help characterize environmental and genetic changes in secondary metabolite profiles.