Terpenoid metabolism

MCCASKiLL D and CROTEAU R (1998) Some caveats for bioengineering terpenoid metabolism in plants . Trends Biotechnol 16, 349-55. 

Kappers IF, Aharoni A, van Herpen TWJM, Luckerhoff LLP, Dicke M, Bouwmeester HJ (2005) Genetic engineering of terpenoid metabolism attracts bodyguards to Arabidopsis. Science 309 2070-2072... 

McCarvey DJ, Croteau R. (1995) Terpenoid metabolism. Plant Cell 7 1015-1026. 

The possibility of nucleophilic attack on different carbons in the resonance-stabilized carbocation facilitates another modification exploited by nature during terpenoid metabolism. This is a change in double-bond stereochemistry in the allylic system. The interconversions of geranyl diphosphate, linalyl diphosphate, and neryl diphosphate provide neat but satisfying examples of the chemistry of simple allylic carbocations. 

Aharoni A, Giri AP, Deuerlein S et al (2003) Terpenoid metabolism in wild-type and transgenic Arabidopsis plants. Plant Cell 15 2866-2884... 

BOHLMANN, J GERSHENZON, J., AUBOURG, S., Biochemical, molecular genetic and evolutionary aspects of defense-related terpenoid metabolism in conifers, in Evolution of Metabolic Pathways Rec. Adv. Phytochemistry Vol. 34 (J.T. Romeo, R.K. Ibrahim, L. Varin, V. De Luca, eds.), Pergamon Press, Amsterdam. 2000, pp.109-150. 

The subcellular compartmentation of terpenoid metabolism is a matter of controversy. Chloroplasts seem to contain the entire terpenoid biosynthetic pathway and appear to be autonomous in regard to terpene biosynthesis. Carotenoids and the side chains of chlorophyll are synthesized in the chloroplasts. Sterols are synthesized in the cytoplasm (Gershenzon and Croteau, 1990). 

Alkaloids are derived from many biosynthetic pathways, including those of amino acid, polyketide, shikimic acid, acetate, and terpenoid metabolism. In this book, a broad perspective is adopted simple amines, nitrogenous bases of terpenoid origin, neutral compounds such as colchicine, and purines are all considered to be alkaloids. Many alkaloids are poisonous to mammals and a large number are medicinally useful. 

According to our recent knowledge, it is obvious that the genetic determination of essential oil compounds should be complex. Besides the direct regulation of the biosynthetic processes, other types of regulation interact with the formation of volatile compounds like intra- and intercellular transportation mechanisms, primarily metabolic processes, or regulation through transcription factors, which are still less known in terpenoid metabolism. 

Dinesh, A. and D. A. Nagegowda. 2010. Plant volatile terpenoid metabolism Biosynthetic genes, transcriptional regulation and subcellular compartmentation. 584 2965-2973. 

McGarvey DJ, Croteau R (1995) Terpenoid metabolism. Plant Cell 7 1015-1026 Langenheim JH (1994) Higher plant terpenoids a phytocentric overview of their ecological roles. J Chem Ecol 20 1223-1280... 

Terpenoid metabolism includes terpenoid biosynthesis (from simpler precursor acetyl-CoA to IPP), terpenoidogenesis (the biosynthesis of terpenoids from IPP and the metabolic intercOTversion among diverse terpenoids), and terpenoid degradation (p-oxidatimi pathway). 

Hop bitter acids and hyperforin are both derived from three different building blocks a branched short-chain CoA ester derived from amino acid metabolism and three C units derived from malonyl-CoA constitute the acyl phloroglucinol core, which carries two to several isopentenyl side chains that originate from terpenoid metabolism (Adam et al., 2002 Drawer and Beier, 1976 Goese et al., 1999 Karppinen et al., 2007). 

As far as the biosynthesis is concerned it was soon established that the indole nucleus is derived from the amino acid tryptophan. It was much more difficult to determine the origin of the residual C skeleton but it has been found in recent years that it is furnished by mevalonate or iso-pentenyl pyrophosphate. Thus, in the ergoline alkaloids the indole nucleus is linked with a 5 C unit derived from terpenoid metabolism. 

Triterpenes and Steroids in Invertebrates Insects.—Terpenoid metabolism in insects will be considered separately from other invertebrates. Although insects do not possess the complete machinery required for biosynthesis of sterols from small molecules, it has been reported that a Sarcophaga bullata homogenate converts squalene into a compound with the chromatographic properties of squalene 2,3-oxide. However, this report warrants substantiation. The major insect juvenile hormone (133 R = Me) becomes labelled from [ C]acetate and also from l-[ H or... 

Curiously, few purely radioactive tracer studies of phenols have been reported and the emphasis has been on the biosynthesis of the more commonly occurring phenolics. Compounds with exotic structures, particularly of the flavonoid class, continue to be discovered at an ever increasing pace. A whole range of isoprenoid flavones is now known, for example, and some information on (heir biosynthetic origin and their relationship to terpenoid metabolism would be welcome. 

Anastasis P, Freer I, Picken D, Overton K, Sadler I, Singh SB. The role of leucine in terpenoid metabolism. Incorporation of [2-i ]- and [3- C]-leucines into... 

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