Carbon terpene biosynthesis

Carbon-Carbon Bond Formation in Terpene Biosynthesis... 

CARBON-CARBON BOND FORMATION IN TERPENE BIOSYNTHESIS... 

Other enzymes involved in terpene biosynthesis have also been harnessed for biocatalytic reactions of arenes. Prenyltransferase enzymes that can affect the addition of Cj isoprenyl units both at carbon and at heteroatoms have been used for biocatalytic arene alkylations. For example, L-tryptophan 49 undergoes prenylation at various positions on the indole core in a wholly regiose-lective fashion, depending on the enzyme used [28] (Scheme 32.6). 

Acetyl Coenzyme A 993 Fats, Oils, and Fatty Acids 994 Fatty Acid Biosynthesis 997 Phospholipids 999 Waxes 1001 Prostaglandins 1002 Nonsteroidal Antiinflammatory Drugs (NSAIDs) and COX-2 Inhibitors 1004 Terpenes The Isoprene Rule 1005 Isopentenyl Diphosphate The Biological Isoprene Unit 1008 Carbon-Carbon Bond Formation in Terpene Biosynthesis 1008 24.10 The Pathway from Acetate to Isopentenyl Diphosphate 1011 Steroids Cholesterol 1013 Vitamin D 1016... 

Figure 3.2 Schematic representation of terpene biosynthesis in higher plant cells. Blocks represent 5-carbon isoprenyl units (IPP or DMAPP).

In addition to the classical structures, certain genera of dictyoceratid sponges produce atypical terpenes, most often sesterterpenes, the carbon skeletons of which do not conform to the usual schemes of terpene biosynthesis. This is the case for the next to last carbon skeleton shown in Figure 19.118, which occurs in only a few molecules. These include the wistarins, the first known examples of natural enantiomers whose antipodes were isolated from two different species of the genus Ircinia, and ircinianin, whose sulfated derivative was not discovered until 20 years... 

Strategy Problem 6 A labelled compound for biosynthetic studies. Mevaloitic acid (TM 418) is an intermediate in the biosynthesis of terpenes and steroids (Tedder, volume 4, p.217 ff). To study exactly what happens to each carbon atom during its transformation into, say, hmonene (418A), we need separate samples of mevalonic acid labelled with in each carbon atom in the molecule. This turns our normal strategy on its head since we must now look for one carbon discoimections. You can use reagents like Na CN, and... 

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