Practice Natural Rubber Biosynthesis

We will now apply to natural rubber, i.e., NR, biosynthesis what we have learned so far. As mentioned before, in 2005 approximately 10 million tons of NR was produced worldwide for commercial use, from which about 15% was consumed in the United States. While the United States is self-sufficient in S5mthetic mbber production, with substantial export activities, no NR is produced domestically. The development of a U.S.-based supply of NR is recognized in the Critical Agricultural Materials Act of 1984 (Laws 95-592 and 98-284). The Act recognizes that NR latex is a commodity of vital importance to the economy and the defense of the nation. It is important to emphasize that synthetic polyisoprene does not match the performance of imported Hevea NR in several applications, so NR remains irreplaceable. 

FIGURE 4.17. Proposed chemical structure of NR from Hevea. 

FIGURE 4.18. Structure of the allylic oligoisoprene pyrophosphates. DMAPP dimethyl allyl pyrophosphate, GPP geranyl pyrophosphate, FPP famesyl pyrophosphate, GGPP geranylgeranyl pyrophosphate. 

We have no information on this elementary step in rubber biosynthesis. 

FIGURE 4.21. Biochemical representation of rubber biosynthesis (K. Cornish and K. Chi-ang). 

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