|CHIANG, CHENG CHING|
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/25/2008
Publication Date: 10/14/2008
Citation: Puskas, J.E., Chiang, C.K., Heidenreich, A., Xie, W., Mcmahan, C.M. 2008. Identification of the composition and growth of in vitro natural rubber using high resolution size exclusion chromatography. American Chemical Society Rubber Division Meeting, Louisville, KY, October 14-16, 2008.
Interpretive Summary: The USDA’s Domestic Natural Rubber project, aimed at developing natural rubber-producing crops in the USA, is collaborating with The University of Akron (Ohio) in an NSF funded project on rubber biosynthesis. National Science Foundation funding (NSF-CHE-0616834) was secured (Puskas, PI, McMahan, co-PI) for “Novel Processes for the Synthesis of Polyisoprene and Polyisoprene-Polyisobutylene Block and Graft Copolymers based on Natural Rubber Biosynthesis”. The CRC (Collaborative Research in Chemistry) GOALIE program includes international (Prof. Alain Deffieux, France, Prof. Herbert Mayr, Germany) and industrial (The Goodyear Tire & Rubber Company) participation. Natural rubber has outstanding properties which have never been duplicated by synthetics. One reason may be the almost-perfect stereochemistry of rubber produced by the rubber transferase enzyme. The research collaborators recently proposed that NR biosynthesis proceeds via a carbocationic polymerization mechanism. Based on this theory, a general mechanism termed “Natural Living Carbocationic Polymerization” (NCLP) was developed. In this paper, precise gel permeation chromatographic analyses were employed to measure in vitro rubber produced by enzymatically-active washed rubber particles.
Technical Abstract: Recently, Puskas et al. have proposed that the molecular mechanism of natural rubber (NR) biosynthesis is through carbocationic polymerization. To acquire further insight into the mechanism, in vitro NR biosynthesis experiments are performed at the United States Department of Agriculture (USDA) with combinations of enzymatically active rubber particles from H. brasiliensis,(RRIM600), isopentenyl diphosphate (IPP), farnesyl diphosphate (FPP), isoprene (IP), Mg2+, and ethylene diamine tetraacetic acid (EDTA).1 In this study, high resolution size exclusion chromatography (SEC) is used to decipher the distribution of polyisoprenoids and oligoisoprenoids of rubber particles to monitor the growth of in vitro natural rubber.