Abstract - Structural Characterisation of the Terminating Groups of some Polyprenyl Phosphates and of Rubber from the Lactarius Mushroom


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	Publications of MRB Latest Publications MRB Digest Journal of Rubber Research 3^rd Qtr 2008 Vol 11(3) 2^nd Qtr 2008 Vol 11(2) 1^st Qtr 2008 Vol 11(1) 4^th Qtr 2007 Vol 10(4) 3^rd Qtr 2007 Vol 10(3) 2^nd Qtr 2007 Vol 10(2) 1^st Qtr 2007 Vol 10(1) 1^st Qtr 2006 Vol 9(1) 2^nd Qtr 2006 Vol 9(2) 3^rd Qtr 2006 Vol 9(3) 4^th Qtr 2006 Vol 9(4) Submit paper/article Order Form	Abstract Structural Characterisation of the Terminating Groups of some Polyprenyl Phosphates and of Rubber from the Lactarius Mushroom A series of trans- and cis-allylic diphosphates were synthesized as model compounds of natural rubber and were analysed by NMR techniques. The ¹H-NMR spectra of terminal methylene protons of polyprenols linked to mono- and di-phosphates showed a triplet signal, centering around d 4.41-4.44 and d 4.46-4.49, respectively. The coupling constants of 5.0 Hz – 6.0 Hz and 6.0 Jz – 7.0 Hz were observed for trans- and cis-allylic diphosphate groups, respectively. In the a-terminal isoprene unit of polyprenols, the cis- and trans-allylic C-4 methylene protons resonate at d 4.081 and d 4.150, respectively. The a C-4 methylene carbon of mono- and di-phosphate groups showed a doublet signal around d 61-63 in the ¹³C-NMR spectrum, the chemical shift value of which decreased with increase the chain-length of polyprenols. The ³¹P-NMR spectra of mono- and di-phosphate groups showed a signal around d 1.5 and d -7 to d -8, respectively, independent of chain-length and configuration of the allylic compounds. A long-chain polyprenol from Lactarius volemus, composed of about 300 isoprene units, was phosphorylated to analyse the effect of chain length.
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