Phospholipids associated with natural rubber molecules inducing long-chain branching part i: Nmr analysis of phospholipids as a model for structural characterization

Abstract

Phospholipid - Phosphatidylcholine - Model compound - Natural rubber - High-resolution NMR High-resolution 1H, 13C and 31P NMR spectra of L-α-phosphatidylcholine and L-α-phosphatidic acid sodium salt from egg yolk were measured at 750 MHz. In C6D6 the phospholipids were expected to form micelle structure. The NMR signals were assigned by using 1H-1H COSY and 1H-13C HMQC experiments. The three-bond scalar coupling constant (3JPH) between the phosphorus nucleus and the CH2OP protons was determined by one-dimensional 1H{31P} HMBC experiment. 3JPH of CH 2OP linkage of glyceride backbone was about 6.5 Hz, while that of CH2OP linkage of choline group was 9.0 Hz. These assignments were used as models of the terminal group of natural rubber, which is presumed to contain phosphate group at the chain-end.