title: Structural characterization of rubber from jackfruit and euphorbia as a model of natural rubber.
abstract: A structural study of low molecular weight rubbers from Jackfruit (Artocarpus heterophyllus) and Painted spurge (Euphorbia heterophylla) was carried out as model compounds of natural rubber from Hevea brasiliensis. The rubber content of latex from Jackfruit was 0.4-0.7%, which is very low compared with that of 30-35% in the latex from Hevea tree. The rubber from Jackfruit latex was low molecular weight with narrow unimodal molecular weight distribution (MWD), whereas that obtained from E. heterophylla showed very broad MWD. The 1H and 13C NMR analyses showed that Jackfruit rubber consists of a dimethylallyl group and two trans-isoprene units connected to a long sequence of cis-isoprene units. The alpha-terminal group of Jackfruit rubber was presumed to be composed of a phosphate group based on the presence of 1H NMR signal at 4.08 ppm corresponding to the terminal =CH-CH2OP group.
authors.affiliation: Department of Chemistry, Faculty of Science, Mahidol University, Rama VI Road, Bangkok 10400, Thailand.
authors.forename: Dararat
authors.initials: D
authors.lastname: Mekkriengkrai
authors.forename: Koiichi
authors.initials: K
authors.lastname: Ute
authors.forename: Ewa
authors.initials: E
authors.lastname: Swiezewska
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Chojnacki
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Jitladda T
authors.initials: JT
authors.lastname: Sakdapipanich
mesh_terms: D031622:Artocarpus; D028481:Euphorbia / Q000737:chemistry*; D015394:Molecular Structure; D010316:Particle Size; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry; D012408:Rubber / Q000032:analysis / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D012408:Rubber