Mushroom rubber

The arrangement of trans isoprene-units is observed more in detail from the 13C-NMR signal splitting of C-l methylene carbon [94, 97], as shown in Figure 11.19. The mushroom rubber shows two peaks due to the trans isoprene-unit in dimethylallyl-trans and trans-trans linkages similar to those of the two-trans polyprenol. On the other hand, the rubbers from Goldenrod and Sunflower exhibit three peaks similar to the overlap of peaks of two-trans and three-trans polyprenols. This suggests the presence... 

Little was known, however, about the exact configuration of the rubber molecule or the molecular mechanism of rubber elasticity. Two world wars and the mushrooming development of the automobile and the airplane raised the demand for elastomeric materials to a level that, by the 1950s, dozens of large industrial organizations produced some 2 million tons of synthetic rubber per year. Most of the production steps are now fundamentally well known, and most of the basic properties of raw and cured elastomers are now reasonably well understood. 

C HisNjOj, Mr 197.23, mp. 237 -238°C (decomp.), [a]o+44-5° (5 m HCl). An intermediate product in the biosynthesis of ergothioneine from histidine. H. occurs in the milk juice of the rubber tree (Hevea brasi-liensis), in various fungi, e.g., c6pe (Boletus edulis), fly agaric (Amanita muscaria), field mushroom (Aga-ricus campestris), and also in the king crab (Limulus polyphemus). 

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