ABSTRACT
Natural cis-1 ,4-po1yisoprene occurs in over 2000 species of higher plants, the most well known of which is natural rubber from Hevea brasiliensis. Other plants, such as guayule (Parthenium argentatum), Russian dandelion (Taraxacum kok-saghyz), goldenrod (Solidago altissima), Jelutong (Dyera retusa), and fungal genera such as Lactarius volemus have also been known to produce cis-1,4-polyisoprene. Only a relatively few plant species such as balata (Mamusops balata) and Gutta percha (Palaquium gutta) produce gutta or trans-1,4-polyisoprene. Chide (Achras sapota) is known to produce a mixture of trans-1,4-polyisoprene and cis-1,4-po1yisoprene in a ratio of about l :4 (Schlesinger and Leeper, 1951; Stavely et al., 1961, Archer and Audley, 1973).
