A. Ohsaki et al., Phylogenetic and chemotaxonomic significance of diterpenes in some Portulaca species (Portulacaceae), BIOCH SYST, 27(3), 1999, pp. 289-296
An instance is presented in which skeletal features of chemical constituent
s provide valuable information on the phylogenetic relationship in plant sp
ecies. A close examination of diterpenoid constituents was carried out on t
hree Portulaca species, each of which has a different basic chromosome numb
er. Major diterpenoid constituents in P. cv. Jewel, P. pilosa and P. grandi
flora were found to be, respectively, of the clerodane ([6.6]-fused ring),
prinziane ([7.6]-fused ring) and portulane ([7.5]-fused ring) types. From a
biosynthetic viewpoint, a linear evolutionary relationship among the Portu
laca plants in question would be assumed. All the diterpenoids found in the
above three species have 1,4-dihydroxy-2-buten-2-ylethyl side chains and t
he relevance of this feature for chemical systematics of Portulaca plants i
s pointed out. (C) 1999 Elsevier Science Ltd. All rights reserved.