Terpenoids and Phenylpropanoids in Ligularia duciformis, L. kongkalingensis, L. nelumbifolia, and L. limprichtii

Abstract

The diversity in root chemicals and evolutionally neutral DNA regions in the complex of Ligularia duciformis, L. kongkalingensis, and L. nelumbifolia (the d/k/n complex) was studied using eight samples collected in central and northern Sichuan Province of China. Cacalol (14) and epicacalone (15), rearranged eremophilanes, were isolated from the complex for the first time. Two new phenylpropanoids were also obtained. Seven of the eight samples produced phenylpropanoids and the other produced lupeol alone. Two of the seven samples also produced furanoeremophilanes or their derivatives and one produced oplopanes. The geographical distribution of the sesquiterpene-producing populations suggests that the production of sesquiterpenes evolved independently in separate regions. L. limprichtii collected in northern Sichuan was also analyzed and its chemical composition and the sequence of internal transcribed spacers (ITSs) in the ribosomal RNA gene cluster were found to be similar to that in the d/k/n complex and L. yunnanensis, which are morphologically similar.

Chemical Composition of Intergeneric Hybrids Between Ligularia and Cremanthodium Collected in Sichuan Province of China

“…However, the spectrum suggested that the major constituent was likely to be O -geranylsinapyl alcohol, which has been isolated from L. nelumbifolia and related species. 29 Compounds 1 and 2 were detected in sample 4.…”

“…The typical compounds in each chemotype are eremophilane sesquiterpenes (type 1), oplopane sesquiterpenes (type 2), phenylpropanoids (type 3), and no sesquiterpenes or phenylpropanoids (type 4), although the entire chemical spectrum is somewhat continuous. 29,35,36 Since lupeol ( 5 ) was isolated from sample 3 ( L. nelumbifolia ), the sample belongs to chemotype 4. We previously inferred that the ability to produce sesquiterpenes in types 1 and 2 had introgressed from some other Ligularia species.…”