Diversity of polyisoprenoids in ten Okinawan mangroves

The distribution and occurrence of polyisoprenoids (dolichols and polyprenols) in the leaves and roots of nine true Okinawan mangroves and the leaves of one associate mangrove were analyzed using two-dimensional thin layer chromatography. In the leaves, the distribution of three types (I, II, and III) of polyprenols and dolichols were detected. (I) The predominance of dolichols over polyprenols (more than 90%) was observed in Avicennia marina, Bruguiera gymnorrhiza, B. gymnorrhiza (yellow leaves), and Rhizophora stylosa. (II) The occurrence of both polyprenols and dolichols is observed in Excoecaria agallocha, Kandelia obovata, K. obovata (yellow leaves), Lumnitzera racemosa, Pemphis acidula, and Sonneratia alba. (III) The predominance of polyprenols over dolichols (more than 90%) is observed in Heritiera littoralis and Hibiscus tiliaceus. However, in the roots, a type-I distribution was observed in A. marina, B. gymnorrhiza, E. agallocha, H. littoralis and S. alba. A type-II distribution was observed in K. obovata, L. racemosa, P. acidula, and R. stylosa with no type-III distribution. The chain-length distribution of dolichols in the leaves and roots was C50–C140 and C60–C120, respectively. A similar chain-length distribution of polyprenols of C45–C140 and C65–C85 was detected in the leaves and roots respectively. Taken together, sixteen out of twenty-one tissues indicated that dolichols are more abundant than polyprenols in both leaves and roots. The present study is the first to clarify the diversity of polyisoprenoids in both the leaves and roots of mangrove, suggesting the chemotaxonomic significance of polyisoprenoids in the mangrove tree species.