Changes to the polyisoprenoid composition in aging leaves of mangrove plants

Polyisoprenoid (polyprenols or dehydrodolichols and dolichols) content and composition of four true mangrove plants namely Excoecaria agallocha, Lumnitzera racemosa, Rhizophora apiculata, and R. lamarkii were investigated with particular emphasis on leaf senescence. The distribution and occurrence of polyisoprenoids was analyzed using the two-plate thin layer chromatography (2P-TLC) method. The age of the leaves was divided into young leaf, leaf, and yellow leaf. In the leaves, the distribution of polyisoprenoid was found to show the presence of both polyprenols and dolichols. The occurrence of ficaprenols (C₅₀–C₅₅) was observed in young leaves and leaves of the mangrove samples studied. On the other hand, dolichol contents were not altered in the leaves with senescence. By contrast, longer polyprenols were found in yellow leaves of E. agallocha, L. racemosa, and R. apiculata. In addition, it should be noted that there were changes to the polyprenols in leaf senescence identified. Furthermore, the formation of ficaprenols, longer polyprenols, and dolichols was modulated in the mangrove plants. These findings suggest that the accumulated polyprenols in the yellow leaves may be due to the catalyzation process that converts ficaprenols into longer polyprenols.