Chemical structure of a sporinite from a lignite: Comparison with a synthetic sporinite transformed from sporopollenin

The maceral sporinite is thought to be derived from spores and pollen. Both sporinite and sporopollenin, the insoluble cell wall residue after chemical treatment, are considered to have a highly polymerized, cross-linked aliphatic structure with some aromatics. Many investigators have endeavored to characterize the physical and chemical nature of sporinites and sporopollenin; however, their chemical structures have not been well defined. Furthermore, little is known about how sporopollenin transforms to sporinites during the early stage of coalification. The aim of the present study is to compare chemical structures of an immature sporinite and its precursor, sporopollenin. In a parallel experiment, the transformation of sporopollenin into a synthetic sporinite has been carried out in the laboratory using thermal catalytic reactions under conditions of simulated catagenetic maturation.